Japan Fukushima nuclear thread

[Busa_Rush]

llewop said:

so I'm quite fine thank you.

is that Chernobyl now ? You have a fascinating job

[llewop]

Busa_Rush said:

is that Chernobyl now ? You have a fascinating job

Now-ish - not sure exactly when that picture was taken, I just found a decent recent piccie on the web. It's from close to the visitor centre and viewing platform and certainly within the last 5 years, but not within the last couple of months as there is actually a new stack 'behind' the old one that has just been put up (different project).

[llewop]

Globs said:

As for the level, 30,000 Bq/m2 is way too hot for me. That's 30,000 events per second, if you were to eat vegetables grown on that ground you'd be ingesting over time tens of thousands of particles that when they decay are capable of causing cancers.

Unfortunately that's too simplistic a way of looking at it. Okay, I accept that the Caesium isn't natural so a non-voluntary risk, which seems to be part of the issue from the way you're phrasing things. But the same could be said for the various emissions from fossil fuel stations (including radioactive emissions) or a range of other risks or hazards we have little individual control over.

Anyway, to simplify, but not quite as sweepingly:

Take the 30,000 Bq/m2 of Cs-137 and consider exposure pathways - the easiest 2 to show what I'm trying explain is external dose, assuming someone were to stay there a year and consumption of food from the area.

Integrated external dose for a year would come to roughly 0.33 mSv for a year - so less than 1 microSievert per day - a typical european flight would probably be about 10 microSieverts for comparison. In terms of relocating residents or evacuation - that level of exposure wouldn't justify it (every counter-measure/action has costs and risk associated with it)

Eating the veg: CFILs: Council Food Intervention Levels - effectively the EU food ban level. The CFIL is actually Bq/kg in the food, but there is a value quoted in the stuff I'm looking at that shows a threshold deposit for exceeding the CFIL in Bq/m2. Which for Cs-137 is 4,200 Bq/m2. So, if it had happened in Europe, there would be be a food ban on veg from that area, but almost certainly not evacuation or relocation of the population.


The above is an over-simplification and there are likely to be other radioactive materials present, even if Cs-137 ends up being the decision driver as it tends to be one of the largest dose contributors, also the number we keep using is only for one location. If we were doing it properly we'd have a lot more data and information... in the UK at least, and treat each location on its merits. I can provide links to where I got the dose factors from if anyone wants. I could compare the surface contamination level with, for instance, whats permitted for shipping radioactive materials, even by air and actually the 30,000 Bq/m2 would be within the limit for beta/gamma emitters.

Unfortunately from the point of view of 'wow that's a big number' the Becquerel is very very small - our American friends (and older colleagues!) still love the Curie, since you have a much smaller number to get your head round. But as someone else chipped in with: different materials will emit different radiations and the relative risk of them can be quite telling when you start to consider things like limits of intake or things like that.

I 'just' do the safety side of things, so can't particularly comment on the goings on within the plant right now, since information seems difficult to get hold of - sadly Tepco seem to be consistent in their reluctance to admit to what is going on. I've seen recent dose data on the IAEA website which suggests that doses, so presumably dose rates, at the plant have significantly reduced, which suggests there is progress, although a good chunk of the reduced dose rates is going to be the short-lived stuff fading away.

[thinfourth2]

llewop said:

Now-ish - not sure exactly when that picture was taken, I just found a decent recent piccie on the web. It's from close to the visitor centre and viewing platform and certainly within the last 5 years, but not within the last couple of months as there is actually a new stack 'behind' the old one that has just been put up (different project).

The visitor center :rolf:

I bet hat sales are fantastic as most visitors will be leaving with an extra head

[rovermorris999]

thinfourth2 said:

The visitor center :rolf:

I bet hat sales are fantastic as most visitors will be leaving with an extra head

This sort of comment, while extremely original and witty, merely illustrates and reinforces the common misconceptions surrounding radioactivity.

Edited by rovermorris999 on Monday 12th December 18:43

[Mojocvh]

"Vladimir Chuprov, the head of the energy department of Russia’s Greenpeace:

The situation at the moment at Fukushima in Japan at whole is not stabilized. The dangerous radionuclides such as Cesium 137 ....


http://english.ruvr.ru/2011/12/13/62114355.html

[thinfourth2]

rovermorris999 said:

thinfourth2 said:

The visitor center :rolf:

I bet hat sales are fantastic as most visitors will be leaving with an extra head

This sort of comment, while extremely original and witty, merely illustrates and reinforces the common misconceptions surrounding radioactivity.

