5 workers exposed to radiation at Japan nuclear lab - Sensationalist Headlines

[t]https://storage.googleapis.com/afs-prod/media/media:b1606830a2ad4ee1a4f6029d21a319cc/800.jpeg[/t] [QUOTE]TOKYO (AP) — Five workers at a Japanese nuclear facility that handles plutonium have been exposed to high levels of radiation after a bag containing highly radioactive material apparently broke during equipment inspection, the country’s Atomic Energy Agency said Wednesday. The incident occurred Tuesday at its Oarai Research & Development Center, a facility for nuclear fuel study that uses highly toxic plutonium. The cause of the accident is under investigation, the state-run agency said. It raised a nuclear security concern as well as a question whether the handlers were adequately protected. The agency said its initial survey found contamination inside the nostrils of three of the five men — a sign they inhaled radioactive dust. All five were also found to be contaminated on their limbs after removing protective gear and taking a shower, which would have washed off most contamination. Agency spokesman Masataka Tanimoto said one of the men indicated high levels of plutonium exposure in his lungs, with the dose showing nearly 1,000 times that of his earlier nostril survey. Internal exposure poses a bigger concern because of its potential cancer-causing risks. The figure, 22,000 Becquerels, could mean exposure levels in the lungs may not be immediately life-threatening. Nuclear Regulation Authority Chairman Shunichi Tanaka blamed work routine complacency as a possible cause. The Oarai workers did not have any visible signs of health problems, Tanimoto said. They were taken to a special radiation medical institute for further checks.[/QUOTE] [url]https://apnews.com/c64b3cff716845f297369ca213f68192[/url]

see if this is another case of not keeping things to a strict safety standard and it then gets used as another reason why "Nuclear isn't safe"... eugh.

22 kBq is fuck all. The only reason this is even notable is that Japanese radiation limits are retardedly low and the media loves to milk and radiation story for all it's worth. For comparison the average Potassium-40 in the human body emits about 5 kBq of radiation, a smoke detector contains about 50 kBq of Americium-241, and the maximum permitted level of tritium in drinking water in Canada is 7 kBq.

22000 Bq isn't a very significant amount of activity but the inhalation of plutonium dust may be an issue. Plutonium isotopes tend to decay by spontenous fission and alpha emission and those are rather nasty to get inside. I would guess that there are no acute (short term) effects but there may be an increased risk of problems later on in life (stochastic)

So can the plutonium be washed out safely or something?

Plutonium is only dangerous if ingested. You can handle raw plutonium no problem. This is the result of an overabundance of caution.

[QUOTE=RIPBILLYMAYS;52322924]22000 Bq isn't a very significant amount of activity but the inhalation of plutonium dust may be an issue. Plutonium isotopes tend to decay by spontenous fission and alpha emission and those are rather nasty to get inside. I would guess that there are no acute (short term) effects but there may be an increased risk of problems later on in life (stochastic)[/QUOTE] Another problem is that plutonium is a bone seeking isotope much like Strontium 90, hopefully their flushed quickly which should mitigate any current damage and lessen long term risk such as bone/lung cancer.

[QUOTE=download;52322822]22 kBq is fuck all. The only reason this is even notable is that Japanese radiation limits are retardedly low and the media loves to milk and radiation story for all it's worth. For comparison the average Potassium-40 in the human body emits about 5 kBq of radiation, a smoke detector contains about 50 kBq of Americium-241, and the maximum permitted level of tritium in drinking water in Canada is 7 kBq.[/QUOTE] 22 kBq of Pu-239 produces a committed dose of about 3000 mSv when inhaled. They won't get radiation poisoning, but they will probably get lung cancer.

[QUOTE=Headhumpy;52323012]22 kBq of Pu-239 produces a committed dose of about 3000 mSv when inhaled. They won't get radiation poisoning, but they will probably get lung cancer.[/QUOTE] Not sure how you made that determination. Assuming a heavy metal that's not excreted, to convert Becquerels to Sieverts you'd need to know how long the person is going to live for. You could calculate how much the person will be exposed to each year from the inhaled dose. I would like to know your calculations. Also, even using the horrible flawed LNT model, 1000 mSv equates to a 5.5% cancer risk. 3000 mSv and a 16.5% cancer risk is not "probably".

[QUOTE=Headhumpy;52323012]22 kBq of Pu-239 produces a committed dose of about 3000 mSv when inhaled. They won't get radiation poisoning, but they will probably get lung cancer.[/QUOTE] There is no way that they could get 3Sv of dosage, that's typically a near fatal dose. (In a short timespan of a few hours) We'll make some assumptions, assuming that they were exposed to pure Pu-239 @ 22kBq (The article was vague beyond MOX & U/Pu). [URL="https://en.wikipedia.org/wiki/Becquerel#Calculation_of_radioactivity"]22kBq = (m / (239AMU)) * Avagadro's Const * (ln(2) / Pu-239_HalfLife_In_Seconds)[/URL] m = 9.5micrograms That small amount coupled with the relatively long half life of Pu-239 comes nowhere close to 3Sv in dosage. Maybe a few tens of mSv/yr at worst. So no radiation sickness, small increase (<1%) in cancer risk, and probably limited work leave (Assuming Japan has the same yearly limit on radiation workers).

