Safety assessments of JMTR facilities for the new regulation

Hanakawa, Hiroki ; Watahiki, Shunsuke; Ide, Hiroshi  ; Kitagishi, Shigeru  ; Imaizumi, Tomomi; Araki, Daisuke; Tobita, Masahiro; Yamaura, Takayuki ; Kaminaga, Masanori  

On 18th December 2013, the new regulatory requirements for Japanese research reactor were enforced by the Nuclear Regulation Authority in Japan. This new regulatory requirements are also applied to any research reactor in Japan, even if licensed research reactor. Thus the verification of conformity in the JMTR facilities to the new regulatory requirements was carried out. In this reports, the safety assessment against the beyond design basis accident will be described. At first, events tree analyses were carried out to select beyond design basis accidents. From these analyses, it was confirmed that 8 events can be representative cases. These events were analyzed from the viewpoints of public dose exposer. As the result of analysis, it was confirmed that 3 events out of 8 has a possibility to give the considerable public dose exposer so that the counter measerments were taken account to reduce the dose exposer to acceptable limit.