It also shows why we are screwed in the UK as think all the nuclear visitor centres have closed in the UK which is quite depressing

Also i do know that you don't grow an extra head because of radiation.

[Busa_Rush]

Mojocvh said:

"Vladimir Chuprov, the head of the energy department of Russia’s Greenpeace:

The situation at the moment at Fukushima in Japan at whole is not stabilized. The dangerous radionuclides such as Cesium 137 ....


http://english.ruvr.ru/2011/12/13/62114355.html

Unfortunately it's very sad that Greenpeace these days carry about as much authority as the typical Daily Mail reader could muster in a Philosophy lecture. Tending to zero.

Whilst there are some issues to be dealt with in Japan, Greenpeace are a group which specialises in propaganda and at the time of Chernobyl incident were telling the world there would be millions of deformed babies - hence why there were so many terminations at the time. (with the associated mental health issues) The number of deformed babies was no higher than had been expected for a poor, rural area of Ukraine in the 80's with limited healthcare, nutritional standards and education.

Greenpeace are still trying to stir the waters with propaganda and fear here: http://www.greenpeace.org/international/en/news/fe...

Their position is not upheld by any scientists of any credibility outside their own circle and their own staff (eg the W.H.O.) and many of the people they rely on for opinion also rely on Government money for their income . . . so if there's no problem the money will dry up . . . where have I heard that before ?

[hidetheelephants]

thinfourth2 said:

It also shows why we are screwed in the UK as think all the nuclear visitor centres have closed in the UK which is quite depressing

Also i do know that you don't grow an extra head because of radiation.

One of British Energy's first acts when they bought Scottish Nuclear was shutting the visitors centre at Hunterston(presumably they did the same at Torness) and get rid of the 3 part-time guides who had collectively been there for 35 years.

[hairykrishna]

hidetheelephants said:

thinfourth2 said:

It also shows why we are screwed in the UK as think all the nuclear visitor centres have closed in the UK which is quite depressing

Also i do know that you don't grow an extra head because of radiation.

One of British Energy's first acts when they bought Scottish Nuclear was shutting the visitors centre at Hunterston(presumably they did the same at Torness) and get rid of the 3 part-time guides who had collectively been there for 35 years.

As far as I'm aware they're all closed - even the big one at Sellafield. I think it's at least partly driven by the whole terrorism hysteria making it a ball ache to have people on site, even if they go nowhere sensitive. Last time we took a group to Sellafield they had to background check everyone before we showed up.

[thinfourth2]

hairykrishna said:

hidetheelephants said:

thinfourth2 said:

It also shows why we are screwed in the UK as think all the nuclear visitor centres have closed in the UK which is quite depressing

Also i do know that you don't grow an extra head because of radiation.

One of British Energy's first acts when they bought Scottish Nuclear was shutting the visitors centre at Hunterston(presumably they did the same at Torness) and get rid of the 3 part-time guides who had collectively been there for 35 years.

As far as I'm aware they're all closed - even the big one at Sellafield. I think it's at least partly driven by the whole terrorism hysteria making it a ball ache to have people on site, even if they go nowhere sensitive. Last time we took a group to Sellafield they had to background check everyone before we showed up.

I'm sick and tired of terrorism

[Globs]

hidetheelephants said:

One of British Energy's first acts when they bought Scottish Nuclear was shutting the visitors centre at Hunterston(presumably they did the same at Torness) and get rid of the 3 part-time guides who had collectively been there for 35 years.

Makes you wonder how much the bean counters 'saved' in the reactors...

llewop said:

Interesting stuff +

Unfortunately from the point of view of 'wow that's a big number' the Becquerel is very very small

It's true that a single decay is very very small, but also true that the decays do the damage. I suspect alpha is the most damaging and Cs137 is a beta source IIRC. So if you were contaminated with a 200mm x 200mm patch of ground from a 30k/m2 site for a while you'd get 0.2^2 * 30k = 1200 Bq. Now that's 1200 decays per second ingested (for this example), which is that stayed inside you for a week would give you 725,760,000 beta bombardments, which I think is quite a lot.

If you lived off that land for a year you'd be at 37,739,520,000 internal beta hits, so I guess the question is how much internal radiation can ones DNA take until something goes wrong?

[llewop]

Globs said:

so I guess the question is how much internal radiation can ones DNA take until something goes wrong?

