Ministry of Health, Labour and Welfare

Ministry of Health, Labour and Welfare

In Focus: Radiation Protection at Works Relating to TEPCO's Fukushima Daiichi Nuclear Power Plant Accident

To:
Directors
Prefectural Labour Bureau
From:
Director
Labour Standards Bureau
Ministry of Health, Labour and Welfare (official seal imprint)
28 April 2011
Labour Standards Bureau Notification
No.0428-1

Re: Guidance about the radiation exposure dose during later radiation works other than emergency works for the workers who had been engaged in emergency works

The Ministerial ordinance on exemption of the Ordinance on Prevention of Ionizing Radiation Hazards in response to the situation resulting from the Tohoku-Pacific Ocean Earthquake in 2011 raised the upper radiation exposure dose limit during emergency works from 100mSv to 250mSv only for the particularly unavoidable emergency case at the Fukushima Daiichi Nuclear Power Plant and the detailed provisions were specified in item No.2 in the Note of the Labour Standards Bureau Notification No.0315-7 (15 March 2011) in accordance with Article 1 “Basic Principles” of the Ordinance on Prevention of Ionizing Radiation Hazards. Guidance about the radiation exposure dose during later radiation works other than emergency works for the workers who had been engaged in emergency works at the Fukushima Daiichi Nuclear Power Plant is shown below and careful attention should be paid to it.

Notes
  1. For the workers who received the cumulative dose equal to or less than 100 mSv during the time when they had been engaged in the particularly unavoidable emergency case at the Fukushima Daiichi Nuclear Power Plant, instructions should be provided to ensure that radiation exposure when they are engaged in later radiation works other than the emergency works will be controlled so that their individual cumulative radiation exposure dose does not exceed 100 mSv for a time period of five years including the period when they were engaged in emergency works at the Fukushima Daiichi Nuclear Power Plant.
     
    It should be noted that this applies only to the total radiation exposure dose of individual workers including exposure during the particularly unavoidable emergency works at the Fukushima Daiichi Nuclear Power Plant. So for the ordinary radiation works other than emergency works, the radiation exposure dose exceeding 50 mSv corresponds to violation of the law in a conventional manner.
     
  2. For the workers who received the cumulative radiation exposure dose exceeding 100 mSv during the time when they had been engaged in the particularly unavoidable emergency case at the Fukushima Daiichi Nuclear Power Plant, instructions should be provided not to have additional radiation exposure when they are engaged in later radiation works other than emergency works for the residual period of the five years including the period when they were engaged in the emergency works at the Fukushima Daiichi Nuclear Power Plant.