Why haven’t world leaders learned the most useful lessons from Fukushima?
Despite the tens to hundreds of billions of dollars that have been spent by governments and nuclear plant operators in the wake of three core melt events at the six-unit Fukushima Daiichi nuclear power station, the most useful lessons available from the experience remain unlearned.
At Fukushima Daiichi, the robust, defense-in-depth approach used in nuclear power plant design, construction and operations protected the public from the effects of massive damage at the plant. A clear-eyed look at the physical results indicate there is little or no reason to conduct early evacuations. There is no need to force people to abandon their homes and communities for periods in excess of five years and counting. There is certainly no need to be so worried about the possibility of something else happening at another power plant to shut them all down — just in case.
Special interests benefit by such drastic overreactions, with a majority of the benefits accruing to the interests involved in supplying fuel to produce the electricity that shut down nuclear plants are not producing. In Japan’s case, the imported fuel bill since March 11, 2011 has been more than $200 billion above what it would have been had the operational reactors continued to reliably produce their emission free output.
That cost to the Japanese people has been a revenue windfall to the fuel supply chain participants. Another group of beneficiaries has been the owners of the well-connected contracting companies that have employed thousands of low wage workers to move good topsoil from the fields where it can do the most good into unsightly plastic bags. One more group of beneficiaries are those people who have been well compensated for doing nothing. Unlike the real victims of the earthquake and tsunami whose homes were destroyed, they were able to point to a deep-pockets entity as the root cause of their homelessness. It’s hard to cash a check from Mother Nature, but easy to cash one from Tepco.
Fukushima reminded us that nuclear power plants are not perfect; there can and will be occasional accidents. However, it provides a visible “theory to practice” showing that the consequences of nuclear accidents can be limited to the plant boundaries with an effective, well-informed, calm response. The wild, fictional tales of widespread death and destruction that have been spun over the years are about as real as those that accompany a grade B horror movie.
Of course, implementing the lesson that nuclear plant events require mature, informed, rational corrective action is much easier said — or written — than done.
Around the world, people have been taught that the proper response to an event — almost any event — at a nuclear power station is to pack up the station wagon, grab the kids from school, and flee. After all, that is the response that happens in the movies and in one or two real life events that strangely resembled movie depictions. Experience from three different events — TMI, Chernobyl and Fukushima — with detailed post accident analysis available shows that the opposite is true; the best response is to remain in place, take a few simple precautions, and then go on with life.
Government leaders may claim that the public is so terribly frightened that they feel compelled to “do something,” but that attitude abandons the responsibility that accompanies the decision to accept a leadership position.
I might be oversimplifying here, but the problem is that we’ve collectively lost all sense of perspective associated with the words “contaminated” and “radiation” in the event of a nuclear accident. It is as if people believed that the phrase “that person has money” applies with equal emphasis to anyone with money, ranging from a panhandler with two nickels rubbing together in his pocket all the way to the opulence of the Saudi royal family, the Rockefellers, the Kochs, Bill Gates and Warren Buffett.
There are many powers of ten difference between having enough money to enjoy power and comfort and simply having a few coins. In the same way, there are many orders of magnitude between the kind of radiation dose that can cause harm, the dose that might provide a slight decrease in long term health, and the dose where the only effects that can be measured turn out to be somewhat beneficial to overall health.
Jim Conca published an excellent piece on Forbes titled After Five Years, What Is The Cost Of Fukushima? that attempts to tally up the costs associated with the Fukushima Frenzy. Here is how he starts that piece.
The disaster at the Fukushima Daiichi Power Plant following the devastating tsunami in Japan on the 11th of March in 2011 has proven costly in many ways – politically, economically and emotionally. Strangely, the costs that never materialized were the most feared, those of radiation-induced cancer and death. No radiological health effects have yet to result from the Fukushima disaster – neither cancers, deaths nor radiation sickness – although the WHO models indicate a slight increase is statistically possible. No one received enough dose, even the 20,000 workers who have worked tirelessly to recover from this event.
Though his article is well documented and worth reading and sharing, I had to respond to the following section.
By March 13th, 150,000 people were ordered to evacuate from within 20 kilometers of the nuclear plant. This was very effective in preventing any and all radiation-induced health-effects to the public thus far.
You see, I believe that the reason that international bodies have made such statements about the evacuation’s efficacy is that they are too polite or diplomatic to say that it was not needed. Not only did it cause a great deal of expense, but it cause some immediate injuries and early deaths among hospital patients who shouldn’t have been moved and it has created long term negative health effects from stress, uncertainty and distrust.
