[2E10-13] Accident Progression

4:45 PM - 5:00 PM JST(7:45 AM - 8:00 AM UTC)

[2E10] 1F1 AC pipe contamination due to flashing at S/P venting and FP re-entrainment from the pool surface

*Akihide Hidaka¹, Hidetoshi Okada² (1. Niigata Univ., 2. Institute of Energy Safety Technology, Ltd.)

Keywords:

Fukushima Daiichi NPS accident,AC pipe contamination,Containment venting,Flashing,Re-entrainment

The cause of the contamination of the AC piping on the first floor of the R/B at Fukushima Daiichi Unit 1 (1F1) accident cannot be explained by a leak from the vacuum break valve or a decrease in the decontamination factor (DF) due to S/P water boiling, as previously considered. By analogy with the aerosol re-entrainment experiment from flashing pool at JAEA, the cause may be explained by an increase in the amount of re-entrained droplet from the contaminated flashing pool during the containment venting.