Fission Reactor Operations and Availability…and How These Influence Our Choices for IFE

HAPL - 19

University of WisconsinMadison, Wisconsin October 22 - 23, 2008

C. A. Gentile

Motivation • Compare fission light water PWR’s operations, maintenance, and outages for

comparison with conceptual design of IFE direct drive power reactor. Evaluate advantages and disadvantages of both technologies.

• Begin to define maintenance requirements, duty cycle, ES&H items. Where possible relate to current ES&H criteria for DOE, NRC, CFR (i.e. 10CFR835 / 10CFR part 20). Begin to consider PSAR, Technical Specifications.

• Establish lines of communication with people who are currently producing electricity with fission power reactors. Identify areas of common ground. Develop a common technical / regulatory language. Provide solutions to those aspects which hinder greater exploitation of fission generated power. Perception with some that fission is not safe. Spent fuel a very big problem. On-site fission reactor spent fuel pools are reaching capacity. Building new on-site storage for spent fuel capacity, or high density storage racks, not always embraced by the public.

• Pointed out at TOFE - 18 that in the book “The World is Flat” Thomas Friedman does not mention fusion energy as a future power source. Interactions with the fission community healthy in getting our message understood.

Presentation Outline

• PWR fission reactor operations / outages - Palo Verde Nuclear Generating Station. Three PWR light Water Reactors costing ~ $ 9.3B. Entering the second 20 year cycle of operational life. NSSS = Combustion Engineering, A/E = Bechtel

• Producing ~ 3825 MW(e). Approximately twice the output of the Hoover Dam.

• Unit 2 (with new steam generators) @ 1335 MW(e) is currently the largest US reactor

• Remote Maintenance for IFE• ES&H • Summary

PWR Refueling Outages / Operations

Palo Verde Unit 1 Coasts to Continuous Operation Record PHOENIX--(BUSINESS WIRE)--Oct. 1, 2002 Palo Verde Nuclear Generating Station's Unit 1 operated for its entire fuel cycle -- running "breaker-to-breaker" for a unit-record 502 continuous days -- when it shut down for its scheduled 10th refueling over the weekend. In 1999, Palo Verde Unit 2 set the station's existing record of 515 days of continuous operation, prior to its eighth refueling. In 2000, Unit 3 completed a run of 509 continuous days prior to its eighth refueling.Unit 1's refueling is expected to be completed in about 40 days. Palo Verde's previous refueling -- the 10th for Unit 2 -- was completed this past April in 32 days, the second shortest for the site and part of an ongoing record of short refueling durations.

During PWR refueling outage, 25 to 40% of the fuel assemblies are typically replaced depending on the cycle length and number of fuel assemblies in the reactor.

Cost Savings and Reliability

• Reducing the refueling outages at the station by 1 day saves the rate payers > ~ $ 1M due to the replacement fuel costs @ > ~ $1 M / day when the reactor is not producing electricity (not including replacement by hydro-power).

• Efficient refueling / maintenance outage planning second only to operating the reactor safely. Same as in fusion.

• Limited supply of qualified / certified nuclear workers. The cost of occupational radiation doses a factor in fission outage planning and will be the same for fusion. Robotic and remote handling can help alleviate this problem.

• Nuclear power becoming more relied upon. The South Texas Project (2 - PWR’s) sited 60 miles SW of Galveston stayed on-line throughout hurricane Ike, although Waterford - 3 and River Bend - 1 (both in Louisiana ) were taken off-line during hurricane Gustav.

• Deregulation has emphasized the need for affordable power to ratepayers….business, municipalities.

IFE power reactor - PWR Fission light water reactor. The two technologies lead to similarities in general arrangement.

Goal of both…produce safe, economical electricity.

Most significant maintenance task at PWR is repair and replacement of steam generator(s). Can take up to 1 year but have been completed at some stations in

~ 6 months. Occupational radiation doses in fission industry coming down.

Average PWR annual dose last year was 97 person rem. IFE will need to address the change out of primary components.

• Site construction started in 1976. Unit 1 came on-line 1986. Unit 2 & 3 came on-line1988. Site cost = ~ $ 9.3B

• Palo Verde Unit 1 rated at 1,314 MW (e). After house power requirements the reactor sends out ~ 1250 MW to the US South Western grid ( note 1 MW runs ~ 400 houses )

• Location ~ 40 miles west of Phoenix, AZ

• Combustion Engineering PWR

• Note…refueling / maintenance outage durations are on the order of 30 - 40 days. Outages planned for non-peak periods

Plant Unit Owner Rx Type Output Length(dy) Cycle(mo) StartDate NotesPalo Verde 1 APS PWR 1250 39 18 10/4/08Palo Verde 2 APS PWR 1250 36 18 10/3/09 reactor head replacement, Palo Verde 3 APS PWR 1250 39 18 4/4/09

Palo Verde Nuclear Generating Station

Palo Verde, the USA largest nuclear power site. Palo Verde 2 was recently uprated to 1,335 MW(e). Palo Verde 2 currently the Nation's largest nuclear

reactor, surpassing the South Texas Project Unit 1 and Unit 2 reactors.

