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Japan Science

Nuclear Risk Expert: Fukushima Fuel May Be Leaking 500

Posted by timothy
from the so-step-lively dept.
An anonymous reader writes "Three weeks after the nuclear crisis began at Japan's Fukushima Dai-1 power plant, there's still a real danger of melted nuclear fuel escaping the reactor buildings and releasing a large dose of radiation. So says Theo Theofanous, an engineer who spent 15 years studying the risks of nuclear reactors. Theofanous believes that melted nuclear fuel has already leaked through the reactor vessels and accumulated at the bottoms of the primary containment structures. All attempts to keep the reactor buildings cool may not be enough to prevent the overheated fuel from eating through the concrete floors, he says."
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Nuclear Risk Expert: Fukushima Fuel May Be Leaking

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  • by Antisyzygy (1495469) on Friday April 01, 2011 @09:42PM (#35691592)
    HAHAHA
    • by Anonymous Coward on Friday April 01, 2011 @10:22PM (#35691722)

      From TFA:

      But the drywell's concrete floor is probably 5 to 10 meters thick, so Theofanous says there's not an immediate risk of a release of radioactive materials via this route. "A lot of melting has to take place before you get through 5 meters of concrete," he says.

      And:

      "We don't really know where the fuel is," he says

      .
      Also:

      Theofanous found that as long as there was a typical amount of water in the drywell--about half a meter--and that water was continuously cycled through to prevent it from heating up and boiling away, the nuclear fuel would not immediately make its way out into the environment. "We showed that if there's a severe accident, you must make sure there's water in the drywell," says Theofanous.

      So, yeah... Article is hype but the summary is outright lying.

      See... these are the moments when I wish that I was religious.
      So that I could find some modicum of relief believing that there is a special hell for people who are hyping up these stories just so they'd get more fucking clicks and page-views.
      You know... Trying their best to make a cent or two from their fellowman's suffering. Cunts.

      • by Anonymous Coward on Saturday April 02, 2011 @12:34AM (#35692098)

        Exactly. The reactor is failing through the modes it was designed for. First melting through the inner steel containment, then the outer containment shell, then sinking through a few meters of concrete, there to be dispersed harmlessly through the water table.
         
        Pfft! And some people thought the people who engineered the thing had no plan for graceful degradation!

  • Some actual facts: (Score:5, Informative)

    by John Hasler (414242) on Friday April 01, 2011 @09:46PM (#35691608) Homepage
    • Good link. I was rather curious on why this particular researcher was relevant as all of his thoughts seem to be nothing more than conjecture.

    • by nido (102070)

      "Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence." - John Adams [quotationspage.com]

      Nuclear power has one thing going for it:

      • * High Energy Density

      Nuclear power also has several strikes:

      • * High maintenance - everything has to work all the time so that your plant doesn't explode and make hundreds of square miles uninhabitable
      • * High initial cost
      • * High shutdown costs
      • * stuck with billion-dollar boiling water reactors [wikipedia.org] and pr [wikipedia.org]
      • by khallow (566160) on Friday April 01, 2011 @11:43PM (#35691982)

        Nuclear power also has several strikes: * * High maintenance - everything has to work all the time so that your plant doesn't explode and make hundreds of square miles uninhabitable
        * * High initial cost
        * * High shutdown costs
        * * stuck with billion-dollar boiling water reactors and pressurized water reactors

        As the Fukushima accident showed, everything doesn't have to work right. The high cost thing is a real problem. And you're just repeating yourself with the last point.

        The best argument in favor of nuclear power is that "it may have problems, but it's all we've got". Nuclear advocates rightly point out that, compared to coal, oil, natural gas, and even hydropower (complicated), perhaps nuclear isn't so bad. Coal is abundant but dirty, oil is expensive and dirty, natural gas is cleaner but still poisons the ocean with CO2, and hydropower has it's own challenges.

        I hate to say it, but the economic argument for nuclear power is the weakest link. It's all heavily subsidized with liability protection that no other industry (well to my knowledge, which isn't so hot) has.

        GRC's site talked about applying the technology to tar sands, to coal mining, breaking down hundreds of millions of used tires piled everywhere... How would the energy equation change if harvesting coal and tar sands didn't require massive amounts of energy?

        The problem is that these do require significant amounts of energy either to harvest or to turn into a viable vehicle fuel. If the energy is cheap enough, then you can do things like the above to produce vehicle fuel.