You're right - alpha can cause more damage than beta; and you get beta and gamma with Cs-137

The answer to you DNA question; proven by the fact we live and have have evolved in a radioactive world is 'quite a lot'. You could equally count how many photons of cosmic radiation pass through you each day and ask if any one of those could be the one to initiate the event that becomes, many years later, a cancer. But most of the time, these decays and other (such as photons fromm cosmic or gamma radiation) have no noticable effect, either because they actually cause no particular effect or because the effect they have is not important - think for example that the DNA that is damaged is the bit that says your eyes are blue...but in a cell in your arm; not important.

Even though the concept of having radioactive materials inside yourself, especially ones that you didn't get a choice about because of some release or accident isn't an easy one to take. Evidence, statistics and data - back to those extremely educated guys - years of data and analysis tells us that the dose (which in effect is the representation of risk) per Bq can be quantified and the dose per unit intake Sv/Bq is generally a very small number. For Cs-137, inhaled, the accepted figure is 6.7 x10-9 Sv/Bq so 6.7 nanoSieverts for each Bq. Everyone in the UK gets something of the order of 2.7 mSv (2.7 10-3) per year from background radiation each year. If you eat a bag of brazil nuts you could be getting 10 x10-6 Sv (10 microSieverts), if you go to Cornwall or the USA your dose will probably go up (USA national average is higher than in the UK).

The last time I checked, my personal intake of Cs-137 was about 150 Bq, it seems quite 'stable' at that level even though it would naturally decrease if I left here - not from work on site, but from the local food (at below food ban levels). The DPUI (dose per unit intake) is slightly different for ingestion: 1.3 10-8 Sv/Bq. I expect my wife's average would be very similar, since she eats pretty much the same as me whilst we're here.

I guess I'm trying to put a sense of proportion on 'lots and lots of decay events' happening inside someone all the time. Compared to many other man-made hazards, radiation exposure is incredibly well monitored, measured and regulated. Exposure to other hazards and risks are often more difficult to quantify and regulate - I can remember trying to quantify exposure to asbestos many years ago, a damned sight more difficult!

[rovermorris999]

^^^ Nice to see some sense of proportion. The lack of understanding and the irrational responses in the media and the public generally is depressing. Is that the fault of scientists not explaining things well enough or do people not want to hear? It's the latter for the eco-left but what about Joe Average?

[supersingle]

rovermorris999 said:

^^^ Nice to see some sense of proportion. The lack of understanding and the irrational responses in the media and the public generally is depressing. Is that the fault of scientists not explaining things well enough or do people not want to hear? It's the latter for the eco-left but what about Joe Average?

Is radiation exposure incredibly well monitored, measured and regulated in Japan?

[hidetheelephants]

Globs said:

hidetheelephants said:

One of British Energy's first acts when they bought Scottish Nuclear was shutting the visitors centre at Hunterston(presumably they did the same at Torness) and get rid of the 3 part-time guides who had collectively been there for 35 years.

Makes you wonder how much the bean counters 'saved' in the reactors...

If the overmanning I witnessed at Hunterston was typical, 'not very much' would be the answer. Penny pinching operationally isn't worth the effort; if you get caught breaching the operating rules the fines are eyebleeding, and if it breaks down(as has happened at Hunterston and Torness with gas circulator problems recently) it costs hundreds of thousands every day it isn't generating.

[thinfourth2]

hidetheelephants said:

If the overmanning I witnessed at Hunterston was typical, .

I grew up just over the water from Hunterston and i enjoyed the visitor center before they shut it down.


I would of loved a more in depth tour

[llewop]

supersingle said:

Is radiation exposure incredibly well monitored, measured and regulated in Japan?

hmm... the one that perhaps could be questioned is regulation, but no particular evidence that there are shortfalls in monitoring, although the sharing of that data seems to leave a little to be desired!

Maybe there is something lacking there - the last nuclear accident to result in radiation related deaths was also in Japan - look up Tokaimura if you're interested - not a power station, a processing facility.

[rovermorris999]

supersingle said:

Is radiation exposure incredibly well monitored, measured and regulated in Japan?

Haven't a clue. I was pondering the public perception of radiation generally.

[supersingle]

llewop said:

hmm... the one that perhaps could be questioned is regulation, but no particular evidence that there are shortfalls in monitoring, although the sharing of that data seems to leave a little to be desired!

Maybe there is something lacking there - the last nuclear accident to result in radiation related deaths was also in Japan - look up Tokaimura if you're interested - not a power station, a processing facility.

They've certainly got form.

It's all very well saying that British nuclear is safe but what about India, Pakistan, Iran, Saudi Arabia and dare I say it... The USA?