1. This all makes sense, but is it not possible the water level of the pool was reduced in some other manner – damage to the structure, or pipes conncting the structure, by the explosion, or even the earthquake?
    The most recent updates from the people on site is that the pool is not empty, but they don’t say what the water level is, so it is possible that the fuel is at least partially exposed.
    The next question is what possible mechanisms are there for a buildup of hydrogen in #4, there is no venting required because there’s nothing in the reactor, so from my limited knowledge on the subject it seems that the only mechanism would be the reaction with the zircalloy cladding of the fuel. Is that correct?
    We know there was an explosion in #4, and most informed sources seem to be assuming it was a Hydrogen explosion, does this not then imply the water level is low enough to leave the fuel exposed? Or are there any other possible causes for an explosion?

    1. @David – of the material that is in the used fuel pool, only about 5% is zirconium. According to recent national laboratory tests, even that portion of the material is not easy to burn.
      The spent fuel pool fire scenario is as much of a myth as the China Syndrome. Neither are possible in the real world.
      How do you know there was an explosion? How big was it? What portions of the building did it damage? Did it damage the structure of the used fuel pool?
      What is your source?

      1. I didn’t say anything about the zirconium combusting, I was asking whether if some of it was exposed it could cause a buildup of Hydrogen.
        Recent photographs clearly show a large amount of damage to the #4 reactor building, see: http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi1_march16_2011_dg.jpg
        #4 Is the one on the left, it seems to have had the side cladding blown off, rather than roof, if that tells you anything.
        So, if there was definitely an explosion in #4 what are the posisble causes? If the only reasonable explanation is Hydrogen, then what could have caused a build up of it.
        Don’t get me wrong, I’m not one of the doomsday crowd, regardless of the cause it doesn’t look likely that the current situation will result in any large scale release of radioactive material.

        1. here’s more recent info on the state of #4:
          “The explosion at unit 4 is thought to have been from a build-up of hydrogen in the area near the used nuclear fuel pond. It severely damaged the building, as well as that of adjacent unit 3, with which it shares a central control room.
          Now the situation of the cooling ponds is the priority of authorities. Containing highly radioactive heat-generating nuclear fuel, they require an adequate level of water to be maintained as well as pumped circulation to control water temperature.
          In the previous two days the temperature of unit 4’s pond had been 84

          1. Here’s the photo just after the 1st explosion at Unit 3: (1) http://www.flickr.com/photos/digitalglobe-imagery/5526481182/sizes/o/in/photostream/ . Unit 4 appears to be undamaged
            Next there are these two photos showing significant damage to Unit 4: (2) http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi1_march16_2011_dg.jpg and (3) http://www.nytimes.com/imagepages/2011/03/16/world/16nuclear4_span.html
            What I am seeing with photos 2 and 3 is that the damage to Unit 4 appears to be from teh direction of Unit 3. Look at the top level siding of Unit 4 that isfacing Unit 3. It is bent into the crane area volume. In photo (2), the right side of Unit 4 is in shadow, except for the top level siding on that side.
            I don’t think we are getting all the info out of Japan. Could it be that the “explosion at Unit 4” was actually a second explosion at Unti 3?

        2. @David – If there is a zirconium and water reaction that releases hydrogen, how much hydrogen can it release before you run out of zirconium? At what temperature is the reaction supposed to take place? Do you have a proposed mechanism that will achieve that temperature in a pool of water whose temperature was measured at 84 C within the past two days and that contains fuel that has been out of a reactor since late November?

          1. I’m not an expert so I can’t answer those questions, that’s why I’m asking you!
            All we know for a fact is that there was an explosion. What do you think caused it?

            1. If you can tell me how big it was, I might be able to propose some mechanisms. Otherwise, I am left with a situation where it appears to be damage that can be done by a fairly modest overpressure or one of those aftershocks. There is no evidence that safety significant systems, structures or components that are built to certain seismic standards have been damaged.

      2. Something destroyed the building since it looks similar to Units 1 and 3. Any ideas if not a hydrogen excursion? Would be glad to know that it was from the fuel.

  2. Well, I’ve known this for quite some time, but now it should be obvious to everybody. Jaczko is simply out of his league.
    It was irresponsible to make him head of the NRC.

  3. From the pictures it appears quite clear that there is little or no water in the spent fuel pool of Unit 4. With the open nature of the Rx Bldg there should be vapor coming from the pool and that does not appear to be happening. Based on the reports that they had a full core off load boiling should be evident. Unit 4 is a fairly large unit and if the core offload is relatively fresh there would be a very large heat load. At VY 4 days after refueling this would amount to >20E6 Btu/hr just for the core off load. Of course, based on time this would rapidly decay but not go away. Residual loading would probably approximate 4-6E6 Btu/hr. That and the radiation levels on Unit 4 point to a loss of spent fuel pool level, integrity or both.
    I’m not privy to any exact information, however, based on my knowledge of the design this is what I think may have happened. Unit 4 was in refueling with the Rx cavity full, the gate to the spent fuel pool open and a full core off load in the spent fuel pool. At some point either during the earthquake or at the time of the Unit 3 explosion the Rx cavity water seal became degraded (there are other potential failures such as fuel pool cooling piping but my first thought is that they are less likely) either way they began to lose water. A combination of water loss through leakage and possibly boil off reduced the fuel pool level considerably below the top of active fuel. This would have been sufficient to initiate a Zr water reaction liberating H2. The extensive destruction of the Rx Bldg points to this potential failure mode.
    Clearly they have an acute fuel pool issue at Unit 4 and at least one of the other Units. I would also be very concerned at Units 1 & 3, particularly 3 since the devastation is clear and there appears to be much rubble on the refueling floor. Since the fuel pool is designed with 5′ walls and a 9′ base it is unlikely that this was completely destroyed, although it may be degraded. However, there appears to be rubble on top of the fuel. This would not promote healthy natural circulation of the remaining water in the pool. It would very likely also impact the ability to maintain Keff <1.0. So it may be possible for the fuel in some areas to reach criticality.
    I suspect that they will first try to spray water over the damaged pool followed by dumping Boron in to limit the criticality potential.
    I have great empathy for all the operators, technicians and engineers at Fukushima. As someone who lives and breathes the design of a Mark I Type 4 every day I can only imagine the difficulties these people are facing. However, being in the Nuclear Industry it is critical that we face the brutal facts. These are that the response of TEPCO has been pathetic. There is no excuse for recognizing 6 days ago that this could occur. A BWR and for that matter any current design is in a critical condition without AC power. In this case it is clear that restoration of AC power was not likely. The response has been mind boggling, appalling and possibly criminal. Remember I am not talking about the personnel at the site but TEPCO and the rest of the Japanese Nuclear Industry – Shame on them.

    1. Unit 4 was shutdown in late November. The fuel pool is a low density configuration; never re-racked like some US plants.

      1. As I understand they had about 700 assemblies in the pool. It is encouraging that the heat load would have been more like 4E6 Btu/hr or less. But nonetheless without any evident vapor and the high Rad levels the fuel appears to be uncovered. They have an entire ocean at their disposal and a country as technologically advanced as Japan should be able to get water there.
        My other point is what I am most concerned about. Everyone should have realized as early as Saturday that this could happen. In the US I would expect an army of people at our disposal. Where is there help?

