Were the Nuclear Protesters Right?

[M Paquette]

Quote:

Originally Posted by Nords Nukes wear dosimeters which are sensitive to gamma radiation. IIRC though nobody gave a darn about documenting neutron exposure, either from the reactor or from the nuclear warheads in the ICBMs or TOMAHAWK cruise missiles. I think the logic was that it was too low to matter (as far as we know!), but M_Paquette might have a better response to that.

The Engineering Lab Technicians did occasional neutron surveys with a special neutron counter. Neutrons are just really easy to stop, though. Any material with lots of hydrogen atoms, which mass about the same as a neutron, will slow down fast neutrons to a crawl, and adding a bit of boron, such as boric acid or borated polyethylene will absorb the slowed neutrons.

There is shielding installed in a power plant, sufficient to stop neutron leakage out to areas where delicate meat-based types might lurk, and if that shielding isn't tampered with there is no reason to expect a surprise flux of neutrons. (This reminds me of a funny story involving an incident in an S5G class power plant, which alas is probably too sensitive to be discussed here...)

Gamma rays leak out pretty readily, being difficult to stop, so everyone in the crew has to have a Tiny Little Dosimeter to check their exposure. Oddly enough, my exposure when underway on nuclear power was about half of what I got in similar periods when in port with the plant shut down. A few hundred feet of seawater makes wonderful shielding from that fusion reactor in the sky and all the radioactive junk in granite...

[kumquat]

Out of curiosity, where do all these free neutrons end up? Do they eventually get absorbed by some random atom or do they bounce around forever?

[BigNick]

I'm not sure why this is getting so much "OMG near miss" discussion. If a meltdown is caused by the aftermath of a tsunami, it seems likely that there's going to be seawater nearby. Nuclear power plants tend to be built close to very large supplies of water. He also didn't show that the amount of rediation going into the sea was particularly harmful; "20 times what a nuclear power worker can be exposed to" is /a/ not all that much anyway and /b/ doesn't contain the dimension of time (ie, how long the exposure continued for at that level).

What we now know is that at least one core melted and we still only have 3 or so fatalities.

[Tigger]

Quote:

Originally Posted by BigNick What we now know is that at least one core melted and we still only have 3 or so fatalities.

They've admitted in the mean time that the cores of reactors 1, 2 and 3 melted down soon after the tsunami. And it looks like they may not only have melted down, also melted "through", according to this news from Bloomberg: "The Japanese government will submit a report to the International Atomic Energy Agency that raises the possibility the fuel dropped through the bottom of the pressure vessels, a situation described as a “melt through” and considered more serious than a “meltdown”.

The fatalities will come later, much later. And it will probably often be hard to link them to the disaster.

From an interview with Arnie Gundersen: "Well, I am in touch with some scientists now who have been monitoring the air on the West Coast and in Seattle for instance, in April, the average person in Seattle breathed in 10 hot particles a day. (...) The average human being breathes about 10 meters a day of air, cubic meters of air. And the air out in the Seattle area are detecting, when they pull 10 cubic meters through them, this is in April now, so we are in the end of May so it is a better situation now. That air filter will have 10 hot particles on it. And that was before the Unit Four issue."

The Italian oncologists are more worried than people in this forum: "From the ASCO congress in Chicago, the world's most important oncology summit, AIOM (Italian association of medical oncology) urges the people to vote 'yes' at the referendum to be held on 12 and 13 June. "Nuclear radiation is the most carcinogenic thing that exists - said AIOM president Carmelo Iacono - and it cannot be kept under control, as the Fukushima tragedy proved. Let's drop the nuclear plants project and let's start staking on alternative energy, which pollutes much less and which, unlike nuclear energy, does not pose a threat for health"."

From Time.com: "One recurring theme that has emerged after Fukushima is the tendency of nuclear experts to underestimate (publicly at least) the severity of the disaster. Today we received further proof of this when the Japanese government more than doubled the estimate for the amount of radiation released from the plant in the immediate aftermath of the crisis in March." (and it's not yet over, it's not under control, there are leaks and unit four may become a very big problem)

[BigNick]

Quote:

Originally Posted by Tigger From an interview with Arnie Gundersen: "Well, I am in touch with some scientists now who have been monitoring the air on the West Coast and in Seattle for instance, in April, the average person in Seattle breathed in 10 hot particles a day. (...) The average human being breathes about 10 meters a day of air, cubic meters of air. And the air out in the Seattle area are detecting, when they pull 10 cubic meters through them, this is in April now, so we are in the end of May so it is a better situation now. That air filter will have 10 hot particles on it. And that was before the Unit Four issue."

