Reconstitution technique on the power reactor fuel assemblies after post-irradiation examinations

This paper describes the reconstitutions of PWR fuel assemblies after finishing the post irradiation examinations (PIEs) in hot cells of the Reactor Fuel Examination Facility (RFEF) at Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI). Since December 1979, the RFEF has examined 10 fuel assemblies in order to certify the integrity of the currently designed reactor fuel assemblies used in PWR, BWR and HWR (Heavy Water Reactor, FUGEN), respectively. The PIEs have been programmed by stopping over at the hot laboratory on the way of transportation from the power reactor sites to the reprocessing plant, so that fuel assemblies should be brought to the reprocessing plant after finishing the PIEs. Some out-cell examinations and trial tests had been performed in advance of the reconstitution of fuel assemblies, and some manufacturing and inspecting devices were developed to assure the integrity of fuel assemblies. The results of these works were applied to the procedure as follows: 1) Remaking the punctured fuel rod; 2) Inserting the fuel rod into the assembly; 3) Remaking the top nozzle. These PIEs procedures wre applied to four PWR fuel assemblies and their reconstitutions were successfully carried out. Three out of four fuel assemblies were transfered to the reprocessing plant as of July, 1987. Another one is scheduled in December this year. Moreover, two BWR fuel assemblies were transfered to the reprocessing plant after finishing the PIEs and reconstitutions, successively as of July, 1987. (author). 6 refs, 13 figs