Posted on 03/13/2011 9:19:24 AM PDT by Errant
I am writing this text (Mar 12) to give you some peace of mind regarding some of the troubles in Japan, that is the safety of Japan’s nuclear reactors. Up front, the situation is serious, but under control. And this text is long! But you will know more about nuclear power plants after reading it than all journalists on this planet put together.
There was and will *not* be any significant release of radioactivity.
By “significant” I mean a level of radiation of more than what you would receive on – say – a long distance flight, or drinking a glass of beer that comes from certain areas with high levels of natural background radiation.
I have been reading every news release on the incident since the earthquake. There has not been one single (!) report that was accurate and free of errors (and part of that problem is also a weakness in the Japanese crisis communication). By “not free of errors” I do not refer to tendentious anti-nuclear journalism – that is quite normal these days. By “not free of errors” I mean blatant errors regarding physics and natural law, as well as gross misinterpretation of facts, due to an obvious lack of fundamental and basic understanding of the way nuclear reactors are build and operated. I have read a 3 page report on CNN where every single paragraph contained an error.
We will have to cover some fundamentals, before we get into what is going on.
(Excerpt) Read more at morgsatlarge.wordpress.com ...
Thank you for a very informative article. I’ve seen it referenced at two other sites and I’m sure it’s being read by a lot of people.
Unfortunately, it appears that we cannot automatically assume the author is right.
I’ve read the whole article at the source blog, including the comments.
There is apparently at least one significant error in the article. The reactors in question do NOT have a feature designed to catch and disperse the material from a core meltdown. That feature is apparently part of newer designs for reactors of this type, but this reactor is too old to have it.
If the comments at the source blog are correct, the author is NOT a specialist in nuclear reactors. He obviously knows more about them than the vast majority of us, but his expertise is limited.
All in all I’d say this an excellent article that adds to the discussion. But, if the comments on the source blog are correct, it cannot be considered authoritative.
All diagrams I see do not show one.
I think another part of it is because credible information is not readily available to the general public. I blame the MSM and the plant operators for not seeing that it is.
Also, I don't want to hear about all the fail safes that can't fail but do. I want to hear about what is or isn't physically possible. After that, I'll make up my own mind as to what is likely and I think that's what the average Joe/Jill wants to hear.
It only makes sense (forget economical sense) to build these things (and I know they can) so that massive contamination in event of total meltdown isn't physically possible.
That may mean building reactors that could never reach the temperatures required for meltdown, by simply making them smaller.
http://www.nucleartourist.com/type/bwr.htm
Let's give them a rating of say from 1 to 10 on possibility of catastrophe. Example: Reactors constructed near the ocean and along known tectonic plate lines get a 10. Any reactors with a rating greater than say 5, are to be converted to the pebble based system you mentioned. Over a period of time, all should be converted to a system whereby meltdowns are physically impossible.
Probably hugely expensive, but vastly superior to wasting billions on windmills and current solar PV installations (except of course in certain instances).
Making them safe would make more of them available and we really do need the power.
http://www.nirs.org/factsheets/bwrfact.htm
Excellent.
Thanks so much for posting.
I kinda had a feeling that once it was posted on FR, it would be dissected and the parts grouped into relevant and bogus piles. ;)
What is "massive contamination"?
Who says we will have "massive contamination"?
Depending on what your definition of "massive contamination" is, it may or may not be possible to build the perfect plant. There is always "something else" that could go wrong.
NP, thanks for the link.
Sure. My idea of "massive contamination" is somewhere way below what was released at Chernobyl.
As a starting point for safe reactor designs, consider the Voyager probes. :)
“Problem is, he doesn’t know the model of reactor in question.
The GE BWR-1 at Fukashima...”
—This isn’t correct. Fukushima reactors are all BWR-3 and higher:
http://www-pub.iaea.org/MTCD/publications/PDF/CNPP2010_CD/pages/AnnexII/tables/table2.htm
Will do. Sorry if I seemed flippant and thanks for your very knowledgeable comments.
Power plants are not refineries that can be changed out as you suggest.
As I'm learning, especially any involved in a partial meltdown or otherwise.
I've actually gotten off track in pursuit of an answer to the question, "is a meltdown with containment breach possible in this particular design". From what I've heard so far, while highly unlikely, it is possible.
“I’ve actually gotten off track in pursuit of an answer to the question, “is a meltdown with containment breach possible in this particular design”. From what I’ve heard so far, while highly unlikely, it is possible.”
Helping to get back on track here....
I’ve been reading about the “core catcher” that is built into the bottom of these plants. It’s pretty rudimentary compared to what is being designed today, but the intent is the same.
In short, directly underneath the reactor is an enormously thick, dense concrete “catch basin” if you will, with some sort of graphite absorbent material in and/or on it, that is still sealed withing the thick metal containment shell. It’s intended to catch all of the molten products from a core melt down, and spread them out so that any nuclear reaction has a chance to subside and over time allow the flattened out mass to cool. The idea is to prevent the melt down products from staying in one big hot mass and spread it out.
There are modern “core catchers” that are being designed for pressurized water reactors that will fit inside the pressure shell, protect it from melting and allow emergency cooling of the mass as it spreads out; essentially preventing the traditional “China Syndrome” where the core supposedly keeps on going to China. These newer catchers are made of very sophisticated ceramic coatings that are designed to survive high heat an severe radiation and several designs are being tested.
In short, what I have learned is that these BWR series reactors were designed with multiple layers of safety in mind, and they recognized very early that a complete loss of water and resultant meltdown could occur in an extreme emergency, just by the nature of the Boiling Water Reactor design. They built the foundations accordingly and planned for the most extreme emergency they could think of by providing multiple layers of protection and many different ways of managing the waste heat.
But it takes days to remove enough heat under these kinds of emergency conditions, and the conditions they are operating under are as extreme as you get. Has anyone heard if relief crews have been able to get to work, or if they were even still alive?? I wonder how long some of the nuclear operators have been onsite without relief.
And remember, the nuclear reaction was halted withing seconds of the beginning of the earthquake. They have been managing the removal of waste heat all along, and the emergencies that have been declared are statutorily required under Japanese Law. If this occurs, you do that immediately, and we evacuate out so far.
They have a process in place, it is being used as far as I can tell, and although the situation is very serious it still appears to be under control. I think the biggest problem with this is poor Japanese emergency communications and a completely hysterical American media in the depths of yet another 24/7 crisis....
Perhaps I misunderstand this remark, but if I interpret it in a straightforward manner that better reactor designs are now available...
Nuclear reactors are expensive to build. The costs are amortized over the expected lifetime of the reactor. Investment is upfront, and payback is deferred (as in deferred gratification). Do you go out and buy a new cell phone every month because your current cellphone has been rendered obsolete by the latest model? Probably not, if you signed a 2 year contract. Similarly with nuclear reactors, only there is several years of studies, permits, regulations, and change orders to deal with. Not to mention tree huggers, pandering politicians, and a population who knows nothing more about energy than how to look for the nearest wall outlet.
Everything you said. I know the Japanese will not make the same mistake twice. BTTT.
Biblical is the only word I can find that even comes close. I can’t believe the death toll isn’t in the hundreds of thousands by now.
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