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Ibaraki 22k bqs in workers
22,000 becquerels measured in worker's lungs https://www3.nhk.or.jp/nhkworld/en/news/20170607_16/

The original article reported 24 bqs http://www.japantimes.co.jp/news/2017/06...Tf6tsm1ufd
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Majia and a French source both announced that JAEA has changed their determination about the five workers, saying no internal exposure occurred.

Majia: http://majiasblog.blogspot.com/2017/06/h...japan.html
Huh? Radiation Exposure Politics in Japan

"A couple of days ago I blogged about workers' exposure to Plutonium,the element of death in Japan. Now the Japan Atomic Energy Agency is reversing its previous announcement, saying that workers were not contaminated internally by plutonium after all:

Quote: JAEA, citing new test, says no plutonium in lungs of worker: THE ASAHI SHIMBUN June 10, 2017 at 18:30 JST http://www.asahi.com/ajw/articles/AJ201706100022.html

The Japan Atomic Energy Agency now insists that none of the five workers exposed to radiation in an accident at a research center in Ibaraki Prefecture several days ago has plutonium in their lungs.  The stunning about-face follows a statement June 7 that a worker in his 50s had internal exposure of 22,000 bequerels of plutonium during a medical check after the accident at the JAEA's Oarai Research and Development Center in Oarai... The JAEA said it now suspects the initial reading resulted from the fact that plutonium was detected on the man's skin prior to him undergoing proper decontamination....

I recall that a similar reversal in the wake of 3/11 when residents and workers were found free of internal exposure after previous reports alleging the opposite.

Of course, as the article points out, it is difficult to detect plutonium atoms that have been inhaled or ingested."

Google Translated: http://fukushima.eu.org/contamination-au...s-poumons/

Plutonium contamination of personnel in a nuclear research center: nothing in the lungs!

Published on
 10 June 2017

"The explosion of a plastic bag containing nuclear fuel powder resulted in the contamination of 5 people at a nuclear research center in Japan. The Japan Atomic Energy Agency (JAEA) had announced a lung contamination of up to 22 000 Bq for plutonium-239 alone ( see our article on this subject ), resulting in a very high dose given the high toxicity of plutonium.

These five people were sent to the National Institute of Radiological Sciences (NIRS), a center specializing in Chiba province, where they underwent further decontamination and controls. They are still under surveillance.

According to the Asahi , the JAEA now claims that no lung contamination has been detected in these five people! It is based on controls carried out at NIRS. The first very high values would be due to contamination of the skin measured after partial decontamination. And it is by mistake that this contamination has been localized in the lungs.

On arrival at the NIRS, one of the employees still had skin contamination and had to be decontaminated again.

These new results do not exclude internal contamination, but indicate that it must be much lower than originally reported.

Recall that the JAEA was deemed unfit to operate the breeder reactor Monju because of a lack of safety culture. The events that led to the exposure of his 5 employees (described in another article ) confirm this diagnosis. It is also known that the JAEA is not prepared to deal with an incident and to assess the internal contamination of its personnel."
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Union of Concerned Scientists' Ed Lyman discusses worker exposure and implications.

Increase in Cancer Risk for Japanese Workers Accidentally Exposed to Plutonium http://www.allthingsnuclear.org/elyman/c...-plutonium

"According to news reports, five workers were accidentally exposed to high levels of radiation at the Oarai nuclear research and development center in Tokai-mura, Japan on June 6th. The Japan Atomic Energy Agency, the operator of the facility, reported that five workers inhaled plutonium and americium that was released from a storage container that the workers had opened. The radioactive materials were contained in two plastic bags, but they had apparently ripped.
We wish to express our sympathy for the victims of this accident.
This incident is a reminder of the extremely hazardous nature of these materials, especially when they are inhaled, and illustrates why they require such stringent procedures when they are stored and processed.

According to the earliest reports, it was estimated that one worker had inhaled 22,000 becquerels (Bq) of plutonium-239, and 220 Bq of americium-241. (One becquerel of a radioactive substance undergoes one radioactive decay per second.) The others inhaled between 2,200 and 14,000 Bq of plutonium-239 and quantities of americium-241 similar to that of the first worker.

More recent reports have stated that the amount of plutonium inhaled by the most highly exposed worker is now estimated to be 360,000 Bq, and that the 22,000 Bq measurement in the lungs was made 10 hours after the event occurred. Apparently, the plutonium that remains in the body decreases rapidly during the first hours after exposure, as a fraction of the quantity initially inhaled is expelled through respiration. But there are large uncertainties.

The mass equivalent of 360,000 Bq of Pu-239 is about 150 micrograms. It is commonly heard that plutonium is so radiotoxic that inhaling only one microgram will cause cancer with essentially one hundred percent certainty. This is not far off the mark for certain isotopes of plutonium, like Pu-238, but Pu-239 decays more slowly, so it is less toxic per gram.  The actual level of harm also depends on a number of other factors. Estimating the health impacts of these exposures in the absence of more information is tricky, because those impacts depend on the exact composition of the radioactive materials, their chemical forms, and the sizes of the particles that were inhaled. Smaller particles become more deeply lodged in the lungs and are harder to clear by coughing. And more soluble compounds will dissolve more readily in the bloodstream and be transported from the lungs to other organs, resulting in exposure of more of the body to radiation. However, it is possible to make a rough estimate.

Using Department of Energy data, the inhalation of 360,000 Bq of Pu-239 would result in a whole-body radiation dose to an average adult over a 50-year period between 580 rem and nearly 4300 rem, depending on the solubility of the compounds inhaled. The material was most likely an oxide, which is relatively insoluble, corresponding to the lower bound of the estimate. But without further information on the material form, the best estimate would be around 1800 rem.

What is the health impact of such a dose? For isotopes such as plutonium-239 or americium-241, which emit relatively large, heavy charged particles known as alpha particles, there is a high likelihood that a dose of around 1000 rem will cause a fatal cancer. This is well below the radiation dose that the most highly exposed worker will receive over a 50-year period. This shows how costly a mistake can be when working with plutonium.
The workers are receiving chelation therapy to try to remove some plutonium from their bloodstream. However, the effectiveness of this therapy is limited at best, especially for insoluble forms, like oxides, that tend to be retained in the lungs.

The workers were exposed when they opened up an old storage can that held materials related to production of fuel from fast reactors. The plutonium facilities at Tokai-mura have been used to produce plutonium-uranium mixed-oxide (MOX) fuel for experimental test reactors, including the Joyo fast reactor, as well as the now-shutdown Monju fast reactor. Americium-241 was present as the result of the decay of the isotope plutonium-241.
I had the opportunity to tour some of these facilities about twenty years ago. MOX fuel fabrication at these facilities was primarily done in gloveboxes through manual means, and we were able to stand next to gloveboxes containing MOX pellets. The gloveboxes represented the only barrier between us and the plutonium they contained. In light of the incident this week, that is a sobering memory."
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It was bound to happen.

Traces of plutonium in workers' urine https://www3.nhk.or.jp/nhkworld/en/news/20170619_27/


"On Monday, the institute said checks of the 5 workers' urine later revealed extremely small amounts of plutonium and other radioactive materials.

It says the workers have so far suffered no damage to their health, but that they have reentered hospital to take medicines that will purge the plutonium from their bodies. They will take the drug for 5 days, after which doctors will decide if further medication is necessary.

An official related to the institute says the radioactive materials in the workers' bodies are at levels that will not immediately affect their health."
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