Here is the comment I contributed to the Forbes discussion:
Jim:
My understanding is that the public would not have experienced measurable ill effects from radiation even if they had never evacuated.
The doses were too small and the isotopes of concern short lived.
Even if we accept that evacuation was politically prudent, there is no excuse at all for having forced people to remain in temporary lodging for five years while their homes, farms and communities wasted away from a lack of human attention.
The tales of starving livestock and the images of abandoned buildings are being used by those who want to impose almost infinite costs on nuclear power plants in order to ensure that a Fukushima-like event “never happens here.”
In my opinion, a far more cost effective way to make sure that the negative impacts of forced relocation never happen anywhere else is to invest in efforts to build trustworthy knowledge about the actual health effects of low level radiation.
It is something to be understood, not something from which to flee in panic.
Rod Adams
Publisher, Atomic Insights
Additional Reading
March 14, 2016, William Hollingworth at Japan Times – Fukushima evacuations were not worth the money, study says
March 11, 2016, Andrew Karam at Popular Mechanics – Five Years Later, Cutting Through the Fukushima Myths
March 11, 2016, Gerry Thomas interviewed by BBC as reported on World Nuclear News – Time to look again at radiation safety
March 11, 2016, Steve Aplin at Canadian Energy Issues – Accurate and inaccurate predictions, garbage dumping, and death threats: an easy lesson about nuclear power, still not learned after 1,827 days
March 11, 2016, Les Corrice at Fukushima Commentary – Fukushima at Five Years: Rampant Radiophobia Ham-strings Japan (Note: Will need to search or scroll after new blogs have been posted at this location.)
March 10, 2016, Will Davis at Atomic Power Review – Five Years From Fukushima: Where Are We Now?
March 10, 2016, Margaret Harding at ANS Nuclear Cafe – Japan Moving Forward – Needs Nuclear
March 10, 2016, Rupert Wingfield-Hayes at BBC reporting from Fukushima – Is Fukushima’s exclusion zone doing more harm than radiation?
March 9, 2016, Sarah Fallon at Wired – Cancer rates spiked after Fukushima, but don’t blame radiation
“Government leaders may claim that the public is so terribly frightened that they feel compelled to “do something””
This is particularly tragic given that “doing something” will have the effect of confirming the public’s belief that the risks are such that something had to be done. It will actually increase, or cement, public fears. The people don’t look at what we say (e.g., that the risks are actually quite small), they look at what we do. And they assume that actions taken are warranted.
What a vicious circle. What a case of circular logic.
Great article overall, BTW. Everything was spot on. Couldn’t have said it better myself.
@Jim Hopf
Thanks for the kind words. I’m blushing and happy you liked it.
You are not alone in thinking that the evacuation did a lot more harm than good. This recent study is interesting:
Fukushima relocations were unjustified, kneejerk reaction: UK academics
Depending upon how close people were to the spread of radiation, the team found that between 21 days and just under one day of life was saved by the relocations in Fukushima.
It would appear that mandatory evacuations are grossly unethical.
I shudder to think that Jazko would have evacuated a million more people from an 80 km radius, from areas where the additional lifetime dose would have been somewhere between 0.1 and 10mSv.
Great post, Rod.
Sooo….KCET ran a special last night, about what it was like in the control room for the succeeding 88 hours after the quake. What I find curious is the concern, bordering on panic, the the control room operators exhibited, by their own accounts, through interviews. You would think that actual operators would recognize the relative harmlessness of the event, if in fact it was as inconsequential of an event as is claimed on this website. Heck, to hear you guys tell it, these operators coulda yawned and taken a nap throughout these 88 hrs. I mean, what the heck, it was just a harmless meltdown, that was going to have no dangerous consequences. Perhaps, if in fact they ain’t gonna restart Fukushima Daichi, they should turn it into a day care center and park.
@poa
First of all, I never deny that the power plant site is hazardous and that the interiors of the destroyed reactors are inaccessible to humans who like living.
Secondly, plant operators were correctly worried and stressed about their assigned tasks. They were very difficult given the lack of power, light, and the high radiation levels in places they needed to go in order to operate or monitor status.
Most, if not all, were also sure, based on their training, that their community and nation was depending on their performance. We certainly don’t want people with a walk-away attitude as nuclear plant operators. They are part of the defense-in-depth approach I described.
However, there was no snatching of victory from the jaws of defeat. Things happened rather slowly and the public was never in any real danger.