        That leads to the fundamental problem in your calculation. Vehicle fuel is not just any form of energy, but a rather costly one. If you're going to make it using exotic methods like the above, you will need a cheap source somewhere, perhaps nuclear power (if they ever get the issues sorted out).

        What if Raphial Morgado's MYT (Mighty) pump really is as good as he says it is? Suppose you could get 25% more water pumped for the same amount of electricity, or generate 25% more electricity with the same amount of steam?

        That's not much of a saving. And it probably is not petroleum powered.

        If supply exceeds demand by a significant percentage, we'd be back to $1/gallon gas in a heartbeat.

        Supply never exceeds demand for very long in an oil market. Where would the oil be stored?

    • by Terranex (1500465) on Saturday April 02, 2011 @12:10AM (#35692052)
      Having been in regular contact with good friends in Tokyo, it seems the general mood in Tokyo is one of calm, and it's the rest of the world that are panicking.
  • Then, quite appropriately...OMG GLOWING PONIES!
  • by rednip (186217) <(rednip) (at) (gmail.com)> on Friday April 01, 2011 @09:48PM (#35691618) Journal
    I couldn't imagine that they had 8 hours to get a generator to the site of the plant, and yet failed to return any service for days. The idea of having an eight hour backup is that you'd expect to have a mobile generator on site in that time. I might have missed it, but can anyone tell me why the couldn't drag or fly power to them in less than, what 3 or 4 days? Was it that cut off? Are they just that bone headed?
    • Incompatible power connectors...
      • Re:8 hour backup (Score:5, Interesting)

        by the eric conspiracy (20178) on Friday April 01, 2011 @10:23PM (#35691724)

        Oh pooh. Any electrician working at an industrial facility knows exactly how to fix this and with an emergency of this nature the parts would come in via very special delivery very very quickly.

        The problems were a LOT more serious - switchgear wiped out, pumps destroyed, no water supply, no instrumentation working, and a lot more.

    • Re:8 hour backup (Score:5, Informative)

      by Orne (144925) on Friday April 01, 2011 @10:38PM (#35691778) Homepage

      The information I have is that they did bring mobile generators to the site.
      * Fukushima Dai-ichi units 1, 2 & 3 successfully shut down when the plant lost off-site power during the earthquake. Units 4, 5 & 6 were already offline for maintenance.
      * On-site diesel backups successfully engaged to continue the cooling process, but the diesels were knocked offline when seawater from the tsunami flooded the fuel tanks. They got about an hour of cooling before these diesels were ruined.
      * At that point, an backup battery supply engaged, and ran for about 8 hours before it was depleted. This is 2x the average capacity of the battery backup system at an American nuclear power plant.
      * Meanwhile, they did get mobile diesels brought in, but the were only able to generate enough power to stabilize units 2 & 3. Unit 1 lost cooling water, and in 4 hours they were forced to vent the built up hydrogen gas.
      * I found some discussion that the coolant pumps require 5 MW to power, which a generator at 100,000 lbs is above what even a US chopper could airlift. This is why the helicopters were focusing on transporting coolant (seawater).
      * The issue then was they were physically leaking coolant water, and the rods were exposed at units 1 & 4. The exposed rods resulted in hydrogen explosions (which is what all the videos show).
      * The transco's goal was to get off-site power restored, which was basically rebuilding the transmission line to a neighboring plant. It took 6 days to get it restrung.
      Yes, it was that cut off.

      This appears to be a very informative article. I did not know that the batteries were actually the 4th backup system:
      http://www.backsidesmack.com/2011/03/explaining-the-fukushima-1-incident/ [backsidesmack.com]

    • by Anonymous Coward on Saturday April 02, 2011 @02:43AM (#35692356)

      The battery backup in commmercial nuclear plants does NOT run the large scale cooling equipment, that is what the multiple independent channels of diesel backup power (which failed along with offsite power) are for.

      The battery backup is for instrumentation and control only, including computer monitoring systems, process control computers, some valves, etc. At a typical GE BWR (like fukushima, I was an operator at a newer GE BWR myself) the entire basement of the control/auxialiary building is filled with lead acid batteries (multiple THOUSANDS of car battery sized cells) and large UPS's (27 of them at the plant I worked at) for backup power to intrumentation and control only.

