Pool Near U.S. City Contains More Radioactive Cesium than Released By Fukushima, Chernobyl and All Nuclear Bomb Tests COMBINED

George Washington's picture

Radioactive Fuel Fires: Not Just a Japanese Problem

The spent fuel pools at Fukushima are currently the top short-term threat to humanity.

But fuel pools in the United States store an average of ten times more radioactive fuel than stored at Fukushima, have virtually no safety features, and are vulnerable to accidents and terrorist attacks.

If the water drains out for any reason, it will cause a fire in the fuel rods, as the zirconium metal jacket on the outside of the fuel rods could very well catch fire within hours or days after being exposed to air. See this, this, this and this. (Even a large solar flare could knock out the water-circulation systems for the pools.)

The pools are also filling up fast, according to the Nuclear Regulatory Commission:

fig044 Fuel Pool 35 Miles from Major American City   which Is Highly Vulnerable to Earthquakes   Contains More Radioactive Cesium than Released By Fukushima, Chernobyl and All Nuclear Bomb Tests COMBINED

The New York Times notes that squeezing more rods into pools may increase the risk of fire:

The reactor operators have squeezed spent fuel more tightly into the pools, raising the heat load and, according to some analyses, raising the risk of fire if the pools were ever drained.

Indeed, the fuel pools and rods at Fukushima appear to have “boiled”, caught fire and/or exploded soon after the earthquake knocked out power systems. See this, this, this, this and this.

Robert Alvarez – a nuclear expert and a former special assistant to the United States Secretary of Energy – notes that there have also been many incidents within the U.S. involving fuel pools:

Even though they contain some of the largest concentrations of radioactivity on the planet, U.S. spent nuclear fuel pools are mostly contained in ordinary industrial structures designed to merely protect them against the elements. Some are made from materials commonly used to house big-box stores and car dealerships.




All spent fuel pools at nuclear power plants do not have steel-lined, concrete barriers that cover reactor vessels to prevent the escape of radioactivity. They are not required to have back-up generators to keep used fuel rods cool, if offsite power is lost.




For nearly 30 years, Nuclear Regulatory Commission (NRC) waste-storage requirements have remained contingent on the opening of a permanent waste repository that has yet to materialize. Now that the Obama administration has cancelled plans to build a permanent, deep disposal site at Yucca Mountain in Nevada, spent fuel at the nation’s 104 nuclear reactors will continue to accumulate and are likely remain onsite for decades to come.


According to Energy Department data:

  • The spent fuel stored at 28 reactor sites have between 200-450 million curies of long-lived radioactivity;
  • 19 reactor sites have generated between 100-200 million curies in spent fuel; and,
  • 24 reactor sites have generated about 10-100 million curies.

Over the past 30 years, there have been at least 66 incidents at U.S. reactors in which there was a significant loss of spent fuel water. Ten have occurred since the September 11 terrorist attacks, after which the government pledged that it would reinforce nuclear safety measures. Over several decades, significant corrosion has occurred of the barriers that prevent a nuclear chain reaction in a spent fuel pool — some to the point where they can no longer be credited with preventing a nuclear chain reaction. For example, in June 2010, the NRC fined Florida Power and Light $70,000 for failing to report that it had been exceeding its spent fuel pool criticality safety margin for five years at the Turkey Point reactor near Miami. Because of NRC’s dependency on the industry self-reporting problems, it failed to find out that there was extensive deterioration of neutron absorbers in the Turkey Point pools and lengthy delays in having them replaced.


There are other strains being placed on crowded spent fuel pools. Systems required to keep pools cool and clean are being overtaxed, as reactor operators generate hotter, more radioactive, and more reactive spent rods. Reactor operators have increased the level of uranium-235, a key fissionable material in nuclear fuel to allow for longer operating periods. This, in turn, can cause the cladding, the protective envelope around a spent fuel rod, to thin and become brittle. It also builds higher pressure from hydrogen and other radioactive gases within the cladding, all of which adds to the risk of failure. The cladding is less than one millimeter thick (thinner than a credit card) and is one of the most important barriers preventing the escape of radioactive materials.




