AT THE START of the 2000 ANS/ENS In-ternational Meeting—held November12–16, 2000, in Washington, D.C.—

ANS President Jim Lake welcomed delegatesto the “new ANS, the ANS of the future.” Thismeeting, he said, was different—”more valu-able, provocative, and learned”—and markedby a gratifying increase in attendance. Fur-thermore, he declared, nuclear’s excellentsafety record and improving economic per-formance provide a solid foundation for en-tering the new millennium, which will be anew era for nuclear energy.

The event had high attendance and a well-received program. Some 1451 persons at-tended the conference, including 328 from 25foreign countries, with a 26-person delegationfrom Russia. The event also included threetopical meetings and a professional develop-ment workshop. The conference used a “tracksystem,” grouping sequences of kindred tech-nical sessions to help attendees focus on theirareas of interest.

The theme of the meeting was Nuclear Sci-ence and Technology: Supporting SustainableDevelopment Worldwide. In the face of ex-pected growth in energy demand, said Lake,

the challenge for nu-clear power is to find anew balance of eco-nomic competitive-ness, environmentalstewardship, and so-cial responsibility.

The theme wastimely, as sustainabledevelopment is an in-creasingly importantissue for the industry.Opponents of nuclear

power, supported by a number of Europeangovernments, are pushing to exclude nucleartechnologies from the clean developmentmechanisms provided for under the KyotoProtocol to reduce greenhouse gas emissions.They claim nuclear is nonsustainable, essen-tially because the industry does not have anacceptable solution for disposing of its waste.

As a joint ANS/European Nuclear Societyinternational meeting,delegates were alsowelcomed by AgnetaRising, president ofENS and the SwedishNuclear Society. Eu-rope, she said, is un-decided on the nuclearissue. There have beenharsh warning signals:Germany’s decision tolimit the lifetimes ofits reactors to little

more than 30 years and Sweden’s prematureclosure of one reactor, Barsebäck-1, with thesecond unit expected to close in 2003–04. Onthe other hand, she stressed, there is no pub-lic support for closing nuclear plants. Even inSweden, a majority favors increasing the useof nuclear power to combat global warming.One particular worry for her is that nuclear ed-ucation and research are receiving reduced re-sources, leading to a lack of young peoplewho are entering nuclear careers.

The session’s co-chair, Clyde Jupiter, ofJupiter Corp., then handed the meeting overto co-chair Bertrand Barre, of Cogema, and avice-president of ENS, to introduce thekeynote speaker, Donald J. Johnston, secre-tary general of the Paris-based Organizationfor Economic Cooperation and Development(OECD). A Canadian, Johnston had previ-ously served as his country’s minister for sci-ence and technology. On this occasion, John-ston was speaking for himself and not for theOECD, whose membership includes a num-ber of antinuclear governments. He clearly be-lieves that nuclear energy can play an impor-tant role in creating a sustainable future.

Sustainable developmentJohnston was asked to address the question,

“Does the future have a constituency?” Hisanswer, which came from the theme of themeeting, was: “Those who espouse sustain-able development, one of the most important

issues of our time, are committed to acting forthat constituency. That is what sustainable de-velopment is about.”

While there are different definitions of sus-tainable development, he opted for: “devel-opment that meets the needs of the presentwithout compromising the ability of futuregenerations to meet their own needs,” whichhe said is as good as any, combining environ-mental, social, and economic considerations.

Johnston said that the world is on an un-sustainable energy path that has led to a highconcentration of greenhouse gases, particu-larly CO2. The potential effects of radical cli-mate change are frightening, he noted, point-ing to the frequent extreme events and unusualweather patterns seen all over the globe in re-cent years.

“Can we do something to turn the situationaround?” he asked. While the industrializedcountries are wealthy and smart enough to de-velop clean sustainable energy technologies,he said, solutions must take account of worldpoverty and population growth. The UnitedNations projects a 50 percent increase in glob-al population by the middle of the century.Virtually all of that growth is outside theOECD area.

If the rest of the world is to enjoy the sameenergy standard as the OECD does today, en-ergy production will have to grow by a factorof 30, said Johnston. While, he added, no oneexpects such a jump, his examination of the

A N S / E N S I N T E R N A T I O N A L M E E T I N G

The new millennium—A new era for nuclearMajor themes of the plenary:

� Nuclear power’s challenge: Find a new balanceof economic competitiveness, environmentalstewardship, and social responsibility.

� Europe is undecided on the nuclear issue.

� The world is on an unsustainable energy paththat has led to a high concentration ofgreenhouse gases.

� Nuclear power is undergoing a quietrenaissance in the United States, and powerreactors are competitive with fossil-fired plants.

42 N U C L E A R N E W S January 2001

Meetings

Lake

Rising

different energy sources (including renew-ables), like that of others before him, led tothe conclusion that only nuclear power is ableto meet the needs of the future population.“Since 1955, the global population has dou-bled with most living in poverty. Yet we aredenying ourselves the nuclear option,” hesaid.

Johnston has spoken to many distinguishedscientists, and, like them, he said he has foundthe opposition to nuclear power by the greenmovement bewildering. But, he said, “bewil-derment must not suffice. We must ensure thatthe nuclear option is the subject of informedpublic debate.”

Public perception of many technologies to-day is negative and fearful, and so he said hedoes not find it surprising that politicians giveway to those fears or simply refuse to dealwith an issue. This characterizes the nucleardebate in many countries, he noted. Public ed-ucation campaigns that lay out facts and dis-pel fears and myths are needed. Ideally, thisshould be carried out by political figures whohave no vested interests, he noted, and if theyabdicate this responsibility, the industry musttake it up.

The plenary session then went into a paneldiscussion, led by the journalist and publish-er of The Energy Daily, Llewellyn King. Wecannot proceed, he said, on the present trajec-tory of economic development without anenormous non-air-polluting source of energy.This can only be nuclear. King said he foundit distressing to see ever new claims of tech-nologies that cannot do the job. He is amazedwhen he hears talk of “clean coal.” Cleanercoal, he said, is not the same thing as cleancoal, which, he notes, is nothing but an oxy-moron.

King also reminded meeting attendees thatbeyond energy is electricity. “Nothing does somuch to enhance the quality and expectationof lives as electricity. . . . It gives to us expo-nentially. . . . It is astounding and we do nothave enough of it,” he stressed.

Looking to the futureThe next panelist, Nuclear Regulatory

Commission Chairman Richard Meserve,fleshed out the future. Population growth is

projected to be mostlyin regions alreadystressed by numbers,with 80 percent of thepopulation living inurban areas by 2050,he said. The signs ofserious strain are al-ready apparent—de-forestation, reducedfish reserves, degrada-tion of fresh water re-sources, greenhouse

gases, loss of species and ecosystems, emer-gence of infectious diseases, and more. Thechallenge—the imperative—is to recognizethe interdependence of societal demands andenvironmental limitations and define a path tosustainable development, he declared.

Meserve also reminded session attendeesthat while energy has an adverse effect on the

environment, it drives the technologies for im-proved use of water and land, recycling, andminimization of environmental impacts. Thefinding of acceptable energy sources is need-ed to drive the entire process, he added.

Meserve observed that nuclear power isundergoing a quiet renaissance in the UnitedStates. Relicensing is one area where theNRC has a particular role. The commissionhas been formally advised by some 40 per-cent of U.S. nuclear power plants that theywill seek license renewal, with the portion ris-ing to 85 percent if all those planning to ap-ply are included.

While the NRC does not have a promo-tional role, Meserve said, it nevertheless seeksto ensure that the regulatory system does notstand as an impediment to the role that nuclearenergy can play in sustainable development.The commission accepts that needless regu-lation is a burden to the industry, he ac-knowledged, and it is engaged in rethinkingthe regulatory process. For example, one ofthe most significant programs undertaken isin the use of risk insights in revising regula-tions and regulatory processes. Meserve saidthis has permitted the agency to focus atten-tion on those aspects of design and operationthat are important to safety, while eliminatingregulatory requirements that do not serve toenhance safety.

The NRC must also be and be seen as a rig-orous, independent, and capable regulator, hedeclared. It has identified enhancing publicconfidence in the commission as one of fourmajor goals in its strategic planning.

Pascal Colombani, head of France’s CEA,set out the situation in Europe. While there isconsiderable opposition to nuclear energy, henoted, he remains confident that when Europeis confronted by social, environmental, andindustrial reality, the nuclear issue will even-tually have to be revisited. What the U.S. in-dustry is doing today suggests that Germany’srecent decision to phase out nuclear may notbe in step with the times, he observed. Mostpeople in the European Union (EU) are hap-py with the 30–35 percent of electricity de-mand being met by nuclear power, but theyare wondering now how to proceed, he added.

The EU, Colombani said, is under consid-erable pressure. The recent oil crisis showsthat it is excessively dependent on oil. Elec-tricity demand is growing rapidly—2 percentwithin the EU and 3 percent in countries wish-ing to join—and this trend is expected to con-tinue. Furthermore, deregulated energy mar-kets have a tendency to disregard security ofsupply and climate change issues. In fact, hesaid, the European Commission is so con-cerned about energy security that it will soonrelease a “green paper” on the issue.

The chances of implementing an appropri-ate energy policy for sustainable developmentare not good, said Colombani. The import ofenergy is expected to grow from 48 percent ofthe total to 65 percent by 2020; within that, oilimports will grow from 75 percent to 90 per-cent, and gas, from 40 percent to 70 percent.

Regarding global warming, Europe exhibitsa discrepancy between political obligationsand market trends, he observed. Under the

Kyoto Protocol, Europe is committed to re-ducing greenhouse gas releases by 8 percentby 2010 in comparison with 1990. Presentpredictions, however, suggest that it actuallywill be 7 percent higher. Only France andSweden are likely to meet their Kyoto com-mitments, Colombani predicted, becausethese two produce almost all their electricityfrom nuclear and hydropower. He further not-ed that to stay at 1990 levels of emissions, Eu-rope would have to construct about 85 newnuclear units.

Colombani retained some optimism thatnuclear power can get back into the game.There is a political need to address the wasteissue, which he said is the only one standingin the way of further nuclear development. Hesupported redirecting R&D efforts to optimizeperformance, extend plant lifetimes, and pre-pare for the next generation of reactors as amajor component of a sustainable energy pol-icy. Further research, he added, should also befocused on improving the predictability andthe control of the impact of nuclear energy onhuman health and the environment. Also, ra-diobiological research must be reenforced toassess the effects of low-level activity and todevelop scientific bases for more objectiveregulations in radiation protection.

Finally, although not everyone believesthis, Colombani said, the idea that nuclearmust be part of the energy mix is making pro-gress in Europe, particularly at the commis-sion level.

Making nuclear competitiveIn introducing Corbin McNeill, chairman

and co-chief executiveofficer of Exelon,King said no one ismore deserving to becalled a hero by the in-dustry for keeping thenuclear option aliveand even expanding it.“While many werefleeing the field, he re-fused to run awayfrom nuclear power,”declared King.

McNeill began by thanking all those youngpeople who are hogging the Internet and dri-ving electricity growth to 3–4 percent, as op-posed to the 1–2 percent of the previousdecade. He also identified a number of otherdrivers of the market, notably deregulation,for which nuclear power has played a partic-ularly central role. The first regions to dereg-ulate, he noted, were those that had high tar-iffs caused by large nuclear plants coming onto the rate base in the 1970s and 1980s, whenconstruction costs and interest rates were veryhigh. What has driven deregulation, in hisopinion, is the variation in prices. Those stateswith high prices realized they were at a com-petitive disadvantage, and deregulated to re-duce prices.

The key problem, explained McNeill, washow to make these plants competitive in thisenvironment. Operators achieved this bymany means, including reducing outagetimes, developing leaner staffs with increased

January 2001 N U C L E A R N E W S 43

Meserve

McNeill

skills, streamlining administration, etc. Theresult, he said, was capacity factors that rosefrom 66 percent in 1990 to about 90 percentlast year—“and [nuclear plants] becamesafer–dramatically so.”

The final critical factor was getting strand-ed costs included as an element in deregula-tion, McNeill observed.

Today, nuclear plants are competitive withfossil-fired plants, he declared. And now thatnatural gas prices have risen, he added, it isbetter than that. Furthermore, most stateswould not be able to meet the requirements ofthe Clean Air Act without nuclear power. “Itis my belief,” said McNeill, “that we can getnuclear power certified as environmentallypreferable under the guidelines of the EPA.We are working to do that. It will take somework, but I believe it can be done. Many ofour customers are asking us to do that.”

Furthermore, he said, “Our record for han-dling waste is better than any other industry.We must speak up for our industry, of the en-viable record we have in managing spent fueland protecting the environment, avoiding theemissions that would be choking our cities,and that it is economically competitive. No-body else will.”

Showing no lack of confidence, McNeillalso referred to the 85 percent of nuclearplants seeking relicensing, declaring, “I havetold the other 15 percent to come see me andI will cut a deal with them.”

During the discussion period, BertramWolfe (retired vice president and head of Gen-

eral Electric’s nuclearenergy organization)questioned Exelon’sdecision to invest inthe Pebble Bed Mod-ular Reactor being de-veloped by SouthAfrica’s Eskom utili-ty. Experience shows,he noted, that estab-lishing new plant de-signs takes manyyears. Furthermore,

Wolfe maintained, with the price of naturalgas rising so much, if a current design werebuilt now, it would be competitive.

McNeill explained that under the presentcompetitive economy, the investment risks ofa four-plus-year construction time and themarket disruption that will occur when a large1400-MWe plant goes into service—drivingprices down to marginal cost pricing—willmean that the plant will not get an acceptablereturn on investment. He admitted that if therewere average cost pricing throughout the lifeof the plant, the project could succeed. Butthat would not be the case, he noted: The gen-erator would see marginal cost pricing duringthe period of oversupply.

McNeill went even further. Speaking can-didly, he said, “I do not think we will see an-other LWR [light-water reactor] built in theU.S.”

“I tend to disagree with you about this,”said Wolfe.

“That’s fine,” said McNeill, “but I’ve gotthe money.”

President’s SessionJim Lake’s President’s Session continued

the theme of long-term globally sustainableenergy options. Nuclear power is looking at amuch brighter future, he said, than it has inmany years past. There is even hope of an an-nouncement of a decision to construct a nu-clear plant in the United States in the nearterm.

Nuclear power is very healthy, demon-strating excellent economic performance andreceiving relatively good public support, Lakeadded. If global projections of the growth in

population and energy needs are near to beingtrue, there is every reason to believe thataround the world, many nuclear power plantswill be built. The challenge now, he said, is tothink in terms of sustainable development.

Lake pointed to three main imperatives:economic competitiveness, environmentalstewardship, and social responsibility.

The industry needs to develop a nuclearpower technology that is more economic,safer, and proliferation-resistant, and thatdeals with the waste and the fuel cycle in abetter way than it has in the past, he declared.

44 N U C L E A R N E W S January 2001

Sen. Pete V. Domenici (R., N.M.) washonored on November 15 with the HenryDeWolf Smyth Nuclear Statesman Award,presented at the banquet of the ANS/ENSInternational Meeting. He was recognizedfor his longstanding contributions to manyaspects of nuclear energy and technologies.Domenici is a ranking member of the Sen-ate Energy and Natural Resources Com-mittee, and chairman of the Senate Appro-priations Subcommittee on Energy andWater Development.

He has been a leading proponent of pro-viding adequate funding for new nuclear

R&D initiatives.Under his leader-ship, Congress hasincreased fundingfor advanced nu-clear technologyR&D by about $50million during thepast three years.

“Sen. Domenicihas been a tirelessadvocate for allthe many compo-

nents that must come together for nuclearenergy to succeed in this country,” de-clared Joe Colvin, Nuclear Energy Insti-tute president and CEO, who presentedthe award. “He has advocated the use ofnuclear technologies as a major contribu-tor to global peace and an improved qual-ity of life by pointing out the clean air ben-efits of nuclear energy.”

