TEPCO sent workers into the basements of Fukushima Daiichi Units 2 and 3 for the first time after the accident on Wednesday to investigate the pressure suppression chamber near the bottom of the containment vessel Upon opening the suppression chamber entrance door in Unit 2, workers measured over 160 mSV/hr.
In Unit 3, the suppression chamber entrance door was damaged, and could not be opened. The radiation levels registered at the time were 75 mSv/hr. It was confirmed that the 9 meter high suppression chambers in both units are partly submerged by 6 meter deep contaminated water. The inspection time was 20 minutes and the highest worker exposure was 2.87 mSv.
Junichi Matsumoto said “as the radiation is extremely high (…) in the future it will be necessary to use robots”.