PWR全電源喪失時に一次冷却材喪失を伴うROSA/LSTF実験とRELAP5解析

ROSA/LSTF test on PWR station blackout transient with loss of primary coolant and RELAP5 analysis

竹田 武司 ; 大津 巌 

Takeda, Takeshi; Otsu, Iwao

PWR全電源喪失時に一次冷却材喪失を伴う事象におけるアクシデントマネジメント策の有効性等を確認するため、ROSA/LSTFを用いて、窒素ガスの一次系への流入を仮定した条件で模擬実験を実施した。窒素ガスの流入により、一次系圧力の低下率が小さくなるとともに、蒸気発生器(SG)伝熱管群において非一様な流動を示した。また、RELAP5/MOD3.3コードにより事後解析を通じて、窒素ガス流入後の一次系圧力やSG伝熱管の水位等の予測に課題があることが分かった。

The effectiveness of accident management measure should be confirmed in case of PWR station blackout transient with loss of primary coolant. A simulation experiment with the ROSA/LSTF was thus conducted under an assumption of nitrogen gas inflow into the primary system. After the nitrogen gas inflow, the primary depressurization rate became smaller and non-uniform flow behavior was observed among steam generator (SG) U-tubes. In addition, RELAP5/MOD3.2 code indicated remaining problems in the predictions of the primary pressure and SG U-tube liquid level after the nitrogen gas inflow through the post-test analysis.