In his acceptance speech, Domenicipointed to America’s future in the worldeconomy and the importance of nucleartechnology. He declared that globalizationhas a real chance of dramatically affectingthe “deplorable standards of living” that af-fect two-thirds of the world’s peoples. Itcan lift the standard of living for hundredsof millions of people, he noted, and Amer-ica can be in the forefront of involvementwith “its businesses, its technology, and itsworkers” providing the necessary suppliesand services.

Domenici also spoke with optimismabout the future of the nuclear industry.“Nuclear is coming back because we aremoving ahead in the science, technology,

and practicality of nuclear energy in thisvery difficult economic world,” he said.“For a change, in America, there are busi-ness people talking about making an eco-nomic ‘go’ of nuclear power, and theymight be seriously interested in the nextgeneration of nuclear power plants.” Heobserved that in contrast, “three or fouryears ago . . . everyone in this business wasunder the table, frightened to death—atleast in America,” though not in France,Japan, or other nations. Domenici called foraction by the industry: “Let’s move aheadand let’s be bold about it.”

He called for progress regarding somespecific issues. “What we need now is anadvocate or a number of national advocatesto lead America out of the inherent fearof . . . anything that comes from nuclearand that yields low-level radiation or radi-ation.” Domenici said that if in the next 24months, the two issues of a new standardfor low-level radiation and temporary stor-age of nuclear waste “were to come out ourway . . . we would make a huge, huge stridein the direction of common sense.”

ANS and the Atomic Industrial Forum, apredecessor organization to the NuclearEnergy Institute, established the Henry De-Wolf Smyth Award in 1972. The awardrecognizes individuals who have made out-standing contributions to the peaceful useof nuclear energy.

The award commemorates the life’s workof Dr. Henry DeWolf Smyth, a physicistwho played an important role in the devel-opment of atomic energy before his death in1986 at 88. Smyth chaired Princeton Uni-versity’s physics department and authoredthe federal government’s official report onthe development of the atomic bomb,“Atomic Energy for Military Purposes,”made public shortly after the atomic bomb-ings of Hiroshima and Nagasaki in 1945.

He served on the Atomic Energy Com-mission from 1949 to 1954 and, in 1961,was appointed by President John F.Kennedy as the U.S. representative to theInternational Atomic Energy Agency withthe rank of ambassador, a post he held un-til 1970. Smyth advocated the establish-ment of an international partnership to de-velop peacetime uses of atomic energy.

Sen. Domenici honored with Smyth Award

Domenici

Wolfe

There are a couple of major international pro-grams starting to develop the needed solu-tions—the Generation IV initiative and theIAEA’s advanced reactor and fuel cycle pro-gram—in which a lot of countries are in-volved, Lake explained.

He noted, however, that from a socially re-sponsible point of view, things will have to bedone differently from the way they’ve beendone in the past. The industry must confrontthe public with possible solutions and optionsat an early stage and get their feedback. “Wemay then end up with decisions that are a lit-tle different than we would have come up withbefore,” Lake observed. “But if we do thiscorrectly, the technologies we come up withwill fit socially much better than the tech-nologies of the past.”

A large part of future energy consumptionand global pollution will come from China.“By 2020, China will exceed the U.S. to be-come the world’s number-one CO2 produc-er,” said Li Jun Feng, vice president of the En-ergy Research Institute, in China.

According to Li’s paper, annual economicgrowth was about 9 percent in the 1980s and8.2 percent during the 1990s. To drive growth,the energy policy was simple: Increase sup-ply as much as possible. Electricity capacityincreased from 65 GW in the 1980s to 360GW in 2000. The country already consumes27 percent of coal produced in the world. It istherefore no wonder that 40 percent of Chinais suffering from acid rain and 62 percent can-not satisfy air quality standards.

The policy now is to develop renewables,including hydropower and wind power, asmuch as possible. Nuclear energy, however,is the natural choice to satisfy future needs.

Over the next 20 years, the Chinese econo-my is expected to grow by 6 percent annual-ly, and in the following 30 years, 3.5–4 per-cent. Energy demand will double and tripleover those periods. “This will be very bad forthe environment,” Li declared.

By 2050, coal production will reach its lim-it, because of transportation constraints, of2.4–3.6 billion metric tons (t) of coal eachyear. Transporting coal now takes 23 percentof railway capacity, 25 percent of highway ca-pacity, and 20 percent of waterway capacity.To achieve the 2050 target, China will haveto build eight or nine more railways in thesame mountainous areas and in the same di-rections as now.

China has been a net importer of oil since1993, Li said. In 1999, total net oil importswere 50 million t, far beyond projections. Thecountry has limited reserves of natural gas ofsuitable quality, and most of it is located faraway from population centers.

Some argue that nuclear power is not eco-nomically competitive in China, noted Li. Thecapital costs of building nuclear plants aremuch higher than those of coal or gas plants,as are fuel and O&M costs.

Although the state development planningcommission and the Nuclear Power Corpora-tion announced a temporary halt in nuclear or-dering, security of supply and sustainability

demands still makes nuclear power very at-tractive in the long term, Li explained. The en-ergy ministry forecasts that in 2010, the nu-clear capacity will be 20 GW, 3.8 percent oftotal capacity; in 2020, nuclear capacity willbe in the range of 30–50 GW, 6 percent of to-tal capacity; and in 2050, nuclear may reach200 GW, about 12.5 percent of total capacity.Seven provinces are doing feasibility studiesfor nuclear plants, raising finances, and look-ing for sites.

U.S. Rep. Joe Knollenberg (R., Mich.), afierce supporter of nuclear technology, wentstraight to the essentials.

He noted that in 1999, nuclear power sup-plied approximately 20 percent of electricityin the United States, about the same as itsworldwide contribution. By 2020, the currentlist of developing nations will consume moreenergy than the current list of industrial coun-tries do. Looking at global demand in 2020,just to maintain nuclear’s 20 percent marketshare would require 240 additional 1000-MWe plants.

His view of the alternatives is the follow-ing:� Fossil fuel supplies and reserves are sound.This year has seen a large increase in prices,a situation that will hold for at least the shortterm.� Hydropower is limited by geography andby the political pressure of the “extremegreens,” who are against the development oflarge hydro projects.

January 2001 N U C L E A R N E W S 45

M E E T I N G S

Continued

Other renewables are not practicable on alarge scale, but, Knollenberg said, they shouldbe part of our energy mix. In some cases, theycan make good financial sense, but generallythey have not yet proven competitive and arenot able to meet the needs of reliable baseload.The government has been making consider-able investments in these, with little to showfor it. And these technologies have beenaround for a long time.

The Congressman said that in his opinion,nuclear power is experiencing a real renais-sance and that it has a long-term and sustain-able future. He is hopeful for the GenerationIV system, particularly noting the features of “walkaway safety” and reduced time ofconstruction.

One of the less visible problems faced bythe industry is the setting of unreasonable ra-diation standards, which leads to large addi-tional costs. He noted that this issue must bereexamined—outside politics.

On climate change, Knollenberg is one ofa number of Americans who oppose the Ky-oto Protocol as risking unnecessary loss ofjobs and economic hardships on Americans,while leaving developing countries free tocontinue to release greenhouse gases (GHGs).There is deep concern about the climate andits impact on our way of life. Measures, how-ever, have to be based on sound science. Hewarned: “Let us not subsidize failure, let ussubsidize things that work. That’s the direc-tion I think we should go.”

In any case, Knollenberg does not believethat nuclear power’s future needs be tied to re-ductions in GHG emissions. “Nuclear powerdoes not need the schemes and treaties,” hesaid. “It is good for the environment.”

He also pointed to a shift in attitudes inCongress. There is now a bipartisan NuclearIssues Group in the House of Representativeswith about 80 members. Although it is stilldifficult to get anyone in the administrationto say the “n” word, he observed, he said thathe expected that there will be a move in thatdirection. “People are going to see,” he said,“that the extreme greens really stand fornothing.”

Angie Howard, executive vice president ofthe Nuclear Energy Institute, took this mes-

sage further. Since1990, she said, the in-dustry has brought online a virtual nineteen1000-MWe plants be-cause the average ca-pacity factors haveimproved from 58 to88 percent. That isalso why they contin-ue to supply 20 per-cent of electricity.

Perhaps the mostimportant global issue of this century is howto meet humankind’s growing energy needswithout compromising the ability of futuregenerations to meet their own, Howard re-flected. The nuclear industry also has a re-sponsibility to play its part in this challenge,she added. In 1993, the electricity industryjoined the program in partnership with the

DOE to voluntarily reduce GHG emissions.According to Howard, nuclear power ac-counted for almost half of the reductionsachieved under the Carbon Challenge Pro-gram—this is the new capacity, not the exist-ing capacity already in place.

Developed nations also have a moral oblig-ation both to develop technologies and, assuitable, to transfer them to developing coun-tries, she said. They must be given the optionsto progress, but we cannot dictate to them by,for example, giving them a limited set of op-tions. Sovereignty is an integral part of theprinciples that came out of the Rio conferencein 1992.

In the subsequent discussion, Wolf Häfelepointed out that if nu-clear is to make ameaningful contribu-tion as a long-term,sustainable energysource, several thou-sand nuclear plantswill have to be built.This means societywill have to handlelarge amounts of plu-tonium. The compli-cations recently expe-

rienced in arranging the disposition of just 68t from the U.S. and Russian weapons pro-grams indicated how sensitive and difficultthis issue could be, he noted.

A large global nuclear program, Häfelesays, will require operating a large-scale re-processing regime. This task will require fur-ther development of the technology and re-quire other issues to be resolved, including theproliferation problem and various institution-al needs. The solutions cannot be of the samenature as today, he observed.

Global climate changeThe sessions on the Impacts of Global Cli-

mate Change, cosponsored by the AmericanMeteorological Society, were an opportunityto hear from the authors of the main reportsproduced by the U.S. climate change assess-ment program. At last year’s ANS WinterMeeting in Long Beach, Calif., the climatesessions focused on the processes involved inclimate change. This meeting was concernedwith the impacts of climate change on the en-vironment and society.

The U.S. Global Change Research Programwas set up under a 1990 law that called for pe-riodic national assessments of the potentialimpact and consequences of climate change.The assessments, which include topical re-ports, are coming out now.

The first speaker, Anthony C. Janetos, gavean overview of potential impacts in the Unit-ed States and discussed how these were de-termined. Janetos, head of the World Re-source Institute, co-chairs the NationalAssessment Synthesis Team. He was followedby Martin Parry, of the United Kingdom, whodescribed the European climate change as-sessment project. After Parry, the authors ofthe topical reports presented their findings.

The U.S. effort began with a series of work-shops held across the country to listen to the

views and concerns of all interested parties.The results of these were fed into the variousassessment projects to ensure that the con-cerns would be dealt with. At the same time,a national synthesis team was set up to over-see the process. There are more than 20 re-gional and topical studies covering specific is-sues, such as forestry, health, water, andagriculture. The reports were subject to peerreviews, federal agency reviews, and a 60-daypublic comment period.

The assessments make use of climate sce-narios to determine the consequences of pos-sible futures—“they are not predictions of thefuture,” stressed Janetos. The base climatescenario is the Intergovernmental Panel onClimate Change’s “A” scenario, which makesno assumption of any national policies on cli-mate change being implemented—the “busi-ness-as-usual” scenario. Janetos also men-tioned two particular models that all thespeakers referred to: the United Kingdom’sHadley Centre model (the “warm and wet”model) and the Canada model (the “hot anddry” model). These two provide a useful rangeof possible global changes.

Possible effectsOne challenge for the team was to convert

their results into meaningful terms, such as theeffects on quality of life or on ecological sys-tems. For example, the report presents an in-dex of average July heat that tells us some-thing about how “comfortable” futuresummers will be.

Using models of different ecosystems, theteams can determine what would happen to asystem if a particular climate model were tooccur—for example, how the distribution oftrees and plant communities changes acrossthe country over time as a result of a particu-lar change to the climate. Each climate sce-nario will provide different results and eachcan be mapped and compared. The ecosys-tems of particular interest include forests,grasslands, alpine meadows, fresh water, andcoastal marine systems.

Key findings include the following:� Global warming: There is widespread con-sensus that the rise in temperature is real andthat evidence that people have altered thecomposition of the atmosphere outside therange of any natural variability, particularlyfor CO2, is growing. The increase in CO2 lev-els is due to changes in land use and fossil fuelburning; over the last 50 years, fossil fuelcombustion has swamped the effects fromland use change.� Climate variations: Changes in climate andtheir impacts will be different from region toregion.� Ecosystems: Natural ecosystems (those notmanaged) are the most vulnerable; some, suchas alpine meadows and coastal marsh lands,will be pushed out of zones where they canmaintain themselves. They have few ways ofadapting.� Water resources: The supply and avail-ability of water varies from region to region,and depends on factors that may be influencedby climate—snow pack is critical in the north,while the east of the country is dependent on

46 N U C L E A R N E W S January 2001

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Häfele

rain every two weeks.� Food supply: On a national basis, food sup-plies will not be affected overall, but farmerswill be.� Forests: The additional CO2 will increasegrowth of forests, but increasing weather dis-turbances will affect regeneration and growth.� Permafrost: Permafrost regions are alreadyseeing significant impacts. Alaska and centralSiberia have seen the largest regional warm-ing of any regions of the globe in the last 30or 40 years. Permafrost melting and retractingis taking place where it existed for thousandof years.� Coastal regions: Sea levels will rise withglobal warming and there will be an increasein storm surge.� Health: There are many unknowns andquestions. Will malaria and other tropical dis-eases come to the United States? Will respi-ratory problems increase? While health riskswill certainly increase, the actual impact willdepend on the adaptations made and invest-ment in public health infrastructure.

Janetos also noted that the impact on theUnited States will probably be much less thanon most of the developing world, notably inagriculture. “This is not to underestimate thefact that we are sure to be surprised,” he pre-dicted. In the future, he said, we need to un-derstand how the environment responds tomultiple stresses, and not just climate and CO2stresses, and to adaptations strategies.

Possible futures for EuropeTo put this work in an international context,

Prof. Martin L. Parry described the approachtaken in Europe. Parry is director of JacksonEnvironmental Institute, in the United King-dom, and editor of Europe’s climate impactassessment project, called ACACIA (A con-certed action towards a comprehensive cli-mate impacts and adaptations assessment forthe European Union), which has just beenpublished. A summary of the report can bedownloaded from <http://www.jei.uea.ac.uk>.

Parry noted that the U.S. assessment ismuch more research-based. The European re-port is a synthesis with gaps filled by expertknowledge. Unlike the U.S. approach, thereis a good deal about policy. This is possible,he says, as the European effort was not underthe control of government, although the proj-ect was funded by the EU. The report was re-viewed by government, but not approved. Asan example, the potential impact climatechange will have on immigration, which is amajor political issue in southern Europe andNorth Africa, was considered.

The purpose of the report is to answer ques-tions such as: What are the most likely climatechange futures? What would be the impact onbiosystems, economies, and society? Whatcan be done about it in terms of adaptations?It considered the impact on many differentsectors, including transport, energy, industry,tourism, finance, etc.

Parry gave a number of examples of howclimate change may affect Europe.� Winters currently classified as cold (occur-ring 1 year in 10) become much rarer by 2020

and disappear almost entirely by 2080. In con-trast, hot summers become much more fre-quent—by 2080, nearly every summer is hot-ter than the present 1-in-10 hot summer.� Climate change will be more negative in thesouth than in the north, aggravating most cur-rent environmental problems, such as deserti-fication, a degradation of natural habitats, andwater quality issues. It will likely exacerbateexisting political tensions between north andsouth.� The secondary and tertiary sectors, such asinsurance, transport, energy, construction, andtourism, will be challenged by changes in de-mand. For example, there will be reduced de-mand for energy in central heating systems innorthern regions, increased demand for airconditioning in the south. The increased inci-dence of extreme weather episodes will affectmost sectors, particularly insurance andtourism.� Climate change will exacerbate the Euro-pean agricultural imbalance, which alreadyaccounts for well over half of the EU’s budget.

