大成建設
Prior to the accident, the maximum permissible dose for Japanese nuclear workers was 100 mSv in any one year, but on 15 March 2011, the Japanese Health and Labor Ministry enforced the permitted 250 mSv limit, in light of the situation at the Fukushima Nuclear Power Plant. However, the workers at Fukushima plant declined the elevated 250 mSv limit and kept adopting the previous 100 mSv. Tokyo Enesys, a TEPCO's subsidiary, adopts 80 mSv to manage the radiation level monitoring with some buffer. Kandenko, Kajima and Taisei Corporation adopted 100 mSv. Hitachi rewrote internal rule as 200 mSv. TEPCO decided to move workers around 200mSv to low-radiated site while its subsidiaries, Tokyo Enesys and Kandenko, adopted limits around 100mSv. Over 30 workers were radiated beyond 100 mSv by 23 April 2011.