Thermal stratification at the suppression chamber for severe accident analysis

2015 Fiscal Year Final Research Report

• Project/Area Number: 25289350
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: The University of Tokyo
• Principal Investigator: okamoto koji 東京大学, 工学(系)研究科(研究院), 教授 (80204030)
• Co-Investigator(Kenkyū-buntansha): Erkan Nejdet 東京大学, 工学(系)研究科(研究院), 助教 (00513532)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 原子力エネルギー / 流体工学 / 熱工学

Outline of Final Research Achievements

The thermal stratification phenomena had been observed at the Suppression Pool of FUkushima-Daiichi NPP. The mechanism of the stratification had been evaluated experimentally. In order to confirm the geometrical effect, slab-type pool and torus-type pool had been experimentally investigated using PIV, showing the similar natural circulation. Then, the momentum caused by the steam condensation and the natural circulation force had been experimentally evaluated using the high-speed visualization. Finally, the Richardson number was defined, which was a ratio between the buoyant force and momentum force.
Using the Richardson number, the occurrence and disappearing of the thermal stratification had been well explained.

Free Research Field

原子力安全工学