      The RHR (recirc heat removal pumps, used for both emergency and normal shutdown cooling) are huge beasts, batteries could not possibly keep them running. They are 4160v multiple 1000 horsepower motors (can't remember exact size), no way lead acid batteries can do that (let alone the UPS's), simply no way. One easy way to vouch for this fact is that the UPS's only produced 270VAC power!

      There is the HPCI and RCIC systems driven by decay heat steam from the reactor itself (via small to mid sized steam turbines), and in the fukushima situation these likely functioned until control power was lost (assuming piping to these stayed intact). After control power is lost, these systems shutdown or break, or overspeed, can't remember, probably varies with the individual plant. Either way, no control power, no HPCI or RCIC

      The spent fuel pool is another matter entirely. It has a separate electric motor driven pumped cooling system, but once again, batteries do do not drive these, these pumps are something like multiple 100Hp 480v pumps, once again outside the range of what even a ton of lead acid batteries can manage for any significant length of time. (see paragraph about heat sink below too)

      The loss of offsite power, followed by the loss of the diesel backup power is really the root failure, and you need BIG diesels (or gas turbines even) to manage this load. At the plant I worked at, there were 4-4+ MW diesels onsite for a single reactor. 2 at a minumum were needed to keep things cool if offsite power was lost (assuming no other failures). We had fuel for approximately 2 weeks of run time of each diesel within the control building (about 200000 gallons, with another million available in a non safety rated tank outside the buidling). 4Mw locomotive or marine sized diesels cannot be simply trucked or helicoptered in, these are BIG machines, not to mention replacement fuel (they're thirsty!). In my plant's case, each diesel was a 5000Hp, 16 cylinder twin turbocharged monster that was originally designed for use in diesel electric cargo ships!

      Perhaps if they parked an aircraft carrier right on the coast and somehow ran cables that could have made up for the loss of power, or maybe a dozen or so diesel electric locomotives, a few large diesel electric container ships, etc. but nothing smaller than that could have handled this load (original design Nimitz class aircraft carriers have about 20Mw electrical generating capacity INCLUDING their 4 emergency diesel generators at 4160v 60Hz, and remember they need some of that to keep their own engine room and other ship functions operating in this sort of scenario). But even then you would need some hellish power cables and functioning switchgear and control power in the plant itself BEFORE you could consider turning on a big cooling pump

      Oh yeah, you would also need a functioning "service water" system (part of the normal seawater cooling system for the plant, not the emergency seawater cooling that is being used, provides cooling water and makeup water to cooling towers at some plants), those pumps (assuming control power AND intact piping again), needs another megwatt or so to operate. If you don't have service water, you don't have a heat sink even if you get the cooling systems inside the plant building operating.

      Most people have no idea of the scope of the pow

  • Mine it. (Score:2, Interesting)

    by Anonymous Coward

    In Uranium mining, there is a technique called in-situ leeching.
    In summary, it involves drilling a hole, pouring an acid or alkaline into the hole to dissolve the resource, and pumping it back out.
    Once it's out, in the case of uranium, there are a couple of steps involved in turning it into yellowcake.

    Given the probability that it is now leaking onto concrete, an alkaline solution would be more ideal.
    What would be needed is something like an oil drain pan that resists the chosen alkaline.
    The solution would

    • Re:Mine it. (Score:5, Informative)

      by Anonymous Coward on Friday April 01, 2011 @11:33PM (#35691944)

      After fission, there's a whole lot more in there than uranium in there, and uranium is the least of the concerns from a radioactivity point of view.

      The stuff will be a molten mix of uranium, zirconium, ceramic, steel and all sorts of other stuff, mostly the materials with high boiling temperatures. The molten core material would have the gross composition of a mix of metal and silicate rock. It's very dense and very difficult to cut up, if the melted products in the bottom of Three Mile Island are any indication. For leaching to be effective it would have to be crushed up (in order to increase the surface area and let the water percolate through) and you'd have to use a leaching solution that removes all the elements of interest. I'm not sure such a chemical solution exists. Furthermore, you have to do it at high temperatures without the introduced solution reacting with the concrete. Given how chemically reactive concrete is compared to typical metal or silicate rock, I can't think of a solution that would promptly dissolve the latter two without probably dissolving the former. Even if you were successful at selectively removing the dangerous stuff into solution, then you've got a solution full of the dangerous stuff -- a solution that can leak and escape lot easier. Worse, if it is boiling off it might even end up concentrating the radioactive solids as it evaporates and eventually could increase the nuclear reaction where the solids are concentrated.