That article doesn't distinguish between alpha/beta particles, and alpha/beta particle emitters. I stopped reading right there. Either a "hot particle" is an alpha particle, in which case, once it hits you, it stops moving, finds a couple of electrons, and becomes an atom of helium; or it's a "particle" in the sense of "small piece of matter, like dust", in which case it could be nasty, but he has to tell us how big it is. Until he does that, he's just using big scary words with no quantification. (I note that there are very few measured quantities in any of these scare stories, just "Radiation Is Bad" and occasionally "Up to X", with no idea on the overall range or the distribution of probabilities.)

[M Paquette]

Quote:

Originally Posted by kumquat Out of curiosity, where do all these free neutrons end up? Do they eventually get absorbed by some random atom or do they bounce around forever?

Ah yes, stalking the wily free neutron.

They'll usually be absorbed by something, such as hafnium in a control rod, or boron in the neutron shield. If one wanders off and isn't absorbed, after several hundred seconds a free neutron decays by emitting an electron and turning into a proton. That is, the neutron decays to become hydrogen.

[kumquat]

And hence the hydrogen build up and explosion that occurred?

[Nords]

Quote:

Originally Posted by kumquat And hence the hydrogen build up and explosion that occurred?

I suspect most of the H2 was generated from the radioactive decay of the fission products and the heating/melting of the core's materials.

It's been a loooong time since I had to remember any of this, but IIRC the naval reactors used to keep a small amount of hydrogen in solution in the primary coolant-- in order to minimize corrosion? Was that to buffer the pH to minimize stress corrosion cracking or to equilibrate NH3 generation? I don't know anything about the GE reactor design but they might also have been doing something similar.

What's really annoying me is that I can remember the spec is a number between 10-60 but I can't remember the units (cc/kg?) nor the reasoning behind doing it in the first place.

The main reason I remember H2 in primary coolant because you used to have to keep H2 in spec 24/7, whether the reactor was operating or shut down, and after a long shutdown period it could sometimes drift low enough that you'd have to contemplate adding H2 to the primary coolant. Bringing pressurized tanks of explosive gases into a submarine engine room to do an evolution that most people only experienced a few times a decade was always an added thrill to an otherwise routine workday...

Quote:

Originally Posted by M Paquette (This reminds me of a funny story involving an incident in an S5G class power plant, which alas is probably too sensitive to be discussed here...)

I think the saying I used to hear was:
"Nobody served on an S5G plant. They just did hard time on that boat and hoped to be paroled for good behavior before something bad happened..."
http://en.wikipedia.org/wiki/S5G_reactor

[GregLee]

Quote:

Originally Posted by BigNick ... or it's a "particle" in the sense of "small piece of matter, like dust", in which case it could be nasty, ...

I found on Gundersens' web site an interview with a grad student, Marco Kaltofen, who is working at measuring radioactive dusty fallout from Japan. Not much known yet, I gather, beyond detecting the stuff and identifying it as coming from Japan:
http://www.fairewinds.com/content/wh...does-it-matter

Also, Wikipedia has a discussion of this here:
http://en.wikipedia.org/wiki/Radiati..._outside_Japan

[M Paquette]

Quote:

Originally Posted by kumquat And hence the hydrogen build up and explosion that occurred?

No, not that. That would take a lot of neutrons. Bukkits of 'em.

The hydrogen gas probably came from metal/water reactions at very high temperatures. For example, the zirconium alloy used to jacket fuel rods will react with water at 1200 degrees centigrade (i.e., really, really hot) to release hydrogen gas.

BTW, the version of the old BWR plant in this accident that's running in the US has vents in the top of the building put there specifically to vent hydrogen gas in the event of an accident. The gas would normally be vented from the reactor plant through a filtration and scrubbing system (blown up in the Fukushima accident), and then vented outside rather than allowed to accumulate inside. TEPCO didn't do the vent retrofit.

[Nords]

Quote:

Originally Posted by M Paquette BTW, the version of the old BWR plant in this accident that's running in the US has vents in the top of the building put there specifically to vent hydrogen gas in the event of an accident. The gas would normally be vented from the reactor plant through a filtration and scrubbing system (blown up in the Fukushima accident), and then vented outside rather than allowed to accumulate inside. TEPCO didn't do the vent retrofit.

