Status of reduced enrichment program for research reactors in Japan

The reduced enrichment programs for the JRR-3M, JRR-4 and JMTR of Japan Atomic Energy Agency (JAEA, former name is Japan Atomic Energy Research Institute (JAERI)) has been completed by 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. JAEA 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. But the U-Mo fuel development is facing very difficult situation to use a high U-density of U-Mo fuel, so JAEA will carefully study the U-Mo fuel installation plan. In KURRI, the Japanese Government approved a cancellation of the Kyoto University High Flux Reactor (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 the end of March, 2006. After one year cooling time, all HEU KUR spent fuel elements will be sent to the U.S. by March 2008. The full core conversion with LEU fuel of the KUR will be scheduled after 2007. (author)