Let’s suppose some arbitrary person hid in the containment structure of the Fukushima reactor in the hours between the tsunami and the partial meltdown. Is this reactor’s decay & fission product profile such that such a person be more likely to contract thyroid cancer from I-131, as was the case with Chernobyl’s meltdown, or something else?
Also, I’ve heard radiation (especially Chernobyl, obviously) is a major contributing factor to leukemia risk. Is there some basis in fact for this belief?
That would be a very difficult thing to do. The reactors at the Fukushima I plant were of a design that used relatively small containment. Unlike many of the reactors today that have a containment that consists of a voluminous building structure, the first generation of the General Electric reactors used a metal containment that closely surrounds the reactor pressure vessel. It also includes a toroidal-shaped section that is half filled with water, but how would someone manage to enter this space, which is sealed.
Someone that close to the reactor would have much more to worry about than developing cancer down the road. The temperatures would probably kill the person in short time. You might as well ask what would happen to someone who hid under the boiler of a coal-burning plant just after it was shut down.
At large enough exposures, there is an increase in the risk of leukemia. Often this risk is overstated. Compared to other potential environmental exposures that are out there that increase the risk for leukemia, radiation is a fairly weak carcinogen.
Nevertheless, this association does have its uses. When researchers at Columbia University investigated the potential consequences of the accident at Three Mile Island in 1979, the major signal that they were looking for was an increase in childhood leukemia. There are two reasons for this choice: (1) children are generally more susceptible to radiation exposure than adults and (2) leukemia is a cancer that shows up rather quickly after exposure. This study, which was published barely ten years after the accident, examined the cancer statistics for only the first six years. Therefore, they needed something that would be observable in that time frame.
They didn’t find anything.
@Travis Lucy
The reason there were some population effects from the radioactive material released from Chernobyl was because the Soviet Union hid the fact even from their own citizens and did nothing to interdict contaminated food, especially milk, for several days afterwards. This is especially the time when the radioactive iodine can do its damage. As for leukemia, I would suggest going to Rod’s archives: https://atomicinsights.com/even-in-science-there-is-room-for-an-english-major-who-can-parse-words/. He says out of 110,645 Chernobyl clean up workers, 19 might have contracted radiation related leukemia.
A couple of years ago, I was talking to a lady whose son was part of the Boy Scout Troop I and my son were members. She was from Russia and worked at a technical institute near St Petersburg during Chernobyl. As soon as they heard about the accident, several days after, they starting measuring the radioactivity in their milk. According to her, it was clear that there was a problem.
The Japanese government, being much more proactive, ensured that this mistake regarding food and water was not repeated. However, they could not get around the fact that there would be a human toll from the evacuation likely greater than the radiation doses to most of the people being evacuated.
Enjoy!
Flying Finn
Amen
I few hours ago I emailed the lead researcher of the UK study and asked his group used LNT as a risk parameter. It looks like it since the range of time saved per evacuee ranged from 21 days to 1 day. That extremely low “1 day” looks suspiciously like an LNT use.
I’m surprised Jim Conca wrote that and am glad Rod Adams corrected him. What I do not understand is why the US was so incompetent to declare an 80 km exclusion zone. When I first saw that on CNN, I told friends it must be an error and will soon be corrected. When t wasn’t, I spent the next few days thinking what a joke American science has become – yet I knew that also wasn’t true.
So what is possibly going on? Oh, Jaczko…. Can one person alone do that? Or where other powers that be in the decision making process? I’m guessing the latter and especially those at the Pentagon who were highly annoyed at the PM of Japan in 2009 which severely strained relations for several months to the point where one Western expert thought the alliance as it stood was likely over..
@Todd in Japan
If you have the time and interest, you can go through the pages of NRC Ops Center transcripts about what discussions occurred between the NRC Staff and then Chairman Jacsko about the evacuation recommendation for US citizens.
Here is the NRC website for the Fukushima FOIA information: http://www.nrc.gov/reading-rm/foia/japan-foia-info.html
It has been a while since I looked through this but I seem to recall that the concern, rightly or wrongly, was that if the spent fuel pools were burning or about to burn from the units whose roofs blew off, then the calculations showed there would be significant doses to the public out further than the evacuation zone of the Japanese government, if not evacuated. Of course, now we know that the spent fuel pools were always covered with water. However, at the time, there was much confusion about the spent fuel pools.
I also believe that this confusion of what was going on with these pools led to the NRC to issue the order for enhanced spent fuel pool instrumentation.
Enjoy!
