Ibaraki's accident "Level 1"

 May 27, 2013

Nuclear regulator: Radiation leak at INES Level 1

http://www3.nhk.or.jp/nhkworld/english/news/20130527_26.html

Japan's Nuclear Regulation Authority has tentatively given a recent radiation leak at a research laboratory a Level 1 rating. The International Nuclear and Radiological Event Scale for accidents ranges from zero to 7.

The NRA announced the rating on Monday. It said the operator of the facility lacked a safety culture.

The leak occurred last Thursday at a laboratory of the Japan Atomic Energy Agency in Ibaraki Prefecture, north of Tokyo. At least 30 people were exposed to radiation.

The NRA said the accident caused a limited rise in radiation levels to areas outside of the facility. The authority said the released radiation would have no impact on the public.

But the NRA also said the staff operated ventilation fans that emitted radioactive substances to the outside environment. This was done after contamination was confirmed inside. The NRA concluded the operator does not have an adequate management system for radioactive substances.

The Level 1 rating on the INES scale was the same level as a sodium leak in 1995 at the prototype fast-breeder reactor Monju in Fukui Prefecture.

May 27, 2013 - Updated 09:56 UTC

Radiation leak at Ibaraki lab labeled as Level 1 accident

http://mainichi.jp/english/english/newsselect/news/20130527p2g00m0dm078000c.html

TOKYO (Kyodo) -- The Nuclear Regulation Authority on Monday provisionally evaluated the severity of the recent leakage of radioactive substances at a Japan Atomic Energy Agency laboratory northeast of Tokyo as Level 1, third from the bottom of a 9-scale international gauge.

The Japanese nuclear watchdog cited "the lack of safety culture" in the state-run JAEA for the rating as the lab in Tokaimura, Ibaraki Prefecture, released radioactive substances into the atmosphere outside its controlled area through use of a ventilation fan even though it was aware of radioactive contamination within the facility.

The accident occurred around noon last Thursday in the Japan Proton Accelerator Research Complex, one of the JAEA's nuclear physics laboratories, causing at least 30 people out of 55 at the facility to be exposed to radiation.

So far, no abnormalities have been confirmed by seven monitoring posts of radiation dose levels in Tokaimura, according to prefectural officials.

Ibaraki Gov. Masaru Hashimoto criticized the JAEA for reporting the leakage more than one day after the accident, saying at a press conference, "It must be taking the matter lightly."

The radioactive exposure of researchers and other staff members was "very regrettable," he said.

Other Level 1 accidents in Japan include a 1995 sodium leak at the prototype fast-breeder nuclear reactor Monju and a 2004 pipe rupture accident at Kansai Electric Power Co.'s Mihama plant Unit 3, both in Fukui Prefecture.