        1. Hmmm. Let me see. Could it be that the country has a few more important things on its mind – like finding food, water, a few thousand dead bodies, and a few tens of thousand missing persons?

      2. Without Jim’s detailed knowledge, I can still make the following rough estimations:
        Given that the last fission in unit #4 was months back, the heat production in Unit 4 spent fuel pool can be taken as effectively constant over the week.
        Rising from 40C to 84C in four days, effectively without cooling, would mean that sufficient energy to boil off half the water would take about another 25 days, since the energy for boiling water is roughly equivalent to 500 times the energy to raise its temperature 1K.
        Given the problems, I think we can infer that the spent fuel pool at reactor 4 is definitely leaking, perhaps due to the explosion of reactor building #3. The spent fuel pool in #3 must be assumed to be in a similar state.
        (by the same token, the spent fuel pools for reactors #5, #6, probably #2 and likely even #1 should not be an immediate issue.)

        1. @Joffan – I am with you up until the paragraph that says, “Given the problems…”
          What specifically tells you that the pool is leaking? It could just be that evaporation has lowered the level by a meter or more. Why must I assume that the spent fuel pool for unit 3 is also leaking?
          What is the evidence that convinces you?

          1. Radiation levels are very high inside reactor bulding 4, as I understand, and the only source in there is the spent fuel pool, which would not be giving very high levels of radioactivity if the fuel is still being cooled at all. That was what inclined me towards the leaking pool.
            However, if when the temperature of the pool approaches boiling, the boil-off from the rods is at higher temperatures and stays gaseous to the surface, I suppose it might carry some radioactivity out of the pool with it. So that is a mechanism for higher radioactivity without accelerated (general) water loss
            The other unknown, if a leak IS present, is the position of the lowest such leak.

    2. Jim,
      In looking at the radiation numbers something does not seem to add up given the hypothesis that the shielding from the water has been essentially all lost. I do not have my reference books at home but if I remember correctly a reactor will produce approximately 25,000 curies of Cs137/Ba137 per MW year. The smallest reactor is 480 MW and the pools seem to have been used for many years worth of spent fuel rods. If I assume only one years worth of Cs137 that would be 25,000*500 = 12,500,000 curies of Cs137. If my memory serves the gamma constant for Cs137 is 0.33 R/m/hr. Thus, if we assume a point source (I know at one meter we cannot make that assumption but at 1000 feet it is not too bad) the rate at one meter would be 4,125,000 Roentgens/hr and at 305 meters (1000 feet) the exposure rate would be 4125,000/93025 = 44 roentgens per hour. The actual measurement at 1000 feet was approximately 0.4 rem and a one roentgen field should cause an absorbed dose (rads) in tissue pretty close to 1/1 and the Q factor for converting to does equivalent (rems) would be 1 for the 661 keV gamma. Hence the measurement from above is a factor of over one hundred too low if there is no shielding and if they only have one years worth of fuel stored in the pool from the smallest reactor and that is only calculating for the dose rate from one fission product. I neglected the shielding effect due to air but still–
      It does not seem to add up.
      Of course I am old enough to forget a few of the constants and I have been known to make pretty silly arithmetic errors.

      1. Correction,
        I had to be off by almost an order of magnitude on the Cs137 inventory due to the rate at which spent fuel rods activity decreases, and I didn’t allow for self absorbance in the uranium oxide pellets.

  4. There is something that bothers me.
    The spent fuel stored in reactor 4 started cooling a while ago, but I could not find anywhere exactly how long (for sure, this is known by the engineers at the plant). Knowing that, one should be able to determine the activity of the fuel, and hence the maximum temperature that it may reach, even in the event that the pool was completely empty, and to know whether it would be warm enough to melt (part of) the fuel, or to produce a significant amount of hydrogen. That would allow for a much better understanding of the worst-case scenario.
    Similarly, I believe that accurate measurement of the radiation levels at different distances and in different directions from the pool of reactor 4 should be enough to confirm/rule out that the increased radiation level is due only to the spent fuel being no longer shielded by water (that is what Rod is suggesting); furthermore, one may be able to extrapolate from this (and from the activity of the spent fuel, which I assume to be known) how much water is still present in the pool.
    Maybe I am overconfident about how much one could extrapolate (is that so?), but otherwise I find strange that nobody is giving those numbers, that probably would confort the general public.
    @Rod: please note that your last link in this post is broken.

    1. @Alessandro – the fuel in unit 4 was moved from the reactor to the spent fuel pool in late November. That means it has been out of the reactor for more than 90 days.

  5. Hi Rod,
    You and NEI reference the DOE national lab study on how difficult it would be for the zirconium cladding of the spent fuel rods to ignite. Do you have that citation, or a link to the study? Seems important information to get out there. (Perhaps I just missed it.)

    1. @Paul – good question. I am working on that. DOE lab studies are not as easy to search as I would have hoped, but I will post the link once I find it.

  6. Are the fuel pools in these reactors ordinarily covered by something, or open at the top? I’ve seen many pictures of spent fuel storage pools, but the focus is always to show the fuel, so naturally if there were a cover it would be off while the photo was taken. I’ve been looking at the photos that Digital Globe is posting on their Flickr page, and they appear to show lots of debris and rubble at the level of the refueling floor, but no obvious holes where the pool would be. For example:
    That also shows the degree of destruction to Unit 4, and the substantial steam plume from 3, along with what looks like a spray of water from the inland side – perhaps one of the water cannons that have been discussed in the news?
    This image provides a straighter view of Unit 1, with some details visible on the refueling floor, but again nothing that looks like a rectangular outline of a pool:
    That image was ~3 minutes after the explosion at Unit 3, and shows a very similar looking steam plume. Of course, I am neither a nuclear energy expert nor a photo analyst 😉

  7. Go to any store and buy a package of salt. Chances are it will say “Iodized.” It has been like this for over 50 years. Call any doctor that is worth his salt (pun intended) and ask him how much iodine the average person gets from his daily intake of salt. Even the new fad of “Sea Salt” has iodine in it.
    It is a proven fact that most, if not all, get more than an adequate amount of iodine from their daily intake of salt to provide the same level of protection as taking KI tablets. KI tablets are only needed for those people that have no normal iodine intake. “GOOGLE IT”
    Help save the gullible from wasting money on pills that are not needed even if there is a nuclear accident next door to them. Google the hearings before the NRC on the need for these tablets. The NRC bent to the will of the doomsayers, who were only looking for a way to make headlines.

  8. Surely Japan has cement cranes like this, right?
    How hard would it be to connect such a crane to a local fire hydrant/trunk and aim the nozzle at the pool (or the area where the pool once was)?

    1. @Dag – thank you for the photos. They are quite interesting. However, it is important to understand that spent fuel pools have seismic design criteria. They are lined tanks that are not part of the exterior walls of the building. Take a good look at the rather cartoonish graphic below. See on the left how there is a significant gap between the wall of the pool and the exterior wall of the building?
      Also notice that it is not all that easy to see the surface of the pool. The Japanese have repeatedly indicated that they saw no signs of leakage for the first several days. During the course of those several days without power and with other priorities on their plate, the level of the pool probably dropped slowly and steadily due to evaporation. That lowering level is enough to raise the radiation levels from the assemblies inside the pool to a high enough level to make access rather difficult. That is why they are trying to refill the pool from a distance – remember, time, distance, shielding.