I co-authored a report in 2003 that explained how a spent fuel pool fire in the United States could render an area uninhabitable that would be as much as 60 times larger than that created by the Chernobyl accident. If this were to happen at one of the Indian Point nuclear reactors located 25 miles from New York City, it could result in as many as 5,600 cancer deaths and $461 billion in damages.


The U.S. government should promptly take steps to reduce these risks by placing all spent nuclear fuel older than five years in dry, hardened storage casks — something Germany did 25 years ago. It would take about 10 years at a cost between $3.5 and $7 billion to accomplish. If the cost were transferred to energy consumers, the expenditure would result in a marginal increase of less than 0.4 cents per kilowatt hour for consumers of nuclear-generated electricity.


Another payment option is available for securing spent nuclear fuel. Money could be allocated from $18.1 billion in unexpended funds already collected from consumers of nuclear-generated electricity under the Nuclear Waste Policy Act to establish a disposal site for high-level radioactive wastes.

This situation cannot be blamed on the nuclear industry alone (which wouldn’t exist without government subsidization of the nuclear industry). The U.S. government promised to come up with a permanent storage solution more than a decade ago, but has failed to do so. As nuclear affairs chief Terry Pickens for Xcel Energy correctly says:

We were able to get it where we thought we could make it to 1998, and they are still not performing. And now we still want to refuel and operate our reactors, so we have to make more space in the pools.

The New York Times noted in 2005:

Most of the plants now operating were designed to store fuel for only a few years, because engineers expected that it would either be recycled or buried. The Energy Department was supposed to begin accepting fuel for burial in 1998 but has not yet done so.




The Nuclear Regulatory Commission has repeatedly said that cask storage and pool storage are equally safe. On March 14, the commission’s chairman, Nils J. Diaz, told reporters that the pools ”are not easily breached structures.”


After an attack, they would be very easy to cool, he said. ”You get a couple of fire hoses, and spray them, and you have many, many hours,” he said, before there could be any radiological release, giving officials time to contain the problem.

That isn’t working out so well at Fukushima.

Single Pool Near Major American City Holds More Cesium than Fukushima, Chernobyl and all Nuclear Tests … Combined

Nuclear engineers David Lochbaum and Arnie Gundersen provide a stunning figure on the amount of radioactive fuel stored in the fuel pools at Pilgrim nuclear power plant in Plymouth, Massachusetts:

[There is] more radioactive Cesium in the Pilgrim Nuclear Plant’s spent fuel pool than was released by Fukushima, Chernobyl, and all nuclear bomb testing combined.


(And listen to this new must-hear interview with Gundersen).

The Pilgrim Nuclear plant is only 35 miles from downtown Boston.

According to the Nuclear Regulatory Commission, Pilgrim has the second highest risk of damage from an earthquake of any American nuclear facility.

What could possibly go wrong?

Nuclear power can be safe, or it can be cheap … but it can’t be both. For example, we’ve previously noted:

Apologists for the nuclear power industry pretend there are no better alternatives, so we just have to suck it up and suffer through the Japanese nuclear crisis.


But this is wholly illogical. The truth is that we can store spent fuel rods in dry cask storage, which is much safer than the spent fuel rod pools used in Fukushima and many American reactors.


As the Nation pointed out:

Short of closing plants, there is a fairly reliable solution to the problem of spent fuel rods. It is called “dry cask storage.”




But there is a problem with dry cask storage: it costs money….

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Gohn Galt's picture

American indoctrination makes it impossible to think or question.  Comrade

gaoptimize's picture

George, I share your concern, but let's remmember is was people of your ilk that killed the Clinch River reprocessing facility for rediculous peacenik reasons, and effectively killed the Yucca Mountain long term storage facility that would have reduced this risk.  But that is heavy water under the bridge.