      This is not the same rock that they mine uranium from. It's a different material. This is a bad idea even if there was any chance of it actually working, which seems doubtful.

    • Re:Mine it. (Score:4, Interesting)

      by Mr. Underbridge (666784) on Saturday April 02, 2011 @12:12AM (#35692058)

      The problem, I think, is all the crap that's not Uranium anymore. Uranium in the ground hasn't been enriched and then allowed to chain react for a while. As a result, it likely won't have all the daughter products around, certainly not in the quantities you'll find them in the reactor. That reactor is hot, both thermally and radioactively, at a level that I don't think one would see at a working mine.

      I appreciate the creative thinking, but to treat this thing in that manner would require letting the shorter-lived daughters decay so that it more resembles what you'd see naturally occurring in the earth (relatively, at least). And that time scale is a luxury I don't think they have.

      Also, mining it would require completely breaching the core, which is most certainly what they don't want right now (see above).

      In the end - years down the line - what you describe would be potentially a good idea, assuming they don't go with the concrete casket route as in Chernobyl.

    • Re: (Score:3, Informative)

      by Whillowhim (1408725)

      http://mitnse.com/2011/03/16/what-is-decay-heat/ [mitnse.com]

      There is no more uranium fission, that was stopped within seconds of the earthquake hitting. The problem is the decay products of the reaction, which are unstable and thus radioactive. The power given off by the reactor at this point is just a percent or so of its original power, and all of that is coming from unstable isotopes splitting on their own. There is no real point to separating the fuel, the byproducts will continue to fission without any neutrons

    • by lennier (44736)

      We need some miners to step up and advise of the fastest method to dissolve uranium in a steel container and pump it out.

      Seems easy enough.

      1. Add highly toxic mining acid by the boatfuls to leaky glowing reactor core, spraying toxic acid all over mining engineer #1-500 in the process..
      2. Get mining engineers #500-1000 to pump glowing toxic corrosive dissolved uranium goo, which radiates fast enough to kill you in an hour just by standing next to it, into storage tank
      3. Continue until you run out of cake.
      4. Science!

  • by TheGratefulNet (143330) on Friday April 01, 2011 @10:11PM (#35691694)

    an 'america syndrome' ?

  • by Anonymous Coward on Friday April 01, 2011 @10:27PM (#35691742)

    The IAEA is reporting that measured soil concentrations of Cs-137 as far away as Iitate Village, 40 kilometers northwest of Fukushima-Dai-Ichi, correspond to deposition levels of up to 3.7 megabecquerels per square meter (MBq/sq. m).

    Compare this with the deposition level that triggered compulsory relocation in the aftermath of the Chernobyl accident: the level set in 1990 by the Soviet Union was 1.48 MBq/sq. m.

    From http://www.japan.org

  • This is absurd (Score:3, Interesting)

    by jd (1658) <imipak@noSPam.yahoo.com> on Friday April 01, 2011 @10:32PM (#35691758) Homepage Journal

    The first problem is that TEPCO isn't telling anyone what they know (to save face and because they're freaking out)
    The second problem is that whatever they are telling, they're telling to the Japanese government and no-one else (even their own workers, who they convinced to wade through radioactive water without boots, go into radioactive buildings without radiation badges or suitable gear, etc).
    The third problem is that the experts are working with minimal data - and what they do have is suspect
    The fourth problem is that TEPCO has been trying to salvage the reactors at the same time as spraying them with seawater (which would be corrosive) and after the outer shell had exploded on three of them (causing untold damage to electronics, shock-proofing, etc)

    On top of all that, TEPCO allowed the hydrogen build-up in the first place. They could have burned it off with a controlled burn. This would have prevented the explosions, reduced the spillage and possibly prevented the fuel leak. (Reducing pressure may have reduced water temperature and may have conserved some of the cooling pools.)

    As for building the reactors ALONG the fault-line, despite advice not to by their own chief scientists, and building a tsunami wall far lower than the historic tsunami wave-heights....

    This accident was stoppable at so many points in so many ways. The problem wasn't so much the reactor alone as the mindset together with the reactor.

