Decommissioning plan of JRR-4

Ishikuro, Yasuhiro ; Hirane, Nobuhiko; Kato, Tomoaki

Japan Research Reactor No.4 (JRR-4) is a swimming pool type reactor moderated and cooled with light-water. The maximum thermal power of JRR-4 is 3,500kW. Since its initial criticality in January 1965, JRR-4 had been operated about 45 years until in December 2010.Subsequently, the Great East Japan Earthquake occurred on March 11, 2011. Although JRR-4 was no severe damage, we have determined to decommission JRR-4 in consideration of various things. After that, we have submitted the decommissioning plan of JRR-4 to the nuclear regulatory body and have received the approval of it on June 7, 2017. Consequently, JRR-4 has shifted to the phase1 of the decommissioning plan since December.15, 2017 after the approval of its the safety regulation.