THORIDE AS A REACTOR FUEL

Allis-Chalmers believes that the best hope for competitive electric power from nuclear plants lies in the development of high-output reactors using oxide fuels which, when spent, can be reprocessed and returned to the core. The company's basic views on recycle -;? reactor fuel are: (1) that recycle of power reactor fuels is required to remove the present fuel-cycle cost uncertainties, and to help ensure a viable nuclear power industry; (2) that for several decades small refabrication and reprocessing plants will be the only realistic way to provide this recycle; (3) that the unit cost penalty for reprocessing and refabricating in a small plant has been minimized by a plant design concept developed by CNEN and Allis-Chalmers; and (4) that in a large boiling-water reactor, the thorium-U-233 cycle has a neutron economy sufficiently higher than the low enrichment uranium cycle to offset the small disadvantage in unit processing cost in a small plant. For these reasons, Allis-Chalmers is now prepared to offer, at a fixed price, an integrated nuclear power station consisting of a 300-Mwe boiling water nuclear power plant and a complete reprocessing and refabrication facility at the same site. The fuel cycle costs of such a plant will be lower than that of a similar reactor operating on low enrichment uranium with the spent fuel returned to the AEC. The program, however, depends on AEC action to: (1) establish the necessary conditions for storage of fission product wastes on reactor sites; (2) continue development work leading to economic procedures for permanently fixing fission product wastes; and (3) continue support of the existing Italian program, which will demonstrate both the small reprocessing plant and the thorium cycle. The preliminary design of the integrated power-producing and fuel-reprocessing station shown in Fig. 1 has been developed by Allis-Chalmers with the assistance of Stone & Webster in over-all plant layout. The station consists of two complementary facilities which are expected, when operated in conjunction, to produce competitive nuclear power. One is « 300-Mwe nuclear power plant fueled with thoria-urania ceramic rods clad in zirconium* alloy tubes; the other is a reprocessing facility designed to recover the usable fuel from the exposed fuel elements of the power plant, reconstitute it in a suitable form, and use it to fabricate new fuel elements which are to be returned to the reactor. The broken lines in Fig. 1 indicate the second 300-Mwe power plant that could be built on the site and serviced by the single reprocessing plant.