Accident At Tokai Lab Shows JAEA Systemic Failures

More information is coming out about the accident late last week at the Tokaimura nuclear lab.  As of the 26th 26 people in total have found to have internal exposure, 2 of them women. 49 of the 55 people have now been scanned for internal exposure.  Six of the researchers received internal doses of up to 1.6 mSv. The NRA provisionally declared the incident to be an INES 1, the international scale of 1-9 to rate nuclear disasters.

The failures occurred at the Hadron Experimental Facility in the Japan Proton Accelerator Research Complex, run by JAEA at the Tokaimura nuclear facility. The problems began Thursday around noon when an alarm sounded. The alarm caused the equipment being used in the experiment to stop. Researchers disregarded the alarm and continued with the experiment without identifying the cause of the alarm. The lead researcher restarted the experiment about 15 minutes after the alarm sounded. Radiation levels began to rise 90 minutes later and increased as they continued. The researchers turned on an unfiltered exhaust fan and returned to work after the radiation levels dropped. About 4pm the levels rose again prompting them to finally stop the experiment. One of the researchers claimed that because the level was below that of a radiation control zone it was permissible and thought nothing of the release outside the lab building. The vent system was turned on again at 5:30pm and the workers evacuated the building for safety reasons. It was not discovered until the following day that radiation monitors elsewhere in the complex had risen at the same time they ran the exhaust fans. The increase found nearby was 6 nGy, a small increase and JPARC claims no radiation increase was found at the complex boundary.  The experiment used a proton beam to produce elementary particles using a gold target. The malfunction that was ignored caused the proton beam output to jump unexpectedly and vaporized part of the gold target, generating the radiation.

JAEA officials claimed they “did not think radiation was released” even though the level in the lab was elevated and then exhausted through an unfiltered venting system. This has been their excuse for not alerting the NRA or local officials.  A JPARC official admitted the lab is expected to generate radiation but made no excuse for the lack of a filter on the vent system. The researchers assumed the release was not a problem thinking the radiation would quickly decay. As of Sunday the contamination in the lab was still 40 becquerel per square centimeter. An official at the facility has admitted it was not an appropriate move to vent the lab that had radiation levels of 4 microsieverts through an unfiltered vent and not bother to investigate further or notify anyone. A JAEA official admitted they should have taken the incident more seriously and that they ignored and didn’t report the problems because they thought they were below a government exposure threshold.

The slow reporting and handling of the accident was admonished by the Japanese science minister. JAEA’s president resigned last week after the NRA shut down the Monju fast breeder reactor for massive failures and management incompetence. The problem at Tokai a week later raised more questions about JAEA’s ability to manage their facilities. Issues at the lab complex have been tense since the 1999 criticiality accident that caused the nearby towns to be exposed and evacuated. Ibaraki government officials raided the facility Saturday to try to determine why the complex did not alert authorities for almost a day after discovering the radiation release. An official with the prefecture’s nuclear safety office confirmed that the local government is taking a serious look at what happened. The main concerns from the scientific community now seem to be determining if this was due to inexperience, fear of speaking up or systemic problems at the facility that ignored the safety risk. It may be a combination of all things since no one saw a need to put a filtration system on the lab vents. The lack of any urgency to investigate or report the incident also has officials concerned.

A JAXA official called the accident unexpected and unanticipated when questioned about the problem and the delay in reporting it. The head of JPARC admitted their safety standards for the lab were too lax. 38 Similar facilities exist around Japan, now some are questioning the need to have better safety at all of these facilities. There are some rules for radiation safety at these labs but mostly it is left up to the owners of the lab to determine safety measures.

The incident ended up exposing far more lab workers than would have been had better procedures and a simple filtration system been in place. This  incident and the way both the lab staff and the officials running the complex responded to it was again confused and shows the systemic failures at Japan’s nuclear facilities. Had this been a different and more significant incident the outcome could have been much worse. Apparently nothing was learned from the 1999 Tokai accident or the Fukushima disaster. NRA has yet to issue a full response to the incident and has not said if they will impose better safety rules on these lab facilities.

JPARC press release

More about the lab



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