Perhaps a good-news/bad-news situation, as those vents might first have served as tsunami-water inlets...

[Tigger]

I have no doubt that the resident nukes can debunk much of the content of this article:
Fukushima: It's much worse than you think - Al Jazeera English

The words "natural electricity" made me grin, but those words that sound silly in English may just be the translation (probably from Japanese to English, possibly via Arabic).

[Nords]

Quote:

Originally Posted by Tigger I have no doubt that the resident nukes can debunk much of the content of this article: Fukushima: It's much worse than you think - Al Jazeera English The words "natural electricity" made me grin, but those words that sound silly in English may just be the translation (probably from Japanese to English, possibly via Arabic).

Do you have a real pony question in that link, or are you just trolling for another exciting dissertation on reactor physics?

Quote:

In the US, physician Janette Sherman MD and epidemiologist Joseph Mangano published an essay shedding light on a 35 per cent spike in infant mortality in northwest cities that occurred after the Fukushima meltdown, and may well be the result of fallout from the stricken nuclear plant. The eight cities included in the report are San Jose, Berkeley, San Francisco, Sacramento, Santa Cruz, Portland, Seattle, and Boise, and the time frame of the report included the ten weeks immediately following the disaster.

You might want to check these claims on your own to see what sort of peer-reviewed journal they're appearing in. Apparently they managed to sneak past whatever passes for editorial review.

I'm calling hogwash on the credibility of a guy with four decades of nuclear engineering experience referring to it as a "Geiger counter". The media seems to be frantically exhuming anyone in the industry who's feeling the need for their 15 minutes of fame.

[BigNick]

Quote:

Originally Posted by Nords You might want to check these claims on your own to see what sort of peer-reviewed journal they're appearing in. Apparently they managed to sneak past whatever passes for editorial review.

From what I can see, it appears mainly on the web site of Janette D. Sherman MD, "Physician - Author - Activist". Top of the blog is an article claiming that WHO and IAEA are in cahoots to cover up the "truth" about Chernobyl. This was commissioned by that well-known right-wing group, the Bulletin of the Atomic Scientists, but not published - presumably (according to Sherman) "because it was considered too alarming", and not at all, of course, because of any questions about its rigour.

She needs to start cranking up the mortality figures, though, because she has stated that /a/ the death toll from Chernobyl is in fact 980,000 and /b/ that Fukushima will be worse.

Anti-nuclear campaigner is anti-nuclear; no surprises there. When the CDC starts writing about a spike in infant death rates, I'll be listening.

[samclem]

A German organic farm appears to have killed 35 people and permantly destroyed the health of many more. The radiation from the damaged Japanese nuclear plants have killed no one (though it will admittedly take a lot of thorough epidemiological studies over decades to know for sure).

Where's the outrage over organic farming? It's certainly time to re-examine our fatal fascination with this technology. We now have good alternatives that are safer.

[BigNick]

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Originally Posted by samclem Where's the outrage over organic farming? It's certainly time to re-examine our fatal fascination with this technology. We now have good alternatives that are safer.

I'm not blaming organic (although it's a scam). I'm blaming whoever convinced those consumers that beansprouts are a salad vegetable. If your salad is lacking crunch, add croutons, or bacon.

[Tigger]

Quote:

Originally Posted by Nords Do you have a real pony question in that link, or are you just trolling for another exciting dissertation on reactor physics?

You're right, I should have been more precise. While reading the article, the following bits stood out and I'm wondering if they are exaggerating the problems or correct:

"Fukushima has three nuclear reactors exposed and four fuel cores exposed," he said, "You probably have the equivalent of 20 nuclear reactor cores because of the fuel cores, and they are all in desperate need of being cooled, and there is no means to cool them effectively."

Gundersen pointed out that the units are still leaking radiation. “They are still emitting radioactive gases and an enormous amount of radioactive liquid," he said. "It will be at least a year before it stops boiling, and until it stops boiling, it's going to be cranking out radioactive steam and liquids.”

According to Gundersen, the exposed reactors and fuel cores are continuing to release microns of caesium, strontium, and plutonium isotopes. These are referred to as "hot particles". (BigNick earlier wrote that Gundersen's statements about "hot particles" was too vague and that the size of the particles would need to be known - the above statement is clearer about the source and size ("microns") though still a bit vague, but I suppose those who have the means to measure them, aren't inclined to publish more info than obligatory)

TEPCO has been spraying water on several of the reactors and fuel cores, but this has led to even greater problems, such as radiation being emitted into the air in steam and evaporated sea water - as well as generating hundreds of thousands of tons of highly radioactive sea water that has to be disposed of. "The problem is how to keep it cool," says Gundersen. "They are pouring in water and the question is what are they going to do with the waste that comes out of that system, because it is going to contain plutonium and uranium. Where do you put the water?"