      1. So basically you are speculating just like Jaczko did? I can’t see an intact pool. I see a building that has gone through an Earthquake, a Tsunami, an explosion, a fire, and possibly another explosion. Assuming that the pool is intact after all that strains credulity.
        With the amount of at risk, I’d err on the side of caution. They may have see no leakage for the first several days . . . but things have changed. And they see no full pool either. The radiation coming out suggests exposed fuel rods.
        I don’t know the level of the pool . . . but prudent thing to do is to assume the worst.

        1. well, dag, then there’s the simple matter of trusting the folks on the ground who are saying the spent fuel pools ARE intact.

          But in general, I agree that this probably wouldn’t be the best place for them, for reasons of accessibility in case of a disaster..

      2. Rod we typically maintain about 23′ above the top of active fuel. When moving fuel we maintain 10′ above an assembly. At 6′ rad levels start to increase. so in order to get levels in the range of 300-600 mrem I believe that the water level must be gone or seriously reduced. The only reason I vote for gone is the lack of vapor.

  9. Just posted on NEI: TEPCO officials say that although one side of the concrete wall of the fuel pool structure has collapsed, the steel liner of the pool remains intact, based on aerial photos of the reactor taken on March 17. The pool still has water providing some cooling for the fuel; however, helicopters dropped water on the reactor four times during the morning (Japan time) on March 17. Water also was sprayed at reactor 4 using high-pressure water cannons.

    1. @Dave Runyon – thank you for the information. Let’s get it out as widely as possible to provide some comfort for the folks in Japan.
      We will deal with the errant Chairman later.

      1. Great to see that there is evidence of the 3/8″ liner remaining, I expected we would see something like this. It still doesn’t indicate that there is water within the pool. A full core off load would add significant heat enough to indicate pool steaming. I would think you have to explain this or else your theory is highly questionable.

  10. So if I understand this properly, the fuel storage pools are just deep, open, non-pressurized, circulated but nothing like the coolant required for a reactor, tanks of water. The water protects you from the radiation coming from them and does not become overly contaminated by anything (can’t say measurable radiation anymore since we can measure so many zeros off to the right of the decimal place) the last temperature still hadn’t reached a boiling temperature but who knows if they are damaged or not or if the explosions blew water out of them or if big chunks of concrete fell in and splashed out a lot of water or something. So with the levels low more radiation is leaking out, but this is “light” type radiation not contaminant type radiation and just filling up the pools again will shield it. Can fuel in a storage pool really go from 80C to 2200C if the water boils off? I find it unlikely that fuel damage and further release of fission products could result but please correct me if I’m wrong. The only danger is local to the plant making it difficult to get people in there for other important things given this radiation. So keep a firehose pointed at it for a while and top it off. Now if the CNN disaster fairy were to visit and convert the entire stored fuel mass into vapor that would be bad, but I can’t think of a more feasible way this might happen…

    1. @PlanetaryGear – I think you have a pretty fair understanding of the situation.
      Now comes the enormous question – why in the world would the Chairman of the Nuclear Regulatory Commission sit in front of cameras and assert that the fuel pool at unit 4 was empty. Why would he then assert that it was a conservative, prudent time to recommend evacuating all US citizens within 50 miles of the power station?
      This is a question that demands an answer.

      1. No comment on the 50 miles it is not my area of expertise. I do believe I have some area of expertise in spent fuel pools. Indications point to a dry or partially dry pool since at 6-7 days into a loss of power boiling is likely with a full off load of fresh fuel. But since the fuel was off loaded in November it has had 4 months of decay which should reduce the load markedly. I would estimate (a wild guess) that there is about 8 million Btu/hr in the pool. At this rate and a full cavity and dryer separtor pit boiling might occur in 10 days or so. Regardless vapor should be seen.
        Without vapor from the pool the best guess is that it is dry.

  11. I have been reading this blog for a few days. I am not a nuclear scientist, nor a technician, nor do I work in the industry.
    I am certainly not “anti-nuclear” in a theory. And I believe that the vase majority of engineers who work in most plants in the U.S. — and probably Japan — are professional, well-trained, and cautious.
    That being said, I do not trust industry executives as far as I can throw them. And I do not trust the government,at present, to properly regulate the industry.
    I appreciate many of the points that Rod Adams has made over recent days. I am generally convinced on his argument of what the worst case scenarios are with regard to the reactors themselves.
    However, there are several things that I find off-putting in the extreme:
    1. The knee-jerk assumption that all critics (of either this specific incident or the nuclear industry in general) are completely “anti-nuclear” when that simply isn’t the case.
    2. In analyzing the immediate crisis, the acceptance of all positive data as fact and the dismissal of all negative data as “rumor.” The reality is that there is much that we don’t know. And we should question every report that comes out. It is lost on me how Adams can insist that there is still water in the #4 fuel pool when he is 6000+ miles away and out of direct contact with the people on the ground. My understanding is that he had to be corrected on the actual location of the pools. That does not instill confidence in his claim that they aren’t leaking.
    3. The failure to provide a worst case scenario analysis (and if I missed it, I apologize) that includes the spent-fuel pools losing all their water. Look, I don’t question Adams’ math, given his assumptions (i.e. when #4 core was removed, the water levels and temperatures that have been reported, and that, theoretically, the pools should be structurally sound even post-earthquake). I question how Adams can have complete confidence in his analysis when there are credible reports that the water level is significantly lower, if not gone. Is it IMPOSSIBLE that his assumptions are incorrect?
    4. His refusal to factor in empirical human data. I get that there is a lot of mis-reporting and ignorance. And it is fine to point that out. But presumably the workers themselves have perspective on the situation. If I was a nuclear engineer, even one with a background as distinguished as Mr. Adams, and I was analyzing an incident at a nuclear plant that I had never visited or never worked and I was receiving incomplete and perhaps inaccurate data, I would look hard at what the workers on the ground were doing. Even if I personally didn’t think the situation was life-threatening, I WOULD STRONGLY QUESTION MY OWN CONCLUSIONS IF THE WORKERS ON THE GROUND WERE TREATING THE SITUATION AS A SUICIDE MISSION. These are not concerns that can be dismissed simply by criticizing Arnie Gundersen’s resume or questioning Greg Jaczko’s operational experience.
    If Rod Adams wants to salvage his credibility after his “gloating” and “garden hose” comments, I would suggest that he provide a credible worst case scenario involving an inability to re-establish power, a loss of all water in at least the #3 and #4 spent-fuel pools, and a shifting of winds back on-shore. I understand that he does not believe that such a scenario is likely. But he needs to admit that his assumptions might be wrong.

    1. I couldn’t agree more.
      I’ve been reading this blog for several days as well. I’m a professional engineer (although not a nuclear engineer, many of the same fundamental processes are the same), and what strikes me most about this blog is the absolute hubris and absence of vocally self-critical thinking. I don’t know how you can learn from your mistakes if you are unwilling to admit making them, and I don’t know how you can appear credible at all unless you are willing to admit where you don’t have data.
      Very disappointing for sure. I tend to agree that the assessment that the worst case is probably correct, but the fact of the matter is that the tenor and tone of this blog treats non-nuclear industry folks as uneducated and misinformed, without correcting for the very real human reaction to radiation: potentially lethal, invisible, can’t smell it, can’t see it, can’t touch it, and you can’t hear it. When dealing with irrational behavior (and in this case, risk assessment), you have to first at least *acknowledge* why people are acting they way they are. Another thing I haven’t seen on this blog.

