Hydride formation never sleeps; What do they have to do to make the dry casks safer?

5/6/2014

Dear Readers,

The zirconium cladding which encloses the fuel pellets that were used at San Onofre (and every other light water nuclear reactor in America) will continue to degrade even after the fuel rods are crammed into their "dry casks", which are then welded and/or bolted shut and -- if the nuclear industry has its way -- forgotten about (until something goes wrong).

The loss of cladding integrity is a serious failure the nuclear industry needs to face, because a permanent solution to the waste problem is NOT on the horizon, but the fuel cladding degradation is very much on the horizon, and the horizon is getting closer every day.

The cladding may NOT degrade "gracefully," meaning, we may not see the failure coming, and won't be able to do anything about it until it happens. The nature of brittle-failure is that once a crack grows past a certain size it becomes dangerous. That size is unknown without lots and lots of testing, and each rod will behave differently. As the cracks form, stresses change throughout the rods.

Failure of even ONE rod among the hundreds of thousands of fuel rods can lead to a cascade effect and would be a significant environmental problem on its own. That cask would have to be resubmerged, opened, and the damaged fuel rod(s) "canned." "Canning is a process which isolates each fuel assembly (of approximately 150 fuel rods). But "canning" requires taking up additional space inside the dry cask. It also changes the thermal properties, and costs additional money to implement. Normally only fuel that is already obviously damaged in some way gets "canned." Without canning, fuel accumulations due to failed fuel rods have a greater potential to form a critical quantity. Also, any radioactive releases that would have been kept in the can will escape into the rest of the dry cask and possibly out the cask's vents (yes, these casks have vents). A radioactive release inside the dry cask will also make handling that fuel in the future more difficult.

We could see, several decades down the road or maybe tomorrow, that all the fuel that seemed fine is now starting to crack. Failure rates can increase exponentially because small cracks are both harmless and invisible to the naked eye (not that you could get a naked eye close to a spent fuel rod without dying long before you got close). Over long periods of time, temperature has an enormous effect on fuel cladding integrity. With dense packing and mixing high burnup fuel with low burnup fuel, the average temperature of the oldest fuel will be significantly higher than it otherwise could be if the high burnup fuel were kept in the spent fuel pools longer and/or packed less densely.

Cracks tend to grow at roughly the same rate under the same conditions, so the fuel that is in the dry casks the longest is normally the fuel that is the most worrisome. However, some damage also is done in the pools and some occurs in the reactor during operation so the exact state of each fuel rod cannot be decided without very careful non-destructive testing and accurate estimating of the heat loads during operation and while inside the pools and the dry casks. Southern California Edison does not want to do ANY of this sort of testing. They just want to accept dry cask industry estimates as fact.

It appears that the reason Edison set up the Citizens advisory committee (known as the C.E.P.) is so that a few hand-picked elected officials and others, including one activist (Gene Stone of R.O.S.E.) among 18 members, will have a hand in rejecting expensive solutions to the problem, and will keep demanding someone, somehow, move the waste away from SoCal "as soon as possible." It is a hollow demand. There will never be, on this earth, a safe place to store nuclear waste (nor is there a safe or cost-effective way to get it into outer space, beyond earth's debris field). There will never be an energy efficient (and safe) way to neutralize all of the nuclear waste, even if some portion of it can be reused or reprocessed or fed into a breeder reactor or transmuted or anything. These problems are terminal and are not going away.

Stopping nuclear power is the #1 thing everyone should do.

Below is a transcript of a nuclear fuel suggestion by a friend of mine, a metallurgist who worked at the International Atomic Energy Agency, PSE&G, Westinghouse, etc.. for many years before a head injury put him on disability several decades ago.

Every suggestion I have heard for improving the storage of spent nuclear fuel costs enormous amounts of money. Earthen berms between each cask would enhance safety, as would thicker cement sarcophaguses, not to mention rebar. Less fuel in each cask enhances safety in some ways, but means there are many more dry casks. Not one of these questions is easy to answer, but the fact is: Southern California Edison's dry cask solutions are notorious. They will be the death of southern California if an airplane strikes them, or a terrorist.