Many of us who would like to continue a high-energy utilization advanced (and advancing) civilization believe nuclear power and its risks will be necessary in the medium term.  We are not going to convince you of that and you are not going to like the economic consequences of a transition away from nuclear power. So, why don't you accept that some form of nuclear power is going to happen and advocate for safer and more environmentally sensitive alternatives?

Matt's picture

Because nuclear is a behemoth of energy production, at less than 10 percent? http://cdn.physorg.com/newman/gfx/news/hires/2011/usenergyuse.jpg

Because Nuclear power is so cost effective, it can only exist with massive government subsidies?http://www.zerohedge.com/contributed/2012-15-11/nuclear-power-expensive-and-bad-environment-%E2%80%A6-it%E2%80%99s-being-pushed-because-it-go 

And how do you propose storage? you need to employ people for thousands of years. No civilization has ever lasted that long. Sticking it in the ocean or flying it into the sun just isnt going to happen.

Hopefully, the masses make this a major issue, and by forces of numbers, democratically bring an end to this madness. It seems this is one issue that has the ability to wake the masses and get them to pay attention, at least once a generation when a catastrophe occurs.

Stuck on Zero's picture

It's insane to store spent fuel in big masses.  It's only a risk in large masses because of self excitation.  Divided up into small amounts it will never go critical.  The solution is to take spent fuel rods, encase them in stainless steel and hand them out for people to store as nice heat sources.  Stack a few of these babies in the cellar and you'd be warm all winter with no risk of radiation.

gaoptimize's picture

Great idea in a perfect world, but regrettably there is a risk that Mo, Amed, and Haji would sign up for the program and then misuse the active ingriedients.

Stuck on Zero's picture

Mo, Amed, and Haji are smart enuff to know that Home Depot sells everything they need to Jihad the infidels.  Besides, cutting into a 200lb stainless bar full of Cesium 137 is suicide. 

parch702's picture

What bullshit is this? Boston IS NOT HIGHLY VULNERABLE to earthquakes.

Clowns on Acid's picture

Gene - you are a dumb fuck.

The last earthquake in Boston was in 1755. The article you reference calculates an Index based on the amount of damage an earthquake could cause if...

From your lazy reference

"According to the index, Bostonians face an overall earthquake risk comparable to San Franciscans, despite the lower frequency of major earthquakes in the Boston area. The reason: Boston has a much larger percentage of buildings constructed before 1975, when the city incorporated seismic safety measures into its building code."

Gene Parmesan's picture

I'm the dumb fuck, or are we talking about "vulnerability" to earthquakes (vs frequency of earthquakes)?

stickyfingers's picture

Maybe so but the REALLy big threat is from the wind farm.

Bicycle Repairman's picture

Dead birds, dude.  Including ....... bald eagles.

americanspirit's picture

Store compressed natgas securely at the site set up with flexible couplings and shock isolators ready to power shock-isolated emergency pumps to flood damaged storage tanks with seawater when electric power is knocked out. Build redundancy into the CNG storage and hookups, and be sure the seawater intake pipes have multiple isolated lines. Even if the waste storage tanks are leaking badly design the system to put as much seawater as needed on top of those rods. Power the whole system with redundant solar-charged batteries that are on 24/7 standby. Oh - sorry. Might cost a bit. Never mind.

cpnscarlet's picture

GW - You are an absolute wingnut and it's because of your stupid comments that I decided to post here again after many months. However, your inept commentary is shear genius compared to the general scientific ignorance of the general US populace.

The answer has always been simple and the French know it. Simply encase the waste in concrete and bury it in some granite vault, then cap with more concrete. Problem solved, case closed. There are some clear thinking people here who have said pretty much the same.

Even better - encase in concrete and drop it all in the Marianas Trench - 7 miles down and you'll never see it again. The radiation will be buffered by the water and the latent heat will give rise to wonderful new colonies of organisms. Life is beautiful. 

ArrestBobRubin's picture

Asswipe scarlet, go crawl back under your rock. Please stay away from ZH, just continue to plague the poor fools and morons left over at Turd Ferguson's once fine blog. They're more your speed anyway.

You can't wipe the shit off GW's shoes fool.