      1. @John – who wrote:
        “…very real human reaction to radiation: potentially lethal, invisible, can’t smell it, can’t see it, can’t touch it, and you can’t hear it. ”
        The actual human reaction to such forces is to ignore them, unless they have been carefully and repeatedly taught to fear them. One thing that gives nukes confidence, not arrogance, is that we know that radiation is rather simple to detect at levels FAR below the levels that will harm you. Yes, you need to have a device; we do not have natural senses that protect us. However, those devices are not complicated; they have been available for many decades.
        It is irrational to be afraid of unseen and UNMEASURED radiation when there have been people trying to measure it without finding anything but traces.

        1. I agree that, from the perspective of a nuclear professional, fear of low levels of radiation is irrational.
          Two points, though:
          1. In my opinion, there are strong reasons to believe that the official pronouncements about this accident are extremely optimistic. I think that the radiation measurements that have been made public have been measured at a safe distance from the plant, or were measured in a partly shielded location, or are several days old.
          2. The people who are afraid in this case (Japanese citizens, foreigners in Japan who are thinking of leaving, etc.) are not nuclear professionals, and may have difficulty comprehending technical details of radiation effects and exposure to various levels of radiation. They do know radiation *can* be harmful. They can’t see, smell, hear, or taste it, and they don’t have instruments to measure radiation levels or the technical knowledge to make sense of any measurements.
          The average Japanese citizen affected by this quake, tsunami, and nuclear accident can easily tell that the earth isn’t going to kill him or her right now. The ground isn’t shaking, no tsunami waves are visible offshore, and their house may be damaged but is clearly not, say, on fire.
          If the ground does start shaking, they see unusual waves, or their house catches fire suddenly, there are obvious ways they can avoid death or injury (go outside, head for higher ground, whatever.)
          Would the same average person on the ground be able to think the same way about possible radiation from Fukushima Daiichi?
          Again, just my opinion, but if I were there I think it would be more rational to conclude that my best course would be to get as far away from the nuclear plant as possible *right now* any way I could, and worry about the adverse effects of the earthquake and tsunami later.

      2. @John – as a Twitter follower who is a professional engineer reminded me – I am not an engineer. I was an operator and I was the manager of operators when I was the Engineer Officer on a submarine. I have led many damage control teams, both in practice and during real casualties. I was also trained as a first responder for natural disasters as a member of the Naval Reserves.
        There is plenty of time for “green tables” lessons learned, and post accident self flagellation about what went wrong and what we will change before something happens again. The time for that stuff is not while there are people being told to leave their perfectly safe and intact homes to join 500,000 other newly homeless people.

        1. The time for that stuff is not while there are people being told to leave their perfectly safe and intact homes to join 500,000 other newly homeless people.
          Mass evacuation may or may not be a good plan. But what I can say with certainty is that your opposition to evacuation is not logically derived from your expertise as a nuclear expert.
          As you have repeatedly said on you blog, you reduce exposure through time, distance, and shielding. Since residents serve no operational purpose for the power plant, there is no nuclear-related reason not to put as much time, distance, and shielding between Japanese residents and the power plant. There may be OTHER, practical, reasons why relocating thousands if not millions of Japanese is not a good idea. Particularly in the wake of the earthquake and tsunami. But that analysis does not require a background in nuclear power.

    2. @square1 – the workers at the plant are not treating this as a “suicide mission”. They are doing what nuclear workers have been doing for many decades when faced with elevated radiation levels – they are using time, distance, shielding and rotations to keep their exposure down. They are doing the same kind of work as is common among many types of first responders.
      Please understand that I have sources of information that are not widely available. I retired from the US Navy just 7 months ago as a Commander. I have classmates and former colleagues all around the world. I have spent a lot of time on the phone and on email.
      If you have such a lack of faith in government and industry, what are you thinking about the effects of the oil refinery fire that is still burning, the natural gas pipelines that were damaged, and the other industrial facilities that were washed over by the very same tsunami that has caused some controllable damage at the Fukushima Daiichi nuclear power station?

      1. My take on the nuclear-power industry is that it is much, much, much safer than the oil and gas industries….right up to the point where it becomes much, much, much more dangerous.
        And while I would love to be an unabashed proponent of nuclear power, I cannot help but be repeatedly disappointed by proponents who refuse to admit risks, refuse to acknowledge the necessity of oversight, refuse to take responsibility for mistakes, and refuse to accept that, for better or worse, their industry exists within the universe of imperfect and often irrational human beings.
        I do not question your expertise or your contacts. I question your certainty of facts. If your analysis is based upon statements of TEPCO and TEPCO’s credibility is being questioned, then your analysis, no matter how well-intentioned, is also questionable.
        I also find your dismissive attitude toward public ignorance to be offensive. Look, the average person is not a nuclear engineer. They judge the industry by the standards the industry sets. The term “meltdown” wasn’t coined by a lay person. It was coined by the industry. The industry has told the public, for decades, that meltdown = bad and that the industry takes rigorous precautions to avoid meltdowns. Now you want to argue that, in this case, meltdowns might not be catastrophic? Knock yourself out. Just don’t treat the public (or the media) like they are a bunch of morons.
        Again, the public judges the industry by the standards that the industry sets. If the industry says a plant is seismically safe, the public doesn’t want to hear “we didn’t expect an earthquake THAT big.”
        If the industry says that there is backup, emergency power, the public expects the backup to work in an emergency.
        If the industry says that they build massively reinforced containment vessels to protect people from core meltdowns, don’t blame the public when they hear that a used core, outside of a containment vessel, may be at risk of melting down and the public starts to lose their sh-t.
        I don’t have the facts or the scientific or medical expertise to conclude that this is a “suicide mission” or not. What I can say is that the Japanese, between raising the acceptable level of exposure and asking for older volunteers, is tacitly admitting that they are asking workers to expose themselves to levels that would significantly increase the risk of cancer over the lifetime of a younger worker.
        But this all leads to another question that I ask, the media asks, and the public asks: Why bother? If there are no significant health risks beyond hazards to the responders, why go through all the effort? If any core meltdowns will all be contained in the reactors and there is no significant risk of water loss in the spent-fuel pools, why not just pull the workers out, risk letting the cores melt to the floors, and come back and scrape up the plant later, after Japan has finished dealing with the earthquake/tsunami problems?
        I am sure that many of the workers would rather be spending their time mourning lost friends and relatives. But they are at the plant fighting. If they aren’t fighting against a release of radioactive material that would be significant enough to seriously threaten public health, what are they doing there?

        1. @square1 – I think you will find that I do not represent the industry. I vehemently disagree with many of the choices that the industry has made over the years. I think that many of the decision makers are greedy, not technically astute and short sighted. Do a search on Atomic Insights on John Rowe, for example.
          I started this blogging effort in 1995, before anyone had developed the software that makes it easier. Back then, I had to build all of my indexes and use manual HTML coding. However, you can still find all of the articles that I wrote; no pay wall at all.
          The taxpayers of the US gave me an amazingly generous gift. They sent me to college, trained me in a valuable trade, sent me to graduate school, and let me practice my trade for almost 30 years. They even gave me a decent paycheck and a defined benefit pension plan.
          This effort is my payback. It is wonderful to have such appreciative visitors.