During war, our pilots learn not to line up their airplanes in a row if the enemy is near, for example alongside the runway, because then one enemy fighter plane, in one strafing pass, can destroy an entire row of airplanes (this happened to our land-based bombers at Pearl Harbor). At San Onofre with our dry cask storage system, we have the same situation: Everything all lined up and packed in tight, UNDER MAJOR AIRLINE ROUTES, just a few miles from an open airstrip, and just a few hundred feet from rail, truck and passenger traffic to the tune of hundreds of thousands of trips per day.

To the best of my knowledge, San Onofre's dry cask storage system is the tightest-packed dry cask system anywhere in the country -- but all dry cask "farms" are as compact as possible. This decreases the "target size" for a terrorist but increases the damage if an airplane falls on it accidentally or on purpose. Nuclear waste needs to be stored either underground or under "no fly" zones. San Onofre's nuclear waste is neither.

This is an outrageous situation, but what can be done about it? Move the waste? To where? One activist, Roger Johnson, suggests the Chocolate Mountains military range as a temporary location, on the California border with Arizona. Personally, I do not believe a temporary solution is useful; it just enables the nuclear industry to claim that there is some solution at all! More useful is to point out to Diablo Canyon's local community (and Palo Verde's and others) that storing old nuclear waste isn't any fun, and the less of it, the better. Furthermore, we should make sure it's clear that storing it is going to be a lot more expensive than ANYONE had ever expected, and the cost will go up significantly with each new fuel rod accumulated at the site. Who's going to be paying for our waste to be stored when we are all dead and buried, and even our children, and our children's children, are all gone?

There is no solution but shutdown. Before anyone can properly even think about what to do with the waste, we need to shut down the operating reactors -- the waste production facilities. Prior to shutdown, the waste is a hidden part of the nuclear industry. Now, here in southern California, it's all we have, and we need to do SOMETHING with it.

Nuclear waste problems have been ignored for about 70 years, but now southern Californian residents are forced to grapple with the problem.

Wish us luck.

Ace Hoffman
Carlsbad, CA

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What do they have to do to make the dry casks safer?

This is a transcript of metallurgist Ed Siegel's comments from May 4, 2014, with some speako corrections and a few other things (all in brackets) added to enhance the average person's understanding. Some non-relevant comments have not been transcribed.

Ed's solution is much, much more expensive than anything the nuclear industry is planning to do, but would presumably last a lot longer (depending on how many layers are involved) and will do a better job. In the long run, it would be far, far cheaper than to have to repackage early, let alone than having an accident, which could cost in the trillions of dollars and thousands of lives.

I would appreciate hearing from anyone who has any technical comments or suggestions, or inquiries about this transcript.

Ace

==================== Transcript: =====================

There's a phenomenon called DIFFUSIVE-MAGNETO RESISTANCE. I'm one of the developers of it. The discovers are Conyers Herring, died 20 years ago from Bell Labs, back in the '70s -- in the 40s -- back in World War II, when I was discovering who the girls and boys were -- and I'm still not sure.

If you have hydrogen diffusing in steel, ferritic, body-centered cubic steel, it diffuses at 60 meters per second [as fast as a rifle bullet], and it was found that you could contain the hydrogen by magnetizing the steel. Now, earlier someone named Youdelis (University of Windsor) had found that if you took an aluminum-copper junction, and just look at one diffusing into the other, if you put a magnetic field on, it retarded the mobility of the ions.

Plutonium is a lot larger than... what are the wastes, primarily?"

Well, there's plutonium, cesium, strontium...

"Okay, cesium's a heavy alkali metal, plutonium's a very heavy metal, the ionic radia are huge, the masses are huge, if hydrogen's retarded in ferritic steel, then certainly in a ferritic steel, plutonium would be retarded maybe (he pauses for second...) ten thousand times as much.

