Year
2001
Abstract
Accountancy and control of nuclear material at research reactors is an essential part of the IAEA’s safeguards measures. Currently, there are approximately 160 research reactors and critical assemblies under IAEA Safeguards. Considering the total number of IAEA inspections, the largest effort is spent on power plants, immediately followed by research reactors. Whereas the verification of fresh and spent fuel is relatively simple, e.g. by taking a physical inventory, the verification of core fuel, in the majority of cases, requires more complex test methods. The main reason for possible complications is the difficult access to the core inventory. Verification by physical inventory taking yields a result at a high level of assurance, but the procedure is very intrusive and time-consuming for both, the IAEA inspectorate and the facility operator. With the objective to conduct the inspection more efficiently and with an adequate confidence, the IAEA has introduced various safeguards measures. In addition to known IAEA inspection methods, the new Core Inventory Verification (CIV) method will be presented. Although the CIV method is still in the development stage, a substantial improvement of the inspection quality is foreseeable. The CIV method is an extension of the Criticality Tester, which is an already implemented safeguards method for zero power research reactors and critical assemblies. In addition to the new development, a selection of existing measures and methods will be characte rized and assessed with respect to furthering the IAEA’s ability of core verification and coping with diversion scenarios. The IAEA is interested in knowing to what extent a specific inspection method can give assurance of conformance with declared design information and reactor operations. In particular, it must be ensured that the reactor has not been used to produce undeclared plutonium-239 or uranium-233. The paper will discuss the capabilities and limitations of the safeguards measures.