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information about Fukushima published in English in Japanese media info publiée en anglais dans la presse japonaise

Any accident should be reported

May 26, 2013

Researchers hurt at Ibaraki nuclear facility

JIJI, Kyodo



At least six researchers suffered internal radiation exposure when an experiment involving elementary particles went awry and up to 24 more are feared to have been similarly exposed, the Japan Atomic Energy Agency said Saturday.

Radioactive substances leaked following the accident Thursday in the Hadron Experimental Facility of the Japan Proton Accelerator Research Complex (J-PARC) in Tokai, Ibaraki Prefecture, the government-affiliated agency reported.

Officials from the Ibaraki Prefectural Government raided the complex Saturday afternoon to investigate the delay in reporting the incident. A malfunction occurred at 11:55 a.m. Thursday during an experiment to produce elementary particles by aiming a proton beam at a target made of gold, the agency said.

An alarm went off shortly afterward and the experiment was halted. But a researcher in charge of the equipment restarted it at 12:08 p.m., despite not having pinpointed the cause of the alarm, sources familiar with the investigation said.

As a result, the proton output jumped unexpectedly, causing part of the gold to evaporate and the generation of radioactive substances that leaked out of the controlled area, according to the agency.

It said the radioactive leak has stopped, but not before at least six male researchers suffered internal radiation exposure. Four of them received doses of up to 1.6 millisieverts.

Later Saturday, the agency reported that another 24 researchers may have been similarly exposed to internal radiation. A total of 55 people were working in the facility at the time of the accident.

All work at the Hadron Experimental Facility has been suspended.

Agency officials said they initially thought there had been no leak outside the radiation-controlled area and therefore did not report the accident to the Nuclear Regulation Authority. The leak was only discovered Friday night and the NRA was informed at 10:15 p.m., the officials said.

When radiation readings rose during the experiment, researchers released radioactive substances outside the facility through a fan on the assumption that they would quickly decay, the agency explained.

The level of radioactive contamination at the facility stands at as much as 40 becquerels per square centimeter, it said.

The research complex is jointly run by the atomic energy agency and the High Energy Accelerator Research Organization.

The agency’s president, Atsuyuki Suzuki, resigned earlier this month over its failure to conduct a proper inspection of its Monju prototype fast-breeder reactor in Tsuruga, Fukui Prefecture.

Science minister Hakubun Shimomura criticized the agency for its delay in reporting the accident to the prefectural and central governments, and the NRA. The delay indicates that the agency “lacks a sense of urgency and crisis,” Shimomura said, stressing that it is required to report any accident, regardless of its severity.



May 25, 2013

Radiation leak reported day after incident at Ibaraki laboratory



TOKYO (Kyodo) -- Radioactive substances were released into the atmosphere Thursday outside the controlled area at one of the Japan Atomic Energy Agency's nuclear physics laboratories in Ibaraki Prefecture, the Nuclear Regulation Authority's secretariat said early Saturday morning.

Fifty-five researchers and others who were engaged in experiments and other work at the laboratory may have been exposed to radiation as a result of inhaling the substances, but none were taken to hospital, the government body said. Four have so far undergone checkups and the highest radiation dose detected was 1.6 millisievert.

No impact from the radiation is expected beyond the premises of the accelerator laboratory in Tokaimura.

The NRA secretariat said it received a report on the incident at the laboratory of the Nuclear Science Research Institute from the JAEA at around 9 p.m. Friday. The incident occurred at 11:55 a.m. Thursday.

Officials of the JAEA said in a press conference held early Saturday in Tokyo that it failed to report the incident to the NRA immediately because it believed the leak had been confined to the laboratory.

The Ibaraki Prefectural government said it was notified at around 9:40 p.m. Friday, adding that it will conduct an on-the-spot inspection of the facility Saturday afternoon.

The latest incident follows the resignation of the president of the state-run JAEA last week. Atsuyuki Suzuki resigned over the agency's failure to conduct a proper inspection of its Monju prototype fast-breeder reactor in Tsuruga, Fukui Prefecture.

The researchers at the lab in Ibaraki were engaged in an experiment to generate particles by applying a proton beam to gold. The equipment they were using suffered a malfunction, causing it to overheat, which resulted in the evaporation and release of radioactivated gold, the authorities said.

Contamination within the laboratory building is estimated at 40 becquerels at most, they said.

The JAEA initially thought that the leak had been confined to the lab area and that the radiation was within acceptable levels. As a result, workers switched on the ventilation fan, which eventually caused radioactive substances to escape into the outside atmosphere.

All work at the facility has been suspended, they said.

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