        2. square1 – I’ve got to say that your “take” is understandable for someone who is a layman when it comes to nuclear engineering and who is getting all of his information from network news. (By the way, I’d say that CNN is probably providing the most accurate coverage; the worst reporting is coming from Fox, ABC, and MSNBC.) What I don’t understand is why so much anger?

          1. @Brian Mays: Ironically, I may come away from this incident more pro-nuke than I was before. And even if I am not, I will certainly come away with a greater understanding of the ways in which nuclear power is safe and the ways in which it is dangerous.
            To a significant extent, Rod Adams deserves credit for that understanding. And for that, I thank him.
            However — and I am not so much angry as irritated — it is unfortunate that Mr. Adams’ valuable information comes wrapped in a veneer of arrogance. One senses that Mr. Adams is so used to journalists and the public over-hyping the dangers of nuclear power that he now reflexively dismisses legitimate claims out of hand.
            In this case, Mr. Adams appears to have made an initial pronouncement about the “worst-case” scenario that ignored the potential hazard of spent-fuel pools if the water-level drops. Rather than admit that maybe he rushed to a conclusion, based upon the fact that loss of structural integrity of the pools was a wildly unlikely event, Mr. Adams appears to be trying to save face by engaging in a d-ck-waving contest with Jaczko over his credentials.
            Make no mistake. I am not claiming that Jaczko is right and Adams is wrong. I am simply trying to get Adams to admit that there is a possibility that TEPCO is misrepresenting the water levels and risk, that there is a possibility of exposed fuel rods, and that the “worst-case” scenario would have to be revised if the rods in the pools were exposed.

            1. square1 – So Rod’s an optimist. Eh, is that so bad?
              The truth is that much of the media has irresponsibly over-hyped this issue. To see this, all you have to do is to compare what is coming out of, say, Fox News with what has been published by respectable organizations, like the IAEA. When this story first broke, several networks actually had Bill Nye (the “science guy”) on their shows as a “nuclear expert.” Never mind that he has no experience, training, or knowledge of nuclear science and technology. Never mind that his only connection to “science” is that he used to host an annoying TV show for children over a decade ago. The coverage has been that bad.
              As for Jaczko, Rod’s not the only one who thinks that he made a very stupid mistake with his announcement. I expect that we’ll be talking about this one for years. As for his credentials, his background is simply not very strong. It is not much of a stretch to claim that he is not qualified to be in charge of the NRC.

    3. @square1:
      Don’t be terribly surprised, then, if the perspective in your own post is “off-putting in the extreme” to others.
      With all due respect, despite your claim that you’ve been reading this blog for days, you seem to have missed the basic idea that inspired Rod Adams in the first place: that is, the simple and obvious notion that, though serious in their own context, the problems with Japan’s nuclear plants rank far lower on the list of IMMEDIATE concerns in the aftermath of an earthquake and tsunami — among them disease, homelessness, rescuing those who may still be alive buried under rubble, potential food and water shortages, or contamination from the myriad toxins released into the biosphere during this disaster.
      I think Rod has been fairly consistent in arguing this point while (oddly) people who disagree with Rod tend to avoid addressing it. You yourself use the typical disclaimers of the “neutral” or “agnostic,” but in fact you sound very much like an anti-nuclear person. The dead give-away stems from the simple fact that you seem to have missed the entire point with respect to RELATIVE RISK and, quite frankly, relative importance.
      For example, you scold Rod for being arrogant, relying on certain assumptions, not acknowledging the inherent uncertainty of the crisis, and so on. But clearly you, like the openly anti-nuke people in these discussion threads, are subject to the same blind spots you attribute to Rod.
      When, for example, are you going to address the basic premise of this whole discussion? When are you going to concede that certain statements in the media or from members of the government may be contributing to an atmosphere of panic that is unnecessary, unhealthy, and potentially even fatal? Talk about being “unwilling to factor in empirical human data” and refusing to examine alternative possibilities. This is very the thing that anti-nuke people tacitly consider IMPOSSIBLE — the notion that encouraging unreasonable fear may actually have harmful consequences — and it has become an unfortunate feature of some environmental activism (see, for example, Stewart Brand’s discussion on how Friends of the Earth and Greenpeace, in opposing genetic engineering of staple crops, may have been responsible for potentially thousands of famine deaths in parts of Africa).
      We know, from credible scientific studies, that the tragedy of Chernobyl was magnified by chronic stress and fear after the fact (the rates of abortion, divorce, and suicide increased significantly in this environment). Some people have even contended that the human toll paid as a result of misinformation in the aftermath of Chernobyl exceeds the toll attributable to physical causes like exposure to radiation.
      So when are Rod’s implied “opponents” in this debate going to address that dimension of his argument? Why is he put in the position of constantly defending the NUCLEAR DIMENSION of his argument, and yet those who disagree with him on that front appear to be under no compulsion to address the implied corollary: the HUMANITARIAN DIMENSION in which the stakes of focusing all of our attention and concern on nuclear reactors in this much broader tragedy may result in loss of life or increased suffering?

      1. YMP Refugeee:
        FWIW, I will leave this comment thread for dead after this. But to reply:
        you seem to have missed the basic idea that inspired Rod Adams in the first place:
        No. I have already said that I welcome Mr. Adams pointing out scientific inaccuracies. And I do not dispute that the concern for the nuclear threat may be disproportionate to the dangers and problems arising out of the earthquake and tsunami.
        But, to be blunt, you can make that point without being an a–hole about it.
        You yourself use the typical disclaimers of the “neutral” or “agnostic,” but in fact you sound very much like an anti-nuclear person.
        Actually, I used neither of the terms that you placed in quotes. In reality, I am someone who is tremendously concerned about both climate change and continued, safe access to cheap fossil fuels. I recognize that, in theory, nuclear power could be enormously beneficial.
        However, I remain seriously concerned that the top of the nuclear power industry is populated by the same type of greedy, amoral bastards that populate any large and potentially-lucrative industry. And I remain seriously concerned that the industry engages in the same type of regulatory capture as we have seen in other large industries (e.g. petroleum production, banking, insurance, etc.)
        The irony is that I am EXACTLY the type of person who nuclear proponents should be trying to convince. I have an open mind. And if a system is safe and economically viable then I am perfectly willing to support its construction. Yes, even in my backyard.
        But I require the ENTIRE system to be safe and economically viable. Not just the reactor. That means transportation and disposal of fuel, both on and off-site. And for years, I have believed that — for no other reason than costs — the industry has ignored the safety vulnerabilities of spent-fuel pools.
        And yet, for years, the industry has spoken out of both sides of its mouth. It has claimed, to the public, to be safe. But it has simultaneously lobbied for decades for insurance subsidies to cover the cost of a catastrophic accident.
        My personal preference would be to remove all long-term subsidies for ALL industries: oil, gas, coal, and nuclear. Allow the actual costs of energy production for each industry to be factored into the price. In the case of carbon-based fuels, that includes accident cleanup costs, the costs of climate change, and the costs of maintaining a large military presence overseas. But in the case of nuclear power, it includes the cost of providing security to transport fuel, the cost of securing nuclear facilities, the cost of disposing waste safely, and the cost of insuring (or cleaning up) serious accidents.
        If nuclear power can compete on an even playing field, I am all for it.