Flying Finn
The Unit 4 Reactor Building explosion occurred from Unit 3 Hardened Vent Path flow to the common stack piping. Unit 3 and Unit 4 shared a common connection to the stack. When Unit 3 was vented at a very high Containment Pressure, Hydrogen was pushed into Unit 4. The Unit 4 Standby Gas Treatment Train dampers failed open due to power loss. Unit 3 effluent had sufficient Nitrogen inertion, but after pouring into free air in Unit 4 the Hydrogen found Oxygen and the rest is history.
A defueled plant had suffered a Reactor Building explosion.
Unit 4 Spent Fuel Pool included a full core discharge – since Unit 4 was in a Core Shroud replacement project outage when the accident occurred. That fact led some to incorrectly conclude that Unit 4 Spent Fuel Pool quickly heated up, evaporated, and the Unit 4 explosion must have been caused by cladding oxidation / Hydrogen generation. The evacuation order coincided with this incorrect assessment.
Limited information can cause such incorrect assumptions. I’m a BWR SRO – and at the time I couldn’t get coherent information any of my industry or government contacts.
The Standby Gas Treatment Trains have a sweep exhaust that runs along and a few inches above the normal Spent Fuel Pool Water Level. This duct work can provide several paths to poke a semi rigid hose up from lower (shielded) elevations in the Reactor Bldg to accommodate spray / fill function. The refuel floor itself is radiologically inaccessible if pool level drops more than 15 feet or so.
It is also possible that with a full core discharge condition, that RHR had already been aligned in Spent Fuel Pool Cooling Assist mode. If so, temporary pumps can be attached to RHR Piping – resulting in filling the Spent Fuel Pool through an existing pathway.
Unit 4, having no core melt in the Reactor Vessel, likely had accessible Reactor Building equipment below the damaged grade of the refuel floor.
I conveyed that information to US NRC Emergency Operations Center and to the IAEA in Vienna Austria, to ensure the Japanese had a chance of getting these ideas.
Not much useful information was coming from Japan early on.
That makes bad recommendations more likely.
“Not much useful information was coming from Japan early on.
That makes bad recommendations more likely.”
So….is it your conclusion that the evacuation of Americans in such a wide zone was a prudent error on the side of caution?
@poa
I cannot ever agree with evacuating a wide zone to avoid minor radiation doses (in the range of microsieverts per hour) as a “prudent error on the side of caution”. Rapidly moving — Evacuating — people is dangerous even in the best of circumstances; it is worse when there is are major constraints on transportation infrastructure caused by natural disaster damage.
But, in truth, Rod, won’t you admit that it is impossible to draw comparisons, or compile statistics, had the evacuations not taken place? There is no way of knowing what pyschological problems, suicide rates, etc, would have resulted had the evacuations not taken place. Whether or not a true radiological danger existed is irrelevent if the dvacusted citizens believed one existed. Remaining in place, with such fears, and widespread distrust towards TEPCO and the government, may well have taken a greater toll on the collective pysche than displacement has. There is simply no way of knowing. Attaching firm statistics to the toll of the evacuations, and claiming that this toll is higher than what would have occurred had no evacuations taken place, is a disenguous attempt to slant the argument in the favor of the “the accident is no big deal” advocates.
@poa
You’re not getting the purpose of my post.
The damage of this evacuation has already been imposed. What I’m trying to do with Atomic Insights is to stimulate a major reevaluation of the utility and hazard of nuclear energy and radiation. Part of that effort should be establishing a science based understanding of the actual effects of radiation exposure so that the chances of the kinds of psychological problems are vastly reduced the next time there is a radiological event.
You may be uncertain, your friends may be uncertain, and many of the people who oppose nuclear energy may want to encourage uncertainty.
However, we have a very good understanding of how radiation affects human beings and other living things. It isn’t guesswork. It’s science.
No. It turned out to be unnecessary.
My point is that better decisions could have been produced with more information.
The information I was able to obtain was near useless – the U.S. NRC made some erroneous judgements.
The decay heat load and boil off times didn’t support a dry pool cladding oxidation reaction. Reactor Building explosion on Unit 4 wasn’t well understood until Standby Gas Treatment Train radiation levels indicated that reverse flow had occurred. Downstream HEPAs had higher rad levels than Upstream HEPAs and pre filters.
No, Rod, you are mistaken. I understand your motive here. My post was directed at the argument often offered by commenters here. An argument, I must add, that cannot be buttressed by logic. You cannot make comparisons between two scenarios when one scenario is real, with actual statistics, and the other is imagined, with no actual statistics. Will you admit as much?