    • Re:This is absurd (Score:5, Informative)

      by borrrden (2014802) on Friday April 01, 2011 @11:03PM (#35691870)
      Burn it off with a controlled burn? How do you suggest that they do that? Light a match next to where it is coming out? It's not like they had a lot of options for the hydrogen gas with no power whatsoever on site. Also I don't know what you mean by "build the reactors along the fault line" You do realize that the fault line is in the ocean right? Not directly under Fukushima. By that reasoning, Tokai and Onagawa should not have been built either. "far lower than the historic tsunami wave-heights" where did you get this information? I can't find any data on historic wave heights of Fukushima. Don't just say "Oh there was such and such a high wave in Hokkaido" either, because the geography of the sea floor and the coast makes a big difference. They had a wall ready for a 5.5 meter tsunami, which is still a huge wave. The earthquake sunk the Japanese coast by about 1 meter AND it was hit by a 14 meter tsunami. This is documented in NOVA's documentary on the subject: http://www.pbs.org/wgbh/nova/earth/japan-killer-quake.html [pbs.org] . Salvage the reactors? They wrote off the reactors the minute they injected them with seawater. They have publicly said that reactors 1 - 4 will never run again. There is a good deal of information out there if you speak Japanese. Otherwise, you have to wait for someone to translate it which doesn't always happen. If you don't speak Japanese then you are in no position to comment on the amount of information that is or is not coming out.
      • by khallow (566160) on Saturday April 02, 2011 @12:36AM (#35692102)

        There is a good deal of information out there if you speak Japanese. Otherwise, you have to wait for someone to translate it which doesn't always happen. If you don't speak Japanese then you are in no position to comment on the amount of information that is or is not coming out.

        Nonsense, there is a one-size-fits-all narrative to describe anything in nuclear power. The management is corrupt, incompetent, and greedy. Nuclear power itself is like a coiled serpent, ready to strike at any moment, laying waste to hundreds of square miles of land.

        • Re:This is absurd (Score:4, Interesting)

          by jd (1658) <imipak@noSPam.yahoo.com> on Saturday April 02, 2011 @01:41AM (#35692236) Homepage Journal

          I take it that is sarcasm. Not very good at it, are you?

          Nuclear power is perfectly safe, if done properly. So is coal mining. Both become extremely dangerous when not done properly - nuclear power due to the risk of reactions getting too hot (decay causes heat, accelerated decay through neutron emissions causes a lot more heat), which can lead to a failure of the structural integrity of the system or - worse - uncontrolled chemical reactions resulting in a chemical explosion (essentially a "dirty bomb"), coal mining due to the risk of coal gas (methane) igniting, resulting in an explosion and/or an uncontrolled fire within the coal seam itself, beyond the confines of the mine.

          In both cases, the problem is not so much the initial event (although nobody likes fatalities - unless they're newsreaders or Fox TV presenters), the problem is that event zero can lead to the problem spreading in a way that cannot be controlled or stopped.

          In both cases, competent design and competent management can make the probability of event zero happening at all virtually zero. The number of nuclear reactors worldwide is extremely high, but other than the Windscale core fire, Three Mile Island, Chernobyl and the Fukushima complex, there really hasn't been any major accident in the industry in 50 years. That's not bad, given that our knowledge of the physics is the same age.

          (The Windscale core fire was an interesting piece of history. A graphite nuclear reactor core was allowed to burn for 3 days before anyone even thought to check why the temperature gagues were showing excessive readings. This was not corruption or greed, and even calling it incompetence is a stretch as maintenance was due over that time.)

          The fact of the matter is this: in ALL of these accidents, there was a VERY long chain of events from the the initial point that turned towards disaster and the disaster actually happening. ANY person along that chain COULD have broken that chain at ANY time. They failed to do so.

          Typically in disasters, this is because the difference between what they should have done and what they did do was so small that the person disregarded the difference. A very large sum of very small deltas will eventually add up.

          (Even the Titanic's sinking was not due to a single person's failure or a single event, but a laundry list of very tiny deltas from the time the iron was first processed to the time the helmsman mistook what sterring order the helm was set to. R101, likewise, failed because of an incredibly large number of people making incredibly tiny errors.)

