Investigation of multi-dimensional effect in sodium leak and fire behavior

ナトリウム漏えい燃焼挙動における多次元熱流動現象の検討

大野 修司  

Ohno, Shuji

高速炉冷却材ナトリウムが大流量でコラム状に漏えいし床で衝突飛散する場合の燃焼挙動と熱影響について、大規模ナトリウム燃焼試験における試験容器内部温度や酸素濃度の測定結果をもとに分析評価した。その結果、ナトリウム燃焼が大空間内部の限定された領域で生じる場合の局所的な酸素欠乏によって燃焼が抑制・緩和される効果が存在することを明らかにした。

This paper presents the typical characteristics of sodium combustion and subsequent reaction heat transfer behaviors observed and investigated in sodium columnar leak and fire experiment which was conducted in an enclosed steel vessel with large inner volume of about 100 m. Especially the experiment was carried out with the main focus on the burning phenomenon within a limited spatial area in the case of large sodium leak rate as well as on the multi-dimensional thermal-hydraulics both near a sodium burning zone and in a whole region in the vessel. The investigated experimental results show us that the sodium combustion of columnar leak and its splashed droplets would lead to important oxygen deficiency behavior near the burning region, and be followed by the limitation or saturation of maximum sodium burning rate.