Water resources and agricultureClimate change effects on water resources

was described by Peter H. Gleick, presidentof the Pacific Institute for Studies in Devel-opment, Environment, and Security, who wasco-chair and lead author of the water sectorteam.

He noted that there is now compelling evi-dence of changes occurring to water re-sources. These include changes in precipita-tion and temperature patterns, in snowfall andsnow melt patterns and timing, and in migra-tion patterns of birds and butterflies. It is alsoseen in glaciers receding and permafrost melt-ing in Alaska.

Gleick mentioned the runoff of the Sacra-mento basin, which supplies most of Califor-nia’s water. The spring snow melt from theSierra Nevada mountains has been decreas-ing, although the total has not. This meansrunoff in winter is increasing, which is the op-posite of what is wanted, he explained. Cali-fornia needs the water in the summer, whenthere is little rainfall, for agriculture and oth-er uses. This is precisely the sort of impact ex-pected from climate change.

Generally, climate change could pose seri-ous challenges to water systems, said Gleick,who expressed concern about how they will bemanaged. Water planners and managers havetraditionally assumed that the future will looklike the past, he noted, and reservoir designsare based on historical records. In the future,this approach could lead to wrongly designedsystems, which could result in flooding, and,at the same time, unfilled reservoirs. In the fu-ture, water management must take account ofclimate change, he declared.

Gleick admitted that water resources wouldbe more affected by demand than climatechange. He showed a graph of water demandthat the nuclear business would find familiar.In the 1960s and ’70s, he noted, forecasts ofhow many man-made reservoirs would beneeded by 2000 were about as accurate asforecasts of how many nuclear power stationswould be built by then. In fact, he said, con-

sumers actually withdraw less water todaythan they did in 1980, for a variety of reasons.“We have broken the hard link between eco-nomic development and water demand, aswith energy demand,” he observed.

The potential impact of climate change onagriculture was described by John Reilly, ofthe Massachusetts Institute of Technology.Agriculture, being a managed resource, is in-fluenced by many factors besides temperatureand precipitation. He noted recent exampleswhere the location of corn and soy beans hadmoved northward, which would be an ex-pected result of global warming. In this case,though, this movement was not due to climatechange. Global warming, however, is expect-ed to shift the economics toward dry landfarming from irrigated farming. The net effectin the United States, he concluded, is gener-ally positive, although better for consumersthan producers.

Steven McNulty, of the U.S. Department ofAgriculture, described the forest sector as-sessment, which considered several aspects offorestry, including forest processes (e.g., pro-ductivity, carbon storage, and water use), bio-diversity (change in distribution of plants andanimals), and economics of forest resources(timber and lumber supply).

The range of climate factors used in the as-sessment included ozone concentrations, acidrain and nitrogen disposition, temperature,and precipitation. Some of conclusions were:� Average forest areas are expected to de-crease by 11 percent.� Pine forests will move north, leaving moregrasslands in the south.� High alpine forests will move up the moun-tain and will then disappear.� Bird species will move northward.� Colder adapted species will decrease.� Pests and diseases may move into the north.

Because productivity is going to go up,however, there will be a greater supply oftimber, with consumers being better off thanproducers.

Coastal areas and marine resourcesDonald Boesch, of the University of Mary-

land, described the impact of climate changeon coastal areas and marine resources, whichare quite vulnerable to changes in water tem-perature, in the ingress of saltwater into fresh-water around coasts, in the number and sever-ity of storms, and others. Coastal land, heexplains, is not static, but continually risingand falling. Coastal wetlands are particularlythreatened, but are difficult to predict sincethey are so dynamic.

Temperature changes will affect ocean os-cillations, like El Niño, the Gulf Stream, andocean “conveyor belt” currents. There is evena mechanism that could stop the Gulf Stream,which would have large effects on westernEuropean weather. The impact on coral reefs,whose organisms are killed off by heat stress,was of particular concern to Boesch. Therehas likely been a considerable loss recentlyfollowing the rise in temperature due to ElNiño. The level of CO2 concentrations in trop-ical waters is another critical factor.

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Continued

The effects of climate change on healthwere discussed by Michael A. McGeehin, ofthe National Center for Environmental Health.His team looked at areas where weather mightaffect health and then examined the possibleeffects of climate change on these. The mainareas identified were waterborne disease, vec-tor-borne disease (usually involving an insect,such as a mosquito), heat effects on morbidi-ty and mortality, respiratory effects of pollu-tion, and injuries from extreme weather events.

McGeehin said the point is that there are al-ready problems in these areas, and globalwarming will exacerbate them. Waterbornedisease, whose symptoms typically include di-arrhea, is not heard much about, but there arenow billions of such cases each year in theUnited States. About 200 people die from heatstress each year, and in a bad year this can riseto hundreds. “We know how to prevent andmitigate these problems,” he argued, “but wehaven’t done very well at it. We need to pre-pare now to save lives and lessen the costs.”

At the start of the discussion, a questionerasked McGeehin why he had not spoken aboutcancer caused by the burning of fossil fuels.McGeehin explained that this was not relevantto the climate change effects he was studying.

The ANS audience apparently wanted toknow why the climate scientists were notmaking recommendations on energy sources.The speakers were clear that their task was tolook at the impact only if no action were tak-en to reduce greenhouse gases. As one personstated, the question “Is nuclear better or worsefrom a public health point of view than the al-ternatives?” is outside the scope of this na-tional assessment. The team was not asked tomake policy recommendations on whichadaptation measures to introduce, or to assessthe effects of different strategies to reduceGHGs. There is an enormous machinery ingovernment, it was said, that considers whatcan be done to mitigate the effects. Congressseparated the two sides of the question. Deci-sion-making on what to do was to be ham-mered out in policy circles. The assessments,on the other hand, are to inform that debate.

New constructionRecent developments in the nuclear power

industry indicate a possibility of seeing third-or fourth-generation plants operating in theUnited States by 2020. A special sessionchaired by Carolyn Heising was organized todiscuss the likelihood of new construction.

ANS President Jim Lake opened the ses-sion by saying that the U.S. nuclear powerprogram is still seen around the world as atrailblazing industry. During his travels, henoted, even in countries with healthy con-struction programs such as China, Korea, andJapan, there is great interest in the U.S. pro-gram, both in the operating side and the newconstruction side. “I think it is viewed as animportant signal around the world that one ofthe most powerful nations—and one of theearliest countries involved in nuclear power,and with the most nuclear power plants oper-ating—has enough faith in nuclear technolo-gy that we’re willing to move forward,” hesaid.

Victor Reis, director of the Center for Nu-clear Strategies, an organization of ScienceApplications International Corporation(SAIC), followed Lake with a talk on the Nu-clear Strategies Project. Developed in the pastyear, the project develops relatively simpleand focused models for various nuclear-relat-ed issues, including new construction. Theproject is sponsored by SAIC, along with theSandia, Los Alamos, and Lawrence Liver-more national laboratories and the DefenseThreat Reduction Agency. Representativesfrom those organizations work on the project.

The project built a model that emulates thedecision-making process of an independentpower generator faced with the choice ofbuilding a nuclear or natural gas plant to sat-isfy shortfall in baseload electricity demand.“We assume all power generators go throughthe same process, have the same criteria (dis-counted profit), and we aggregate the resultsfor a set of power generators and watch whathappens to market share and other relevant pa-rameters over time, typically 50 years,” Reissaid.

Inputs to the model are chosen in real timeand consist not only of physical and cost pa-rameters of the plants, but also of economicand policy parameters that will affect esti-mated discounted profit—for example, impo-sition of a carbon tax on fossil, or streamlinedlicensing for nuclear.

Because the model is relatively simple,much discussion by project participants re-volves around how it can be improved, whichis, “of course, part of the learning process,”Reis explained.

But the most important output of the proj-ect, according to Reis, is not a specific strate-gy or model, but the development of a lan-guage that connects policymakers withindustry leaders. “The development of such alanguage will permit a deeper and richer un-derstanding of nuclear issues and opportuni-ties,” he said.

Reis concluded by offering his personalview of nuclear development, separate fromthe official stance of the project. “There arefew programs as critical for global economic,environmental, and, yes, national securitywell-being as the fourth generation reactorprogram,” he declared.

George Davis, director of governmental af-fairs for Westinghouse Electric Company,commented that there is “a lot of comfort inthe industry by what is occurring.” What is oc-curring, according to Davis, are conditionsthat are paving the way for expansion of nu-clear energy. These include:� The deregulation of the power industry,which is driving many changes.� Nuclear plant sales, coupled with consoli-dation of plant owners and suppliers, whichare creating a “healthy, viable industry,” ac-cording to Davis.� Continued reductions in operating costs andimprovements in performance, which aremaking nuclear a low-cost option.� An improved regulatory environment,along with license extension, which is creat-ing optimism about nuclear’s future.� Nuclear’s environmental contribution to

clean air.� Nuclear’s exemplary safety record.� The shrinking of electricity reserve marginswhile demand growth increases.� The availability of space on existing nuclearplant sites to build new units.

In order to construct a new plant, vital stepsmust be taken, Davis continued. These includereducing “overnight” capital costs to $900–$1000/kWe, with construction schedules ofthree years or less; establishing business mod-els “for allocating risks and responsibilities”;demonstrating a regulatory process that worksfor new plants (e.g., construction and operat-ing license); and establishing government sup-port where appropriate.

Davis then reviewed the Westinghousenext-generation designs: the AP-1000 (NN,Sept. 2000, p. 39), which is a 1000-plus–MWereactor that is expected to reduce overnightcapital costs to the $900–$1000/kWe targetand is expected to receive design certificationfrom the Nuclear Regulatory Commission by2005; the Pebble Bed Modular Reactor, whichwill have overnight capital costs of $1000/kWe for a 110-MWe module and is the subjectof a South African demonstration project (in-cluding the participation of BNFL and PECO)that could provide Generation IV technologyby 2005; and the IRIS (International ReactorInnovative & Secure), which has an eight-yearstraight burn core and could be deployed by2010.

Ward Sproat, director of strategic programsfor Exelon Generation, explained that com-mercial reality for nuclear power means itmust be safer, faster, and cheaper in the futureor face extinction. “The nuclear option is stillviable, but not with its current offering,” hesaid. “It will only survive if it can provide acompetitive return in the marketplace.”

Sproat warned that time for resurgence ofthe industry is small and continuing to de-crease, with perhaps a 10-year window fornew nuclear plants to kick-start the industry.“The nuclear infrastructure is shrinking,” hesaid. “All you have to do is take a look at howmany people are [in the industry] today andcompare it with how many there were in thelate ’70s and early ’80s. Also, the intellectualinterest in the technology is waning. The av-erage age [of nuclear plant workers] is prob-ably in the mid-40s. Quite frankly, this is nota happening industry. People are not comingout of college saying ‘I’ve got to go into thenuclear business!’”

The reason it is difficult to attract new peo-ple, according to Sproat, is that “engineers liketo build things, we don’t like to go into an in-dustry just to maintain existing plants andmake them run.”

And as the industry shrinks, Sproat contin-ued, competing technologies are developing,such as fuel cells and microturbines. “We onlyhave a limited amount of time before thesetechnologies are not only technically viablebut economically viable, and the infrastruc-ture to put them in on a widely distributed ba-sis is there,” he said.

Frank Lopez, manager of new generationfor Bechtel Corp., questioned whether theUnited States is ready for standardized (mod-

48 N U C L E A R N E W S January 2001

ular) plants, which is how the fourth-genera-tion units would be constructed. He answeredwith the affirmative. “I believe the opportuni-ty—if we’re ready to accept the challenge tobuild a standardized plant—is there,” he said.“Certainly, we have limited U.S. experiencein nuclear standardization, but growing inter-national experience has shown that it can hap-pen.”

Lopez added that significant fossil devel-opments have shown how standardized pow-er plants can be taken to the marketplace.

Ron Simard, senior director of the NuclearEnergy Institute, talked about a program beingquarterbacked by NEI to assist in makingplant-building decisions. “Don’t think of it as

a plan, rather more ofa framework for iden-tifying what we needto do to help us moveforward,” he said.

Goals of the pro-gram include reducingcost and schedule un-certainties for newplants, achieving thenecessary changes toregulations and legis-lation, and integrating

and coordinating industry efforts to supportnew construction and continued operation ofexisting plants.

Ongoing activities of the program, Simardadded, include assessing financing approach-es to similar capital-intensive, long-lead proj-

ects in other industries, and identifying andachieving necessary changes to NRC regula-tions, such as treatment of financial qualifica-tions and decommissioning funding assur-ance.

To reduce time to market, the program isworking on developing rulemaking to im-prove the design certification process, whileevaluating an early site permit process; de-veloping a proposal for combined operatingand construction license conditions; andmeshing NRC inspections with the licenseconstruction schedule.

Looking ahead, Simard continued, the pro-gram seeks to define a role for the Departmentof Energy in removing barriers to commercialdeployment of advanced designs, to continueto broaden the base of support for new plantswithin the Congress and administration, andto continue to broaden the base of supportwith private sector policy groups and the fi-nancial community.

To ensure “a robust infrastructure” that willlead to new construction, Simard said, the in-dustry must have enough qualified people towork in design, construction, operation, andregulatory oversight. It must have necessarymanufacturing capabilities and equipmentsuppliers. And there must be reliable and eco-nomic sources of fuel fabrication, conversion,and enrichment services. To that end, NEI isforming a task force to investigate and worktoward solutions to these issues.

“I am going to leave here today remember-ing a couple of points that were made,”

Simard concluded. “First of all, extinction isa possibility, but second, there really is a win-dow of resurgence. It’s real and we have anopportunity to take advantage of it.”

Hot topicsDecommissioning and spent fuel manage-

ment were certainly appropriate subjects forthe “Hot Topics and Emerging Issues” ses-sion, chaired by Tom LaGuardia, of TLG Ser-vices, Inc. A lot of money is tied up in nuclearplants, and the many elements of decommis-sioning, including funding, waste storage anddisposal, decontamination and dismantling,and regulations, need to be right. And it wasobvious from the discussion that there is along way to go.

First, Tom Tuschen, whose company—Grantham, Mayo, Van Otterloo & Co. LLC—sets up decommissioning trust funds, de-scribed the effects of deregulation andindustry changes on funding. Tuschen ex-plained what a fund is and how it is set up andoperated. The idea is simple: While the plantis earning money, the utility puts some of itinto a decommissioning fund, which is in-vested to generate more income. Once opera-tion ceases, money is used to finance all theactivities leading to the plant’s being fullydelicensed.

There are many variables and uncertaintiesto funding. Tuschen’s list included:� Income (from customers and the state).� Core inflation.

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Continued

� Tax rates.� Decommissioning costs.� Liability streams (e.g., decommissioningand storage of spent fuel).� Changing regulatory involvement of regu-lators (Tuschen listed the state, the FederalEnergy Regulatory Commission, the NuclearRegulatory Commission, and the InternalRevenue Service).� Funding shortfalls.� Funding surpluses (many would want theirshare, including ratepayers, owners, regula-tors, state and federal governments, and oth-er “stakeholders”).

Plant owners will want to control these asmuch as possible to limit exposure, reducecosts, and increase income.

