Japan Fukushima nuclear thread

[supersingle]

iodine-131 contamination in Europe no longer negligible

I just bought a fricking water butt.

[llewop]

supersingle said:

iodine-131 contamination in Europe no longer negligible

what a jumble of 'facts' and figures, most of which don't directly scale to each other.

For context: the EU food intervetion level for baby food is 150 Bq/l - which would suggest that at least one of the values in the linked report is way off the mark, sadly I can't find the true dose per unit intake figure for infants to absolutely confirm that.

[supersingle]

How did the EU arrive at a limit of 150 Bq/L for babyfood? Just curious.

Haven't the EU been upping the limits since Fukushima started?

[llewop]

supersingle said:

How did the EU arrive at a limit of 150 Bq/L for babyfood? Just curious.

Haven't the EU been upping the limits since Fukushima started?

it would be based on dose per unit intake: so Sieverts (dose) per Becquerel (intake) and then modelled on typical or worst case consumption patterns for ingestion or on breathing rates for inhalation. I did find a figure for DPUI for infants which was 1.8 10-7 Sv/Bq so that would suggest that the intake mentioned of 50 Bq would be a dose of about 9 microSieverts. Maybe I'm being unkind and they've just got milli and micro mixed up, but there were a few other odd things that made me blink a bit.

ETA: I didn't trace the DPUI back to something I could rely on, so hadn't originally quoted it. but have since checked another that was with it against something I trust so expect it to be correct

ETA2: EU food intervention levels are based on potential exposure not current events, the point being you act when the levels are exceeded, not make it up as you go along.

Edited by llewop on Thursday 14th April 09:18

Edited by llewop on Thursday 14th April 09:21

[hairykrishna]

Go to the CRIIRAD source document - it makes a little more sense.

"Many people have asked if they could continue to consume water from their tank (water collected on the roof of their house). Given the levels of contamination measured so far, the consumption of a few glasses of water do not pose a problem. In contrast, if the water collected to serve as the main source of drinking water for 15 days or three weeks the dose could reach or exceed the threshold at which the risk is no longer considered negligible, especially if consumers are young children. These are very low levels of risk but
best avoided." (my translation - use with caution!)

Here is a map of France with the measured activities;

http://www.criirad.org/actualites/dossier2011/japo...

Their advice seems pretty cautious although I suppose there's no reason to drink rainwater if you can avoid it. I hate to go to the banana equivalent dose again but bananas average around 120 becquerels/kilo.

[supersingle]

So the radioactivity limit is based on the dose. But isn't the dose arbitrary?

The EU seems to have enacted a regulation allowing an increase in radioactivity for food imports to avoid food shortages. Seems strange as the EU must have tiny imports from Japan. It seems that the rules date back to Chernobyl.

It looks like the EU does indeed alter allowable radioactivity limits in food based upon events. They could hardly do otherwise as a nuclear incident in Europe would potentially lead to shortages.

Austrian report

[hairykrishna]

supersingle said:

The EU seems to have enacted a regulation allowing an increase in radioactivity for food imports to avoid food shortages. Seems strange as the EU must have tiny imports from Japan. It seems that the rules date back to Chernobyl.

This is nonsense. The EU spokesman in that report even says so - they were enacting the emergency powers to test food imported, not raising limits. Normally there's not an import/sales limit because they don't bother testing everything imported into the EU for radioactive cesium/iodine.

This is the report referred to; http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?...

[supersingle]

The report stated that stricter controls with be placed on imports from Japan i.e they're going to be measuring the radioactivity. But radioactive caesium limits have been raised 20 times.

What have I missed?

[hairykrishna]

supersingle said:

The report stated that stricter controls with be placed on imports from Japan i.e they're going to be measuring the radioactivity. But radioactive caesium limits have been raised 20 times.

What have I missed?

Where does it say limits have been raised 20 times?

[supersingle]

Sorry, in the Austrian news report. That's what it says. They might be wrong, I don't know, but it's in the report.

[llewop]

supersingle said:

So the radioactivity limit is based on the dose. But isn't the dose arbitrary?