TSA gropee's picture

Yeah, that concrete sarcophagus at Chernobyl is working out so well that it needs replacing already. Great thinking dumbass.What the hell do you think the constant bombardment of radioactivity does to the integrity of said concrete? And you want to put it in the bottom of the ocean? LMAO, there'll be new colonies alright, colonies of mutated species.

Nice work as always GW.

OpenThePodBayDoorHAL's picture

Read the National Sciences Foundation report fer chrissakes. That is an unimpeachable organization, and what they found is truly terrifying. Estimated 150 million people exposed to a cocktail of 66 different radioactive isotopes. The so-called "safe" exposure levels touted by scientists have gone steadily downward over the decades and for many substances are now at 1 microgram. That's one billionth of a gram.

When Chernobyl blew the Russians needed manpower to shovel sand into the pit. The lifetime exposure limit was 2 minutes. So they went to new army draftees and told them they could do two years in the army or two minutes at Chernobyl. The number that chose the two minutes: more than *800,000* young men.

Wild boar hunters in Germany were finding boars that *glowed in the dark* due to ingesting radioactive mushrooms.

They built the concrete sarcophagus at a cost of billions of dollars. Now the thing needs a rebuild and they're going around begging the world for the money to build it. They are asking for a cool $100 billion. Seems to me that would buy a lot of photovoltaic panels.

geekgrrl's picture

Exactly. Nuclear was a colossal misallocation of capital, and that will become more obvious as plants age further and accidents become more frequent. If we would have put that money into solar PV and solar hot water, we would be well along the way to complete energy independence and we wouldn't have all these outrageously dangerous overloaded spent fuel pools all over the country.

mess nonster's picture

What the FUCK is wrong with us as a species? Where does this kind of evil short-term thinking pathology originate? How can we endanger the planet like this, so casually, and then lie about the real dangers in the blandest sort of Eichmannesque way?

The human race as it is currently evoloved must be exterminated. Oh wait, this time around, it is too late to fix the problem of pervasive evil by a Flood. Any catastrophe that falls short of a total solar inferno that has temperatures high enough to literally incinerate nuclear radioactive materials back to safe levels is not going to cleanse the planet.

"By fire next time" takes on a new meaning after reading this article.

Hubbs's picture

Relax <sarc>, evolution in most cases takes place over long periods of time, although there are a few exceptions noted where dramatic evolutionary changes occurred over very short time, at least from what can be documented from fossil records, etc.

Mother nature really doesn't care whether living organisms are smart or dumb..if it the random design generated product works and reproduces, it continues. H. sapiens seems to be very successful in an evolutionary sense...so far..but if we really screw up just once, then mother nature will just quietly chortle: "I guess "intelligence" doesn't insure reproductive success in the long run", and turn the baton back over to cock roaches, insects, or small furry mammals.

Transformer's picture

"What the FUCK is wrong with us as a species?"

Simple answer: Psychopathy.   There is a rogue gene in our DNA that ends up affecting 1-2% of our population.  These individuals are defective in that they feel no emotions, or no emotions with the exception of the joy of winning.  As a society grows, eventually, the psychopaths end up in control.  They have no feelings, and care only about winning.  Most of us have strong feelings about what happens to our children.  Psychopaths have none.  If you really want to understand what's wrong, do some research.  Once you understand the psychopath, and his ability to do wrong, it will blow you away.  If we could fix this, the earth would be a different place.

taxpayer102's picture


Deranged minds of those 1-2% created this scenario described by the U.S.Nuclear Regulatory Commission :

"Because of their highly radioactive fission products, high-level waste and spent fuel must be handled and stored with care. Since the only way radioactive waste finally becomes harmless is through decay, which for high-level wastes can take hundreds of thousands of years, the wastes must be stored and finally disposed of in a way that provides adequate protection of the public for a very long time."