When Congress passed legislation estab-lishing waste compacts, it expected that thiswould foster the creation of several regionalrepositories. Since then, no new repositorieshave been set up. And now, virtually the onlydisposal site available to the whole country,Chem-Nuclear’s Barnwell repository, is tostop receiving waste from all but three statesin 2008.

James Latham, of Chem-Nuclear, describedhow the governor of South Carolina charted apath to end the state’s role as a waste site fornumerous states. This year, South Carolina,and with it Barnwell, joined the compact al-ready in existence with Connecticut and NewJersey, renamed the Atlantic Compact. Thismeans that South Carolina is now allowed tolimit, and ultimately exclude, other statesfrom disposing waste at Barnwell. Latham de-scribed what this would mean for its presentcustomers.

Decommissioning methodsThe traditional idea of decommissioning a

nuclear plant is to decontaminate any materi-al that can be released and ship the rest for dis-posal. One variation of this is “Safe-store,”where the facility is left untouched for a timewhile contaminated material decays.

The NRC’s Stephanie Bush-Goddard dis-cussed another option that had not been givenmuch consideration until recently: entomb-ment. Entombment involves leaving the ma-terial on site encased in a structure of long-lived material, such as concrete, and leaving it,maintained and under surveillance and insti-tutional controls, until the waste decays to anacceptable level for unrestricted release(greenfield status) of the site, which is 25mrems per year.

While this solves some of the problem offinding adequate disposal capacity, Bush-Goddard explained, it does mean that the sitewill have to remain under control for a verylong time.

Small-scale entombment has been done atDepartment of Energy facilities—for exam-ple the Hallam, Piqua, and Bonus reactors—and at some plutonium production facilities atHanford. She noted that as there is no experi-ence entombing power reactors, the PacificNorthwest National Laboratory (PNNL) didan assessment using a reference pressurizedwater reactor, looking particularly at how ef-fective the isolation would be. Previous work

on low-level waste sites was seen as relevant,but the source term and site characteristicswould be different. Entombment would haveless waste generated and lower doses. PNNLconcluded that it would be a viable option.

After PNNL completed its report, a work-shop was held with licensees, industry, andsome states’ officials. The participants agreedthat something structurally sound could bebuilt. The states are particularly interested, asthey see this as reducing decommissioningfunding requirements. The workshop partici-pants preferred to exclude the greater- than-Class-C waste, although Bush-Goddard saidthat the NRC is considering allowing thiswaste to be included by “concentrate averag-ing.” They concluded that a site-specific studywas needed.

NRC is putting out an advanced notice forthe industry and other stakeholders to com-ment on how to proceed, looking particularlyat licensing issues, the extent and timing ofsurveillance, dose levels, and release criteria.Other issues concern intrusion, long-term con-trol, and ownership responsibility.

Ed Davis, of NAC International, explainedhis concerns about the licensing of dry stor-age casks. He said it is generally agreed, bothinside and outside the NRC, that rulemakingreform is needed. He expressed concern thatthere are not enough resources at the NRC’sspent fuel management project office to re-view all the applications and other work to bedone.

He expressed particular concern about thelength of time involved for rulemaking on ap-plications for storage canisters, which requiresa review of 12–14 months. Any changes to aCertificate of Compliance, no matter howsmall, require the same. That process has tobe streamlined, Davis said. He said the officeis under-resourced, adding that the needs ofdecommissioning have turned out to be muchgreater than expected and that the resourcesare not there. He said that he fully supports thework done by the staff. The NRC wants tochange it, but that will also take resources thatare not there.

Spent-fuel policyAnother hot issue is what the United States’

spent fuel management policy is going to beover the next four years. There is now a defacto policy—to leave spent fuel in place—asa result of the default of the DOE on contractsto take spent fuel.

A future issue is high-burnup fuel (over50 000 MWd/t), which is now coming out ofreactors. The present canisters are not licensedfor these levels of burnup. In fact, it is not pos-sible to license any, because there are no tech-nical standards.

Two prematurely shut down reactors,Maine Yankee and Connecticut Yankee,chose to contract out the bulk of their decom-missioning activities to general contractors.Although the idea seems simple, there are po-tentially large commercial risks for a contrac-tor. Of course, the extent of the risks may nothave been appreciated when these contractswere agreed upon.

Session attendees heard the presidents of

both plants, Michael J. Meisner (Maine Yan-kee) and Russell A. Mellor (Connecticut Yan-kee), describe their experience of transferringrisk to decommissioning operations contrac-tors (DOCs). Maine Yankee first placed a gen-eral contract with Stone & Webster. Con-necticut Yankee followed, choosing Bechtelas its DOC. The experience at both plants with

the DOCs has beenrelatively good—butMaine Yankee’s con-tract with Stone &Webster was terminat-ed in May 2000 be-cause S&W was go-ing into bankruptcy(NN, June 2000, p.17). Meisner said thatMaine Yankee has ac-cepted bids for anoth-er potential DOC and

is evaluating them now.Meisner described the risks carried by dif-

ferent activities, pointing out some surprisingitems. While decontamination and dismantle-ment activities are being straightforwardlydealt with, the plant was found to contain aconsiderable amount of material covered inpaint contaminated with low levels of PCBsand lead, as well as a lot of radiologically con-taminated soil that will have to be dealt withat considerable cost. Maine Yankee is alsoconcerned about sub-slab contamination (be-low the foundations), a potentially expensiveunknown.

On the regulatory side, an operator must de-velop a license termination plan. As no planthas yet completed one, this task is considereda medium risk. There is also concern that af-ter the NRC terminates the license, the Envi-ronmental Protection Agency could step in,label it a Superfund site, and require addi-tional cleanup beyond the NRC’s 25-mremstandard. It is generally believed that EPAwants primacy over all radiological issues.

Maine Yankee had planned to use rubblefrom demolished concrete structures for fill-ing the foundations of new buildings beingconstructed on site. Being slightly contami-nated, the rubble was to be decontaminated toNRC 25-mrem standards. This was initiallyconsidered a low-level risk activity. Thegroundswell of opposition from local and statepeople to leaving on site any contaminatedmaterial that could be removed, however, wasunexpected. Meisner admitted that MaineYankee went into the area of state licensingvery naively.

Finally, having described the downside ofbeing a DOC, Mellor (who is also CEO ofConnecticut Yankee) listed reasons a con-tractor would be interested in this business:� Marketplace advantage.� Acceptable level of risk.� Business profile fit.� Capability of the organization.

It is unlikely, however, that a DOC wouldtake on all risks, even if the plant owner werepaying, Mellor explained. Besides those li-censed responsibilities that cannot be trans-ferred, the contractor would likely not be theappropriate party to deal with challenges

50 N U C L E A R N E W S January 2001

Mellor

brought by regulators or intervenors, nor beresponsible for long-term spent fuel storage.

Tokaimura: Lessons learnedOne surprising aspect of the accident at a

uranium conversion facility at Tokaimura,Japan, on September 30, 1999 (NN, Nov.1999, p. 42), was that there was no real pub-lic panic in the vicinity. Of course, explainedKenji Sumita, chairman of the Japan AtomicEnergy Society, Tokaimura is a special caseas local people were fairly knowledgeable.Furthermore, he found that the media handledthe accident very well.

Tom McLaughlin, cochair of the session on“Lessons Learned from the Tokaimura Nu-clear Criticality Accident,” noted how differ-ent this was from the response of the publicand media in the United States during theThree Mile Island-2 (TMI) accident. And, asat TMI, the industry responded immediatelyto the Tokaimura event, reviewing policiesand practices, and putting measures in placeto improve criticality safety and emergencyresponse.

In November 1999, the U.S. Department ofEnergy began a criticality safety improvementinitiative. One task, a review of five key siteswhose work included solution processing, wasled by the DOE’s Jerry N. McKamy, who de-scribed the effort. Over 120 days, his team as-sessed the sites, focusing on four major areas:criticality safety controls and limits, workcontrol, configuration control, and line man-agement oversight. They found no imminentcriticality accident risks. The sites had imple-mented criticality standards very well.

For the review, the team toured the facili-ties, giving pop quizzes to staff, asking them,for example, to describe the contingencies re-lied on and barriers to criticality. They foundstrengths and weaknesses across the sites, saidMcKamy. At Los Alamos, the team found theinteraction between criticality safety staff andoperations staff exemplary. Operations staffknew the criticality scenarios and their con-trols; criticality safety staff were seen and wel-comed in the operations area.

Some common weaknesses were identified,McKamy noted. Most sites did not have a for-malized process to ensure that criticality safe-ty engineers understood the operations and theprocesses they analyzed. There was a tenden-cy to assess the processes remotely, ratherthan walking the facility to understand andidentify risks. This also meant that they werenot available to teach operators about criti-cality safety controls.

The team’s recommendationsThe review team made several recommen-

dations, including:� Ensure that criticality controls and theirtechnical bases are understood. Criticalitysafety engineers must be made familiar withoperations and interact with the operators sothey understand what can go wrong and whythe controls are in place and get their partici-pation in developing the controls.� Ensure rigorous adherence to proceduresand controls. It is particularly important thatoperators understand they have “stop-work”

authority when something is out of bounds.� Improve feedback to senior managers.Managers need to know the overall conditionof the criticality safety programs to improveoversight.

The team also recommended that the DOEstrengthen its programs, attract more experi-enced professionals, and train those in place.

Following the incident, the Nuclear Regu-latory Commission asked licensees to reviewtheir operation, focusing on processes involv-ing comingling of high- and low-enriched ura-nium, training procedures, startup authoriza-tions, accident recovery operations, andmanagement oversight.

The NRC’s investigations of the gaseousdiffusion plants and high-enriched uranium(HEU) facilities identified no significant crit-icality safety issues. According to Dennis C.Morey, of the NRC, the commission con-cluded that the existing regulatory programmakes it unlikely that an accident could oc-cur. Licensees review criticality potential inthe licensing process, using a defense-in-depthapproach that considers prevention, mitiga-tion, and emergency preparedness. Licenseerequirements for criticality safety also includeadministrative controls, internal auditing, op-erator training, independent plant safetygroups, and event reporting. The NRC alsofound that its current oversight programmakes an event unlikely, and concluded thatno revisions to the program were required.

Chris Robinson, of the Y-12 facility at OakRidge, explained that soon after the Tokaimu-ra accident, the plant stood down for a fewdays to discuss the situation with staff, to lookat the plant’s vulnerability to a similar inci-dent, and to undertake plant-wide training incriticality safety. A rather rigorous formal as-sessment of the more vulnerable facilities andprocesses was undertaken. One particular con-cern was the effectiveness of the large-geom-etry exclusion program to avoid the introduc-tion of containers with large geometries intothe HEU solution areas.

Operators at the plant reasonably asked ifthey had been working unsafely before. Theanswer, Robinson said, is no. It is the level ofdocumentation and information that are need-ed today that has changed. In addition, effortsare being made to explain why the rules are inplace. This is very different, notes Robinson,from earlier times when information such aswhat the real limits were was held back in caseit could be used for causing industrial prob-lems. Workers were expected to follow pro-cedures blindly.

Another example of how industry reactedwas given by ChristaReed, manager of nu-clear criticality safety(NCS) at the NavyNuclear Fuel Division(NNFD) of BWXTechnologies. TheLynchburg, Va., planthas operated for 45years and can handleuranium of all enrich-ments. Her group of11 engineers has con-

siderable experience with plant operations.Right after the Tokaimura accident, daily

briefings were set up with operations in casesomething needed to be done immediately,said Reed. Fortunately, this did not happen.The general manager also posted informationfor the whole plant. Chemical process opera-tors were particularly interested, so one-on-one talks and training were arranged for them.

Areas examinedTwo weeks after the Tokaimura accident,

the plant manager chartered a group to see ifthe facility was susceptible to a similar event.It particularly looked at:� Operator training.� Geometry of solution transfers (at Tokai-mura, the workers did not appreciate the im-portance to criticality of the geometry of thecontainers).� Availability of containers of nonfavorablegeometry in solution process areas.� Enrichment controls.� Emergency response capabilities.

The group did not find any unsafe condi-tions, but suggested upgrading training insome areas and improving material transfers,Reed noted. They found that the chemical pro-cessing area has expanded so it was right nextto the shipping and receiving area, where dif-ferent types of containers may be located. Sol-id walls were built to prevent problems.

It also found that a good emergency re-sponse plan was in place that included quar-terly drills for practicing criticality incidentscenarios all the way to the hospital. It found,however, that the plant was not prepared tocommunicate with press, local agencies, orcompany headquarters. Since then, a scriptdescribing what a criticality accident is andwhat it means for the surrounding communi-ty was prepared. The response team has nowcoordinated with state and local emergencyagencies to discuss what the plant would ex-pect from them and what they could expectfrom the plant if an incident occurred. Al-though arrangements with local hospitalswere already in place, they were contacted tomake sure they could handle highly irradiat-ed people.

The plant was also visited by an assessmentteam from the Nuclear Energy Institute (NEI),which found a good culture at the plant, not-ing the presence of NCS officers on the floor.The NEI team interviewed the operators andfound that they knew the procedures, under-stood that they could not deviate from them,and could stop operations they felt were un-safe or they did not understand.They also un-derstood that a criticality accident is a badthing and could kill them.

The NEI discovered, however, that opera-tors could not explain what criticality is, in thesense of a self-sustained nuclear chain reac-tion, some suggesting it means an explosionor metal ingesting. They could not explain thefundamentals of mass, moderators, and con-trols. The NCS unit is working to improve thisand is finding it quite a challenge.

Reed noted a lot of willingness at the plantto change things after the accident, as did thenext speaker, Kathleen E. Bhanot, of British

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Nuclear Fuels plc (BNFL), in the UnitedKingdom. She said that once the managementand commercial people in her organizationdiscovered that the incident would affect theirbusiness, they became very supportive of hergroup’s work.

Although most of the material processed atBNFL’s Springfields fuel fabrication facilityis low-enriched uranium, the plant does han-dle small quantities of HEU recovered duringthe decommissioning of BNFL’s old HEU fa-cilities. The residues are dissolved and down-blended before being put back into the plantprocess.

The accident had a direct impact onBNFL’s business. The company was in themiddle of selling its integrated dry-routeprocess, which converts UF6 to UO2 powder,to JCO Company, Ltd. Contracts had beenplaced and equipment was being manufac-tured. The sale ceased. “The commercial peo-ple now realized what criticality safety wasabout,” she said.

This led the director to ask her to look at thefindings of the reports on the Tokaimura ac-cident from the Japanese government, the In-ternational Atomic Energy Agency, and theNEI to determine possible implications for op-erations at Springfields. All observations andrecommendations made in the reports werechecked against the situation at Springfieldsto see if any action was needed. The reviewfound no showstoppers or any reason to makechanges to procedures, said Bhanot.

The review did find, however, a lack ofawareness and training of personnel, as well assome complacency among the staff. Im-provements in accountancy procedures in allmass control areas were also needed. Mea-sures are under way to deal with these defi-ciencies.

While no fundamental problems wereidentified at Springfields, the Tokaimuraaccident provided an opportunity to reviewall procedures and policies. Such an oppor-tunity does not arise very often, and the crit-icality group has taken full advantage withsupport from management to improve pro-cedures and practices.

Under normal conditions there is a good no-tification system in place to involve the criti-cality officers whenever there are modifica-tions to plant, said Bhanot. But it is not alwaysearly enough. Problems can also occur whensomething unusual happens, for examplewhen operations are changed or the plant isdown for any reason, like an audit or a VIPvisit. The staff now know to call in the criti-cality officers if there is any change in opera-tion or a production difficulty. This is nowworking well.

Finally, although the media attentionbrought some rewards, Bhanot noted, in cov-ering the JCO accident, the BBC used archivefootage of a hole in a roof of a facility causedby a fire some three years ago. Until then, shehad found the BBC a credible news source.She said that she no longer does.

