Fukushima Nuclear Power Station: Radioactive contamination spreading daily Concerns about damage to health due to radiation exposure Nuke Info Tokyo No. 145


Workers boarding bus to Fukushima Nuclear Power Station from J-Village bus station (Photo released by TEPCO)

Damage from radioactivity released from the Fukushima Daiichi Nuclear Power Station is spreading and there are no signs of the situation being brought under control. The Japanese Government is responding by relaxing radiation safety standards and trying to force people to continue to live in affected areas by claiming that these areas are safe.
However, radioactive contamination is spreading day by day and radioactive substances are turning up in agricultural and fishery products. In addition to external radiation exposure, internal exposure through food also has a very great effect on human health. In the current situation, where the state of the reactors is not clear, we must assume that damage from radioactive contamination will continue to spread.

198.5 person-sieverts collective dose to workers from March 11 to the end of September
How much radiation must workers be exposed to before the situation is brought under control?

On October 31, Tokyo Electric Power Company (TEPCO) released dose figures for radiation exposure to workers involved in emergency work between March 11 and September 30. The figures are cumulative up to the end of September. Internal and external doses were added and broken down on the basis of the month in which the workers began emergency work. Only workers who received whole body counter measurements up to October 21 are included. People who worked at sites other than the Fukushima Daiichi Nuclear Power Station are not included.
Based on this document, the collective dose came to a huge 198.5 person-sieverts. Compare that to the total collective dose of 82.08 person-sieverts for all Japan’s nuclear power plants during the whole of the 2009 fiscal year. How much radiation must workers be exposed to before the situation is brought under control?

Table1; Total value of external and internal exposure levels of emergency workers at Fukushima Daiichi Nuclear Power Station between March 11 and September 30.

A March 15 ministerial ordinance raised the dose limit for workers in emergency situations from 100 mSv to 250 mSv. This led to a serious increase in effective radiation doses. The rules were changed again on April 28 so that workers could continue working after their radiation exposure had exceeded the annual limit of 50 mSv. It is also reported that there are people who have been made to work without dosimeters and that there are some workers of unknown identity among the workers participating in the operations at Fukushima Daiichi. Not only has the dose limit for workers been raised, but in the confusion of the nuclear accident it is undoubtedly true to say that the radiation dose management has become sloppy and workers have been exposed to excessive doses of radiation.
On September 5 the Ministry for Economy Trade and Industry’s Nuclear Industrial Safety Agency (NISA) released its 2010 Fiscal Year (April 2010 to March 2011) report on radiation exposure incurred by people working at nuclear power facilities. The Japanese report (“Concerning the status of radioactive waste management at nuclear power facilities and radiation dose management of radiation workers”) is available at the following link: www.nsc.go.jp/anzen/shidai/genan2011/genan067/siryo5.pdf
The crucial columns for TEPCO’s Fukushima Daiichi and Daini Nuclear Power Stations are left blank. The government said, “At present, the company is still carrying out its assessment. When [the data] is submitted we will collate it and issue a report”
In this inadequate report the highest dose was 19.6 mSv for a subcontractor worker at Tsuruga, while the highest dose for a power company employee was 13.1 mSv at Mihama. Units 1 of both the Tsuruga Nuclear Power Station and the Mihama Nuclear Power Station have been operating for over 40 years. There are serious problems with the operation of these nuclear power stations, so naturally worker exposure has increased.

Negotiations with the bureaucracy concerning problems of radiation workers
Along with the Japan Occupational Safety and Health Resource Center, Campaign Against Radiation Exposure and other NPOs, Citizens’ Nuclear Information Center has held negotiations with relevant government agencies at a rate of about once a month.

The negotiations have covered the following issues:

1. A request for clarification of the basis for raising the emergency dose limit for workers from 100 mSv to 250 mSv;
2. A request for clarification of the basis for allowing workers to continue working after exceeding the annual dose limit of 50 mSv;
3. A request for clarification of the criteria for “emergency work”;
4. A request for publication of documents related to discussions between the Ministry of Health Labour and Welfare (MHLW) and NISA;
5. A rejection of the government’s relaxation of the dose limit for workers engaged in emergency work. The dose limit should not be raised simply as a means of making workers deal with the nuclear accident;
6. If the danger from the nuclear earthquake disaster is unprecedented, all nuclear power plants in Japan should be closed down and priority given to bringing the current disaster under control. To that end, the necessary experienced workers should be sent to work at the Fukushima Daiichi Nuclear Power Station.
Our negotiations have had some successes. As a result of freedom of information requests, documents have gradually been released. We also were able to expose the circumstances behind the raising of the emergency work dose limit to 250 mSv. Aiming for the removal of the individual dose limit that had existed prior to the Fukushima Daiichi nuclear accident, NISA deliberately over-estimated the number of workers required for emergency work (to make it look as if there were insufficient numbers of workers to do the work) and demanded that MHLW compromise.

We are currently demanding the following:

1. Application of a 100 mSv dose limit for all workers engaged in emergency work;
2. Adherence to the limit of 50 mSv in a single year and 100 mSv over five years under the Ordinance on Prevention of Ionizing Radiation Hazards;
3. Publication of the data that forms the basis for calculations by TEPCO, Hitachi and Toshiba of the number of emergency workers required until completion of stage 2 of TEPCO’s roadmap, as well as the data that forms the basis for calculations of worker radiation doses.
Radiation work at sites other than Fukushima Daiichi Nuclear Power Station
Due to the fact that large quantities of radioactive material have spread over a wide area, high concentrations of radioactivity have been detected in sludge and ash from sewerage treatment facilities and incinerators. During negotiations with the government about radiation exposure issues for workers working at these facilities, we demanded application of the Ordinance on Prevention of Ionizing Radiation Hazards, specification of radiation control zones, and assignment of officers responsible for radiation control. MHLW responded that it would draft a second ordinance on ionizing radiation and is aiming for it to come into effect on January 1, 2012.

Mikiko Watanabe (CNIC)

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