Tokyo Electric Power Co. failed to submit radiation dose data to an industry database, compromising the health of 21,000 people who worked at the Fukushima No. 1 nuclear plant after the March 2011 disaster.
The development shows that Tokyo Electric Power Co. remains lax about protecting the safety of workers, many of whom are employed by subcontractors. It also underscores flaws in the private records system to prevent nuclear plant workers from being exposed to dangerous accumulated doses.
A big problem is that many nuclear plant workers often switch companies—including unscrupulous ones--and they can be exposed to more radiation than legally allowed unless the dose data are kept at a centralized database.
The Ministry of Health, Labor and Welfare has repeatedly told TEPCO to submit the dose data of the 21,000 people to the Central Registration Center of Radiation Workers, operated by the Radiation Effects Association, a public-interest corporation that manages dose data of nuclear plant workers in an integrated manner.
The workers were at the Fukushima plant between March 11, 2011, the day the plant was destroyed by the Great East Japan Earthquake and subsequent tsunami, and March 31, 2012, or the end of fiscal 2011.
More than 80 percent of those workers, or 17,600, were from other companies, including subcontractors.
TEPCO on Feb. 18 agreed with the Radiation Effects Association to submit workers’ accumulated data for fiscal 2010 and 2011 by the end of March. The provisional data will be replaced when full-fledged records, including the names of employers and other details, are ready.
“We are extremely sorry for the delay,” a TEPCO spokesman said.
The company has said it took several months before data were retrieved from a computer system damaged by the tsunami. After the disaster, records were initially kept on paper, and it took time to convert them into electronic form.
In May or June each year, electric power companies submit dose data for the previous fiscal year to the center.
Around June 2011, TEPCO said the submission of data for fiscal 2010 would be delayed, and it also did not provide data for fiscal 2011. Records for fiscal 2010, excluding the post-disaster period, were submitted around July 2012.
Electric power companies, primary contractors and subcontractors are legally required to measure doses of nuclear plant workers and keep them under 50 millisieverts a year and 100 millisieverts over five years.
Many primary contractors set 20 millisieverts as the annual ceiling.
Of the 25,000 people who worked at the Fukushima No. 1 plant between March 11, 2011, and Dec. 31, 2012, more than 4,800 were exposed to an excess of 20 millisieverts a year, compared with seven for all of Japan in fiscal 2009.
The average among 76,000 nuclear plant workers across the country that year was 1.1 millisieverts.
Electric power companies have said data management in an integrated manner is not essential. They argue that they can check information in radiation management records--a dose record book kept by individual workers--when new workers arrive at their nuclear plants.
The companies say they make inquiries to the central registration center only when they need to confirm entries in the record books. The center receives 60,000 to 90,000 inquires a year.
However, workers themselves say dose data cannot be strictly managed by radiation management records alone.
Primary contractors or subcontractors enter data into the record books. But some do not comply with laws and regulations.
One subcontractor had workers cover dosimeters with lead plates at the Fukushima No. 1 plant to keep readings low so that they could continue working at nuclear facilities. Other lax practices about dose management have been uncovered.
A man in his 40s who left the Fukushima No. 1 plant more than a year ago said accurate dose data have not been written into his radiation management record.
The worker was illegally sent there as an employee of a company he does not know well. Moreover, a different company’s name is listed in his record book.
The worker could be exposed to more radiation than legally allowed if he continues to work at nuclear plants with his dose data being left uncorrected.
The Radiation Effects Association says both the system based on the central registration center and radiation management records are essential to manage dose data accurately.
The record book usually includes the latest data available for the worker, but the figures may be revised later. Some workers even lose the record book.
The central registration center, on the other hand, keeps closely examined data, but they are updated only once a year.
The dose data management system including the central registration center was established in 1977 with financial support from the government.
But it is a private-sector framework based on contracts between electric power companies and the Radiation Effects Association. The utilities and other parties are paying 275 million yen ($3 million) to administer the system in fiscal 2012.
It remains unclear whether the utilities, or layers of contractors involved in the nuclear power industry, are responsible for managing workers’ dose data and protecting their safety.
The government is not directly responsible, although the science ministry, the health ministry, the Nuclear Regulation Authority’s secretariat and other branches are involved.
“No ministry or agency is expected to take the lead because the health of individuals is at stake and the responsibility is heavy,” a government official said.
The momentum for change could come from politicians.
Some lawmakers, led by those in the Liberal Democratic Party and New Komeito, submitted a bill to establish a state management system in August, when the two parties were in the opposition camp.
Under the bill, utilities would be required to enter dose data into a government-issued record book and the government would collect and manage the data in an integrated manner.
The bill was scrapped when the Lower House was dissolved in November for a snap election. But some politicians plan to submit the bill to the Diet again.
(This article was written by Jun Sato and Toshio Tada.)
- « Prev
- Next »