Year
2016
File Attachment
F5027.pdf225.6 KB
Abstract
A canister loaded spent fuels stored in a concrete over-pack is planned to be taken out from the concrete over-pack, and to be shipped to a reprocess plant and /or a final disposal repository facility by a metal transport over-pack (a transport cask) after the scheduled storing period of several decades. For the safe transport, it is necessary to confirm that the canister shall satisfy the technical requirements specified in the transport regulations for radioactive materials. The canister shell will be containment boundary. As the canister is usually filled with inert gas such as helium gas, corrosion from the outside surface of the canister during the storage period is one of the technical issue to be solved for the safe transport after the storage. As a spent fuel storage facilities is possibly to be installed near sea shore in Japan, stress corrosion cracking induced by chloride ion in saline air becomes an issue to be considered in addition to other corrosion. Using high anti-corrosion material such as super austenitic stainless steel and/or duplex stainless steel might be one of the solutions to solve the issue. However, we selected ordinary austenitic stainless steel for the canister material. In this paper, we explain the reasons why ordinary austenitic stainless steel is selected for the shell and lid material, taking into consideration of corrosion, workability and weldability, availability of material, and economy.