Status of reduced enrichment program for research reactors in Japan

日本の研究炉における濃縮度低減計画の状況

木名瀬 政美 ; 佐川 尚司; 中込 良廣*; 宇根崎 博信*

Kinase, Masami; Sagawa, Hisashi; Nakagome, Yoshihiro*; Unesaki, Hironobu*

日本におけるRERTRに関連する研究炉はJRR-3, JRR-4, JMTR及びKURである。JRR-3, JRR-4及びJMTRは既に低濃縮化されており、低濃縮化後燃料に関する問題は生じていない。KURは、低濃縮化に向け2006年2月に運転を一旦停止し、今後、設置許可変更を経て、炉心全体の低濃縮化を2008年までに行う予定である。また、U.S.のFRRSNFA計画に基づき行われている研究炉の使用済燃料の対米輸送について、JRR-3, JRR-4及びJMTRは継続して使用済燃料の輸送を行う予定であり、KURは2008年3月を目標にすべての高濃縮燃料をU.S.に輸送する。

The reduced enrichment programs for the JRR-3M, JRR-4 and JMTR of Japan Atomic Energy Research Institute (JAERI) has been completed until 1999. The KUR of Kyoto University Research Reactor Institute (KURRI) has been partially completed and is still in progress under the Joint Study Program with Argonne National Laboratory (ANL). The JRR-3M using LEU silicide fuel elements has done a functional test by the Japanese Government in 2000, and the property of the reactor core was satisfied. JAERI established a "U-Mo fuel ad hoc committee" for feasibility study concerning future LEU fuel instead of the silicide fuel in 2001, and an installation of the U-Mo fuel was estimated from 2012, even the irradiation tests are carried out successfully. The U.S. Policy of Foreign Research Reactor Spent Nuclear Fuels is strongly expected to expand the policy until U-Mo fuel installed. The Japanese Government approved a cancellation of the KUHFR Project in February 1991, and in April 1994 the U.S. Government gave an approval to utilize HEU fuel in the KUR instead of the KUHFR. Therefore, the KUR will be operated with HEU fuel until March 2006, then the full core conversion with LEU fuel will be done. All KUR spent fuel elements will be sent to the U.S. by March 2008.