The NEI teamJohn C. Brons, a special assistant to Joe

Colvin at NEI, described the findings of the

NEI team that visitedthe country’s 10 com-mercial facilities thatprocess uranium solu-tions. “We were look-ing at how safety pro-cedures were appliedand the attitudes ofstaff applying them.Are they used consis-tently and whole-somely?” The report,Assessment of Nuclear

Criticality Safety and Emergency Prepared-ness at U.S. Nuclear Fuel Plants, was praisedby many at the meeting.

At the beginning of a plant visit, the NEIteam asked plant managers to explain howthey achieved their safety goals, and what theyexpected the team to find. The team then wentinto the plant to see if they could find it. De-spite the business and other commercial pres-sures, the team found uniformly good linkagebetween operations staff and management re-garding what was expected. Safety was con-sidered crucial, and the operators had a clearsense of their authority to stop the process forany reason. The NEI team found proceduresin use flowed well from the license conditionsof the facility.

At all facilities, operators said that they ex-pected procedures to be followed. Brons said,however, “When you get down to the shopfloor, there is a wide range of interpretation ofwhat that means.” They found that operatorsalways believed they were carrying out the in-tent of the managers. The interpretation of in-tent concerned the team. As Brons said, “Icould argue that at Tokaimura, the intent ofthe procedure was followed, at a very broadlevel. But lots of important details were over-looked.” Basically, the understanding of man-agement and operators regarding what theprocedures mean and how they are appliedmust be the same, Brons emphasized.

The NEI team identified many good prac-tices actually being implemented that are in-cluded in their report. They found only onegood example, however, where operators hada good understanding of criticality and criti-cality controls. Many plants considered thistoo difficult to teach, as if, said Brons, it meantmaking nuclear physicists out of the people.Brons says this must change. If operatorsknow the reasons for restrictions, they aremuch more likely to adhere to them when thecrunch comes. If not, it is easy to bypass them.

Another concern was that some audit andsurveillance programs were unduly respon-sive to the NRC. At the best run facilities, thestaff knew who was running the show.

Finally, the team was reassured, said Brons,because it found no one who believed that crit-icality could not occur.

Neutron applicationsInnovative uses of neutron-related tech-

nologies were reported on in the session,“Neutron Detection, Spectrometry, andDosimetry–II.”

Paul Goldhagen, a physicist at the Depart-ment of Energy’s Environmental Measure-

ments Laboratory, presented a paper on mea-suring cosmic ray–induced neutrons aboardan aircraft, as well as on the ground. Goldha-gen and his group undertook these measure-ments primarily to study radiation protectionfor aircrews. They determined cosmic rayneutron spectra over the full energy range atvarious altitudes and latitudes.

In 1997, there were more than 167 000 air-crew members working for airlines in theUnited States. The hours aloft are typically500 to 1000 hours for each aircrew memberevery year. “As a whole, they are one of themost exposed groups of radiation workers,which we completely ignore here in the Unit-ed States,” Goldhagen said. “But, in the Eu-ropean community, aircrew are true radiationworkers, and starting this year, efforts will bemade to determine their yearly dose rates andkeep records of it.”

Goldhagen explained that cosmic rays areenergetic atomic nuclei coming from space—primarily protons, as well as some helium ionsand heavier ions. When they collide with theatmosphere, they produce neutrons, amid oth-er kinds of radiation. There are two basickinds of cosmic rays: galactic and solar. Thegalactic rays are continual and ever-present,and can have very high energies. They domi-nate the dose to aircrews. Solar rays are spo-radic, occurring only during solar particleevents, of which there are only a few for each11-year solar cycle. They produce high doserates for a few hours to a day or so. They aretypically lower energy, producing significantdoses only at higher altitudes.

Three variablesDose rates from galactic cosmic rays in the

atmosphere depend on three primary vari-ables, Goldhagen explained. The first is alti-tude, because of the amount of shielding pro-vided by air.

The dose rates also depend on magnetic lat-itude. Because of the earth’s magnetic shield,the horizontal component of the magneticfield bends the primary charged cosmic raysback into space (if they’re sufficiently low inmomentum). Subsequently there is a higherflux of these particles near the magnetic polesthan at the equator. As a result, at an equal al-titude, the dose equivalent rate at the poles isroughly six times greater than at the equator.

There is also the variable of the solar cycle,owing to variances in the magnetic field car-ried out by the solar wind. “The importantthing to remember here is you get a maximumof galactic cosmic radiation at the earth whenthe sun spots are at a minimum. So, solar min-imum is radiation maximum,” Goldhagensaid.

Until the last five years or so, uncertaintiesin measuring the neutron spectrum were themain cause in not knowing the effective doseat high altitudes, Goldhagen said. The ioniza-tion chamber measurements from 20 and 30years ago had measured the directly ionizingcomponent fairly well, he said, but there wererelevant uncertainties in what the neutronswere doing.

The experiments Goldhagen reported on,called the Atmospheric Ionizing Radiation

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Brons

Measurements project—or AIR Measure-ments—were started by the NASA LangleyResearch Center and grew into a collaborationof more than a dozen laboratories.

The researchers obtained a NASA aircraftand loaded on to it a suite of more than adozen radiation measuring instruments. Theinstruments were placed in the nose of the air-craft, in wing pods, and in a section of thefuselage. They then flew at a range of alti-tudes, from 52 000 to 70 000 ft, and latitudes,from 18° to 60° north.

The effects of latitude affected the neutronfluence, but had little effect on the spectrum.At the southernmost measurement location,the total neutron fluence was one-eighth ofwhat it was at the northernmost location. Thespectrum, however, hardly changed. “This isvery good news because it means that thisvariable does not affect the shape of the neu-tron spectrum and therefore won’t affect thecalibration factors of simpler [radiation] mon-itors that you might fly on airplanes,” Gold-hagen said.

The effects of altitude were greater. Whenthey dipped in altitude, the fluence hardlychanged—only a 3 percent decrease. But,there was a slight change in the spectrum,which resulted in the dose equivalent chang-ing by 9 percent, and the effective dose by 11percent. “So, that’s big change,” he noted.

The data they collected have other applica-tions besides radiation protection, Goldhagensaid. “Also important . . . are the so-called sin-gle-event effects, when neutrons strike the

very small electronic components in chips andupset them. They can cause bit flips. And ifyou change a bit in a program that’s helpingyou fly your airplane, you could be in trouble.

“So, it’s nice to know what the spectrum ofneutrons is, because it’s an energy-dependenteffect. And neutrons are causing most of thebit flips, even here on the ground. This effecthas become important as computers havemore and more memory and smaller andsmaller sizes. These results could also be usedto validate the radiation transport codes thatare used to determine the doses to the astro-nauts traveling through the much smaller lay-ers of shielding.”

In addition, the surface of Mars is equiva-lent to flying at 80 000 ft above the earth,Goldhagen said, so these measurements havepossible implications for travel beyond Earth.

Brent Lewis, a professor of nuclear engi-neering at the RoyalMilitary College ofCanada, while report-ing on a model of pre-diction for cosmic ra-diation exposure ofcommercial aircrew,said his crew of re-searchers developedan extensive data baseof doses. Over thecourse of taking radi-ation measurements

aboard dozens of flights, they collected over20 000 ambient dose equivalent measure-

ments, which he believes comprises thelargest such data base in the world. Fromthose measurements they developed a code topredict air crew exposure.

Radiation search toolRick Seymour, president and founder of

Nuclear Safeguards and Energy Systems, pro-vided a progress report on the ongoing devel-opment of a briefcase-sized portable radiationsearch tool for the International Atomic En-ergy Agency (IAEA) Safeguards Group.

The device, as designed, uses neutron-sen-sitive scintillating glass-fiber sensors, whichrepresent a new approach to conventional neu-tron detection. They provide several advan-tages over neutron-sensitive gas tubes for plu-tonium detection in portable applications. “Thefibers are much less sensitive to microphonics,to vibration, so they’re quite robust. They’revery good in harsh environments and ideallysuited for portable applications,” Seymour said.

The requirements from the IAEA were veryspecific, he explained. The inspectors travelfrom country to country, and have to be able tocarry the equipment in and out of the country.The device had to be robust and reliable. Theywanted it to be modular so they could makechanges in the field if something happened togo wrong. They wanted to have both neutronand gamma-ray detecting capabilities, but theydid not want a spectroscopy-based system.“They simply wanted a gross counting systemthat had maximum sensitivity,” he said.

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Continued

The neutron-sensitive glass fiber thathelped fulfill the IAEA requirements “is a realalternative for thermal neutron detection,”Seymour said. “It is a solid-state detector forneutron detection. It allows you to do verylarge areas. It allows you to use very robustdetectors in harsh environments. It is verywell-suited for a portable radiation searchtool.”

NucSafe is scheduled to deliver the firstunits to the IAEA next month.

Land mine detectionRichard Craig, who specializes in detector

physics at Pacific Northwest National Labo-ratory, gave a presentation on land mine de-tection using timed neutron methods.

There are thought to be 110 million minesin place around the world, Craig said. Theseare being removed at one-twentieth the ratethe mines are being placed. Mine detectionhas been made more difficult in the last decadebecause fewer mines have metal in them any-more, foiling conventional methods of find-ing them.

Many recently made land mines are fabri-cated using organic material, which containlarge amounts of hydrogen, Craig explained.The moderating property of hydrogen, greaterthan that of other nuclei, provides a mecha-nism for finding these otherwise difficult-to-detect mines.

“Commercial methods do not detect hydro-gen. They’ll detect metal,” Craig said. “If youhave a mine that has absolutely no metal . . .the detection rate is zero. You need some met-al. Even the mines that contain some metalcontain about the amount of a half of a pin.Take a pin, cut it in half: That’s the amount ofmetal it has. . . . The theoretical results are thatwe would be much better than the commercial[detectors], even for metal mines.”

The method that Craig described is basedon timing the reflection of neutrons. On aver-age, a neutron reflecting off of hydrogenousmaterial deposits half its energy. When re-flecting off other material, such as the soil, itloses much less energy.

In that method, if a neutron is emitted fromthe source and goes into the soil, it is reflect-ed back quickly because it loses very little en-ergy when hitting the soil. This principleforms the basis of how to detect nonmetalmines. “We only want to see the slow neu-trons, the ones that have interacted with hy-drogen. So, we don’t count the ones that comeback very quickly,” Craig said. Only moder-ated neutrons that return to the detector afteran appropriate time delay are counted. Neu-trons returning too quickly are rejected.

The method by which the detector signals apositive indication of land mine is important,Craig said. “Typical metal detector devices ormetal detector–based mine detectors use anaudible signal. One of the things the Army hasdiscovered is that the people who are doingthis have heard a lot of explosions in their day,and they can’t hear worth a darn. . . . So, wewant to do something that’s a little more sim-ple to use.”

Craig’s prototype mine detector, whosestructure was once a hardware store weed-

whacker, detected mine simulants in thedesert, he said. “We have an entirely new ap-proach. We’ve demonstrated the physics ofthe approach. . . . Right now we’re workingon getting access to DOD minefields, wherethey’ve planted deactivated, but not inert,mines. So, we can demonstrate with the minesthat have TNT and RDX [explosives] in thembut no detonators. . . .

“We know that our results aren’t as sensi-tive when the ground is saturated. We’re notgoing to find mines in a swamp. At least notyet. But we will find them in dry sand. We willfind them in slightly wet sand.”

Applications of Cf-252The intense neutron-emitting and potential

cancer-killing properties of californium-252have been known and studied for decades.The radioisotope’s promise as a cancer thera-py was recognized by the Atomic EnergyCommission in the 1960s, said Rodger Mar-tin, of Oak Ridge National Laboratory, who,during the session “Medical and IndustrialApplications of Cf-252–I,” gave a presenta-tion on Cf-252 brachytherapy.

The radiobiological advantages of neutronsfor tumor cell killing, when compared to theconventional photon therapy sources such asiridium-192 and iodine-125 sources, are nu-merous. Neutrons have high relative biologi-cal effectiveness (RBE) values, Martin ex-plained, which means that for the same doserate, neutrons will kill significantly more cells.Also, the effectiveness of photon therapies islimited to oxygenated cells. Neutrons are ef-fective on either oxygenated or oxygen-defi-cient, hypoxic, cells. In addition, neutrons arenot as cell-cycle dependent as photons: A cellwill die if hit with a neutron, regardless of themoment in the cell’s life cycle.

Several advantagesThere are several other practical advantages

to using Cf-252 brachytherapy, in which syn-thetic radioactive seeds are deposited near orin the tumor, Martin explained. Treatmentwith neutrons shrinks bulky tumors muchmore quickly than does photon therapy. Thedose is localized around the source, in orderto spare the healthy tissue farther away. Con-formal therapy with multiple sources, whichshapes the dose field around the tumor region,can be performed. There is also the promiseof combined neutron-photon therapy: Attack-ing a tumor first with the neutrons tends tobreak it up and reoxygenate it—which allowsthe following photon therapy to be more ef-fective.

One interesting new possibility for cancertherapy is boron-enhanced Cf-252 brachyther-apy. Martin said that some studies have indi-cated the potential usefulness of using thesame boron pharmaceuticals developed forboron neutron capture therapy in combinationwith fast neutron therapy. “After these fastneutrons have thermalized and been madeavailable for capture by boron, you can startgetting some significant enhancement ofboron, of total dose, at several centimetersfrom the californium source. . . . The advan-tage with this boron coupling is that you can

use another variable to tailor the dose distrib-ution around the tumor to reduce necrosis ofthe healthy tissue. But also, an additional ca-pability [is] increasing the dose to neighboringmetastases, which [present] a problem in long-term tumor control.”

Martin concluded by saying that extensionof Cf-252 brachytherapy to radioresistant tu-mors, such as brain cancer, will require bothsmaller sources and higher doses.

“Our existing source is the wire. . . . For thehigh-dose rate, we’re trying to put more andmore californium oxide into a metallic ma-trix. . . . Ultimately you run into material sta-bility problems when you’re trying to workwith this material. It hardens. So, you’re go-ing to run into a tradeoff between how muchmaterial can you get in and how small can youmake the wire.”

Developments in ChinaChina has made significant progress in con-

ventional radiation therapy—including Cf-252 neutron therapy-—in the last twodecades, said Sharwin Zeng, M.D., ofCafmed-China, who provided a backgroundon Cf-252 neutron therapy in China.

Chinese radiation oncologists were inter-ested in californium neutron therapy in theearly 1980s, but Cf-252 sources for medicaluse were not available in China until 1992,when a joint venture was established betweenthe China Institute of Atomic Energy and Rus-sia’s Institute for Nuclear Reactors. In 1995,25 Cf-252 seeds were sent to China for pre-clinical investigation. Since then, Cf-252 neu-tron therapy in China has developed rapidly.It is estimated that within five years, one outof 10 radiation oncology centers withbrachytherapy practices there will beequipped with Cf-252 units for intracavitarytreatment. Nonetheless, that is, on average,only one unit for every 40 million people inChina, Zeng said.

To address the problems of demand for cal-ifornium neutron therapy in China, Zeng said,attention should be focused on doing basicwork in radiophysics and radiobiology, in-cluding source calibration, clinical dosime-try, and quality control, and establishingtraining courses for radiation oncologists andphysicists involved in californium neutrontherapies.

Cervical cancer treatmentAnita Mahajan, M.D., a radiation oncolo-

gist at the New England Medical Center, inBoston, Mass., has been working with gyne-cologic cancers for the past several years. Shedescribed the potential for Cf-252 brachyther-apy to treat cervical cancer and plans for anew clinical study of the procedure.

Approximately 12 800 cases of cervicalcancer will be diagnosed in the U.S. this year(2000), and there will be 5000 deaths due tothe disease, Mahajan said. When first diag-nosed, 55 percent of the patients have local-ized disease, 31 percent have regional spread,and about 10 percent have distant diseasespread.

