Thermal stratification at the suppression chamber for severe accident analysis

• 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 (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
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥17,420,000 (Direct Cost: ¥13,400,000、Indirect Cost: ¥4,020,000); Fiscal Year 2015: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2014: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2013: ¥9,360,000 (Direct Cost: ¥7,200,000、Indirect Cost: ¥2,160,000)
• 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.

Research Products

• [Journal Article] Effect of non-condensable gas on thermal stratification and flow patterns in suppression pool (2016)
  • Author(s): J. Cai, B. Jo, N. Erkan, K. Okamoto
  • Journal Title: Nuclear Engineering and Design Volume: 300 Pages: 117-126
  • DOI: 10.1016/j.nucengdes.2016.01.022
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Verification of thermal stratification characteristics using a scaled-down suppression pool of the Fukushima Daiichi nuclear power plants (2016)
  • Author(s): D. Yamauchi, B. Jo, N. Erkan, K. Okamoto
  • Journal Title: Mechanical Engineering Letters Volume: 2 Pages: 16-00098
  • NAID: 130005152908
  • Peer Reviewed
• [Journal Article] Relationship between thermal stratification and flow patterns in steam-quenching suppression pool (2015)
  • Author(s): D. Song, N. Erkan, B. Jo, K. Okamoto
  • Journal Title: Int. J. Heat Fluid Flow Volume: 56 Pages: 209-217
  • DOI: 10.1016/j.ijheatfluidflow.2015.07.023
  • Peer Reviewed
• [Presentation] 蒸気凝縮モデルを用いた圧力抑制室内温度成層化の発生条件の検討 (2016)
  • Author(s): 山内大典
  • Organizer: 日本原子力学会春の年会
  • Place of Presentation: 東北大学(宮城県仙台市）
  • Year and Date: 2016-03-26
• [Presentation] Study on the disappearing of thermal stratification at the suppression chamber (2014)
  • Author(s): Daisuke Yamauchi, Nejdet Erkan, Byeongnam Jo, Koji Okamoto
  • Organizer: 10th International Topical Meeting on Nuclear Thermal Hydraulics, Operation and Safety
  • Place of Presentation: Okinawa Convension Center, Okinawa
  • Year and Date: 2014-12-17
• [Presentation] サプレッションチャンバーの温度成層化現象に関する研究 (2014)
  • Author(s): 高橋真二
  • Organizer: 日本原子力学会
  • Place of Presentation: 東京都市大学、東京都