My earlier value of 3 Sv was based on a kBq to mSv conversion factor I got from a 5 second Google search. Assuming the Pu-239 gets uniformly distributed throughout the body (which it isn't, because absorption through the lungs is very slow), and not accounting for decay of daughter nuclei or decrease in amount of Pu-239 (half life of Pu-239 is 24,000 years so it's a reasonable approximation), 22 kBq of Pu-239 produces an absorbed dose of 0.4 Gy over 50 years in a 70 kg human: 22,000 decay/s * 31,536,000 s/yr * 50 yr * 5.245 MeV/decay * 1.60218e-13 J/MeV / 70 kg = 0.416 J/Kg Using the conversion factor of 20 for alpha particles, this results in a total committed dose of 8 Sv. I'll admit this is a very back-of-the-envelope calculation but I think it's reasonable to say that the dose of radiation they're receiving isn't "fuck all" as download said earlier.

[QUOTE=Headhumpy;52323207]My earlier value of 3 Sv was based on a kBq to mSv conversion factor I got from a 5 second Google search. Assuming the Pu-239 gets uniformly distributed throughout the body (which it isn't, because absorption through the lungs is very slow), and not accounting for decay of daughter nuclei or decrease in amount of Pu-239 (half life of Pu-239 is 24,000 years so it's a reasonable approximation), 22 kBq of Pu-239 produces an absorbed dose of 0.4 Gy over 50 years in a 70 kg human: 22,000 decay/s * 31,536,000 s/yr * 50 yr * 5.245 MeV/decay * 1.60218e-13 J/MeV / 70 kg = 0.416 J/Kg Using the conversion factor of 20 for alpha particles, this results in a total committed dose of 8 Sv. I'll admit this is a very back-of-the-envelope calculation but I think it's reasonable to say that the dose of radiation they're receiving isn't "fuck all" as download said earlier.[/QUOTE] I don't know how you can say that. Although I will admit that the possibility of a resonance cascade scenario is extremely unlikely.

[QUOTE=Headhumpy;52323207]My earlier value of 3 Sv was based on a kBq to mSv conversion factor I got from a 5 second Google search. Assuming the Pu-239 gets uniformly distributed throughout the body (which it isn't, because absorption through the lungs is very slow), and not accounting for decay of daughter nuclei or decrease in amount of Pu-239 (half life of Pu-239 is 24,000 years so it's a reasonable approximation), 22 kBq of Pu-239 produces an absorbed dose of 0.4 Gy over 50 years in a 70 kg human: 22,000 decay/s * 31,536,000 s/yr * 50 yr * 5.245 MeV/decay * 1.60218e-13 J/MeV / 70 kg = 0.416 J/Kg Using the conversion factor of 20 for alpha particles, this results in a total committed dose of 8 Sv. I'll admit this is a very back-of-the-envelope calculation but I think it's reasonable to say that the dose of radiation they're receiving isn't "fuck all" as download said earlier.[/QUOTE] Ah see you didn't mention the timespan the dose would be over, again assuming that the same activity/amount of Pu-239 somehow stays in their bodies over that 50 year period, that totals to 160mSv/year [URL="https://xkcd.com/radiation/"]which does have a clear correlated increase in cancer risk.[/URL]

[QUOTE=NassimO PotatO;52323291]I don't know how you can say that. Although I will admit that the possibility of a resonance cascade scenario is extremely unlikely.[/QUOTE] Gordon doesn't need to hear all this he's a HIGHLY TRAINED PROFESSIONAL

[QUOTE=Kylel999;52323804]Gordon doesn't need to hear all this he's a HIGHLY TRAINED PROFESSIONAL[/QUOTE] Ah yes, you're right. Headhumpy, we have complete confidence in you

[QUOTE=Headhumpy;52323207]My earlier value of 3 Sv was based on a kBq to mSv conversion factor I got from a 5 second Google search. Assuming the Pu-239 gets uniformly distributed throughout the body (which it isn't, because absorption through the lungs is very slow), and not accounting for decay of daughter nuclei or decrease in amount of Pu-239 (half life of Pu-239 is 24,000 years so it's a reasonable approximation), 22 kBq of Pu-239 produces an absorbed dose of 0.4 Gy over 50 years in a 70 kg human: 22,000 decay/s * 31,536,000 s/yr * 50 yr * 5.245 MeV/decay * 1.60218e-13 J/MeV / 70 kg = 0.416 J/Kg Using the conversion factor of 20 for alpha particles, this results in a total committed dose of 8 Sv. I'll admit this is a very back-of-the-envelope calculation but I think it's reasonable to say that the dose of radiation they're receiving isn't "fuck all" as download said earlier.[/QUOTE] There's a very big difference between a dose received over a lifetime and a dose received in an instant. [editline]8th June 2017[/editline] I'm not sure why a conversion factor would be needed either. The whole reason alpha and beta particles are more damaging per particle is that they have more energy, something you've already factored into your equation.

[QUOTE=download;52325514]There's a very big difference between a dose received over a lifetime and a dose received in an instant. [editline]8th June 2017[/editline] I'm not sure why a conversion factor would be needed either. The whole reason alpha and beta particles are more damaging per particle is that they have more energy, something you've already factored into your equation.[/QUOTE] Definitely, an acute dose of 8 Sv will almost certainly result in radiation sickness, if not death. The point of my argument was to say that the 22 kBq of Pu in their lungs is not negligible as you initially said, although saying that they would 'probably' get lung cancer was a poor argument on my part as well, since it's more like 'they will have an increased risk of getting lung cancer'. And not really. It's well-known that for the same absorbed dose, alpha particles are more damaging to biological tissue than beta particles or gamma rays. Gamma rays are slowly attenuated and so cause ionisations over a larger area. Alpha particles travel a few dozen micrometres before being stopped, so all of their energy is deposited in a small area.

Yes, the media was going apeshit over this, as usual, even though it is completely overblown, as mentioned earlier in this thread. Unfortunately, because of things like this, at this rate I do not think the majority of Japanese people will ever believe in nuclear energy as a viable and safe source. As I have said before... ignorant.