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HTTR fuel shows the highest quality in the world by 30 day full power operationMay. 9, 2007Point Japan Atomic Energy Agency (JAEA) confirmed that the High Temperature Engineering Test Reactor (HTTR) fuel shows the highest quality in the world as High Temperature Gas-cooled Reactor (HTGR) fuel. The HTTR fuel showed excellent Fission Products (FPs) retention performance through the first 30 day full power operation (about 30MW). The HTTR fuel is the first fuel manufactured by commercial scale factory. Outline JAEA has promoted research and development aiming at establishment and upgrading HTGR technology basis using the HTTR. As a part of the R&D, operational data of the HTTR have been acquired and accumulated. HTGRs use coated fuel particles (CFPs) as fuel. The CFP consists of a kernel of UO2, whose diameter is about 600μm, coated with three layers of pyrolytic carbon and SiC layer. These layers retain FP inside CFPs. The CFPs are suitable to use under high temperature condition than fuel using metallic cladding because the CFPs have high heat resistance characteristics up to 1600�C. The JAEA developed CFPs which used for the HTTR in cooperation with Nuclear Fuel Industries, Ltd.. The FP retention performance of CFP should be confirmed by FP concentration in the primary circuit through more than 30 days long-term full power operation because FP concentration in the primary circuit would be saturated. The HTTR carried out 30 day long-term full power operation with the outlet coolant temperature of 850�C from March 27 to April 26, 2007. It was the first operation with such long term full power operation. It was showed that FP concentration in the primary circuit was 10 to 1,000 orders lower than those of oversea HTGRs. It showed that the HTTR CFP had the world�s best quality of FP retention performance. JAEA will carry out 50 day full power operation with the outlet coolant temperature of 950�C, which is more severe condition for CFPs, to obtain data for FP retention performance of the CFP, core characteristics, high temperature component performance, impurity concentrations in the primary circuit, and so on to establish and upgrade the HTGR technology. An outcome of this result to attract a considerable attention in the world will be useful to �the research and development of technological systems for high temperature gas reactor which will be able to be high temperature heat source for power generation with excellent economic efficiency and hydrogen production based on it� mentioned in the Framework for Nuclear Energy Policy. |