        1. square1:
          “FWIW, I will leave this comment thread for dead after this.”
          It’s a shame that you won’t stick around to hear more. I suspect that this is one of the reasons why you are so “concerned.” You pull out a laundry list of complaints, and then you don’t remain to listen when these complaints and concerns are addressed.
          You’ll never learn anything that way. It’s no wonder that you exhibit such dogmatic attitude.
          “But in the case of nuclear power, it includes the cost of providing security to transport fuel, …”
          Check. The industry pays for this.
          “the cost of securing nuclear facilities, …”
          Check. The industry pays for this.
          “the cost of disposing waste safely, …”
          Check. The utilities have been paying a 1 mil per kWh fee to the government for waste disposal since the eighties.
          “and the cost of insuring (or cleaning up) serious accidents.”
          Check. The owners of the plants pay for their own insurance, which the federal government forces them to purchase.
          For example, after the Three Mile Island accident three decades ago — the most serious nuclear accident in the US — the owner of the plant and its insurers paid for the entire cleanup. The costs borne by the insurers didn’t even come close to the liability limit set by the Price-Anderson Act. In fact, this act sets up a second level of insurance (a pooled arrangement financed by the entire nuclear industry) that didn’t get touched in the aftermath of the accident.
          These costs are covered; you’re just too ignorant of the situation to realize that they covered. Unfortunately, it appears that you will stay ignorant, because you have chosen to bow out.

          1. @Brian Mays:
            My intention was to leave this thread, not because I am unwilling to discuss these issues, but because the thread is simply attached to an older post that is moving down the blog. I am more than willing to keep talking to you.
            I find it curious that you call my attitude “dogmatic” when I have repeatedly shown myself to be anything but. I am neither for nor against nuclear power. I simply have certain, reasonable expectations for the industry. If it can produce power at a profit while meeting those expectations, fantastic. If not, so be it.
            I have a simple method for choosing methods of producing power: force every industry to factor the true costs into the price, including internalizing negative externalities, and let the market decide.
            I never claimed that none of those factors (i.e. transportation, security costs, insurance) were already paid for by nuclear utilities. I was simply stating my belief that they all should be…in any industry. Frankly, I have not studied the issue enough to know whether the fees that utilities pay for waste storage cover the government’s costs or not. My position is simply that the costs should be borne by the utilities. To the extent that that is already the case, wonderful.
            As for the insurance issue, my attitude is and always has been “Don’t tell me how safe your industry is. Go tell a re-insurance agent.” The Price-Anderson Act should be repealed immediately.
            One of two things is true. Either the industry is so safe that an accident that would exceed the caps is virtually impossible, in which case the liability cap is not needed. OR the risk of an accident that would exceed the cap reasonably possible, in which case the taxpayers are currently subsidizing the industry. It doesn’t matter. There should be no liability caps. Period. Not for nuclear power. Not for oil. Not of for coal. And, if you can imagine a wind farm causing multi-billion dollar damages, not for wind or solar either.
            Assuming for the sake of argument that Price-Anderson is no longer necessary — and, make no mistake, when Price-Anderson was first enacted decades ago it was explicitly passed in order to subsidize a fledgling industry — then the nuclear industry has nobody to blame but themselves for creating the perception that there remains a significant risk of nuclear accidents of such devastation that the utilities can neither directly afford to fund the possible losses nor afford to pay the insurance premiums. After all, why ask for the cap if you don’t need it?
            You may find this shocking (since you apparently find it inconceivable that I don’t have an anti-nuclear agenda), but my own suspicion is that the nuclear industry is not too dangerous to operate without subsidies. But I think that many of the executives are, like greedy executives in many businesses, incapable of turning down a government handout and fail to appreciate the long-term p.r. disaster that Price-Anderson represents.

            1. “There should be no liability caps. Period. Not for nuclear power. Not for oil. Not of for coal. And, if you can imagine a wind farm causing multi-billion dollar damages, not for wind or solar either.”
              Do you oppose liability caps for vaccines? I guess you didn’t know that vaccine manufacturers also have liability caps (developed based on the system established by Price-Anderson). Without these caps, no company would take the risk of manufacturing vaccines.
              Do you oppose your own personal liability cap? Yes, you too have your own de facto liability cap, since you can declare bankruptcy and clear your debts.
              Price-Anderson requires plant owners to purchase a substantial amount of insurance. Furthermore, it requires that they pool their insurance to cover the entire industry. Could you imagine car insurance working this way? That is, your insurance company is on the hook for your neighbors car and his poor driving record?!
              Why does the industry put up with this? Well, if there is anything that companies like, it’s predictability. The companies in the nuclear business have lived with Price-Anderson for a long time. They know it, and they know how to plan for it. Removing this predictability involves risk, and companies don’t like risk.

  12. I am looking forward to temperatures coming down, water levels going up, radiation levels decreasing, and the situation becoming stable. Then the doomsayers (especially political) being completely discredited (resign in disgrace maybe?). Frankly, I am wondering when the “adult conversation” will occur in Japan to expedite restoration of some of the non-Daichi reactors so they can stop having rolling black-outs.

  13. Okay, so Mr. Adams is calling Mr. Jaczko a liar. He really is.
    This story clarifies Mr. Jaczko’s claim that #4’s spent fuel pool has boiled dry. He made the claim in congressional testimony, and then again that night. He gave specific attribution to the claim. I very sharply dispute just about everything Mr. Adams has written here, but we’d probably agree on the following: Mr. Jaczko had better be willing to be judged by that claim.
    Just as, say, Colin Powell has been willing to be judged by claims he made at the United Nations in February 2003, and Mr. Adams should be willing to be judged by his claim that the radiation at the Japanese nuclear site is not and never will be dangerous outside of the complex’s boundaries. Mr. Adams has made an issue of his recent status as a naval commander; while I certainly lack deference to his puffed-up ego, I do have a certain grudging respect for the military’s tradition of accountability.
    So, Mr. Jaczko should be held strictly accountable for his statements, if and when the truth can be ascertained without ambiguity, for all to see. The same for Mr. Adams.
    On Wednesday night, Mr. Jaczko reiterated his earlier statement and added that commission representatives in Tokyo had confirmed that the pool at No. 4 was empty. He said Tokyo Electric and other officials in Japan had confirmed that, and also emphasized that high radiation fields were going to make it very difficult to continue having people work at the plant.
    One other thing. The newspaper reports radiation levels of 250 mSv/hr (25 rems/hr) at a height of 100 feet. Mr. Adams has given levels at 1,000 feet and 300 feet, both of which are too high. Mr. Adams also might want to discuss what happens if #4’s fuel rods (which are comprised of both spent and unspent fuel) are knocked into each other by the force of those water cannon. I notice that it’s been a while since Mr. Adams hyped his preposterous garden hose thesis.

    1. @Jack – I most assuredly am willing to be judged by my claims. I have been out in as public a way as I know how to be. I am using my real name and my real hometown. I do not have a bully pulpit, but the internet gives me the next best thing.
      As a friend of mine often says on his blog. A liar is someone who tells a lie. Chairman Jaczko has told the entire world a lie. I am sure that he will attempt to lay the blame off on someone else, but that should not be allowed for a man who is supposedly qualified for his job. In the Navy, we have a rather harsh standard and way of dealing with people who have demonstrated that they are unreliable and people who are in command who lose the confidence of their next superior in the chain of command.
      There is no chance at all of a criticality inside a used fuel pool. Some scientists say that there is always a chance, but the chance of a criticality in a used fuel pool is about as high as my chances of winning a lottery. By the way, I NEVER buy lottery tickets.

