[2O15-18] Accident Behavior inside Building

[2O15] Effect of hydrogen emissions from buildings during significant containment leaks in PWRs.

(1) Parameter study using simple model

*Kenichiro Ueda¹, Yasumitsu Fujii², Hidenori Kanaoka³, Kosuke Takeuchi⁴, Takahide Yoshida⁵, Wataru Urano⁶, Yasutaka Harai¹ (1. Mitsubishi Heavy Industries,Ltd., 2. The Kansai Electric Power Co, Inc., 3. Hokkaido Electric Power Co.,Inc., 4. Shikoku Electric Power Company, Incorporated, 5. KYUSHU ELECTRIC POWER CO., INC., 6. The Japan Atomic Power Company)

Keywords:PWR, hydrogen, significant containment leak

PWRs' hydrogen management strategy in SA is characterized by that hydrogen concentration is suppressed due to the large free volume of CV, and in addition, hydrogen concentration can be controlled by combustion by igniters and recombination by PARs. Even if it leaks into the annulus area surrounding the CV, hydrogen has been released outdoors by fans. In this paper, a sensitivity study between the leakage rate and emissive airflow and annulus hydrogen concentration are performed for typical PWRs, assuming the conditions with a high-concentration and significant leaks to the annulus . It was confirmed that hydrogen concentration could be controlled below the flammable limit even for leaks of 100 times the CV leakage rate in SA by using existing fans.