"The fuels are now a molten blob at the bottom of the reactor," Gundersen added. "TEPCO announced they had a melt through. A melt down is when the fuel collapses to the bottom of the reactor, and a melt through means it has melted through some layers. That blob is incredibly radioactive, and now you have water on top of it. The water picks up enormous amounts of radiation, so you add more water and you are generating hundreds of thousands of tons of highly radioactive water."

"Units one through three have nuclear waste on the floor, the melted core, that has plutonium in it, and that has to be removed from the environment for hundreds of thousands of years," he said. "Somehow, robotically, they will have to go in there and manage to put it in a container and store it for infinity, and that technology doesn't exist. Nobody knows how to pick up the molten core from the floor, there is no solution available now for picking that up from the floor."

Quote:

Originally Posted by Nords You might want to check these claims on your own to see what sort of peer-reviewed journal they're appearing in. Apparently they managed to sneak past whatever passes for editorial review.

Getting articles published in peer-reviewed journals can take ages, while information about ongoing events is most interesting while they're happening.

Quote:

Originally Posted by Nords I'm calling hogwash on the credibility of a guy with four decades of nuclear engineering experience referring to it as a "Geiger counter".

I don't know how big a sin that is, but it seems normal to me to use popular terminology when writing articles for the general public.

[M Paquette]

Quote:

Originally Posted by samclem A German organic farm appears to have killed 35 people and permantly destroyed the health of many more. The radiation from the damaged Japanese nuclear plants have killed no one (though it will admittedly take a lot of thorough epidemiological studies over decades to know for sure). Where's the outrage over organic farming? It's certainly time to re-examine our fatal fascination with this technology. We now have good alternatives that are safer.

Amusingly enough, E Coli and similar contaminants in raw vegetables and fruits are readily controlled using food irradiation. This is, of course, not acceptable in our fear-based technophobe environment.

[M Paquette]

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Originally Posted by Tigger Getting articles published in peer-reviewed journals can take ages, while information about ongoing events is most interesting while they're happening.

Ah, yeah. And I could write all sorts of scary fear-mongering headline-grabbing stuff, too, and even enjoy a nice by-the-word remuneration while pursuing an agenda.

But I don't. (And yes, I have published in peer-reviewed journals.)

[Nords]

Quote:

Originally Posted by Tigger You're right, I should have been more precise. While reading the article, the following bits stood out and I'm wondering if they are exaggerating the problems or correct: "Fukushima has three nuclear reactors exposed and four fuel cores exposed," he said, "You probably have the equivalent of 20 nuclear reactor cores because of the fuel cores, and they are all in desperate need of being cooled, and there is no means to cool them effectively."

I'm not asking for precision, I'm just wondering what you're asking.

I'm a little confused on the difference between an "exposed nuclear reactor" and an "exposed fuel core". Let's say that three reactor pressure vessels have been breached and a cooling pond (holding some number of old used-up uranium cores) is having problems. I guess that would be correct, although I haven't been keeping a scorecard.

Quote:

Originally Posted by Tigger Gundersen pointed out that the units are still leaking radiation. “They are still emitting radioactive gases and an enormous amount of radioactive liquid," he said. "It will be at least a year before it stops boiling, and until it stops boiling, it's going to be cranking out radioactive steam and liquids.”

I suspect that's correct, although I doubt what's happening today is within two or three orders of magnitude of a couple months ago. I can't predict how long boiling will go on, either-- my experience is with tiny little high-density cores instead of big massive low-density industrial cores. But saying how much was leaking compared to how much is leaking would be boring miss the point that leaking is still happening. Fair enough, but it lacks the context of the tremendous amount of work that's gone on during the last few months.

Quote:

Originally Posted by Tigger According to Gundersen, the exposed reactors and fuel cores are continuing to release microns of caesium, strontium, and plutonium isotopes. These are referred to as "hot particles".[/I] (BigNick earlier wrote that Gundersen's statements about "hot particles" was too vague and that the size of the particles would need to be known - the above statement is clearer about the source and size ("microns") though still a bit vague, but I suppose those who have the means to measure them, aren't inclined to publish more info than obligatory)

Yep, the fuel and the fission products are still decaying. I don't know if the fission products are still being released to the atmosphere, nor how much. However I don't feel compelled to change my car's air filter.

