Irradiation Effect on Silo Dry Storage Systems for CANDU Spent Nuclear Fuel

Taehyung Na^*, Yeji Kim, Donghee Lee, Taehyeon Kim, Sunghwan Chung

Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd., 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon 34101, Republic of Korea

Received 2024-02-27 ; Revised 2024-03-21 ; Approved 2024-04-01

Abstract

The 300 concrete silo systems installed and operated on the site of Wolsong nuclear power plant(NPP) have been storing CANDU spent nuclear fuel(SNF) under dry conditions since 1992. The dry storage system must be operated safely until SNF is delivered to an interim storage facility or final repository located outside the NPP in accordance with the country's SNF management policy. The silo dry storage system consists of a concrete structure, a liner steel plate in the inner cavity and a fuel basket. Because the components of silo system are exposed to high energy radiation due to the highly radioactivity of SNF inside, it is necessary to analyze the effects of irradiation during long-term storage. To this end, material specimens of each component were manufactured and subjected to irradiation and strength tests, and mechanical characteristics before and after irradiation were examined. The test results will be used to evaluate the long-term behavior of silo system in the future.

Key Words : dry storage system, concrete silo, irradiation, mechanical property, long-term behavior