nuclear-news

Radiation exposure to Fukushima workers and the community

Fukushima today: A first-person account from the field and the conference table, Bulletin of the Atomic Scientists, 26 Aug 15  Subrata Ghoshroy “……….the building containing the failed reactors has radiation levels as high as 4,000 to 5,000 milliSieverts per hour (400,000 to 500,000 millirems per hour), making even the operation of robots difficult. In fact, two power company robots had to be abandoned while inside the depths of the plant. And some spots, such as inside the primary containment vessel, went as high as 9.7 Sieverts per hour (970,000 millirems per hour). In addition, it has not been possible to precisely locate the melted core. (Another conference speaker, Jun Tateno, who was a former research scientist with the Japanese Atomic Energy Research Institute, accused the government of suppressing voices from the scientific community that were critical of the safety of power plants. He said that we have reached a situation in which we do not even know how much plutonium is in the core.) In the meantime, huge amounts of water must be pumped in to keep the reactors cool; this liquid then mixes with ground water, contaminating it as a result.

The picture is not much better when it comes to the land. In an effort to decontaminate residential areas, radioactive soil is being dug up from approximately 1,000 sites. The government wants to consolidate this contaminated material in semi-permanent storage sites in the “difficult-to-return zones” in Futaba and Okuma towns. Local residents, meanwhile, fear that these could turn into permanent repositories of radioactive material……….

We were told that most workers did not wear dosimeters to record their cumulative radiation dose. There was good money to be made in decontamination work. They did not want to know.

But if one does the math, what the workers and their supervisors were ignoring—or were being told to ignore—could be significant. If a person spent one week working at this part of a supposedly safe parking area for 8 hours per day, then he or she would have been exposed to 40 microSieverts per day. And if that person was there for a 5-day workweek, then over the course of a single week that person would have been exposed to 200 microSieverts. In a year, that person could receive 10 milliSieverts, a significant dose. Of course, scientists are rightly cautious of such “anecdotal” evidence; our Geiger counter readings could have been off, or the machine calibrated incorrectly, or some other source of error introduced—though I doubt it because it had earlier read the background correctly. But the result of such quick and dirty, back-of-the-envelope calculations for what is supposedly a low-risk parking area, well away from the restricted hot zones, do give one pause—especially as the ongoing lack of dosimeters means that no one really knows a given individual’s cumulative dose. The amount of exposure to a thing that you cannot see, hear, smell, taste, or feel sneaks up on you. Even when you think you are safe, you are not.

If nothing else, the fact that a simple, random spot-check registered so highly is an eye-opener, and counter to what has been officially portrayed. ……..An important item seemed to lie further down in the article, which noted: “However, the health ministry said the number of workers surveyed is different from the total number of cleanup personnel reported by the Environment Ministry, which could mean the association failed to record radiation doses of all individuals working around the Fukushima plant.”

No wonder there has been public distrust and charges of a lack of clarity about the radiation clean-up operation, as can be seen in the title of a 2013 Guardian newspaper article: “Life as a Fukushima clean-up worker—radiation, exhaustion, public criticism.”Even when the approximately 7,000 workers involved in the clean-up do wear dosimeters, that is no guarantee of accuracy; there have been reports of a Tokyo Electric Power Company executive who tried to force clean-up workers to manipulate dosimeter readings to artificially low levels by covering their devices with lead shields………http://thebulletin.org/fukushima-today-first-person-account-field-and-conference-table8683#.Vd6Rj7YbwEs.twitter

August 28, 2015 - Posted by Christina Macpherson | employment, Fukushima 2015, Japan