Jaczko is probably the best example of what happens when you turn some institutions into de facto dictatorships. Wrong guy gets in, turns everything into dog’s dinner.
Jaczo declared an emergency which gave him dictatorial powers. That an accident in Japan could be an emergency in the US was non-sense and should have been rejected by others. As I understand the initial diagnosis that the stored fuel rods were possibly dry was presented to Jaczo, but then not too long after he went public it became clear that they were not and Jaczo failed to retract his message.
Given what we knew at the time I wonder if an orderly evacuation for a week or two would have been the proper response. Similar to response to an oncoming hurricane. Things are happening that are far from normal and there is a lot of uncertainty with some chance of large scale exposure so get out of the way. But within a few days there is much more certainty that nothing dramatic is going to happen so you can move back. Since the chance of a large scale release is modest even in the aftermath of the tsunami it does not make sense to do a panic evacuation or to move people that aren’t in shape to evacuate.
“But within a few days there is much more certainty that nothing dramatic is going to happen so you can move back.”
On the face of it, I agree with you. But what you are not considering is the distrust these people had towards both TEPCO, and their government. Are you sure that these people would have trusted TEPCO’s word that it was safe to return to their homes? And what would the toll have been on the collective psyche of those that did return, considering those many alleged purveyers of FUD, who would subject them to a steady stream of doom and gloom about what effect the radiation was having on them and their children? I just don’t buy that any argument stating that the evacuation’s psychological toll is greater than the toll of a non-evacuation is a credible argument. It is a hypothesis at best, and propaganda at worst. There is simply no way to credibly make such a claim. And its a shame I see it repeated here as often as I do, because it does harm to the overall credibility of the premises, opinions, and arguments offered here.
@poa
Suppose I said I agreed with your hypothesis regarding the barrage of doom and gloom from the antinuclear opposition AND the fact that Tepco and the government had been successfully discredited?
Does that mean that the best way to avoid the psychological harm done by an unnecessary evacuation is to merely accept that those activities are going to occur and to evacuate in an attempt to avoid the human-created mythology?
I chose a different path. I will keep trying to encourage people who have professional expertise in radiation health effects to seek all ways they can imagine to share their knowledge and seek improvements in response planning. That will include the same kinds of public engagement that Japan already does to help people understand the potential danger of earthquakes and tsunamis so that they can effectively plan escape routes and calmly implement their plans when necessary.
Of course the opposition will oppose that effort. That is what they do. But the option of giving up simply does not seem acceptable to me.
@poa
Just because some people are afraid doesn’t mean that you should implement a mandatory evacuation. Over time people have been afraid of all manner of things – we can try to help with that by acting responsibly but in the end people will have to make up their own minds. I say it does harm to the credibility by acting as though there was real danger. I think you reinforce the fear by evacuating people.
I think we can be pro-active. If I were head of TEPCO I would have:
a) brought in a cruise ship for the workers
b) moved to the site for the first couple of months.
c) encouraged people of Japan to focus on helping all the victims of the tsunami not just those near the power plant.
d) tried to find a way to hire the farmers and fishermen that were put out of work by my plant
e) demanded comparisons of the projected cancer rate projected (even with LNT) in Fukushima to those inside say Tokyo. Pretty sure Tokyo will be higher.
Lars….
I agree with everything you said. Carefully read my argument. I am not arguing in support of the evacuation. Nor am I arguing against the evacuation. I am arguing against making disingenuous claims that the evacuation caused more casualities and emotional distress than would have resulted had the evacuation not have occurred. It is simply impossible to credibly make such a claim, and I see it made here ad nauseum. Like I said above; you cannot take a real bit of history and its statistical evidence, and compare it to a imagined bit of history. Its a hypothesis, and nothing more. To present it as reasoning based in fact is pure unadulterated BS. And peddling pure unadulterated BS does little to instill confidence in the credibility here.
1. I just got a reply from the lead author of the British team that concluded evacuation around the reactors at Fukushima saved between 1 day at the low end and 21 days at the high end of evacuees’ lives. He said that the study does use LNT as recommended by the ICRP.
2. Even if the pool became dry, dangerous levels of radiation would have been limited to the plant and maybe areas in the immediate vicinity. How does a huge 80 km/50 mi radius make any sense?