Fix It Again Timmy's picture

Better to spend billions on chickenshit military patrols in the middle of nowhere in Afghanistan because they hate us for our "freedoms"...

janchup's picture

We cant put any of this in Yucca Mountain. There might be an earthquake or volcano in 100,000 years.


boogiedown's picture

People in Nevada don't want truckloads full of nuclear waste traversing their roads daily from all over the country. And Native American tribes there don't want to get screwed over (again) by having their land stolen and turned into a toxic waste dump.

Let's send it to the UK: http://www.guardian.co.uk/environment/2004/dec/15/energy.greenpolitics?I...

i-dog's picture

  "raising the risk of fire if the pools were ever drained"

OK, which is it?

  1. "Raising the risk of fire" ... ie. there is a strong probability of no fire, but the risk is raised if more rods are added.
  2. Guaranteed to be a fire ... as in, according to GW: "If the water drains out for any reason, it will cause a fire in the fuel rods"
  3. Guaranteed to cause a nuclear explosion ... as in going "supercritical" as loudly trumpeted by Gunderson for the Fukushima pools.

So much scare mongering, so little time.....

Toolshed's picture

You are clearly just the type of idiot that TEPCO is looking for to put to work, briefly, at it's Fukushima plant. Go now!

flattrader's picture

i-dog is an i-diot.  Put a nickle in him and he'll explain that radiation doesn't cause cancer....only viruses do.

i-dog's picture

LOL ... two more fools who can't put an argument together ... only trite comments.

Go clean your room and get back to your homework.

steve from virginia's picture


1. "Raising the risk of fire" ... ie. there is a strong probability of no fire, but the risk is raised if more rods are added.

A: Adding more fuel rods makes any fire that takes place more destructive. If destructive enough the pool fire cannot be approached to contain it. Adding fuel rods might increase the chances of a fire because the circulation of water in the pool may be adversely effected. The idea is to never expose hot fuel rods or remove them from cooling water.

2. Guaranteed to be a fire ... as in, according to GW: "If the water drains out for any reason, it will cause a fire in the fuel rods" 

A: If the water drains out of SPF for any reason there WILL be a fire GUARANTEED. Note: the uranium oxide fuel will also burn if its temperature is high enough.

3. Guaranteed to cause a nuclear explosion ... as in going "supercritical" as loudly trumpeted by Gunderson for the Fukushima pools.

A: Any amount of fertile material in close quarters that is greater than critical mass is GUARANTEED to become critical. This is the principle by which reactors -- and nuclear weapons -- operate in the first place.

 Almost every piece of equipment in a nuclear power station is designed to prevent fuel from achieving criticality, from the design of the fuel pellets to the operation of cooling water pumps.

i-dog's picture

Nuclear explosions are caused by forcing two pieces of nearly critical concentrations together at high speed and with great force in an enclosure designed to retain the neutrons long enough to go critical. That's quite different from some rods melting and forming a hot, gooey mess at the bottom of an open-air container!

So ... please explain your "GUARANTEED to become critical"?

(If the technology for creating a nuclear explosion were as simple as leaving a few spent fuel rods in the open air for a while, then more than just North Korea and Iran would be aiming nuclear weapons at "our freedoms"!).

Money Squid's picture

Dog, if you are interested you can search for the info to convince/evaluate yourself - as I recall the English determined that you could use fuel grade fissle material to create a nuclear weapon, although not as efficient as a designed weapon's-grade device. The US tested the theory in the US for the English and it worked. The reactor fuel is shaped and stored in the RPV to support criticallity, but to avoid potential situations of super-criticality, and in the SFP to avoid criticality. Once you have a meltdown in the RPV or the SFP it is possible that the molten fuel forms a shape that supports uncontrolled criticality. If there is a significant explose in, or in proximity to the already critical mass, the pressure wave can cause an sudden increase in density that could support a supercrtical event - a nuclear explosion. This would not be as efficient/powerful as desinged device, but devistating nevertheless.


Edit- Here is a link to a video about chernobyl http://www.youtube.com/watch?v=yiCXb1Nhd1o&feature=related

Just watch from 31 to 35 minutes when Hans Blix shows up and there is a discussion about a steam explosion setting off a nuclear explosion of 3-5 Mt. Decide for yourself why the Russian nuclear experts thought that someting like this could happen.

