Irradiation experiments of Fugen PuO sup 2 -UO sup 2 fuel assembly in WSGHWR.


Four irradiation tests, type A, B, C and D, have been carried out for the development of the design and fabrication of fuel assembly for the advanced thermal reactor ''Fugen''. This paper reports on the irradiation conditions and the results of post-irradiation tests for the type D fuel assembly which was fabricated prior to the production of mixed oxide fuel for ''Fugen'' in the Plutonium Fuel Fabrication Facility in PNC. The fuel assembly was irradiated in the Winfrith steam generating water reactor (WSGHWR) to the peak burnup of 8690 MWd/tMO. The post-irradiation tests were carried out in Windscale Nuclear Power Development Laboratories, UKAEA, from December, 1977, to June, 1978. The summary of design data of the fuel assembly is shown. The assembly was loaded into the reactor on October 21, 1975, and the irradiation was performed up to 360 effective full power days. The reactor operation of 30 cycles was carried out during the irradiation. The irradiation was successfully completed without major problems. As the post-irradiation tests, nondestructive examinations, neutron radiography, the measurement of fission gas release, the metallography of pellets and claddings, the measurement of fuel density, burnup analysis, hydraulic pressure test and burst test are reported. The failure and defect of fuel pins were not found. The design and fabrication of this fuel assembly seemed adequate. (Kako, I.). Yokouchi,-Yoji; Yokosawa,-Naoki; Kajiyama,-Takashi; Kiyonaga,-Yoshiharu; Yumoto,-Ryozo (Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works)