So what you want to do is you want to have alternate layers, a non-spinodally decomposing, no Wigner's disease, low carbon stainless -- nickle-based, too expensive -- followed by around that a ferritic steel -- I don't know which one -- carbon-manganese might work well like for pressure vessels -- and you want to magnetize that parallel to the axis. Then you want ANOTHER layer of the 304 L or whatever, then ANOTHER ferritic steel and at that one you want to magnetize circumferentially -- and I'm the only one and Tony Aaron that knows how to do that -- it's very clever. We're talking about magnetizing it in place. Now if you wound a coil around it you can magnetize it parallel to the axis. But were talking about getting RADIAL magnetic fields in addition to longitudinal magnetic fields.

Tony Aaron came up with a solution which is brilliant, something that goes back to high school science. Tony Aaron's a genius. [Note: Ed later told me what the "trick" is. I don't think it's that hard to figure out...]

So, how many layers do you want? As many as it takes. You've got to estimate the number of years you've got to contain it. If we're talking about 1,000 it might take 100 layers. If you don't like it, then have it for dinner!"

A low number with L -- NOT "360" and definitely L!

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One last thing: That's also the way to retard things leaking at Hanford, I gave testimony on this at the uh, Washington State Department of Ecology hearing on the future of Hanford, August, 2012, and they redacted it for about a year and they finally put it online, my witness is Janis Udall, a biologist, she went with me [Ed then rattles off her phone number and email address]... And the guy you want to get it from ... is Deder Boohrmann who I believe is the public relations man for the Washington State Department of Ecology, Bellevue, Washington, and they kept it offline because they were playing "CYA"...

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Lastly, the alternate layers are something like a hydrox cookie... um, if you don't understand the technology of that, the next girl scouts are selling their little mint cookies go buy some and pull them apart and you'll see alternate layers of different flavor[s]. This is what we want, some flavors are magnetized, the other[s] are not. They're not magnetized because they're stainless steel, because stainless steel is non-ferromagnetic it's paramagnetic and the magnetized layers are ferritic steel magnetized in different directions, and that's like the nice white cream between the dark chocolate wafer sides.

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Clean room contamination.

Typically clean room benches and chairs and sputtering systems and CVD systems, the chassis, like, for example made by Applied Materials, is stainless steel. If it's not 304 L stainless it embrittles over time or when it was heat treated, they didn't, when they formed it, they didn't re-heat treat it. The typical particulates in the air, the most dominant mineral in the earth's atmosphere, on the surface of the earth is plagioclase feldspars, they have a Moh hardness of number 6 1/2, quartz has a Moh hardness of 7. The typical particulates in the air are small quartz particles and small plagioclase feldspar particles. When they hit a surface, if it's soft they just mush down in asperity. If the asperity's brittle they break it off and if you look at the contaminant measurements in semi-conductor and disk drive pad clean rooms, it's EXACTLY the composition of cheap stainless steels with quite a bit of carbon which means they didn't use an L type carbon steel...

That's what the paper's going to be about. The American Vacuum Society. I went to this thing at the Convention Center, at the Town and Country -- they made me the keynote speaker...

[He then comments on a few people, including Bill Gates who's Small Modular Reactors is a terrible idea. "They know nothing about metallurgy up there" and when one fails, they'll all fail because they're all alike. he then suggests I buy some of the spent fuel to get cheaper radiation treatments for my wife, who, as he knows, is undergoing radiation treatments at the current time (she has exactly ONE more treatment to go, tomorrow morning.]

Plutonium's going to diffuse -- a proton is 2000 times heavier than an electron. So hydrogen is 2000 times heavier roughly than an electron. Plutonium is [94], so it's [almost] 100 [times] heavier [than hydrogen] so if this retards hydrogen, certainly it would retard plutonium [which is] real slow [in comparison]. And now, what plutonium's radiation damage does in terms of enhancing it's diffusivity, that's another story. I'm just talking about plutonium diffusing through something, not counting the radiation damage. The radiation damage might enhance the diffusivity because you'll get what are called thermal spikes, radiation damage spikes, so it might scoot along those a little, but they might be sideways, not through. You need multiple layers. Remember: A box of hydrox cookies. In fact, you should say, if you're testifying, "A box of girl scout cookies would be an effective shield around it. But only Hydrox!"

================= Transcribed May 4th - 5th, 2014 ===================


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