TOKYO (Kyodo) -- Companies dispatching workers to Tokyo Electric Power Co.'s crippled Fukushima Daiichi nuclear power plant are refusing to adopt the government-imposed provisional limit on radiation exposure for those workers at the plant, saying it would not be accepted by those at the site, Kyodo News learned Saturday.
The limit was lifted from 100 millisieverts to 250 millisieverts in an announcement made March 15 by the Ministry of Health, Labor and Welfare at the request of the Ministry of Economy, Trade and Industry, which has the Nuclear and Industrial Safety Agency under its wing, and other bodies.
The increase was requested to enable workers to engage in longer hours of assignments and to secure more workers who meet the restriction.
The advisability of the hastily decided limit may be called into question as workers have to handle a wider range of work over an extended period of time. They are now faced with tasks such as removing rubble and disposing of contaminated water in addition to their initial job of restoring the lost power sources at the plant that was crippled by the March 11 quake and tsunami.
The contract companies say they are sticking to the previous limit.
The health ministry said, "Based on medical expertise, a maximum limit has been adopted that would not cause health damage such as a temporary decline in white blood cell count." The ministry's decision was made after consulting with the science ministry's advisory body Radiation Council.
The ministry said it referenced a view of the International Commission on Radiological Protection that sets the upper limit in an emergency situation to a dose of 500-1,000 millisieverts.
The limit was upheld at 100 millisieverts when Japan was faced with a serious accident at a nuclear fuel processing plant in 1999 in Tokaimura, Ibaraki Prefecture.
According to Tokyo Electric, 21 workers were exposed to a cumulative dose of more than 100 millisieverts as of April 1. On March 24, three workers from Kandenko Co. and a subcontractor were exposed to high doses of radiation during their work at a building close to a reactor, making employers of plant workers nervous.
A public relations officer at Kandenko, a TEPCO affiliate, said, "Those at work sites would not agree to accept a suddenly lifted" limit. The three in question were exposed to 173-180 millisieverts and two of them suffered burns to their feet.
"We have to be prudent. Considering safety, we will maintain the 100 millisievert limit," the officer said.
An official at Tokyo Energy & Systems Inc., a TEPCO subsidiary, said, "The control target rate at the site is 100 millisieverts. In practice, we have set a limit lower at 80 millisieverts to make room for controlling radiation exposure."
Construction companies Kajima Corp. and Taisei Corp. have also adopted 100 millisieverts as their yardsticks.
Hitachi Ltd. has adopted "200 millisieverts under an in-house regulation," a public relations official said.
TEPCO has been going along with the higher limit. Just days ago, however, it was disclosed that not all its workers were equipped with radiation monitors due to shortages of units with alarms.
(Mainichi Japan) April 10, 2011
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