Radiation levels in the atmosphere were unchanged on June 20 after the double doors of the No. 2 reactor building at the Fukushima No. 1 nuclear power plant were opened.
Radiation levels in the atmosphere were unchanged on June 20 after the double doors of the No. 2 reactor building at the Fukushima No. 1 nuclear power plant were opened.
Four workers measured radiation levels inside the building. They will adjust water and pressure gauges to prepare for cooling the reactor on a stable basis.
Workers began opening the double doors before 9 p.m. on June 19. The doors were opened gradually to prevent dust from being stirred up. The doors were fully open at 5 a.m. on June 20.
There were concerns that radioactive material inside the building would be released to the outside.
The double doors were earlier opened at the No. 1 reactor building.
The radiation levels inside the No. 2 reactor building were 5.15-27.1 millisieverts per hour. The workers were exposed to a maximum of 3.24 millisieverts during 12 minutes.
Humidity levels fell from 99.9 percent to less than 70 percent.
The Nuclear Safety Commission of Japan said June 17 that the opening of the double doors would not affect the environment, and the Nuclear and Industrial Safety Agency endorsed the commission's view the same day.
Tokyo Electric Power Co., the plant's operator, informed the Fukushima prefectural government and municipalities around the plant of its plan to open the doors.
TEPCO said 1.6 billion becquerels of radioactivity would be released, or about three times the amount when the double doors were opened at the No. 1 reactor building.
It said the amount of radiation in the atmosphere within the plant site would increase by a maximum of 0.0014 microsieverts per hour.
(This article was compiled from reports by Hiroshi Ishizuka and Naoya Kon.)