The Mainichi Daily News reported today:
The Ministry of Economy, Trade and Industry estimated that approximately 1,600 workers partaking in efforts to rein in the disaster at the Fukushima No. 1 Nuclear Power Plant will be exposed to over 50 millisieverts of radiation, according to a document that emerged July 26 after a citizens’ group lodged a request for access to government information.
The 50 millisieverts standard is set by the Japanese government. The report also indicates that many workers far exceeded that standard:
The law stipulates that the maximum level of radiation exposure that radiation workers are permitted per year in normal times is 50 millisieverts. According to the operator of the stricken power plant, Tokyo Electric Power Co. (TEPCO), as of July 13, six company employees had been exposed to over 250 millisieverts of radiation — the amount permitted for workers in emergency situations.