          Yours is a common, and pitiful, belief that criticism of a sequence means criticism of the entire world in which that sequence lives. I've noticed such a mindset most amongst the right-wing and the libertarians. There is, sadly, no known cure and they are doomed to live in a world that really doesn't exist outside of their own interpretation.

      • by hey! (33014)

        Actually, I did read something the other day about the the issue of the historical wave-heights. The reactors *were* built to that standard, however (a) the exact heights of historical tsunamis are estimates, which were subsequently revised upward and (b) seismic models suggested (correctly) that a much larger tsunami than any historically recorded was a serious possibility. (Prays to Google for a reference.... Ah here we are: http://www.post-gazette.com/pg/11087/1135345-82.stm [post-gazette.com] ).

        So, *yes* it is absolutel

  • by BoRegardless (721219) on Friday April 01, 2011 @10:44PM (#35691802)

    From what I read Tepco, their regulators and the general government in Japan has ignored all 3 items in my subject.

    For doing that they will pay the huge price of a 10-20 year cleanup with enormous damage to their economy and the respect the people have for their institutions.

    It is not only the Middle East that may see governmental changes in the near future.

  • by DrJimbo (594231) on Friday April 01, 2011 @10:47PM (#35691814)
    Jeeze Louise. Literally thousands of tons of highly radioactive water have gotten past containment already. They are planning to pump it into barges and ships with a total capacity of 15,000 tons. A lot of the radioactive water is 100,000 times more radioactive than water found in a functioning nuclear reactor. The only way this radioactivity could have escaped is if the fuel rods melted or broke contaminating the water and then the water escaped through leaks in the secondary stainless steel containment vessel.

    The authorities don't know how the water is leaking out and don't know the upper bound on the total amount of radioactivity released. The lower bound is already rather staggering. In addition, radioactive materials have already leaked into the ocean and the ground water. TEPCO said the level they measured in the ground water was the similar to the high levels found in the turbine buildings and the tunnels outside the plants. The Japanese Nuclear and Industrial Safety Agency said those readings were way too high so they asked TEPCO to measure again more carefully.

    The only specific theory I've heard of how the thousands of tons of highly radioactive water got out of the containment vessel is that it got out via graphite seals in the bottom of the vessel. There are holes there for control rods and the holes are blocked with graphite seals. The seals will fail at high temperatures and melted fuel rods falling to the bottom of the vessel would provide more than enough heat to cause the seals to fail. If it is any solace, reactors that don't contain melted fuel rods probably don't have leaks all over the bottom of the containment vessel.

    The radioactivity released at Chernobyl escaped upward into the air. This made it easier to get a handle on the magnitude of the total amount of radioactivity released. The release at the light water reactors at Fukushima is for the most part traveling downward, to basements, tunnels, ground water, and the ocean. This makes it extremely difficult to get a handle on the total amount of radioactivity that has been released. They really don't know of the bulk of it is in the thousands of tons they have already discovered or if that is just the tip of the iceberg.

    • by Technician (215283) on Saturday April 02, 2011 @12:03AM (#35692036)

      Often glazed over in reporting is the amount of heat that was in there in the residual heat. The core was producing residual heat of about 7% of the power level it was running before shutdown.

      If a unit was running at 700 Megawatts, the core would then be running at 49 Megawatts, but with no output outside the shell. When the cooling quit for a couple of days, it did not take long to boil the kettle dry.

      In the US a partial meltdown of a small sodium reactor happened before 3 Mile Island. Google it. They could not add cooling water due to the flammable Sodium.

      All the experts that have covered reporting current situation has not said a word about flammable Zirconium. Zirconium is highly flammable in water just like Sodium. The only difference is one is flammable at room temperature and the other catches fire at much higher temperature. When the core was exposed and overheated one of the experts said the cladding oxidized.

      If you heat a chunk of Zirconium with a torch and get it dull red, it will catch fire. If you then throw it in water, it will burn using Oxygen from decomposing water and leaving Hydrogen as a byproduct, just like burning Sodium the reaction is exothermic. Zirconium melts at 1852 C. It catches fire at a lower pressure than it melts. To simply say it melted is false.

      When they had fluctuating core pressure and a large Hydrogen release, I knew a large amount of Zirconium burned. This includes reactors 1-3 and fuel rod pool in #4, and possibly the fuel ponds in 1-3. This Hydrogen confined in the outer containment combined with air went boom. The boom most likely happened when the rods in the cooling ponds boiled dry and got hot enough to be an ignition source.

