Developing a Safeguards Approach for a Graphite Moderated Reactor and Associated Fuel Cycle Facilities

摘要

Only a small number of graphite moderated reactor facilities exist in the world today;however, there has been some interest in reviving this concept especially for application indeveloping states. The materials needed in their construction and the engineering required tosupport them are easier to acquire for developing countries than typical light water reactordesigns. Also, most graphite moderated reactor designs are more “grid appropriate” in poweroutput. Graphite moderated reactors though pose a problem to the international community dueto the fact that they may produce weapons-grade plutonium. Since so few systems of this typeexist, experience in designing safeguards systems for these facilities is limited. In this work, asafeguards approach for a small graphite moderated reactor co-located with a fuel fabrication andreprocessing facility was developed. This approach demonstrated that IAEA safeguards, usingconventional technologies, is sufficient to provide timely detection of a diversion of a significantquantity of nuclear material and to provide deterrence against such a diversion with minimalimpact on facility operations in the case of an off-load refueled core. A unique test case (theYongbyon complex in the Democratic People’s Republic of Korea) was used to assess theviability of this approach. For a core which can be on-load refueled some challenges still exist. Inthis paper, the safeguards approach is described as well as its applications to the on-load and offloadrefueled systems. Successes and challenges for this approach are discussed.