“The local control of the bulky tumors is amajor problem,” Mahajan noted. Local con-

54 N U C L E A R N E W S January 2001

trol is obtained in 50 to 60 percent of the pa-tients. About 70 percent of the patients whohave local disease, however, relapse.

With conventional radiation treatment of thedisease, a dose of 45 to 50 gray has generallybeen delivered to the large pelvic area, incor-porating the primary site, as well as the lymphnode drainage, Mahajan said. The treatment istypically given over five-week period.

In traditional brachytherapy techniques, low-dose rates have been delivered using cesiumsources. “It’s effective,” Mahajan noted, “butit is somewhat cumbersome for the patient.They have to be admitted into the hospital.They’re immobilized for 48 to 72 hours.” Thebenefit is, though, because of the brachythera-py dosimetry, the surrounding tissues receiveless dose. The low-dose rate brachytherapydoses are generally 20 to 40 Gy per application,given in combination with the external beamdose, for a total dose of about 80 to 90 Gy.

Over the last two decades, high-dose rate(HDR) therapy, using cobalt-60 and iridium-192, has been explored because of physical aswell as practical issues, Mahajan explained.The advantages are that patients can be treat-ed on an outpatient basis. Treatment is deliv-ered usually in a half hour or less. There isrigid immobilization during the delivery of theradiation, which is not the case during low-dose rate brachytherapy. Subsequently the in-struments are generally smaller and less cer-vical dilation is required, so it becomes a lessinvasive procedure.

The promise of HDR Cf-252 neutronbrachytherapy for treating cervical cancer isbased on several factors. For one, the higherRBE of neutrons is considered to be benefi-cial in treating slow-growing tumors.

Also, neutrons are not as dependent on oxy-gen as photons are to be effective. Oxygen isnot diffused very far from capillaries, and so,in bulky tumors there is going to be a signifi-cant hypoxic area.

In addition, neutrons have a higher linearenergy transfer. At the amount of damage de-posited, neutrons would potentially cause adouble-stranded break in cellular DNA, whichwould be more lethal to the target cell. Thesingle-stranded break of a photon can be re-paired. “It seems that there’s going to be lesssublethal damage repair going on with neu-tron irradiation, which is beneficial with tu-mor cells,” Mahajan said.

The double-stranded DNA breaks are alsoless likely to cause cell mutation from radia-tion damage. “I’m led to believe that the dou-ble-stranded breaks that are occurring fromthe neutron irradiation are less likely to causecarcinogenic effects, because the cell will ei-ther die or survive,” Mahajan said. “And oncethe cell is dead it cannot go through immuno-genesis. Whereas in photon irradiation, withsingle-strand DNA damage, repairs can bedone in an abnormal fashion and carcinogen-esis is a high risk.” She added that the proce-dure may be beneficial for pediatrics becauseof the possible decreases in carcinogenesis.

Several clinical trials testing the suitabilityof Cf-252 for cancer therapy have been con-ducted. One trial examined 82 patients treatedbetween 1976 and 1979. They were treated

one of three ways: external beam and cesiumbrachytherapy, external beam and californiumbrachytherapy, or californium brachytherapythen followed by external beam. The resultsshow that in all cases, the Cf-252 given earlyin the course of disease achieved the best out-come. Overall survival was not very good, butmuch better than regular irradiation, Mahajansaid. Another trial revealed the safety of esca-lating the dose in hypoxic situations.

For their clinical study, Mahajan and hergroup are planning on selecting patients withadvanced cervical carcinoma, with bulkystage 2B, 3A, 3B, and 4 tumors. They will teststandard external beam radiation, chemother-apy, and conventional brachytherapy, inwhich iridium will be replaced by HDR Cf-252.

“The use of the californium will have a ra-diobiological benefit, as theoretically sug-gested and which has been observed in the pri-or studies. The HDR brachytherapy will havea geometric benefit as well as a radiation safe-ty benefit. And toxicity is going to be moni-tored closely because we’re not quite surewhat dose will be required. But dose escala-tion will be part of that protocol to optimizeand characterize response,” Mahajan said.

She said she does not expect the side effectsof Cf-252 brachytherapy to be any differentfrom those of photon therapy. “It’s always abalance of side effects versus tumor control.And the situation where we are now, withconventional photon irradiation and photonbrachytherapy, the control rates are subopti-mal—as I suggested, there are . . . 70 percentrelapse rates within the pelvis. And with thatwe still have about a 10 or 20 percent long-term side effect profile. . . . With the neutronbrachytherapy I expect the same type of sideeffects. And we’re going to be controlling ourresults, as far as toxicity, so that we’re not go-ing beyond what we expect in photon radia-tion. But the type of side effects should be thesame.”

Space applicationsThe session “Space Nuclear Power II: The

Future” covered near-term strategies to suc-cessfully develop and fly space fission powerand propulsion systems.“Compared to other ad-vanced systems,” notedMike Houts, of the Propul-sion Research Center atNASA’s Marshall SpaceFlight Center, “fission sys-tems are really very simple:You put the right material inthe right geometry and thenturn it on. . . . To my knowl-edge there’s no other energysystem with that kind of en-ergy density that’s that con-ceptually simple to work.”

Speakers noted through-out the afternoon thatNASA (the National Aero-nautics and Space Adminis-tration) has realized thatconventional chemical sys-tems are nearing their per-

formance limits. The usefulness of solar pow-er, which may perform well in some applica-tions, degrades rapidly as the distance fromthe sun increases. Fission, however, appearsto have tremendous performance potential andcan allow for more robust spacecraft design.Conceivable near-term space applications forfission-based systems include power andpropulsion for craft on the surface of Mars, aswell as for ambitious outer planet missionsand an exploratory mission to Jupiter’s satel-lite Europa.

“We’ve demonstrated that these systemscan be safe during development and opera-tion,” Houts said. They are “virtually nonra-dioactive at launch,” and “even a large fissionsystem would have an order of magnitude lessonboard radioactivity than the little Sojourn-er rover on Mars,” he said.

Radioisotope systemsPaul VanDamme, of the Jet Propulsion Lab-

oratory, who spoke about the challenges ofpowering spacecraft and future space sciencemissions using radioisotope systems, said thatmost missions use solar cells and batteries forpower aboard a spacecraft. There are times,though, when it is impossible to use those re-sources, such as when a spacecraft is far awayfrom the sun. Also, there are certain environ-ments, like Jupiter’s, that are extremely radia-tion-intense, and using solar cells is nearly im-possible because of degradation concerns.

In a less obvious case, even if the spacecraftis going toward the sun or near the sun, solarpower is still not necessarily easy to use, Van-Damme said. If a mission requires launchingthe spacecraft into solar orbit, the craft mayrequire a gravity assist from a Jupiter. “We[need] a spacecraft that has to work in twovery different environments: one that’s verycold and dark and radiation-intense, and thenalso [in one] very close to the sun. That be-comes a very difficult technological challengefor power,” he said.

One solution is to use a radioactive powersystem. Radioisotope thermoelectric genera-tors (RTGs) can convert heat into electricityusing thermoelectric converters. The heat isproduced in modules that contain plutonium

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Mars Pathfinder’s Sojourner rover (NASA)

dioxide, a ceramic form of plutonium. Thereare typically 18 such modules in an RTG. Theunit will produce, at first, about 280 We. Overtime, as the plutonium decays and less heat isavailable, the power output decreases.

NASA is currently working with the De-partment of Energy to improve the design,VanDamme said. “Ideally, we would like adevice that is smaller, has less mass. And mostpeople involved would also like it to use lessplutonium, for lots of different reasons—oneof which is, of course, plutonium-238, whichis the main ingredient here, is a limited re-source and one not currently produced in theUnited States,” he explained.

Radioisotopes can also produce thermalheat in space applications. Radioisotopeheater units (RHUs) are small—about the sizeof a large marshmallow—and produce about1 Wt of energy. The Sojourner rover on theMars Pathfinder mission had three RHUs on-board to keep the electronics warm enough tosurvive the cold Martian nights. Without themthe electronics would not have been able tooperate for more than a day, VanDamme said.

He outlined space science missions that arein the planning stages. Between now and2005, there are 22 space science missions be-ing planned—none of which, however, re-quire a radioisotope power system. Two ofthe missions—the recently announced rovermissions to Mars—may require RHUs. Forthe 2006–12 time frame, five potential mis-sions are being studied that may require ra-dioisotope systems. Two other missions toMars are planned for the 2007–13 time frame.

One interesting mission in the 2006–12time frame, which is still in the conceptualphase, is the Europa Orbiter mission. NASAwould send a craft to the Jupiter satellite,which is believed to be encrusted with an icelayer—underneath which is believed to be aliquid ocean. “We want to send a probe there,get it in orbit, get an idea of how thick the iceis [there] and all around the moon,” Van-Damme said. “Maybe find, ideally, a thin spotin the ice, which could be a potential landingsite. . . . We [would] actually land on Europa,melt the ice, and get some kind of scientificinstruments down into that liquid ocean,which would be an amazing feat.”

There are, however, many technologicalchallenges for the Europa mission, not theleast of which is generating the 400 or 500 Wof power that would be needed. “Spacecraftpower is a challenge,” VanDamme explained.“You’re going around a satellite of Jupiterwhere there’s a very harsh radiation environ-ment. You’re in the dark a lot of the time be-cause you’re [blocked] from the sun becauseof Jupiter or the satellite itself. And it takes awhile to get there, so you need something thatcan live a long time. . . .

“Even though this is in advanced study,NASA is always faced with competing [proj-ects]. We have scientists that say they want todo a lot of science, and science requires morepower.”

Fission-based systemsGeorge Schmidt, deputy manager of the

Propulsion Research Center, spoke about fu-

ture nuclear space applications and the ad-vantages that fission-based systems offer overchemical- or solar-based systems. “Ultimate-ly, if we want to really realize the full poten-tial of nuclear systems for space, we have toevolve to fission-based systems,” he said.From a performance standpoint, there aremany advantages to using fission, especiallywhen looking at very ambitious deep spaceexploration, he noted.

The extent and sophistication of future ro-botic and human exploration is ultimately lim-ited by propulsion and power technology.Chemical energy sources both for power andfor propulsion are now near their theoreticallimits. “The specific impulse that you can getwith the best propellant combination . . . isabout as good as the chemical technology isgoing to get,” Schmidt said.

Natural energy sources, such as solar ener-gy, are highly dependent on the location ofspacecraft. Radioisotope sources, which havegreat advantages and work extremely well forsome applications, are ultimately encumberedby low efficiencies and lower power densities.Other more speculative energy concepts, suchas fusion or the beamed-energy concept, re-main immature.

“When we really look at it in terms of allthe different types of energy or resources thatwe have at our disposal, the one that clearlysurfaces that has the most potential is nuclearfission,” Schmidt said.

An appeal of nuclear fission is that there aremultiple ways to utilize the energy source.One is to produce electrical power for veryhigh performance electric thrusters, a conceptthat has been studied for decades. Much high-er power densities would then be achievable,compared to those of a radioisotope or solarpower system.

More important, Schmidt said, “some of themore advanced forms of nuclear thermalpropulsion have an incredible evolutionarypotential. They can really evolve to performthe missions that we have heretofore been as-suming for fusion and some of these real ad-vanced nuclear energy sources. We can do alot of that with nuclear fission. So, it really hasa lot of potential for the future.”

The rationale for using fission systems is afunction of the power that is needed for space-craft applications and the duration of use. Thechemical energy supplies, such as the auxil-iary power units used on the space shuttle, areuseful for high powers, but are going to beconstrained to very short durations. Solar en-ergy holds appeal for extended durations, butplaces limits on the amount of power becauseof the massiveness of the systems and the lowefficiencies for conversion. Even within fore-seeable technological improvements to that,there are still going to be constraints. And ra-dioisotope sources are certainly going to begood for low-power applications.

“But when we start talking about high pow-ers and long durations, that’s when fission re-ally comes into play,” Schmidt explained.

“Also, and I think this is probably most im-portant, if you look at solar flux as a functionof distance from the sun, you see [on a graph]that [the slope] drops off very steeply,”

Schmidt explained. “And because of that,even though solar for electric propulsion andother forms of propulsion has a lot of appealaround earth orbit—possibly up to Mars—be-yond that it doesn’t really make sense, notonly for the spacecraft power supply but alsofor the propulsion. It just does not provide theadequate power density.”

There are three applications for nuclear fis-sion on a spacecraft. The nearest-term appli-cation would be to provide electric power tosupport operations of a spacecraft in-flight orstationed on the surface of a planet. Such asystem would consist of a nuclear energysource, some type of solid-core reactor deliv-ering heat to a power conversion system,along with a waste-heat disposal system.

Another space application for nuclear fis-sion is for electric propulsion. The setupwould be similar to power provision, exceptmost of the power taken out of the systemwould be delivered to a thruster. “That wouldallow us to [achieve] very high specific im-pulse propulsion that we could use for deepspace missions,” Schmidt noted.

Third, in a considerably different approach,nuclear energy could power thermal rockets.“Here we’re utilizing direct heating of aworking fluid or propellant, and expandingthat propellant out in some form to producethrust,” Schmidt explained. “The appeal ofthe nuclear thermal rockets is it can deliververy high power densities. But you are goingto have lower exhaust velocities and specificimpulses than you would with electric propul-sion. But for missions where you’re reallyconcerned about acceleration, where time isgoing to be a key concern, then nuclear ther-mal is the appropriate type of system to use.”

The payoff of a fission-based nuclear elec-tric power system becomes apparent in lightof the different types of missions, Schmidtsaid. Looking at a piloted Mars mission, forinstance, fission can provide a substantial re-duction in the amount of propellant that isneeded, which can greatly reduce the flight-time of the trip.

“Now, you’re going to ultimately be con-strained by your specific impulse and the var-ious structural fractions in your vehicle,” hesaid. “But, overall, you get a tremendous ad-vantage over chemical-based systems.”

Looking at other ambitious missions, suchas a Neptune orbiter, there is still a tremen-dous performance advantage: a two- to ten-fold reduction in propellant when using nu-clear electric propulsion.

“Finally, it becomes apparent, . . . [when]compared to chemical systems, nuclear fissionnow becomes an enabling technology—some-thing that you really can’t do with chemical-based systems. . . . From a straight perfor-mance [standpoint], fission is certainlysuperior, at least for most of the missions thatwe’re considering.”

The problem, however, is that the UnitedStates has conducted only one flight demon-stration with a fission-based system. Andtechnology without flight heritage, Schmidtpointed out, has little or no impact on spaceprograms. The U.S. has conducted consider-able research and development in this area,

56 N U C L E A R N E W S January 2001

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but of all these efforts, only one reactor-pow-ered craft has ever flown, the SNAP-10A inthe mid-1960s. “Even though the U.S. has in-vested the resources and has developed thetechnology to a large degree, really, in termsof flight, we haven’t really done that much.”

If it hasn’t flown, it doesn’t count, he said.“Unless you have a fully mature technologythat’s flown, most of the time [NASA] won’tconsider it in the program. And I think that’swhat’s critical about this.”

The inactivity, however, is not for lack ofsafety. “When we start looking at all the dif-ferent issues, these types of systems can bemade almost absolutely safe—certainly assafe as other alternative types of approachesto power and propulsion,” he said.

Current studies are centered around a three-phase program that will allow the space pro-gram to incrementally build capability towardrealizing fission’s potential.

Phase one is aimed at using existing facil-ities and technology, focusing on applicationsfor near-term scientific exploration. With thisapproach, NASA researchers are looking atvery small systems—300-kW energy sourcesusing electrical resistance heating. Schmidtsaid most of the design issues can be workedout using nonnuclear elements, and that thenuclear material would be incorporated in thefinal stages of development. “What this doesis it minimizes the amount of environmentalconcerns . . . and ultimately we’re focusingon small applications that have a near-termbenefit to scientific exploration,” Schmidtsaid.