If the radioactivity limit was based on anything other than dose, it would be arbitary! Dose is the best we have in terms of judging and weighing up the radiological risks from a product, activity or intervention. Just quoting activity gets faily meaningless because there can be huge differences in dose per unit intake - the classic 'plutonium is the most dangerous substance known to man' quote - because the ALI (annual limit of intake) is lower than most other radioactive materials - the ALI being based on the DPUI so more dose per becquerel the less you want to inhale or ingest. Having said that, there are other isotopes with lower ALIs and some are quite accessible!

[hairykrishna]

supersingle said:

Sorry, in the Austrian news report. That's what it says. They might be wrong, I don't know, but it's in the report.

They're referring to that primary source I referenced I believe, so are wrong. I don't speak German though. Can you find it mentioned anywhere else? I can't.

[supersingle]

I understand that dose is the relevant figure in terms of health effects. Lots of media reports are quoting bequerels or even water contaminated with sieverts. Not much understanding from media and public alike.

My question was how they arrived at a figure for a safe dose. Even background radiation kills people, so surely adding to it increases risk, if only slightly.

Do they have studies to find the effect of low dose radiation then decide how many extra deaths are acceptable in the population? Or is the dose a best guess?

[supersingle]

hairykrishna said:

They're referring to that primary source I referenced I believe, so are wrong. I don't speak German though. Can you find it mentioned anywhere else? I can't.

The report you cite doesn't give radioactivity limits. It refers to another report which gives the limits. I cant find that report. Maybe it's been altered.

If the news report is an error then Austrian politicians are getting awfully worked up over nothing. I'm not convinced. :scratching:

There are reports all over the net of US and EU authorities upping the limits in response to Fukushima. Nothing in the MSM though.

I don't think limits have been breached yet in Europe although some milk in western US has.

[llewop]

supersingle said:

Do they have studies to find the effect of low dose radiation then decide how many extra deaths are acceptable in the population?

The short answer is 'yes'

The link below gives a bit more - dig around on their website for other explanations and more information
Health Protection Agency: Risks from Low Levels of Radiation

[supersingle]

Thanks for that, it's good to stay informed.

I'm off to weld the sills on my 205. The B-pillar has detached itself from the sill. Should cheer me up.

[hairykrishna]

supersingle said:

The report you cite doesn't give radioactivity limits. It refers to another report which gives the limits. I cant find that report. Maybe it's been altered.

If the news report is an error then Austrian politicians are getting awfully worked up over nothing. I'm not convinced. :scratching:

There are reports all over the net of US and EU authorities upping the limits in response to Fukushima. Nothing in the MSM though.

I don't think limits have been breached yet in Europe although some milk in western US has.

It refers to 3 reports, all of which are available with about 2 seconds googling. Example;

http://www.google.co.uk/search?sourceid=chrome&amp...

[MOTORVATOR]

Couple of links here with monitoring data.

http://www.mext.go.jp/english/radioactivity_level/...

http://www.mext.go.jp/english/radioactivity_level/...

http://www.mext.go.jp/english/radioactivity_level/...


Any thoughts LLewop? Seems to be elevated some 30km North West of the plant but other areas not particularly.

[llewop]

MOTORVATOR said:

Couple of links here with monitoring data.

http://www.mext.go.jp/english/radioactivity_level/...

http://www.mext.go.jp/english/radioactivity_level/...

http://www.mext.go.jp/english/radioactivity_level/...


Any thoughts LLewop? Seems to be elevated some 30km North West of the plant but other areas not particularly.

I'd glanced at the MEXT stuff before - my adobe was messing about regarding reading Japanese just now so had a struggle with getting to see some of them. The interesting one to me from a quick glance were the dust samples - almost all of the latest ones are ND - none detected - except one or two 60km to the west, which was a bit odd as previous measurements there were ND. The significance being whether there was anything in the air: i.e. was the release still continuing? That recent readings could suggest that it/they may have stopped; or that the current prevailing wind is out to sea...

[Globs]

Japan nuclear emergency at Fukushima to continue for six to nine months

article said:

It will take another six to nine months before the crisis at Japan’s stricken Fukushima nuclear power plant is resolved, operator Tepco has admitted.

Link

But it's not all bad news, Banri Kaieda, Japan’s trade minister, said some could return home within six to nine months - coincidentally. Assuming there are no more surprises of course.