Japanese Nuke

Hmmm, just been out for the day and came home expecting a long thread about this on this ng. Nothing catastrophic seems to have happened (except that the reactor itself is prolly a write-off), but It's irritating it has happened at this point, before the new UK nukes were firmly under construction.
Cue foaming at the mouth, though, by e.g. loonies at the Lib-Dem Spring Conference.
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Tim

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But all that has been reported is speculation by reporters with nothing more than a meja studies qualification.
It may be called news but don't expect any truth in what is being said.
--
Alan
news2009 admac myzen co uk
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On Sun, 13 Mar 2011 00:26:26 +0000, Alan wrote:

Unless you count the guy from the IAEA and a few others, of course.
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wrote

Really? The BBC reporter on the spot, Damian Grammaticas , has worked for the them for at least fifteen years so he is hardly lacking experience is he? It is you that needs to check your facts before spouting rubbish just as you accuse others of.
Peter Crosland
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And what are his qualifications for reporting anything of a scientific nature? Just because someone is qualified in English Literature, has a Diploma in Broadcast Journalism and has spent 15 years travelling the world doesn't mean that he isn't speculating rather than reporting facts. Much of the "quality" BBC radio coverage on this subject is much the same as for other incidents, such as a rail crash, where the tame "experts" are wheeled in five minutes later to tell us exactly what has gone wrong. 24 hour rolling news relies on speculation rather than hard facts.
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Alan
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On Sun, 13 Mar 2011 08:43:10 +0000, Alan wrote:

You obviously didn't actually listen to him. You just want to rant for the sake of it.
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wrote

It seems to me that this is pure hypocrisy on your part. You are doing exactly what you accuse the BBC of i.e. making statements that are not supported by facts. In all the reports I saw from the BBC reporters they made it abundantly clear what had, and more to the point what had not, been confirmed. The BBC have a very clear policy of reporting things that are substantiated and saying when confirmation is still required.
Peter Crosland
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Alan wrote:

There have been two real experts called in, who were in one case sanguine and factual, and in the second a tad more alarmist.
The rest of the the so called experts have been alarmist speculation.
The story is being covered factually here:
http://www.world-nuclear-news.org/RS_Battle_to_stabilise_earthquake_reactors_1203111.html
It looks like the reactors are probably toast, but that if they can dump enough water in to lose the decay heat, they will be able to finally get the rods out for reprocessing, and decommission them.
Primary and secondary containment seems to be intact: It's the water circuits and pumps that seem to have failed.
The design pre-dates new PWR types where no pumps are needed in emergency shut down situations.
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http://www.world-nuclear-news.org/RS_Battle_to_stabilise_earthquake_reactors_1203111.html
Yes, new PWRs are better than 40 year old PWRs. They're still shite though. They are still relatively fragile technology IMO, the bean counters prefer them for cost reasons. I prefer the idea of reactors with greater thermal mass. Where incidents take days or weeks to become an issue.
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Steve Firth wrote:

As do we all. I personally prefer reactors that have to be 'kept alight' rather than one's that have to be 'damped down'. PWR is a lot better in this respect than BWR, in that failure in the cooling circuit (provided the reactor core is fully shut down) doesn't lead to loss of contaminated steam.
But its all about cost and development.
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wrote:

They're not even PWRs, they're BWRs. This means (most relevantly) that there's barely any "containment" worthy of the name anyway. The primary water circuit goes through the core, and through the turbines in the turbine hall (i.e. no primary / secondary heat exchanger). Turbine halls are just too big to make credibly strong as a containment against a real explosion in the primary circuit, as has long been done for PWRs and was what saved Three Mile Island from becoming a disaster.
The large external explosion seen yesterday would have involved a lot of steam, thus would have involved the primary circuit (there's nothing else big enough to make that bang). So that means that for at least one reactor, it's now damaged, and exposed to the atmosphere. Hopefully the rods themselves are still intact, so the contamination is only secondary fission products, not fuel.
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Andy Dingley wrote:

Yes. They need to keep the rods under water, or they may melt and block further coolant flow, for several days.
I believe PWR can also maintain enough coolant flow by convection in the primary circuits as well. Which are so highly pressurised that the water never boils anyway.
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On 12/03/2011 23:42, Tim Streater wrote:

Current reports suggest that the radiation levels in the area, at 1,204 micro sievert, are very similar to those after the Three Mile Island accident. If that is as bad as it gets after being hit by the sixth largest earthquake ever recorded, it should serve as an excellent example of just how safe modern designs are.
Colin Bignell
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Well said. And of course, it isn't a modern design, it's been operating for forty years and was due to be shut down anyway. Nevertheless, it could hardly be worse timed for UK "new build".
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newshound wrote:

Which is why the Priests of Green will be all over it like a rash.
BTW I think Nightjar means milli-sieverts? Background is about 10mSv IIRC.
From Wiki
"The level of natural background radiation varies depending on location, and in some areas the level is significantly higher than average.[5] Such areas include Ramsar in Iran, Guarapari in Brazil, Kerala in India,[6] the northern Flinders Ranges in Australia[7] and Yangjiang in China.[8] In Ramsar a peak yearly dose of 260 mSv has been reported (compared with 0.06 mSv of a Chest radiograph or up to 20 mSv of a CT scan).[9] The highest levels of natural background radiation recorded in the world till date is from areas around Ramsar, particularly at Talesh-Mahalleh which is a very high background radiation area (VHBRA) having an effective dose equivalent several times in excess of ICRP-recommended radiation dose limits for radiation workers and up to 200 times greater than normal background levels. "
BTW sieverts represent total dose. Not 'radiation level' as such.
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On 13/03/2011 12:32, The Natural Philosopher wrote:

Dose rates are measured in Sieverts/hour.
In the UK, when working with radioactive sources, we set up a 'controlled area' at the 7.5uSV/h point. Only trained and badged Radiation Workers are permitted inside this cordon.
This value is derived from taking maximum permitted Annual Total Dose ( in Sieverts ) , and assuming an un-classified individual stands at the boundary during working hours ( iirc ). So any member of the public would never be exposed to a total annual dose greater than the specified maximum. There is also 3-monthly max dose limits too, and we set 'investigation' levels if a badged individual exceeds this.
--
Ron


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Ron Lowe wrote:

Yup.
Yup.
The point being that it's reckoned that 'total dose' is what counts safety wise, not 'peak exposure'.
If you get a years worth in an hour, (like a CT scan) that's OK ish. As long as it doesn't happen every day
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On 13/03/2011 14:18, The Natural Philosopher wrote:

Just for the record, I should I should probably state that I am the responsible RPS for a small facility that uses gamma and neutron sources. It's part of my job to maintain and enforce the Local Rules, and ensure compliance with the applicable Ionising Radiation and HASS legislation.
Deep Joy.
--
Ron





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On 13/03/2011 12:32, The Natural Philosopher wrote: ...

The report I read said 1204 micro-sieverts. The measurement given in the follow up reports on Three Mile Island was 100 millirem = 1000 micro-sieverts, which was considered to be insignificant.
1204 milli-sieverts would be a whole different problem.
Colin Bignell
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newshound wrote:

/Ironic Yeah, can't expect these new fangled designs to stand up to the worst disaster in a long time the way the old, proven stuff has. :-/ Ironic/
Looking at the TV and other pictures, it's impressive just how much of the infrastructure *is* still usable.
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Tciao for Now!

John.

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