      When the experts say they don't expect any more hydrogen explosions, it is because there is no Zirconium left.

      The high radiation levels in the water is because the Uranium Oxide was subjected to both the residual heat and the cladding fire.

      Speaking of cladding fire, remember a couple of rod storage areas with some fires?

      Overheated graphic seals is no surprise if the cladding burnt off and the ceramic uranium oxide overheated.

  • by viking80 (697716) on Friday April 01, 2011 @11:25PM (#35691922) Journal

    Why would someone with no insight into the current status at Fukushima throw wild guesses around. This sounds more like an religious agenda then science.

    He teaches chemistry at UC Santa Barbara.

  • by OneAhead (1495535) on Friday April 01, 2011 @11:28PM (#35691932)
    First sentence says it all: "It's Theo Theofanous's job to worry about worst-case scenarios." The rest of the article is a description of a worst-case scenarios that is not entirely 100% impossible, but quite implausible. The cautious language also reflects this.

    At this point, it seems the bigger risk is a steady stream of isotopes from the fuel pools which are still not full and still steaming hot, and possibly some more from cracks in the reactor containment. It's going to be challenging to isolate it all from the air, given the contamination levels above and around these fuel pools.
  • by DrJimbo (594231) on Saturday April 02, 2011 @01:23AM (#35692214)
    From Japan.org [japan.org]

    The world's largest concrete pump, deployed at the construction site of the U.S. government's $4.86 billion mixed oxide fuel plant at Savannah River Site, is being moved to Japan in a series of emergency measures to help stabilize the Fukushima reactors.

    ... Initially, the pump from Savannah River Site, and another 70-meter Putzmeister now at a construction site in California, will be used to pump water -- and later will be used to move concrete.

    "Our understanding is, they are preparing to go to next phase and it will require a lot of concrete," Ashmore said, noting that the 70-meter pump can move 210 cubic yards of concrete per hour.

    Putzmeister equipment was also used in the 1980s, when massive amounts of concrete were used to entomb the melted core of the reactor at Chernobyl.

    ... Ashmore said officials have already notified Shaw AREVA MOX Services, which is building the MOX plant for the U.S. Department of Energy's National Nuclear Security Administration, that the pump was being moved and will not be returned because it will become contaminated by radiation.

    "It will be too hot to come back," Ashmore said.

  • by unity100 (970058) on Saturday April 02, 2011 @04:02AM (#35692488) Homepage Journal
    Excuse me but this is above any argument. Nuclear power, is like maintaining a glass full of nitroglicerin in your bathroom because it fulfills some of your crucial ass wiping needs - it may be the cheapest way to fulfill your needs, but, it is also a ticking time bomb :

    A lot of nuclear reactors are dotted around the world. And this planet is a moving one - there are always constant earthquakes :

    http://hisz.rsoe.hu/alertmap/index2.php [hisz.rsoe.hu]

    See. Its like a gamble. So far, we are alright because one of those quakes didnt chance up on a critical installation. This japan quake could have been much closer, and all of those 6 reactors could have been already totally shattered and we would be sucking iodine tablets right now.

    Germany did right. At a time when the planet was showing rather increased activity, they shut down all of their 10+ reactors, around 30% or so of their power. They are going to replace nuclear power.

    Indeed. It is the biggest folly of this civilization to rely on VERY dangerous, catastrophic things, because they are cheaper than alternatives. No - these are really dangerous - because ONE failure, may be enough to wreck our civilization and decimate populations. You go figure how the rest will come down with domino effect - it will come down, but the question is, how much it will. All depends on the level of the disaster happening on the next reactor. It may even be this one.
    • Germany did right. At a time when the planet was showing rather increased activity, they shut down all of their 10+ reactors, around 30% or so of their power. They are going to replace nuclear power.

      Germany has been getting rid of nuclear power for some time now, but guess what? They don't have anything to replace it, and so they buy it instead from France - which generates it using *drumroll* nuclear power plants. Talk about NIMBY.

      No - these are really dangerous - because ONE failure, may be enough to wreck our civilization and decimate populations.

      You seem to be severely overestimating the scale of even the worst possible nuclear disaster. It won't "wreck civilization" nor will it "decimate population". It may cause several hundred immediate deaths, and perhaps several hundred thousand later on from cancer from raise

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