Unit 2 steam generator replacement successfully completed. This is a large complicated > $ 300 M task taking ~ 1 year. Other large tasks include maintenance and repair of reactor cooling pumps. In fission power industry large primary components are replaceable, as should be for IFE.

Maintenance & Operations - Requirements, Similarities, Advantages

• No PWR maintenance or repair while reactor under power or within confines of bio-shield.

• Very little human activity inside the containment building, when needed only at reduced power (typically < 50 %).

• Need to operate for relatively long periods of time 24/7 for up to 1.5 years.

• Maybe possible to perform some IFE maintenance activities while the reactor is running using robotics. Robotics maintenance video.

• Need to maintain occupational radiological doses in accordance with 10CFR835 / 10 CFR part 20. Including ALARA levels. Off-site consequences due to misadventure at fission plant an issue. Ten mile emergence planning zone (EPZ) with plans for evacuation a condition of USNRC fission licensing process. 50 mile ingestion pathway zone also required as part of the licensing process. Should be much less restrictive for fusion.

• Need to conform to limits of Technical Specifications, FSAR, and licensing conditions and limiting conditions of operation(s).

CANDU reactors capable of refueling on-line. New fuel assemblies are added horizontally and the spent fuel assemblies are pushed

out to the spent fuel storage area.

The fuel assemblies used in the reactor are ~ 1.5 feet (0.5 m) long, consisting of individual rods. The cladding is Zircaloy and the fuel pellets consist of uranium dioxide.

Primary nuclear systemsneed to be robust & reliable and where possible modular to support maintenance and replacement.

- GIMM’s- Vacuum Pumping System- First wall- Blankets- Magnets- Dumps- Cooling Systems- Target Injector

Components within the confines of the bio-shield must last for the duration of the run.Components within the confines of the containment should last for the duration of the run.

Please see poster presentations on sub-systems and infrastructure- “MI” I. Zatz , et. al., - “Helium Brayton Cycle” S. Wagner, et. al., - IFE Structure, T. Kozub, et. al.

ES&H

• Conceptual design(s) can be evaluated for regulatory requirements where applicable.

• Level and sophistication of safety systems presumed to be less in a IFE direct drive environment due to limiting off-site consequence.

• ALARA systems engineered into the design. T-cleanup systems, bio-shield, remote maintenance, automated systems, evaluate the MTBF for sub-system components.

• Off-site doses from normal and off-normal operations manageable. Although a large inventory of T on a daily basis, T at risk can be attenuated and managed between multiple MC&A locations.

ES&H

• Engineered containment and confinement systems and strategy incorporated into conceptual designs. Modular design important for maintenance and replacement tasks.

• Pre-Licensing components, in the form of a regulatory compliance plan should be developed ( NEPA, FONSI documentation, PSAR, FSAR, Technical Specifications,

etc.)

Conceptual View of the IFE Laser Driven Direct Drive Power Reactor at the Existing Palo Verde Nuclear Power Site.

Builds upon existing infrastructure

Summary• Great advantage of IFE Direct Drive. Low cost targets. No spent fuel. Level of safety

class systems most likely less (perhaps less than MFE due to more stringent vacuum requirements in torus). No refueling outages, only maintenance outages.

• Developing technology moving toward robotic maintenance.

• Robotic maintenance may preclude the need to shut down the reactor to do repairs.

• To be competitive with current (fission) nuclear generation production maintenance periods need to be comparable. Replacement energy costs are expensive.

• ES&H issues need to be identified and considered during the developing conceptual designs.

• A dialogue with the US commercial fission industry being put into place to establish open lines of communication.

• In the near future an IFE direct drive power reactor “ information” article in a main stream fission publication….Nuclear News or Nuclear Plant Journal may be valuable.

Advanced technology may not win the day if not economical, not reliable, or has perceived regulatory impediments

Need to design and build a competitivepower reactor for the production of commercial electricity.

Faster or even better may not survive market forces if reliability, cost,effectiveness, and safety are not part of thepackage.

IFE direct drive power generation is “Green” need to keep our fission colleagues Green” need to keep our fission colleagues engaged in IFE direct drive fusion power engaged in IFE direct drive fusion power development.development.- no green-house gases- no spent fuel & no spent fuel storage- low proliferation threat- produces it’s own fuel- no critically - limited safety class systems- but ( same as fission ) fusion power reactor will be a capital intensive enterprise