CODE CASES OF BASKET MATERIAL FOR SPENT FUEL TRANSPORT/STORAGE PACKAGINGS IN THE JAPAN SOCIETY OF MECHANICAL ENGINEERS - Presentation

The Japan Society of Mechanical Engineers (JSME) established the Rules on Transport/Storage Packagings for Spent Fuel as a part of Codes for Construction of Spent Nuclear Fuel Storage Facilities in 2001, and revised in 2007. The revised Rules provide a material and design code for baskets made of aluminum alloy or borated aluminum alloy. Further, the Rule includes guidelines for the application of aluminum alloy and borated aluminum alloy as a new basket material for the spent fuel transport/storage packagings. In accordance with the guidelines, proposals of code cases for new basket materials, including 4 types of aluminum alloys and one type of borated stainless steel, were submitted to JSME in late 2007. In January 2008 the Subgroup on Spent Fuel Storage Facilities within the Subcommittee on Nuclear Power in the Power Generation Code Committee of the JSME established the Working Group on Packaging Material Evaluation with experts from universities, research organizations, material manufacturers and utilities to entrust the assessment of these applications. The Working Group met 8 times in a half year to investigate and discuss intensely the applications, and reported to the Subgroup that applied materials were complying with the guidelines in July. For aluminum alloys each set of allowable stress has been set forth with consideration to time and temperature effects such as creep or averaging. The code cases were approved by Subgroup in the end of July, by the Subcommittee in August, and approved for public comments by the Code Committee in December 2008. With no public comment the code cases were finally approved by the Code Committee in March 2009, and published. These materials are used in basket designs for transport/storage packagings for the Mutsu Recycle Fuel Storage Facility, the first away-from-reactor interim spent fuel storage facility scheduled to be put into operation in 2012. In the presentation, outline of the materials and major discussions on them within the JSME Committees will be introduced.