ナトリウムスプレイ燃焼試験の多次元効果に関する解析的考察

抄録

Sodium combustion analysis is one of the most important issues in the development of safety measurements in sodium cooled fast reactors. However, conservative assumptions that lead to excessive safety margins and expensive designs were made in the previous safety evaluations. In order to evaluate the effects of sodium combustion in three dimensions, an analysis code AQUA-SF has been developed, which enables more detailed elucidation of sodium combustion phenomena and evaluation of the effectiveness of safety measures. In this paper, we examine the multidimensional effects of spray combustion for the SNL-T3 test as a benchmark analysis. In order to simulate the decrease of pressure and the temperature rise near the floor during the test, a new model is developed to take into account temporal cessation of sodium ignition, increased drag coefficient due to droplet deformation and liquid splash effect due to collision between the jet stream and the floor surface, and the results are compared with the test measurements.