    2. Oops – I forgot to answer the garden hose thesis accusation. I stand by that with the caveats that I provided at the time. Assuming that the operators were able to refill the pool regularly and that they started as soon as they lost power, all it would require to keep the pool full would be a garden hose – running at full capacity, mind you, for several hours every day. Once you have a pool that has been evaporating off for 4-5 days and have a demonstrated level deficit to overcome, I suggest a higher capacity make up system.

      1. Most Spent Fuel Pools have 20+ ft (7 Meters) of water on top of the spent fuel. This provides radiation shielding, and would take a long time to boil or evaporate off. It would also take a long time to heat up this much water. I am very familiar with Oyster Creek, which is of the same vintage, and they should be very similar even if the balance of plant (non NSSS) was designed/built by another architect engineer. The NSSS designer provides very specific guidelines for the non-NSSS portion of the plant. NSSS = Nuclear Steam Supply System – The reactor vessel, core and essential supporting equipment.
        Many of the on-site spent fuel storage systems (for those fuel rods that have decayed a year or so) are stored DRY. The may be in a container with a nitrogen purge, but that is used for leakage detection.

      2. So I just did some quick numbers, assuming that the only reason makeup water would be needed for a spent fuel pool is through evaporation.
        A poster earlier in these comments mentioned that he had some knowledge of spent fuel pools and that he guessed there may be about 8 million BTU per hour going into the pool. For those that think in watts this is 2.3 MW.
        So rod, your garden hose is going to have to provide about 1000 gallons of water per hour. Seems like a garden hose is maybe more like 5 gallons per minute.So I’m thinking you may need 3 or 4 garden hoses, continuous.
        If each meter is 200,000 liters in the pool, then it’s going to be dropping a meter every 53 hours. Not that it really matters, since there is obviously just a hole in the damn tank.

  14. Let me say at the start that I am not an engineer, nor do I have any professional knowledge of things nuclear. I am a Unix systems administrator and software developer — I guess “interested layman” would describe me best. I found this blog while searching for useful sources of information regarding the situation at Fukushima Daiichi.
    I’m finding it difficult to reconcile official statements and media coverage of the accident with some of the imagery that’s available on the Web. The most useful image I’ve found is the Digitalglobe satellite image of the plant taken from an angle of about 45 deg from overhead on 16 March, showing the seaward (east?) side of reactor buildings 1 through 4. I’ve also seen the two videos that show the explosion at reactor 1 on 12 March and the larger explosion of reactor 3 on 15 March.
    The main thing I’m wondering about is the relative strength of the two explosions, as captured on video. From my layman’s perspective, the official explanation of the explosion in reactor 1 (accumulated hydrogen in the refueling bay at the top of the building exploded, blowing the roof off the building and blowing the metal panels off the framing) makes sense. The Digitalglobe image from several days later shows the reactor 1 building appearing intact below the refueling bay, with metal framing exposed above. This is also consistent with the video, which shows a smoke cloud expanding horizontally out from the building with debris (metal panels?) flying out to the side.
    However, the video of the explosion in reactor 3 is very different. It looked to me like the force of the explosion was directed up instead of out, and the smoke plume from the explosion very quickly climbs to an altitude of approximately 10 times the height of the reactor building. The video then clearly shows large pieces of debris (the building’s roof?) falling back down from the top of the smoke plume. Smoke also blows out horizontally, but the huge vertical plume really stands out.
    The Digitalglobe image clearly shows much more severe damage to the reactor 3 building than to reactor 1. It looks to me (again, my layman’s impression) like the explosion in reactor 3 was energetic enough to not only blow the building’s roof many hundreds of feet in the air, but to also blow out the (concrete, right?) walls of the building from below the refueling bay level down to (or close to) grade level.
    Given the degree of damage to reactor 3, is it possible that the explosion originated inside the reactor containment structure instead of the bay at the top of the building? If so, is it reasonable to guess that the spent fuel pool at the top of the building may be gone entirely, and that the spent fuel stored there was dispersed by the blast?
    As I said at the beginning, I am a techie but have no professional engineering or nuclear experience. For what it’s worth, I do have some professional experience in software development for satellite image processing.

    1. @Laurence – good question. My interpretation is that the unit 3 explosion was also most likely an H2 explosion, but it involved a lot more of the gas than the explosion in unit 1. I know there are people who wonder why the lessons were not learned after the first one, but please believe me when I say that the responders have not taken time out for a lessons learned green table. They were still in the thick of things and may have done exactly the same procedural steps as their colleagues in unit 1.
      The fact that the explosion went up so high is encouraging. It means that most of the energy was directed up, not down. As far as your question about whether it could have originated inside the containment structure – not at all likely. In that case, it is very probable that no one would have seen anything. There would have been some noise, but the containments are pretty tough structures.
      TEPCO has indicated that the metal liner of the spent fuel pool is intact and that there is water in the pool. They are refilling it now.

      1. “My interpretation is that the unit 3 explosion was also most likely an H2 explosion, but it involved a lot more of the gas than the explosion in unit 1. I know there are people who wonder why the lessons were not learned after the first one, but please believe me when I say that the responders have not taken time out for a lessons learned green table.”
        OK, that makes sense, and I agree the brief orange flame visible at one side of the roof at the beginning of the reactor 3 sequence is consistent with a deflagration at the top of the building.
        As a Unix sysadmin I’ve seen plenty of cases where people don’t always follow the optimal path to resolve a problem when they’re under some kind of stress. My experience obviously doesn’t include anything remotely approaching the kind of stress the Fukushima staff were and are under (in my world it’s more like the boss demanding to know Why Hasn’t It Been Fixed Yet?) I am definitely not saying the plant’s personnel are at fault because they didn’t somehow prevent the second explosion.
        One more question though, if I may.
        The 16 March Digitalglobe image I referred to before also shows extensive damage to the reactor 4 building. In the image, the side wall damage looks about as bad as the damage to reactor 3, though the roof is clearly still there and a couple of the side panels on the refueling bay framing look like they’re still in place.
        By comparison the reactor 2 building still looks pretty good, so it seems unlikely reactor 4’s building was severely damaged by the explosion in building 3. Is it possible that there was also a large hydrogen explosion in reactor 4’s building before the Digitalglobe image was taken on 16 March?
        The Digitalglobe image I’ve been referring to is this one:

        1. There’s more imagery available now that partly answers my question about reactor 4. Digitalglobe now has an image taken on 17 March when their satellite passed almost directly over the plant. There’s also a shaky handheld video taken from a helicopter flying near the plant that shows the damage to reactor buildings 1, 3, and 4 in much more detail. I found the video at
          It’s clear from the 17 March image and the helicopter video that the reactor 4 building is not damaged as badly as the reactor 3 building.
          3 has all four walls blown out down to near grade level and appears to be completely missing the top 1/3 or so of its structure, with a section of what may be roof truss material lying on top of the wreckage. The overhead view also shows considerable debris scattered around building 3, and a hole in the roof of the long narrow building to the east that I’m guessing was made by a large piece of wreckage falling back down after being blown high in the air by the building 3 explosion.
          4’s seaward (east) wall is blown out below the refueling bay, but there are still a couple of panels attached just below the roof. The overhead satellite view seems to show the roof itself is gone but the roof support framing is still in place, and the north and west walls of the building appear more or less intact. Neither satellite image was taken from an angle that shows the building’s south wall, but the helicopter video shows large holes in the wall on that side. There appears to be less debris scattered near building 4 than near building 3.
          My earlier belief that reactor 4’s building is about as badly damaged as reactor 3 was wrong. I still think there probably was a hydrogen explosion in building 4 before the Digitalglobe satellite pass on 16 March, but if so it was much less powerful than the explosion in building 3.

