INSPECTION OF NFT-TYPE CASK FABRICATION

NFr -type cask has been developed to transport the high Wr1HJp spent fuel from Japanese rudear power stations to the reprocessing plant of Japan Nuclear Fuel limited which is under construction in ~rrura, Aomori prefecture. WT placed orders of 53 casks to 5 fabricators in Japan and overseas , and these casks have been fabricated since 1994. There are two types ofNFr -type casks for PWR spent fuel and four types of NFT -type cask for BWR spent fuel These are designed in consideration of the number of spent fuels accommodated into each type of casks and the handling conditions at domestic rudear power stations. According to Japanese notification , it is required to be oonfinned by competent authority that casks are maruf.actured in accordance with approved designs. Fwthermore , additional tests are performed such as throu~ge test for basket and pressure test on the shieJding material space to ensure the performance of cask by NFr other than items inspected by the competent authority. In order to enhance maintainability of casks , replacement parts such as bolts and valves are shared as JruCh as possible.