Comparison of Nuclear Security Risks of Interim Storage options for

Abstract

The safety and security management of spent nuclear fuels from nuclear power plants has become a one of major national issues for virtually all nuclear power states in the world. Technical and policy options on ultimate disposal have been debated for decades, and are not likely to be determined soon. Due to the dilemma, the Government of Korea is planning to rely on long-term interim storages. However, there are several obstacles awaiting consent-based decisions on design, site and surroundings from the view of safety, security, economy and social acceptance. Moreover, the security issues of interim storage came to the frontline because awareness and concerns about the threat of nuclear facilities terrorism have become acute and pervasive since the attacks on September 11, 2001. The Fukushima accident broke on March 11, 2011 also showed vulnerability of interim storage and importance of nuclear security on this storage. Therefore, the appropriate design to fit Korean spent fuel situation for the management has been simulated in this dissertation.

By Fukushima accident proved the dry storage is safer than wet storage. Considering the security, the underground storage concept including tunnel and subsurface storage is invoked to be desirable for security. However, there are lacks of assessment tool for evaluating overall nuclear security. Therefore, this thesis employed a modified assessment model designed from physical protection guidelines of INPRO and classification system from US Department of Homeland Security. Four types of interim storage such as above ground centralized site, centralized tunnel, above-ground Independent Spent Fuel Dry Storage Installation (ISFSI) and ISFSI in tunnel are examined for assessing nuclear security risks of interim options without deciding a permanent repository.

The relative comparison of the above mentioned four options is performed based on 4 user requirements such as legislative and regulatory framework, facility robustness, site security and contingency plan. As results of comparison, on-site tunnel concept is recommended to introduce in a short or long period of time. The centralized storage for the long term will be better than ISFSI. As demonstrated on CORWM reports, the underground storage concepts will have significant advantages over above-ground options taking into account recent trend of increasing importance of nuclear security. The new recommendation should be considered for security policy on interim storage as well as for improving social acceptance of spent nuclear management.