Recent Research Activities Using NSRR On Safety Related Issues

摘要

This paper reports recent progress in the research activities of the Japan Atomic Energy Agency (JAEA) on safety related issues using the Nuclear Safety Research Reactor (NSRR). JAEA launched ALPS-Ⅱ program in 2010 in order to obtain regulatory data for advanced fuels. After the Great East Japan Earthquake in 2011, five new reactivity-initiated accident (RIA) simulated tests on the advanced fuels have been performed. The first two fuels tested, VA-5 and VA-6, were 17×17-PWR-type with stress-relieved and recrystallized M-MDA cladding tube, and irradiated to ～80 GWd/tU. The cladding failed due to the pellet-cladding mechanical interaction. In addition, fission gas dynamics tests to promote a better understanding of the behavior of fission gas during an RIA are planned in the framework of the JAEA/IRSN collaboration. A recent qualification test on a prototype pressure sensor demonstrated its ability to obtain history data of transient fission gas release. JAEA also launched a new experiment program using NSRR to investigate fuel degradation behaviors in the temperature region beyond-DBA LOCAs. The first preliminary test performed in 2014 confirmed that the shaped pulse operation of NSRR may be able to simulate a high temperature condition in which important phenomena in beyond-DBA LOCAs may occur.