THE CHEMICAL WORLD THIS WEEK

NUCLEAR REACTORS:

Reconstituting a Core With the first reconstitution of an active nuclear reactor core successfully accomplished, Westinghouse is well on the way to carrying out the objectives it has established for the Saxton Experimental Power Reactor's new Core III.

The objectives, according to the company, include validation of fuel element design predictions, including power/burnup failure limits. Con­tinuing tests will also demonstrate performance capability of zircaloy-clad fuel elements over a broad spec­trum of burnups and power levels, and they will obtain depletion" char-

Saxton power reactor

Reconstituting a core

acteristics and transuranic isotope generation data for high-burnup mixed oxide fuel.

The Saxton reactor, located in a rural area about 100 miles east of Pittsburgh, Pa., is a pressurized water reactor owned and operated by Sax­ton Nuclear Experimental Corp., a subsidiary of General Public Utilities. Since December 1967, the experimen­tal program at Saxton has been the responsibility of the Westinghouse nuclear fuel division's field test proj­ects.

Core III, which Westinghouse plans to operate for about two years, uses mixed oxide fuel rods composed of uranium dioxide and plutonium di­oxide. Identified as "loose lattice assemblies," the fuel comprising Core III makes use of a unique combination of fuel rods and water-filled tubes,

arranged in alternate positions in the lattice.

The nine central assemblies of the core were reconstituted from Core II assemblies by removing the plutonium-enriched, zircaloy-clad fuel rods and reinserting them into new assembly grids. These central nine assemblies are surrounded by 12 uranium di­oxide stainless-steel clad assemblies from Cores I and II.

Reconstitution of Core III was ac­complished with the help of equipment specially created for the job. The mo­bile fuel evaluation system (MFES), developed by the Westinghouse nuclear division field test projects, was em­ployed in the Core III reconstitution and examination program. Two 20-ton-capacity trailers house the special­ized equipment for performing com­plete on-site evaluation of fuel. One trailer contains a machine shop and power source for special on-site fab­rication and repair projects. The other trailer houses the MFES tools and associated test apparatus.

SEWAGE:

Irradiation Put Off Commercial prospects of ionizing ra­diation as a practical means of treat­ing sewage don't look as bright as some earlier reports indicated. That's the outcome of results to date from a detailed study that a group at Gulf General Atomic, Inc., San Diego, Calif., is carrying out for the Atomic Energy Commission.

Discussing the work last week in Munich, West Germany, at a sym­posium on the use of large radiation sources and accelerators in industrial processing, AEC's George J. Rotariu noted that direct radiation oxidation of organic matter in waste waters isn't an economically competitive process. Neither can radiation com­pete economically with chemicals now used for conditioning sewage sludge for filtration.

Using spent fuel elements from one of the company's 1.5-Mw. TRIG A reactors as the gamma radiation source, the Gulf General Atomic sci­entists are examining three areas of sewage treatment. One involves de­structive oxidation of organic compo­nents of waste waters such as nonbio­degradable insecticides, which aren't broken down by activated sludge. Another seeks to find out whether irradiation changes the nature of such chemicals in effluents from primary treatment units so that bacteria in the activated sludge of the secondary treatment stage would degrade them. The third seeks changes that irradia­tion might induce in the physical properties of colloidal particles toward

Sewage irradiation

Setting up sample oxygenation

enhancing their sedimentation rate. Results to date for oxidation of ir­

radiated sewage point to a too-low G value—the number of molecules that undergo change under the influence of 100 e.v. of ionizing radiation. To be economically feasible with present radiation sources, a G value of at least 1000 is called for; the Gulf workers find the value closer to 10.

Earlier indications were that radia­tion might increase oxygen uptake rate of organic components in the effluent. But the results show that activated carbon accomplishes much the same result for less than 10 cents per 1000 gallons, compared to $3.00 for irradiation. Radiation effect on colloidal particles is equally disap­pointing.

PUERTO RICO:

A World of Chemicals Look for Puerto Rico's chemical in­dustry to claim a significant place in world, as well as U.S., markets, says Sam H. Casey, president of Common­wealth Oil Refining (Corco). As an importer of U.S. goods, Puerto Rico now ranks fifth in the world and sec­ond in the Western Hemisphere (be­hind Canada), according to 1967 fis­cal year figures, which should offset concern that the flow of money and benefits is one-sided.

About 10% of the Free World's benzene needs will be supplied by Puerto Rico in the near future after

AUG. 25, 1969 C&EN 9