For the last week the history channel has had an about “Pickers” finding an old show X-ray machine that was common in many department stores in the USA in the 40’s & 50’s. Considering that my brothers and sisters and everyone I knew in grade school played with that machine for much longer than would ever be allowed by the NRC for even a podiatrist examining feet today, where are all of the cases of lower extremity cancer, testicular and ovarian cancer that those doses would have given these young (grade school 8 – 12 years old) kids? With two sisters and a brother there was a lot of time playing with that as my mother help one of us get shoes. That was an annual event till I got into Jr, High.
From Wikipedia “Large variations in dose were possible depending on the machine design, displacement of the shielding materials, and the time and frequency of use. Radiation surveys showed that American machines delivered an average of 13 roentgen (r) (roughly 0.13 sievert (Sv) of equivalent dose in modern units) to the customer’s feet during a typical 20 second viewing, with one capable of delivering 116 r (~1 Sv) in 20 seconds.” I spent much more than 20 seconds – closer to a few minutes. same for everyone I knew. Without a doubt, I received more radiation on that machine than my entire time in the Navy and during my recovery efforts at TMI (after you subtract average background radiation levels that are measured along with your “working” dose). I know the “extremities” can take a higher dose, but the articles on the internet claim that the dose was higher at the waist.
I think that MUCH of the early fears of contamination release from the plants stemmed from the nearly total lack of DATA that was (not) available immediately after the earthquake/tsunami. If a COMPLETE mixture of fission products from the melted fuel had been released (only the FPs gaseous at the temperatures encountered were released…Xenons, iodines and cesiums), the hazard would have been MUCH higher and long-lasting. Thankfully, it wasn’t.
That said, I think that it became clear soon enough after the accident and BEFORE any evacuation decisions were made that only relatively innocuous and shorter-lived radionuclides were released and that a fact-based decision would have been to shelter in place.
Mark
@Mark Miller
If a COMPLETE mixture of fission products from the melted fuel had been released (only the FPs gaseous at the temperatures encountered were released…Xenons, iodines and cesiums), the hazard would have been MUCH higher and long-lasting.
What is the physical mechanism that could cause this to happen. Do you realize what the vaporization point of UO2 is?
From Wikipedia:
Caesium, 55Cs
Some silvery-gold metal, with a liquid-like texture and lustre, sealed in a glass
Physical properties
Phase solid
Melting point 301.7 K (28.5 °C, 83.3 °F)
Boiling point 944 K (671 °C, 1240 °F)
*************
Uranium
Phase solid
Melting point 1405.3 K (1132.2 °C, 2070 °F)
Boiling point 4404 K (4131 °C, 7468 °F)
Cesium JUST HAPPENS to have a low “boiling point” (1240F), whereas Uranium has a HIGH boiling point 7468 F). The same was probably the case for many of the other solid fission products, which is why they weren’t released at Fukushima.
Mother nature “caused” the disaster, but at least she minimized it by having higher boiling points for most FPs.
Mark
Hi, Correct me if I misunderstand something, but a zero-valent Cs atom should rapidly reduce U affording a strongly bound species. There must be data for what actually can bake out of used oxide fuel, but a first principals argument based on the properties of cesium metal does not seem reasonable. Chris M.
I can’t comment on the complex chemistry that may occur. My understanding is simplistic only.
@ChrisM
There is no elemental U metal in commercial nuclear fuel. The ceramic fuel pellets are UO2.
@Rod You miss the point. Any non-zero oxidation level of uranium will be reduced by zero-valent cesium. If in UO2 fuel a presumably zero-valent Xe, Xe(O), beta decays to (net) Cs(O), then that powerful reductant will reduce the U(IV) in UO2 to U(III). Uranium will lose a coordinating oxygen and Cs(I) will be bound to that oxygen. Because UO2 is not a molecular solid, a simple molecular formula cannot describe the product.
What I don’t know is if Cs(O) can really be formed in any way in fuel. Since we observe beta-particles it means that they have too much energy to stay around providing charge compensation, so Cs would be born as Cs(I). Charge balance must work itself out on a larger scale.
This is a response to your comment about uranium metal, which I guess is too far down the reply hierarchy for me to reply to directly. Nothing in my earlier comment should imply the existence of U(O)–that is metallic uranium–in oxide fuels. Chris M.
Well, ChrisM… what about it? Cs2O has a melting point of only 490°C. Metallic uranium has a melting point of 1132°C, and nothing in a ceramic pellet will be in pure metallic form after partial reduction.
Yes, cesium (metallic or oxidized) will likely boil off before anything happens to uranium in a ceramic form. What exactly were you concerned about?