Jim in MN's picture

Criticality is just a self-sustaining reaction with enough neutrons flying around to split more atoms, releasing enough neutrons to fly around etc.

It doesn't have to be either runaway or explosive. 

Basically the decay heat and the exothermic cladding oxidation create enough heat to cause the fires and radiation releases.  Criticality would be icing on the demonic cake.  Not needed for an ugly scenario.  But bad in that it would add nastier radiation and make the site that much harder to get to/fix.

flattrader's picture

>>>Criticality would be icing on the demonic cake.  Not needed for an ugly scenario.<<<

It's like i-dog missed both hydrogen explosions...

From i-dog >>>There's no end to the scientific facts and logical deductions one can glean from the latest batch of ZH interns. Sheesh.<<<

Fortunately, we have "experts" like him to rely on....and Trav "the reactors scrammed they didn't melt-down" 7777.

Revert_Back_to_1792_Act's picture

I guess you have never heard of Liquidators at Chernobyl.

I would suggest watching this whole documentary to gain understanding and it doesn't even scratch the surface of the things that went on there.



There was so much radiation that electronic devices like robots failed.

The sarcophagus they built to contain it is now failing.  

Watch the documentary. If you are in this industry, watch everything you can find about Chernobyl.


i-dog's picture

WTF have robots at the Chernobyl reactor meltdown (no Gunderson supercritical explosion there!) got to do with my question about fires and/or explosions in spent fuel rod pools ... ahem, the topic of this thread, ahem ... !?!?!

PS. Thanks for the junk, fuckhead....

Revert_Back_to_1792_Act's picture

I didn't junk you.  Chernobyl was caused by user error.  In complex systems, stuff happens.  The government and corporate structure is now very different than when most of the USA reactors were built. I think it is important to gain a full understanding of the human consequences of a problem at any facillity and count that cost.



i-dog's picture

Some nice motherhood statements there ... well done! ... but still totally avoiding the question.

Try to concentrate, read my original post again, then have another go ... or else, go and annoy some other thread with your off-topic trolling.

Here ... I'll help you ... if the water has run out of the pools, one can already assume that a human or systemic error has already occured. The horse has bolted! The clock can't be turned back. So ... what happens next? It gets a bit hot? Maybe fire? Definitely fire? Supercritical explosion? TEOTWAWKI? Pick one, and give a reason.

Revert_Back_to_1792_Act's picture

I don't know the answer to your question.  You are asking a question for an unknown scenario.  In my way of thinking, there is no way to scale an experiment like this up and test it.   The part of your post that I was replying to was the "So much scaremongering, so little time.".  A full understanding the risks is not scaremongering. 


Let me tell you a small parable. 

This traveller walks up near a new bridge.  All the townspeople are standing around watching.  On the bridge he sees two full locomotive engines and tenders - running and vibrating.  He finds the bridge engineer and asks him "Aren't you afraid that new bridge will break under the weight of those engines?".  The engineer says "Nah, we know it won't break, we are just proving it.".


i-dog's picture

  "Let me tell you a small parable"

*sigh*.... There's no end to the scientific facts and logical deductions one can glean from the latest batch of ZH interns. Sheesh.

Reptil's picture

obvious troll is obvious


RECISION's picture

So however big (or small) the risks of Nuclear are: the risks continue to get bigger over time, not smaller.

And to date, from an industry that is 70 years old, we have had two major catastrophic accidents.

On that run rate, we can expect another within 35 years.

And with increasing frequency thereafter...

Jim in MN's picture

Good morning, world, today is April 12 2012.  You are now roughly 6 days from global catastrophe at any given moment.  Enjoy all your non-world-saving activities and Have A Nice Day.



18:09 12 April

Spent fuel pool cooling system suspended at Fukushima Daiichi plant

TOKYO, April 12, Kyodo

A spent fuel pool cooling system was suspended Thursday at the No. 4 reactor at the Fukushima Daiichi nuclear power plant after an alarm went off, the operator Tokyo Electric Power Co. said.

