Presentation Information
[1A08]Modeling radio-nuclide behavior for estimating their amount in radioactive waste of Fukushima Daiichi NPS(5) Evaluation of iodine chemical forms in the severe accident
*Hidetoshi Karasawa1, Masao Chaki2, Shunsuke Uchida, Yoshikazu Koma3, Yoko Takahatake3 (1. Hachinohe Inst. of Tech., 2. IAE, 3. JAEA)
Keywords:
Fukushima Daiichi NPS,gaseous iodine,mole ratio of I/Cs,I-129
In SA analysis, we have evaluated the amount of iodine(I) released into the environment based on the effects on internal exposure, and cesium (Cs) from the effects on external exposure. Regarding the chemical form of I, it was initially thought to be I2, but since the amount of gaseous iodine (I2, I, HI, etc.) observed in the TMI accident was small, CsI, which is in the form of particles, is also evaluated. Most of particulate CsI, which is water-soluble, is treated as contaminated water even if it is deposited on the wall. However, gaseous iodine can change its chemical form in the containment vessel and become fixed on the wall. Therefore, we evaluated the formation rate of gaseous iodine from the I/Cs mole ratio using the analysis results of WSPEEDI and the radioactivity measurements at the 1F site. Then, the transfer behavior of I in the containment vessel was examined. (150words)