The phase-two studies are the more ad-vanced operations using developed technol-ogy. This would be focused on technologythat would relate to human exploration, andwould involve technology work in nuclearthermal propulsion, advanced fuels, and also

advanced nuclear electric systems. For thatreason it would likely be more of a develop-mental challenge, but something that certain-ly could be done extremely safely and withno impact to the environment, Schmidt said.

And, finally, phase three is “where we re-alize the full potential of fission.” This phaseconcentrates on extremely high-performanceconcepts for rapid interplanetary space flight,building on technology and infrastructurefrom phase one and two. “Here we’re lookingat gas-core reactors—also using gas-corerockets, perhaps. Various advanced forms offission that could be used to realize . . . spe-cific impulses in the range of 5000 to 10 000seconds, even greater perhaps. But, with thatkind of capability we’re really talking aboutsupporting very ambitious, possibly human,exploration of the solar system, and even be-yond.”—Dick Kovan, Rick Michal, PatrickSinco, and Gregg Taylor

ASESSION CHAIRED by Douglas Chapin atthe Embedded Topical Meeting on Nu-clear Plant Instrumentation, Control

and Human-Machine Interface Technologies(NPIC & HMIT 2000), at the ANS/ENS In-ternational Meeting in Washington, D.C.,looked at licensing issues for advanced I&Ctechnologies.

Steven Arndt, leaderof the I&C team of theNuclear RegulatoryCommission’s Officeof Nuclear RegulatoryResearch, introducedthe NRC’s proposedfive-year research planfor digital I&C tech-nology. The purpose ofthe plan, now in draftform, is to provide a“road map for comple-

tion of current research and identification ofnew research needs,” Arndt said.

Digital equipment issues currently underreview by Arndt’s team include environmen-tal qualification, defense-in-depth and diver-sity, verification and validation, interfacingwith plant equipment, real-time performance,commercial-grade dedication, and configura-tion management.

Common problems found during review ofdigital systems, Arndt continued, includesoftware engineering (which is not yet a ma-ture discipline), the lack of standardization,and the current inability to quantify softwarereliability.

The following four areas are among many

targets of research for Arndt’s team:� System aspects of digital technology, whichinclude “environmental stressors,” Arndt said,such as electromagnetic interference/radio-frequency interference (EMI/RFI), tempera-ture, humidity, smoke, and lighting.� Software quality assurance, which entailsthe development of objective software engi-neering criteria.� Risk assessment of digital I&C systems, us-ing digital failure assessment methods appliedby defense and aerospace industries to deter-mine types of failures and their impacts onoverall safety, which “can be useful in nuclearapplications,” Arndt said.� Emerging I&C technology and applications,such as smart transmitters, that will offer infor-mation for providing compensating measuresfor instrument error or control functionality.

“Understanding and measuring reliabilityof systems is the most important issue,” Arndtsaid. “If not the most important, then certain-ly the most challenging.”

Implementation of the plan, which Arndtsaid might come in late December 2000 orsoon after, would involve contractor assis-tance, cooperative programs at universities,participation in international programs, andcontinued NRC research.

Robert Uhrig, distinguished professor ofthe Department of Nuclear Engineering at theUniversity of Tennessee, reviewed varioustypes of intelligent systems. “In the pastdecade, artificial intelligence–based soft com-puting technologies, specifically neural net-works, fuzzy logic systems, and genetic algo-rithms, have been investigated for application

to nuclear power plants,” he said. “However,actual use of systems incorporating such tech-nologies, often called ‘intelligent systems,’ tonuclear power plants has been minimal.”

T O P I C A L M E E T I N G

Licensing issues for advancedI&C technologies

Major points fromthe session:

� Digital I&C softwareengineering is not yeta mature discipline.

� Future I&Cupgrades are toinclude advancedcomputertechnology.

� I&C modernizationis under way inUkraine.

� Several types ofanalyses of I&Csoftware by specialtools are needed.

Arndt

Continued

Uhrig explained the characteristic behav-iors of the three soft computing technologies:Neural network models, he said, are createdby training the networks by using data fromthe system to be modeled; fuzzy systems areconcerned with encoding a priori knowledgein the form of fuzzy rules rather than learn-ing from rules; and genetic algorithms use a“survival-of-the-fittest” approach to opti-mization based on a process analogous to nat-ural evolution.

Within the next decade, Uhrig said, I&C up-grades at nuclear plants should include fuzzysystems to control reactor power levels, opti-mization systems in the non-nuclear balance ofplant, fuzzy logic systems embedded in plantsafety systems, and self-adaptive systems us-ing neural networks and/or genetic algorithms.

Jung Soo Koh, principal researcher for theKorea Institute of Nuclear Safety, presented asafety evaluation of the digital protection sys-tem at the Ulchin-5 and -6 nuclear plants inKorea. Construction of the plants was startedin 1997, and the first commercial operation isscheduled for 2004 for Ulchin-5.

A review of the digital plant protectionsystem (DPPS) and digital safety feature ac-tuation system at Ulchin focused on safetyclassifications related to software qualitycontrol, defense-in-depth and diversityanalysis, equipment qualification of electro-magnetic environment, and independence ofdata communication.

During licensing of the Ulchin site’s con-struction permit, several design changes oc-curred. “The major change was modificationof the DPPS architecture,” Koh said. “Oneprocessor each for the bistable processor [BP]and local coincidence processor [LCP] in theoriginal design was changed to two proces-sors for BP and four for LCP.” This redundantarchitecture provided what Koh called effec-tive features for improving tolerance of singlefailures while simplifying testing.

Mikhail Yastrebenetsky, head of the Safe-ty-Significant Systems Division of theUkraine Institute of Nuclear Safety, ticked offreasons why many of the older I&C systemsin Ukrainian nuclear power plants need to bemodernized: The systems have a low level ofreliability, nonsatisfactory diagnostics ofhardware and software, low-quality man-ma-chine interfaces, discrepancies in seismic andother environmental requirements, low fire re-sistance, the useful lives of most types of in-struments have been expired for as long as 10years, and there is an absence of spare partsfor many types of equipment.

The good news, Yastrebenetsky continued,is that “an I&C modernization program is un-der way in Ukraine, supported largely by theU.S. Department of Energy.” The programwas started in 1996 and led by Ukraine’s StateScientific Technical Center on Nuclear andRadiation Safety. Various upgrades alreadyhave been implemented, including those to thecomputer information systems at the SouthUkraine and Rovno plants; the safety para-meter display systems at the Zaporozhye,Khmel’nitskiy, Rovno, South Ukraine, andChernobyl plants; and the control rod systemat South Ukraine.

Current assessments are now being done onvarious I&C systems at the plants, includingthe automatic power regulators at SouthUkraine and Rovno, and reactor protectionsystems at Rovno and Khmel’nitskiy.

Arndt Lindner, of the Institute for SafetyTechnology (ISTec) in Germany, presented apaper on conducting assessments of variousI&C systems at nuclear units, including theFRM-2, which is the high-flux research reac-tor in Munich, and on I&C systems at the Bo-hunice plants in Slovakia and the Paks plantsin Hungary.

For the FRM-2, a 20-MWt light-water-cooled reactor, IStec performed the failuremode and effect analysis (FMEA) of the I&Csystem (hardware and software); conductedthe reliability analysis based on the FMEA,including a sensitivity analysis for softwarefailures; did an assessment of a vendor’s fac-tory acceptance test, including assessment ofthe test specifications; and verified an appli-cation software.

At Bohunice, which has four 408-MWe(net) pressurized water reactors, ISTec con-ducted assessments of backfits done at theunits during the past few years, including thereactor protection systems.

At Paks, which has four PWRs of about430-MWe (net) each, assessment work in-cluded vendor and utility factory acceptancetests, the Paks-specific concept for periodictesting, and verifying the reliability of the re-actor protection systems.

In his paper (coauthored with D. Wach),Lindner observed, “In addition to the essentialfunctional tests of the I&C system, severaltypes of analyses are necessary to grant an ac-ceptable minimum of residual software fail-ures in the I&C software. The tool-based com-parison of redundant software structures willalso help to detect specification and design er-rors. Our experiences have shown that analy-ses like software analysis by special tools (e.g.,RETRANS), FMEA, reliability analysis, etc.,are extremely important.”—Rick Michal

58 N U C L E A R N E W S January 2001

THE EMBEDDED TOPICAL Meeting on“Best-Estimate” Methods in Nuclear In-stallation Safety Analysis (BE2000),

held during the ANS/ENS International Meet-ing, provided a forum for the exchange of in-formation on current developments in the areaof best-estimate (BE) analysis methods.

The advancement of such methods inachieving reactor safety may be linked to aFederal Register entry from 1971, notably the

Atomic Energy Commission’s “Interim Ac-ceptance Criteria for Emergency Core CoolingSystems for Light-Water Power Reactors.”That document, which was highlighted by theNuclear Regulatory Commission’s Jared Wer-meil during BE2000’s opening plenary, stat-ed: “Ideally, one would have available ana-lytical methods capable of detailed realisticpredictions of all phenomena known or sus-pected to occur during a loss-of-coolant acci-

T O P I C A L M E E T I N G

Current developments in best-estimate methods

Major points from the meeting:

� The NRC has just released a new draft RegGuide with detailed guidance for developingbest-estimate codes.

� An effort is needed for internationalharmonization and practical applicability ofuncertainty methods.

� Although BE methods are complex, theyprovide a nuclear utility with a margin thatotherwise would not be attainable.

dent, supported in every aspect by definitiveexperiments directly applicable to the acci-dent. In the absence of such perfection, ade-quate assurance of safety can be obtainedfrom an appropriately conservative analysisbased on available experimental information.In areas of incomplete knowledge, conserva-tive assumptions or procedures must be ap-plied. When further experimental informationor improved techniques become available, theconservatisms presently imposed will be

reevaluated and amore realistic ap-proach will be taken.”

Robert Long, for-mer ANS president,led off the openingplenary by announc-ing that session chairsand speakers from 19countries were presentat BE2000, along withrepresentatives fromeight universities from

the United States and overseas. Participantsfrom more than 40 national and internationallaboratories, research institutions, and indus-trial organizations also were on hand.

“A full spectrum” of BE elements were sub-jects of scheduled sessions, added Long, ofNuclear Stewardship, LLC, and honorary chairof BE2000. The sessions included licensingand regulatory requirements, methodologies,validation, applications, and simulators.

A history of BE methodsGary Wilson, technical program cochair of

BE 2000 (along with S. Michael Modoro), fol-lowed with a BE-methods history lesson. Wil-son, a consulting engineer with BechtelBWXT, gave a presentation that highlightedthe accomplishments of BE efforts done byU.S. researchers. He stressed, though, that“this should not be interpreted as non-recog-nition of the considerable and important workaccomplished internationally.”

Wilson noted that initial licensing proce-dures that govern analysis methods were

formed in the UnitedStates in 1974. Thoseprocedures estab-lished the primary“safety criteria,” hesaid, for peak claddingtemperature, claddingoxidation, hydrogengeneration, coolablecore geometry, andlong-term cooling.These particular safetycriteria remain un-

changed today in the United States.In the 12 years that followed formulation of

the original licensing requirements, an effortby U.S. and international researchers was con-ducted. The result was the development of anumber of advanced computer codes for re-actor safety, including RELAP, RETRAN,TRAC, and COBRA-TRAC.

Based on research results through 1986, theNRC initiated an effort to develop and demon-strate a licensing-acceptable BE method, Wil-

son continued. This method was successfullycompleted in 1989 and was supported by a re-vised rule for the acceptance of emergencycore cooling system (ECCS) performance. Inthe years since the NRC implemented its rule,the international community has continued todevelop alternate and refined approaches toBE analysis, Wilson concluded.

Review and approval of analytical com-puter codes that are used for licensing appli-cations in U.S. nuclear plants are the respon-sibility of the NRC’s Wermeil, chief of thereactor systems branch of the agency’s Officeof Nuclear Reactor Regulation. Wermeil an-nounced that NRC staff has just released anew draft regulatory guide (DG-1096) thatprovides detailed guidance for use by industryin developing BE codes.

These codes offer “advantages,” Wermeilsaid, in that they characterize accident scenar-ios with greater assurance; reduce unnecessaryconservatism and constraints on operations,thereby reducing risk from narrow operatingwindows, such as reducing potential for oper-ator error; and allow a better understanding ofactual plant behavior and sensitivities of thisbehavior to various perturbations, thereby im-proving safety.

Giving an international perspective on BEmethods was Horst Glaeser, of GRS For-schangesgelände, in Germany. He brieflynoted BE methods that were used on the An-gra-2 plant’s licensing process in Brazil andon a plant’s upgrade renewal license in theNetherlands.

Yet, he commented, while there exists a“great deal of communality of practices ofsafety analysis,” details of BE methods maydiffer because the process to evaluate uncer-tainties in licensing procedures are not yet set-tled in most countries. He said, for example,that some countries prefer the results of BEcalculations supplemented by an uncertaintystatement of the code, rather than conserva-tive evaluation model calculations. “An effortis needed,” he said, “toward harmonizationand practical applicability of uncertaintymethods.”

Robert Tsai, of the Nuclear Fuel Manage-ment department of Exelon Nuclear, com-mented that BE methods had the potential toimprove fuel economics of nuclear plants.Impacts would come through improved“bundle design for energy extraction, for alonger and higher energy cycle,” he said;through improved core loading patterns forenergy extraction; and by increased operat-ing flexibility through less restrictive tech-nical specifications.

Further, Tsai added, incorporation of BEmethods plant-wide would “support relaxingequipment performance requirements, in-crease plant availability, reduce maintenance,and reduce O&M costs.” These increaseswould come from extended emergency dieselgenerator and ECCS injection valve stroketimes and ECCS start times; relaxed require-ments for instrument setpoints and systemflows; reduced surveillance frequencies, per-son-rem exposures, and equipment specifica-tions; and extended equipment life.

January 2001 N U C L E A R N E W S 59

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Wilson

Long

Continued

With all of this difficulty and all the time andeffort spent, was Westinghouse’s effort worthit? Yes, Hochreiter answered resoundingly.With approval of BE methodology, Westing-house can offer plant upratings, improved fueldesigns with higher peaking factors, improvedfuel cycle designs to aid plant extensions, and

relaxation of diesel start-time requirements—all of which provide economic benefit to West-inghouse’s customers: utilities.

And so although BE methods are complex,Hochreiter concluded, use of them will gain autility a margin that otherwise would not beattainable.—Rick Michal

60 N U C L E A R N E W S January 2001

THE RAPIDLY GROWING ANS AcceleratorApplications Technical Group traces itsbeginnings to 1996. Several people at

Los Alamos National Laboratory were con-vinced that recent developments in high-in-tensity proton accelerators meant there werenew applications for which there was not a fo-rum to present technical results or to conducttechnical interchange, explained WarrenFunk, project services manager for the Spal-

lation Neutron Sourceproject office at theThomas Jefferson Na-tional Accelerator Fa-cility. In 1997, anANS technical groupfor accelerator appli-cations was formed,with 29 charter mem-bers. By last year, thegroup had balloonedto 267 members—amore than ninefold in-

crease in three years.The level of interest in the group was ap-

parent in the plenary session for the embed-

ded topical meeting, “Nuclear Applications ofAcceleration Technology” (sponsored by theANS Accelerator Applications TechnicalGroup), for which participants were poised el-bow-to-elbow in the meeting room.

Congressional actionsPeter Lyons, science policy advisor to Sen.