The utility said it is looking into the cause of the trouble, suspecting a possible water leak in the system, which was halted after the alarm was triggered at 2:44 p.m. The pool is storing 1,331 spent fuel rods.

The utility said the water temperature at that time was 28 C and is expected to rise by about 0.5 degree per hour while the cooling system is under suspension.


(by the way that 28 degrees C is a nice warm 83 degrees F even when things are going 'super normal happy great' in TEPCO's view)

flattrader's picture


My understanding was they had 72 hours to restore coolling to any pool before the rods heated to the point where the following reaction was uncontrollable.

Any idea if that is the case?

Jim in MN's picture

What they are saying here is they think they have 6 days until it boils.  Then the water would have to boil off.  Then the rods can 'get busy' destroying themselves.  So they feel that they can suspend the cooling system for a day or two to fix whatever this problem is (all the core and fuel pool cooling systems have had their share of problems and temporary failures).

A crack/leak/collapse would be a lot faster.  Once the water is gone the timing depends on the concentration of the rods, their geometry/arrangement, neutron-absorbing moderator materials in the arrays, etc.  But they do heat up pretty quick, even one rod can be a beast if it's just sitting there in the air.  With this kind of concentration it might not take days and days once it's dry. 

National Academy of Sciences put it this way:


The committee will refer to such scenarios as “loss-of-pool-coolant” events. Such events could have several deleterious consequences; Most immediately, ionizing radiation levels in the spent fuel building rise as the water level in the pool falls. Once the water level drops to within a few feet (a meter or so) of the tops of the fuel racks, elevated radiation fields could prevent direct access to the immediate areas around the lip of the spent fuel pool building by workers. This might hamper but would not necessarily prevent the application of mitigative measures, such as deployment of fire hoses to replenish the water in the pool.

The ability to remove decay heat from the spent fuel also would be reduced as the water level drops, especially when it drops below the tops of the fuel assemblies. This would cause temperatures in the fuel assemblies to rise, accelerating the oxidation of the zirconium alloy (zircaloy) cladding that encases the uranium oxide pellets. This oxidation reaction can occur in the presence of both air and steam and is strongly exothermic—that is, the reaction releases large quantities of heat, which can further raise cladding temperatures. The steam reaction also generates large quantities of hydrogen.

These oxidation reactions can become locally self-sustaining (i.e., autocatalytic3) at high temperatures (i.e., about a factor of 10 higher than the boiling point of water) if a supply of oxygen and/or steam is available to sustain the reactions. (These reactions will not occur when the spent fuel is under water because heat removal prevents such high temperatures from being reached). The result could be a runaway oxidation reaction—referred to in this report as a zirconium cladding fire—that proceeds as a burn front (e.g., as seen in a forest fire or a fireworks sparkler) along the axis of the fuel rod toward the source of oxidant (i.e., air or steam). The heat released from such fires can be even greater than the decay heat produced in newly discharged spent fuel.

As fuel rod temperatures increase, the gas pressure inside the fuel rod increases and eventually can cause the cladding to balloon out and rupture. At higher temperatures (around 1800°C [approximately 3300°F]), zirconium cladding reacts with the uranium oxide fuel to form a complex molten phase containing zirconium-uranium oxide. Beginning with the cladding rupture, these events would result in the release of radioactive fission gases and some of the fuel’s radioactive material in the form of aerosols into the building that houses the spent fuel pool and possibly into the environment. If the heat from one burning assembly is not dissipated, the fire could spread to other spent fuel assemblies in the pool, producing a propagating zirconium cladding fire.

flattrader's picture

Thanks much.

Triple damn...another 5.plus EQ just within the past couple of hours.

Jim in MN's picture



Not seeing those on here yet but N. America is 'going off' today.

flattrader's picture


Happening Now: M5.9 quake hits Fukushima at 10:51a ET (MAPS) — Just hours after nearby M5.5

The link has a Japanese Meteorological Agency Map.