Officials of the Health, Labor and Welfare Ministry will search for lead plates that workers at the crippled Fukushima No. 1 nuclear power plant used to shield their dosimeters and later discarded on the plant grounds.
Officials of the Health, Labor and Welfare Ministry will search for lead plates that workers at the crippled Fukushima No. 1 nuclear power plant used to shield their dosimeters and later discarded on the plant grounds.
The lead plates were used to keep radiation dose readings low enough to not trigger an alarm so the workers could continue with their tasks.
A 54-year-old senior official with the Fukushima-based construction company Build-Up ordered the workers to dispose of the lead plates on the grounds to cover up their use.
Health ministry officials will search for those plates to determine what effect they had in disguising the actual level of radiation exposure for the Build-Up workers. If found, they could be evidence of a violation of the Industrial Safety and Health Law.
According to an explanation given to Takashi Wada, the Build-Up president, on July 21 by the senior official, the official went to a hilly area near the No. 1 reactor of the Fukushima No. 1 plant last November to plan for the work expected of the company workers. At that time, the alarms on the dosimeters that indicated high levels of radiation were being triggered, surprising the senior official. The official decided to cover the dosimeters with lead plates when the workers were actually doing their work.
Nine workers used the lead plates for about three hours to transport materials into the Fukushima No. 1 plant grounds.
According to one of those workers, because the radiation level was not as high as expected, the workers decided to stop using their lead plates to cover their dosimeters after using them only once. They concealed the used lead plates in the car that was brought onto plant grounds for the exclusive use of Build-Up workers.
When the senior official realized what the workers had done, he instructed them to discard the lead plates on the plant grounds because major problems would emerge if they were found hidden in the car.
In response to questions by The Asahi Shimbun, the worker said, "We threw the plates away in grassy areas within the plant grounds. We thought it would be difficult to find because radiation levels were high there."
The senior official initially denied any involvement, including giving instructions to cover the dosimeters with lead plates.
However, on July 21, the official admitted to Wada that the lead plates were used on one occasion and that the used lead plates were discarded at a waste disposal area within the grounds.
Health ministry officials began searching the Fukushima No. 1 nuclear plant on July 21 for alleged violations of the Industrial Safety and Health Law as well as looking into documents related to radiation records for Build-Up workers. The officials will look into the extent of covering up radiation doses for workers at the Fukushima plant.
The Asahi Shimbun has found that the senior official instructed the workers to make the lead plates on Nov. 30, a day before they were to enter the plant to wind insulation around hoses of a treatment system for radioactive water near the No. 1, No. 2, No. 3 and No. 4 reactor buildings.
Of the 12 workers who were initially given the instructions, three refused to cover their dosimeters and they were removed from the team. Of the nine who actually went in to do the work, there was disagreement about whether or not they actually used the lead plates, so it is not clear how many workers actually used the shields.
An official with Tokyo Energy & Systems Inc., which subcontracted the work out to Build-Up, said about the admission by the senior official about using lead shields, "We cannot comment until we receive the results of an in-depth investigation by Build-Up."
An official with Tokyo Electric Power Co., the plant operator, said, "We will make a response after receiving a report from Tokyo Energy & Systems."
(This article was written by Jun Sato and Miki Aoki.)