  15. well, dag, then there’s the simple matter of trusting the folks on the ground who are saying the spent fuel pools ARE intact.
    But in general, I agree that this probably wouldn’t be the best place for them, for reasons of accessibility in case of a disaster..

  16. @Jack – I have been blogging for many years. Ask some of the folks who have been around how many times I pull rank. Go ahead.

  17. Rod, unfortunately I firmly believe you are wrong but would be overjoyed if you are right. As you know Unit 4 was in refueling with a full core off load in the fuel pool. Presumably the Rx Cavity was flooded as well as the separator pit so that this would have provided a significant amount of water. However, if the temperature were at 183F there would be significant vapor coming off of the pool. I know this because I have tested a spent fuel pools up to temperatures of 140F to ascertain the heat load in the pool. Quite a bit of vapor rising from the water at 140F it would be much more at 183F.
    Additionally, since there was no fuel in the Rx the only energy source which could destroy the Rx Bldg to the level seen, barring explosives, was hydrogen which could only come from the spent fuel. If the spent fuel is the source than as a minimum the fuel is partially uncovered. In this condition you would expect that a large amount of vapor would be coming from the pool but non is evident. An initial high temperature in the pool followed by a large explosion in the building with high radiation levels above the Rx Bldg indicates that there is a minimum amount of water in the pool.
    It may be that there are alternate theories that I have not considered. I would appreciate it if you would let us in on an alternate since I do not like the thought of a breached fuel pool.

    1. Jim, Thanks for sharing your perspective on the situation. I am late to this thread, and not part of the nuclear industry, but earn a living making inferences from imperfect and incomplete information in real time (also known as investing). Based on what I have read, the majority of which has been outside of the MSM, it seems most likely to me that there is a leak in the pool in reactor 4 somewhere. As you have noted through the length of these comments, there is a good deal of anecdotal information that would lead to that conclusion.
      I must say that I also find it curious that Rod has never responded to your assertion at any point in this thread, nor does he make any attempt to explain the source of the explosion that clearly took place in building 4. We know it could not have come from the reactor, so what else besides a hydrogen explosion can explain the damage to what is clearly not a flimsily constructed building?
      I wouldn’t know Dr. Jaczko if I ran him over on the street, so I can’t comment on his technical credentials or his motivation for making the statement that he did. However, I have seen plenty of evidence of foot dragging and sugar coating of the situation certainly by TEPCO and probably the Japanese government too, so I would find it not the least bit surprising that they have downplayed the severity of the conditions in the building 4 spent fuel pool.
      While Rod’s assertion that there was little risk *at the time* to the general public when the US advisory to observe a 50 mile evacuation radius was made, it is quite clear that we are well into the “tail risk” section of the nuclear risk distribution, and if there is one thing that the last week proves it is that cascades of failures can change the circumstances and risk levels quite quickly and into scenarios in which it is not possible to respond adequately in real time. Thus, to this nuclear industry outsider who has lived through quite a bit of “tail risk” in the last few years in my own industry (due in no small part to regulators who ignored or underestimated the cascade of risks in the financial services industry), the suggestion that people move farther away from what was a clearly uncontained situation is simple common sense prudence, and an effort to “get in front” of the problem. Lastly, while no one outside of a few miles of the plant has received anything approaching a life threatening dose of radiation, the evidence of contamination of the food supply over a fairly wide area beyond even the US recommended evacuation zone seems to reinforce the “better safe than sorry” approach, particularly since no one has a good handle on when the low doses of radiation that are currently being received might stop.
      For the record, I’m not a no nuke type and feel that nuclear power has a place in our energy portfolio. But Rod, your willingness to turn a blind eye to the potential downside of this situation is not enhancing your credibility nor those of others who advocate for the industry.

  18. Here’s the numbers, and why it is ridiculous to say that the fuel pools BOILED OFF in a day.
    It takes 26 times the energy to boil a given amount of water than it does to heat that same amount from 100F to 184F. If it took 4 days for that temperature rise to happen, and making the reasonable assumption that the energy input into the water remained constant, then it would be physically impossible for it all to boil off in the next day.
    Look you can do it yourself… take the heat capacity of water, 33.1 J/mol-C. Multiply by temperature change. This gives you the energy it takes to heat the water without a phase change. Then it takes 40,700 J/mol to turn that same amount of 212F water to 212F steam. 40700 / 33.1(46C) = 26.2. So that’s the ratio. No need to know a thing about how much water there is or the BTU input from the fuel rods. This all very basic and would be learned in high school chemistry or physics. No PhD in should be making these mistakes.
    In reality, increasing heat loss and evaporative cooling as the pool heats up will make it harder and harder to keep the pool hot. As the water boils the level drops and rods get uncovered. This means you are loosing a source of heat. In other words boiling is going to slow over time. How exactly it is going to boil DRY is beyond me. It would seem then it should take months to largely boil off.
    So If they are empty… then there was a leak.

  19. There is a very good possibility that the NRC does not have any on the ground insights in this case. The spent fuel pool for unit 4 was reported to be at 183 degrees and full on March 15. Where did 23 feet of water above the 14 foot long fuel assemblies go? (Rod Adams)
    Rod, I think the most recent speculation here is that some of the Fukushima Daiichi reactors did not indeed weather the storm of the initial earthquake (and subsequent aftershocks) in perfect working order. Designed for a 7.5 earthquake, and confronted with a 9.0, the spent fuel ponds may have developed a leak (at least in 2 of the 6 reactors on site). Of course, it will be months if not years before we can adequately assess the situation (and valid information is extremely hard to come by given the current hectic situation on the ground), but your speculation above (on evaporation rates) certainly indicate that this may indeed be the case (or that the reports of empty spent fuel ponds, observed steam emissions, and high radiation levels in secondary structures are inaccurate)?
    I’d like to ask one question

    1. @EL – reasonable question. I am positive that every reactor vendor and most potential new reactor owner/operator will study the lessons that can be learned from this incident to make their systems even more resilient. There are plenty of reasons to do that, including the economic one of being able to better ride out some incredibly trying natural disasters without major structural damage to an expensive production asset.
      With regard to whether I think that the current barriers are adequate, I suppose that depends on how you define “adequate”. I liken it to the way that NASCAR engineers do such an amazing job of protecting their riders, partially by having a lot of sacrificial pieces of hardware that can absorb the energy of a collision. Their design goal is not to survive an accident with the car intact and ready to drive again, it is to protect the driver so he can race again. In the nuclear world, though there is a lot of effort to protect the plant investment, the real bottom line of the licensing requirement is to protect the public. I think we will find that, as I predicted on Saturday while standing on the shoulders of a very talented group of engineers, technicians and scientists the goal of protecting the public was reached, even in plants designed 50 years ago.
      By the way – there is not much you can do with “siting guidelines” to protect plants that are already built.

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