4 Mars 2013
March 4, 2013
Radiation dose management for workers engaged in decontamination work near the Fukushima No. 1 Nuclear Power Plant has gone unchecked, it has been revealed, raising questions about the government's control of businesses supplying workers for the hazardous work.
The Radiation Effects Association (REA), a public interest corporation keeping track of individual radiation workers' exposure data, has not received any data on workers carrying out government-led decontamination work near the Fukushima plant, despite an agreement last year between the REA and the Ministry of the Environment that the workers' employers send the data to the association. The failure apparently came because the ministry's instructions to those employers were insufficient.
Under the Industrial Safety and Health Law, the employers of decontamination workers are obliged to keep track of the workers' exposure doses. However, there is no framework for such data to be collected and managed in an integrated manner. If a worker was engaged in decontamination work under multiple employers, that worker's exposure doses cannot be aggregated, allowing the possibility of the total dose topping the legal limit of 50 millisieverts a year or 100 millisieverts over five years.
In the case of nuclear plant workers, radiation doses of individual workers are managed under the industry's voluntary rules, called the "exposure doses registry management system." Under the system, the REA's center for registering workers' radiation doses produces and manages a database on those doses in a uniform manner. Employers of nuclear plant workers are supposed to record individual workers' exposure doses in radiation control handbooks, and the data is then sent to the REA's registration center by power companies.
In May last year, the Environment Ministry produced common contract forms to be used with general contractors and other companies that receive decontamination work orders. The forms clearly state that, as much as possible, contractors must have their workers obtain radiation control handbooks. The REA requested the ministry have contractors send their workers' exposure data to the REA's center on occasions such as when the workers leave their jobs, which the ministry agreed to. However, no such data has been received by the center to date.
An official with the ministry's decontamination work team defended its position, saying that the data transmission is left up to contractors and the REA, and that the ministry hasn't given detailed instructions to contractors. The REA, on the other hand, insisted that for uniform dose management, radiation control handbooks and dose data transmission are inseparable, adding that it has requested the ministry give detailed instructions to contractors.
Out of a total of 25 government-led decontamination projects in 10 municipalities in Fukushima Prefecture initiated in December 2011, 18 have thus far been completed. In three-month model decontamination projects in the prefectural town of Okuma in 2011 and 2012, at least one worker was exposed to 11.6 millisieverts of radiation -- nearly one-fourth of the annual legal limit.
"The government needs to accurately grasp radiation doses workers are exposed to during decontamination work. Otherwise, workers will suffer disadvantages when they apply for workers' accident compensation. If the current framework isn't working, the government should establish a new system," said Kazumitsu Nawata, professor at the University of Tokyo graduate school, who is specialized in the situation of radiation workers.