ISSN オンライン: 2688-7231
ISBN 印刷: 978-1-56700-497-7 (Flash Drive)
ISBN オンライン: 978-1-56700-496-0
Proceedings of the 25th National and 3rd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2019)
IMPORTANCE OF DECAY HEAT CONTRIBUTION TO THE THERMAL AND PRESSURE LOADINGS IN THE CONTAINMENT OF A MEDIUM SIZED SFR DURING A HYPOTHETICAL SEVERE ACCIDENT SCENARIO
In this article the thermal and pressure loading in the containment due to decay power from released radionuclides are
studied. Major contributing radionuclides in the core as well as in the containment are identified. For analysis, severe accident resulting from postulated Unprotected Loss of Flow (ULOF) is considered. Using conservative set of in-containment release fractions, the released decay heat in the containment is determined. We found that although the noble gases contribute 6% of the total decay power after shutdown, the noble gas contribution in the containment will be dominant (64% of total decay power released into containment). After one day most of the noble gas decay heat contribution will be decayed out and contribution from the volatile and non-volatile radionuclide will be dominant. For the reference reactor studied, with deposition of 55% decay heat in the containment atmosphere, the peak temperatures are found to be 5 K higher than that due to only sodium fire. The corresponding peak excess pressures are about 2 kPa higher than the peak excess pressure due to only sodium fire. But subsequently, after one hour, the temperature and pressure is 10 K and 4 kPa respectively higher than the only sodium fire case.