NFT’s Approach to Preservation and Improvement of Technical Skills for Cask Maintenance: Education and Training Program for Cask Maintenance Using the NFT Cask Mock-up

Nuclear Fuel Transport Co. (NFT) owns about 70 casks for transport of spent fuels from nuclear power plants to the reprocessing plant and has periodically inspected and maintained them to retain their performance. However, recently the number of transport in Japan has significantly decreased and almost all the casks have not been used for several years. Presently unused casks are partly exempted from maintenance items prescribed in Safety Analysis Report (SAR).Then, considering the great decrease in experiencing cask maintenance, the education and training program for cask maintenance using the mock-up cask has been developed in order to preserve and improve technical skills in cask maintenance. In this paper, we introduce NFT’s approach about it.(a)Specifications of the mock-up of NFT caskThe mock-up of NFT cask constructed for training of NFT cask maintenance is shorter in length than the real NFT cask, but its structure is basically the same. Therefore, it enables to acquire a good knowledge and technical skills on the almost same level as actual NFT cask. For example, its characteristics are as follows.- It is partly mixed structure of the two types of NFT casks that are often used in actual transport.- Critical components in the function of cask such as seal boundaries are full-sized.- It can be repeatedly used by disassembling and reassembling without managing radiation exposure due to installation outside radiation controlled areas.(b)Education and training program for cask maintenance using the mock-up caskAfter education of current training texts on the desk, practical training using the mock-up cask is implemented. This program can compensate the lack of experience of cask maintenance because participants can improve their technical skills for cask maintenance by practicing maintenance work repeatedly using it.NFT has a plan to start the program from the beginning of fiscal 2019. By continuously implementing this program and improving it as appropriate, it can be expected that technical skills in cask maintenance will be preserved and improved.