[3G01-05] Behavior of Radioactive Nuclides & Fuel Debris 1

[3G01] Estimation of Cs distribution and characteristics in the reactor unde severe accident

(1)Evaluation of amounts of chemisorped Cs in the reactor

*Hidetoshi Karasawa¹, Shuuhei Miwa¹, Chiaki Kino² (1. JAEA, 2. IAE)

Keywords:severe accident, CsOH, chemisorption, structural material, ECUME, SAMPSON, plant analysis

Amounts of Cs chemisorped on surfaces of separators and dryers in 1F1, 1F2 and 1F3 were evaluated by the SAMPSON code under 1F severe accident conditions. Concentrations of CsOH vapors are decreased due to reaction with Mo vapors and to produce aerosols under decreasing temperature. As an existing chemisorption model is independent on Cs concentrations, an ECUME has developed a new chemisorption model which is a function of the Cs concentration. Cs absorbed amounts were changed unit by unit due to different CsOH concentrations and gas temperature. Evaluation of CsOH chemisorption in a SA analysis needs the new chemisorption model with dependency of CsOH concentrations.