Quote:

Originally Posted by Tigger TEPCO has been spraying water on several of the reactors and fuel cores, but this has led to even greater problems, such as radiation being emitted into the air in steam and evaporated sea water - as well as generating hundreds of thousands of tons of highly radioactive sea water that has to be disposed of. "The problem is how to keep it cool," says Gundersen. "They are pouring in water and the question is what are they going to do with the waste that comes out of that system, because it is going to contain plutonium and uranium. Where do you put the water?"

No pleasing the critics, is there? TEPCO should've let it all melt down in a gigantic China Syndrome that would've completely avoided steamy radiation and contaminated seawater.

The Fukushima water is probably going to be treated the way the rest of the industry treats it-- store as much as you can, filter it, dilute the rest, and either re-use it for cooling or (when it's below the legal limits) discharge it.

U.S. Navy submarines routinely discharge ~100 gallons of steamin' hot primary coolant overboard a few times a year, and do the same with a thousand or so gallons of room-temperature primary coolant that's been sitting in a storage tank for a month or two. The difference is that they do this dozens of miles out at sea, and there's no discernible effect on the environment.

Fukushima has pretty well fouled their own back yard for now. I'd be interested in a biological survey of their area compared with, say, the area covered by the Exxon Valdez spill or the BP's Gulf spill. I bet Fukushima's locale recovers a lot faster than Prince William Sound or the Gulf.

Quote:

Originally Posted by Tigger "The fuels are now a molten blob at the bottom of the reactor," Gundersen added. "TEPCO announced they had a melt through. A melt down is when the fuel collapses to the bottom of the reactor, and a melt through means it has melted through some layers. That blob is incredibly radioactive, and now you have water on top of it. The water picks up enormous amounts of radiation, so you add more water and you are generating hundreds of thousands of tons of highly radioactive water." "Units one through three have nuclear waste on the floor, the melted core, that has plutonium in it, and that has to be removed from the environment for hundreds of thousands of years," he said. "Somehow, robotically, they will have to go in there and manage to put it in a container and store it for infinity, and that technology doesn't exist. Nobody knows how to pick up the molten core from the floor, there is no solution available now for picking that up from the floor."

Maybe it's a problem that doesn't need solving. I'm not sure there's a reason to pick it up in the first place. TEPCO could choose the Chernobyl approach of a gazillion tons of wet concrete, slap a plaque on the outside, and start bringing in tour groups.

There's far more radioactive waste (and radioactivity) at Hanford in Washington state, but apparently that's also boring not leaking enough to be newsworthy. Yet Hanford has been dealing with these problems for literally generations (it's where retired U.S. Navy submariners start their bridge careers), and I'm sure that the industry can figure out how to do the same with Fukushima.

Quote:

Originally Posted by Tigger Getting articles published in peer-reviewed journals can take ages, while information about ongoing events is most interesting while they're happening.

Yeah, and the facts have a discouraging habit of ruining the most entertaining breaking news stories too.

I think we're both exaggerating the reality. I suspect a credible physicist, even a slightly wild-eyed activist, would be able to engage the editorial review boards of Nature or Scientific American within weeks of the event. There's a reason these guys are showing up on the fringes instead of in the mainstream media, and it's because they're either desperate for publicity or just... not credible.

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Originally Posted by Tigger I don't know how big a sin that is, but it seems normal to me to use popular terminology when writing articles for the general public.

If by "popular terminology" you mean references to "Howdy Doody", "the Vietnam War" and maybe passing comment on the "Disco Era", then yeah, that'd be popular terminology. Heck, my 1980s-90s "radiac" terminology is probably also quaintly out of date. I would've expected an expert to be able to use terminology that's an industry standard like "radiation detector".

Look, Tigger, this has been fun while it lasted, but I think my work here is about done. I might jump back into this thread if it reminds me of a sea story there's some actual substantive news to interpret, but I'm not going to keep debunking the fringe theories. This article has about equal amounts of credibility and reactor physics, and if there's not much of the former then let's not waste our time on the latter.

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Originally Posted by BigNick I'm blaming whoever convinced those consumers that beansprouts are a salad vegetable. If your salad is lacking crunch, add croutons, or bacon.

CFB has always been trying to call America's attention to the conspiracy surrounding the Warren Commission's suppression of that ground-breaking documentary "Broccoli: The Silent Killer"...