Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Cheng, S.; 松場 賢一; 磯崎 三喜男; 神山 健司; 鈴木 徹; 飛田 吉春
Proceedings of International Symposium on Symbiotic Nuclear Power Systems for 21st Century (ISSNP 2013) (CD-ROM), 7 Pages, 2013/11
In the severe accident analyses for sodium-cooled fast reactors, there is the possibility that a whole-core-scale pool containing sufficient fuel to exceed prompt criticality by fuel compaction might be formed. Local fuel-coolant interaction in the pool is regarded as one of the probable initiators that could lead to such compactive fluid motions. To clarify the mechanisms underlying this interaction, an experimental system using simulant materials has been developed. The experiments were conducted by delivering a given quantity of water into a simulated molten fuel pool. Current paper presents the experimental design and knowledge from preliminary analyses of several typical runs (with water quantity varying from 5 cc to 40 cc). Interaction characteristics including the pressure-buildup as well as mechanical energy release and its conversion efficiency are evaluated and compared in detail. It is revealed that as water quantity increases, a limited pressurization and resultant mechanical energy release is observable.
神山 健司; 飛田 吉春; 鈴木 徹; 松場 賢一
Proceedings of International Symposium on Symbiotic Nuclear Power Systems for 21st Century (ISSNP 2013) (CD-ROM), 9 Pages, 2013/11
A methodology for molten-fuel discharge behavior is required to realistically assess core-disruptive accidents (CDAs) of sodium-cooled fast reactors. In the present study, the SIMMER code was utilized as a technical basis since this code can simulate the multi-phase, multi-component fluid dynamics with phase changes which are supposed to take place around the CRGT during the discharge process. First, dominant phenomena affecting fuel discharge through the CRGT are identified based on parametric calculations by the SIMMER code. Next, validations on the code models closely relating to these phenomena were carried out based on experimental data. It was shown that the SIMMER code with some model modifications could reproduce the experimental results appropriately. Through the present study, the assessment methodology for the molten-fuel discharge through the CRGT was developed.
松場 賢一; 磯崎 三喜男; 神山 健司; 飛田 吉春; 鈴木 徹
Proceedings of International Symposium on Symbiotic Nuclear Power Systems for 21st Century (ISSNP 2013) (CD-ROM), 6 Pages, 2013/11
ナトリウム冷却高速炉の炉心損傷時に原子炉容器下部プレナムナトリウム中へ流出する溶融炉心物質が微粒子状固化物(デブリ)になるまでの距離(デブリ化距離)に関する評価手法を開発するため、模擬物質(低融点合金と水)を用いて溶融炉心物質とナトリウムの液-液接触状態を模擬した基礎試験を行っている。本基礎試験ではデブリ化距離の実測値が従来予測に比べ10%程度以下の短い距離でデブリ化される結果となった。試験結果の分析に基づき、このデブリ化距離の大幅な短縮には液-液接触状態からの蒸気泡の膨張に伴う急速なデブリ化が寄与した可能性を明らかにした。本基礎試験を通じてデブリ化距離評価手法開発に有益な知見が得られた。