Pete Domenici (R., N.M.)—perhaps the nu-clear industry’s strongest advocate on CapitolHill—gave a presentation describing the con-gressional actions that affect high-power ac-celerator systems and the nuclear industry ingeneral, and where the senator fits in to thoseactions. He expressed the frustrations atten-dant with a presidential administration thatopposes many of these efforts to move thefield forward. And he detailed some ofDomenici’s plans for accelerator productionof tritium and advanced transmutation ofwaste, including the senator’s proposal for anew accelerator facility.

Domenici chairs the Subcommittee on En-ergy and Water Development of the SenateCommittee on Appropriations, which over-sees funding for most Department of Energy

A BE method overviewWanting to “stir things up a bit” was L. E.

Hochreiter, professor of nuclear and mechan-ical engineering at the Pennsylvania StateUniversity. Hochreiter’s presentation was on

whether the licensingprocedure for BEmethods makes lifesimpler or more com-plicated for nuclearutilities.

Hochreiter openedwith a brief review ofBE methodology,which has the objec-tive, he said, of mod-eling true physicalphenomena as accu-

rately as possible; modeling plant transientsin a realistic manner; understanding the per-formance of ECCS; and determining realisticplant limits for specific accident scenarios.

The flip side, he added, are very complexcomputer codes and models that are difficultto understand; long running codes that are ex-pensive to use; and high expectations.

Meanwhile, Hochreiter continued, the NRCdeveloped the code scaling and uncertainty(CSAU) methodology. CSAU qualified andprovided the licensing framework for BEcodes; developed a phenomena identificationranking table (PIRT) to identify the most im-portant models and to guide assessments; pro-vided a method to access model/plant uncer-tainties by ranging; and provided a sampleplant calculation.

This CSAU methodology “did provide ameans or path for BE codes where no pathhad existed,” Hochreiter said, and it raised“the difficult issues” that needed to be ad-dressed, such as complete documentation,frozen code assessments, model/modelingconsistent with BE, scaling, propagation ofuncertainty period-to-period, and compen-sating errors.

But while CSAU did provide some sim-plification, the licensing process remainscomplex, Hochreiter affirmed. This is be-cause, for CSAU, there are no specific mod-els in the NRC’s Appendix K; reviews re-quire “a very knowledgeable reviewer,” hesaid; reviews can be very reviewer depen-dent; complete documentation is required, ata level that is difficult and expensive; andthere is a much wider range of assessmentsto address, such as model uncertainties, rang-ing, and scaling.

Hochreiter pointed to a Westinghouse re-view as an example of BE complications.Westinghouse started the licensing process forits COBRA-TRAC code in 1989. It compiledfive volumes of code qualification documents,standing three feet high, and submitted themto the NRC. The NRC’s detailed review of thedocuments took four years, during which timethe agency asked more than 600 questions ofWestinghouse. Responses to the questionsfrom Westinghouse back to the NRC werecontained in documentation piling six feethigh. In the end, the original documentationwas rewritten, and Westinghouse received fi-nal approval for COBRA-TRAC in 1996.

Funk

T O P I C A L M E E T I N G

Overview of acceleratorapplications

Major points from the meeting:

� The neutron community in the United Stateshas decreased to fewer than 1000 scientists,versus some 4000 in Europe.

� The Spallation Neutron Source being builtcould mark a change in reliance—for neutronscattering—from reactors to accelerators.

� A proposed high-current accelerator could be abackup to the DOE civilian reactor-based tritiumprogram, and a means for ATW pilot studies.

Hochreiter

programs—including all accelerator pro-grams. The senator is “very committed” tomaintaining nuclear energy as a viable optionfor the future, Lyons said. Domenici, howev-er, sees that the largest single issue related tothe viability of the nuclear energy industry isa credible resolution of spent-fuel issues.“Senator Domenici is simply not convincedthat the current open cycle is the best choice,”Lyons said. “He is not convinced that YuccaMountain, as envisioned, is ever going toopen. He is not convinced that we knowenough today to say that spent fuel should beequated with waste. He’s not convinced thatthe public will accept wastes with extremelylong-lived toxicities.”

To remedy this, Domenici led legislationthat would create a new office within the DOEon spent nuclear fuel research, with a specif-ic focus on advanced reprocessing and trans-mutation technologies. He wanted to empha-size international cooperation, because he seesthat many other nations have a great deal tocontribute, Lyons said. This proposal waspassed by large margins in both the House ofRepresentatives and the Senate, but was ve-toed by President Clinton. A subsequent vetooverride vote was successful in the House, tofail only by one vote in the Senate. “So, again,the administration, as they’ve done manytimes, succeeded in blocking any attempts tomove more rapidly on dealing with spent fuelin the country,” Lyons said.

The senator has been interested in the po-tential of transmutation and its impact onspent-fuel strategies, Lyons said. In the fiscalyear 1999 budget, he set aside $4 million forstudy of waste transmutation, and last year, $9million. “It’s interesting to note that any fund-ing that’s been put in for ATW . . . has alwaysbeen zeroed by the administration,” Lyonssaid. “And, in general, certainly in my view,the administration has demonstrated repeat-edly that they have no interest in doing any-thing to enhance the future prospects for nu-clear energy.”

Last year, Sen. Domenici wanted to explorewhat he saw as a number of opportunities forsynergism between accelerator production oftritium and accelerator transmutation of waste,Lyons said—despite the DOE’s having madea clear decision to produce tritium in light-wa-ter reactors.

The proliferation concerns with the CivilianLight-Water Reactor (CLWR) Program may ormay not be as benign as many think. “I foundit interesting, at a meeting in Europe just with-in the last few weeks, to hear very very seriousconcerns from a number of the nuclear energyleaders in Europe with the decision in the U.S.to make tritium in civilian reactors,” Lyons ex-plained. “They saw that as an extremely un-fortunate coupling of military and civilian pro-grams. I’m frankly a bit surprised—I think thesenator has been surprised—that there has beenless of an outcry here about that, frankly, thanhe anticipated. But, in any case, we’re waitingto see how CLWR will progress.”

Accelerator facilityLyons closed with a description of

Domenici’s proposal for a new high-current

accelerator facility. By providing tritium pro-duction, the facility could serve as a backupto the CLWR program. It could provide a lo-cation for pilot studies of accelerator trans-mutation of waste and a place to study manyother issues related to the use of fast spectrumsystems for transmutation studies, Lyonssaid. The facility could also include a nation-al production capability for radioisotopes,and would have a strong nuclear engineeringcomponent.

There is, however, a catch.“The senator has indicated that he would

include, as another requirement . . . that what-ever site that would like to take this accelera-tor also agree to take interim storage of spentfuel,” Lyons explained. “In other words,there’s a carrot—and something ‘not a carrot.’

“There have been several sites that havecome in to talk with us on this. And this mightget very interesting over the next year. I seethe AAA [Advanced Accelerator Applica-tions] program as laying the groundwork forthe types of decisions that might go into a fu-ture decision on whether such a complexmight be a sensible thing for the country.”

Los Alamos National Laboratory’s PaulLisowski discussed the status of the $600-mil-lion Accelerator Production of Tritium pro-gram, and provided an overview of the proj-ect’s missions, what it has accomplished, andwhere it is heading.

The United Sates requires tritium for its nu-clear weapons. Because it decays with a half-life of about 12 years, it has to be replaced rel-atively frequently. For well over a decade, theDepartment of Energy has tried to find a newsource of tritium, Lisowski said.

He explained that in December 1995, theDOE decided on a dual-track plan to producethe isotope, and considered both commerciallight-water reactors, which were the lowestcapital cost option, and an accelerator sys-tem, which would have the lowest impact onthe environment. In December 1998, theDOE opted for the commercial light-waterreactor path as primary tritium productionoption, and decided that the accelerator pathwould serve as the backup. The DOE also al-lowed various engineering development andpreliminary design of important elements forthe accelerator system to be completed.“[That] was meant to allow us to move fastif it turned out that the Commercial Light-Water Reactor Program became derailed,”Lisowski said.

In order to meet the demands of the proj-ect, Lisowski said, they would have to buildwhat would be the world’s highest-powerproton linear accelerator. The machine theydesigned would accelerate protons to about1000 MeV at 100 mA, for 103 MW of protonpower. It was designed to begin with an in-jector, and have normal conducting acceler-ating structures pass through a supercon-ducting accelerating structure. It would thendeliver the beam to a tungsten target whereneutrons are produced, moderated, and thencaptured in helium-3—the decay product oftritium.

“Helium has a very high capture cross sec-tion for thermal neutrons, therefore it very ef-

ficiently produces tritium and avoids the wasteform that would result if you were producingtritium from a metal matrix, the way it is donein nuclear reactors,” Lisowski explained.

Lisowski said the group was concernedabout spallation neutron products and othermaterials that were made in the coolant and inhelium. They conducted experiments to ex-amine spallation products and all aspects ofproduction of radioactive gases into tritium,and how they could separate the material outso it was not put it into the tritium processingfacility.

“We were concerned about what mighthappen when the beam was turned off and thematerial heated up from natural radioactivedecay,” he explained. “And so we made awhole series of decay heat measurements toconfirm . . . predictions. As you know, in re-actor physics decay heat is an important safe-ty aspect, and it was an important aspect forus to investigate so that that worked.”

They constructed a prototype of a low-en-ergy accelerator, which will eventually becompleted to 8 MeV, and performed an inte-grated operations test. The project met its mile-stone, operating the low-energy demonstrationaccelerator to an energy of 6.7 MeV. The fa-cility is the third most powerful operating pro-ton accelerator in the world, Lisowski said.

Over the past five years they have com-pleted about 30 percent of the preliminary de-sign of the accelerator plant, and much of thatinformation, Lisowski said, is going to bevaluable to the AAA program in their designwork for the Spallation Neutron Source.

“We went at this because we thought—Ithink a lot of people in this project thought—that we would be the people who supplied thetritium for the country, that this would be thetechnology that the administration wouldchoose, and that national defense was on ourshoulders—that maintaining the nuclear de-terrent was our responsibility. And so we tookthis very seriously.”

Spallation Neutron SourceThere has not been a new neutron source in

the United States built from scratch in 30years, said David Moncton, executive direc-tor of the Spallation Neutron Source (SNS)project. Consequently, the neutron communi-ty in the United States has shrunk to less than1000 scientists, compared to approximately4000 in Europe. Moncton, whose enthusiasmfor the project was contained only by profes-sional reserve, provided an overview of the fa-cility—currently the largest civilian scienceproject in the country—which is expected tolead to a renaissance in the study of pulsedneutron beams for scientific research and in-dustrial development in the United States.

“It’s our hope that the SNS facility will re-claim for the United States the lead that waseffectively yielded to Europe . . . in the 70s,”Moncton said. “I’ve been impressed, in my lit-tle under two years of association with thisproject, how strongly [and] unanimously sup-ported this project has been by the sciencecommunity, and by the administration and thedepartment.”

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Continued

The technical facilities of the SNS—nowprepared for the first concrete pourings—con-sist of what will be the world’s most powerfulproton linear accelerator when it is commis-sioned. The 2-MW linac will accelerate H-mi-nus ions, which are produced in an ion sourceat one end of the site. As the ions enter the ac-cumulator ring, they are passed through a foil,which strips off each ion’s two electrons, con-verting it to a proton. The 1-GeV protons willhave a pulse length of about a millisecond.They will be injected into the accumulatorring, and each pulse will wrap around the ringabout 1000 times. They are then compressedfrom a millisecond to just under a microsec-ond: As the particles are injected into the tar-get, the pulse length is 950 nanoseconds.

“[This is] very innovative technology that,in the beginning, going back five or so yearsago, seemed quite bold and maybe even char-acterized as risky by many,” Moncton said.

They plan to use liquid mercury as the spal-lation target, because of the heat loads and thethermal shock that are deposited by such an in-tense beam. All spallation sources that havepreviously been built use solid targets, Monc-ton said. It wasn’t believed, however, that sol-id targets could be effective above about 1MW in power. So the project took the initia-tive to develop a research and development(R&D) base for mercury targets. “And that’sbeen very successful over the course of thisfour- or five-year period, both in the UnitedStates as well as in Europe and Japan,” he said.

A number of active efforts to resolve a num-ber of the critical R&D issues associated withthe use of mercury have met success. “I don’tthink there’s a person now who’s familiar withthis technology that doesn’t believe that this isquite low risk, at this stage. So, this is a veryexciting development, that we’ve moved fromsomething which was considered five yearsago to be quite risky to something that we be-lieve now is very well in hand. And it bodesvery well for the future of spallation sources,because I think mercury would certainly be thetarget of choice for future sources, going up toeven higher powers,” Moncton said.

Studies on magnetism have been uniquelythe province of neutrons, he explained. Cer-tainly some information can be gleaned fromelectrons by studying X rays and the weakcoupling between X rays and the magneticmoment. But nothing elicits the kind of infor-mation on magnetism from matter like neu-tron diffraction, Moncton said.

“With a source as powerful as the SNS, itwill be possible to go to much smaller sam-ples and very exciting opportunities in thestudy of the structure of thin magnetic films,for example, [which] simply isn’t possiblewith the weaker neutron sources that we havetoday,” he said.

“We believe that neutrons are poised tomake an even bigger contribution in the next50 years. And that’s why it’s so important tohave new neutron sources.”

Synchrotron radiation is popular now in thestructural biology community. People are fol-lowing on the work of the human genomeproject with very active plans to determinerapidly the three-dimensional structures of as

many proteins as possible. This enterprise,Moncton said, is now developing at exponen-tial rates at the X-ray facilities in the country.

“But that has a finite end to it, and it doesn’tlead directly to the understanding of how themolecules themselves function,” Monctonsaid. “Molecular function is directly connect-ed to molecular dynamics. And as we under-stand the three-dimensional structures of theproteins which underpin life, it’s going to be-come increasingly important to understandtheir dynamics. This is where I think neutronsare going to play the next role.” The interestof the biological community in neutrons is notnearly as high as it is in the X-ray field, butthat may change in the next 5 to 10 years.Moncton said he would not be surprised to seethe growth of the biology community in neu-trons very strongly stimulated by the existenceof the SNS.

One field that is recognizing the use of neu-trons is engineering. Moncton said some in-teresting pilot experiments have been under-taken using neutron scattering to determinethe strain distribution in engineering materi-als. “We’re working with a group that’s veryinterested in the development of an engineer-ing instrument—an engineering diffractome-ter—that will have pretty impressive charac-teristics for analyzing strain and helping tooptimize the development of various kinds ofengineering materials. So, we look forward tothis being a growing community as well withthe new source.”

If funding proceeds as scheduled, the proj-ect will be completed in early FY 2006. It willthen require two years of operation to achievea highly reliable, 2-MW performance.

There are two exciting aspects for the fu-ture of neutrons from the construction of thisfacility, Moncton said. “One is that there’s agreat deal of upside to the development ofneutron scattering instruments based on spal-lation sources. We’re at a relatively earlystage in our understanding of how to make op-timal use of pulsed sources. And so there’s atremendous learning curve in front of us. Ithink we’re going to learn a lot about how tobetter optimize instruments. . . . And there willbe many more types of instrument technolo-gies that are invented for spallation sourcesover the next decade or two than for reactors,which are a very mature field.

“We hope that the SNS and the design thatwe have will be able to stay competitive withany facility that Europe or Japan will buildover the next decade. Both communities areactively pursuing designs which they hopewill exceed the SNS. But I think we have thebasic technology here, and with the advance-ments possible—the superconducting tech-nology—to be able to stay competitive withanything that might be built over the courseof the next 10 or 20 years.

“And so if the SNS is as successful as webelieve,” Moncton concluded, “I think it’s go-ing to mark a turning point in the field of neu-tron scattering, from a reliance primarily onreactor sources, which has been the case forthe last 50 years, to emphasis on accelerator-driven sources, which I think have a very ex-citing future.”—Patrick Sinco

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