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Japan News Technology

TEPCO: Nearly All Nuclear Fuel Melted At Fukushima No. 3 Reactor 255

Posted by timothy from the bit-warm-in-here dept.
mdsolar (1045926) writes "Almost all of the nuclear fuel in the No. 3 reactor of the Fukushima No. 1 nuclear power plant melted within days of the March 11, 2011, disaster, according to a new estimate by Tokyo Electric Power Co. TEPCO originally estimated that about 60 percent of the nuclear fuel melted at the reactor. But the latest estimate released on Aug. 6 revealed that the fuel started to melt about six hours earlier than previously thought. TEPCO said most of the melted fuel likely dropped to the bottom of the containment unit from the pressure vessel after the disaster set off by the Great East Japan Earthquake and tsunami."
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TEPCO: Nearly All Nuclear Fuel Melted At Fukushima No. 3 Reactor More

TEPCO: Nearly All Nuclear Fuel Melted At Fukushima No. 3 Reactor

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  • So.. what? (Score:5, Insightful)

    by Joe Gillian ( 3683399 ) on Thursday August 07, 2014 @02:52PM (#47625551)

    This article really doesn't explain why this finding matters. TEPCO themselves said they do not know how this will effect the decommissioning process for the reactor, if at all. The only thing that seems to be different is that they now believe some of the fuel is still inside the pressure vessel, and it's not clear that they didn't already know that to begin with. It doesn't seem like anything will really change until TEPCO actually sends people in to get a look at it.

    • Re: (Score:2, Interesting)

      by Noah Haders ( 3621429 )
      I see this as qualified good news. A power plant had a total meltdown but the world didn't end. There was no China syndrome situation. Maybe we can start to talk about nuclear risk more pragmatically.

      • Re:So.. what? (Score:5, Insightful)

        by i kan reed ( 749298 ) on Thursday August 07, 2014 @03:00PM (#47625605) Homepage Journal

        Maybe we can start to talk about nuclear risk more pragmatically.

        Ha. Hahaha. Ha.

        Yeah. Also, maybe we can go down to hell and make some snow angels. Then get on our swines and fly off to a peaceful middle east.

        • My version of Hell... would be cold. I'd expect ice and snow.
        • I think you're overly pessimistic. the world has seen two catastrophic nuclear power plant accidents (chernobyl and fukushima). For each we can quantify the total lives lost and health impacts (for chernobyl, lifetime impacts over several decates). We can quantify the number of people displaced and the duration of displacement. we can quantify the total costs of cleanup, costs of costs of health care, economic damage. All of this informs a rational debate on nuclear risks vs. benefits.

          right now, we have th

          • Re: (Score:2)

            by putaro ( 235078 )

            Well, if we could get a majority of people to start talking about risks and costs rationally it would be wonderful. As it is, you've got people criticizing solar plants because a few birds got fried. Never mind whatever problems the solar plant replaced. I think the risk/rewards on nuclear are acceptable but trying to get people to talk about nuclear in a rational way is difficult.

      • Idiot speaks: "So.. what?" (Score:5, Interesting)

        by dtjohnson ( 102237 ) on Thursday August 07, 2014 @05:04PM (#47626507)
        A large amount of radioactive material was released into the ocean where it will remain in the food chain for decades. Approximately 100,000 people are unable to return to their homes and a large area of land in a country where land is scarce and precious is uninhabitable. But...that's just the short term. Long term: Japan will have to deal with electric power shortages for years until their power generation can be rebuilt with new technology. Hundreds of billions of dollars will have to be spent over the next 20 years to decommission the mess at Fukushima and attempt to decontaminate the surrounding downwind land. All of this was avoidable...but happened because the resident village idiots were able to prevent realistic plans from being implemented for electric power generation at Fukushima. The Onagawa power station was closer to the earthquake epicenter and yet it survived undamaged thanks to a losing battle by the resident village idiots to ensure that it was built according to their idiot plans. They lost at Onagawa but 'won' at Fukushima. Idiots who said...why spend a lot of money on a bigger seawall at Fukushima? Idiot engineers at GE who said 'there's no need for a failsafe design for something that will never happen,' and idiots who say 'what's the big deal about a meltdown?'

        • A large amount of radioactive material was released into the ocean where it will remain in the food chain for decades.

          what isotopes are you talking about.. Some of this stuff is centuries before it goes away... Oh, and never mind that in Japan they currently occupy the only two locations where nuclear weapons have been used.... So, I'm not so sure this is as totally bad as folks claim.

        • Re: (Score:2, Insightful)

          by CrimsonAvenger ( 580665 )

          A large amount of radioactive material was released into the ocean where it will remain in the food chain for decades.

          Hmm, 1.3 billion cubic km of ocean, at 3 ppb uranium naturally...

          So, the ocean has, as a matter of course, ~4 billion tons of uranium, of which 0.72% is U-235. So 28,000,000 tons of U-235 in the ocean naturally.

          So, if the reactor in question had a MILLION TONS of fuel (trust me, it didn't), it increased the natural radioactivity on the oceans by less than 4%.

          A more realistic number woul

      • Re:So.. what? (Score:5, Insightful)

        by Mr_Wisenheimer ( 3534031 ) on Thursday August 07, 2014 @05:21PM (#47626597)

        Yeah, and maybe we can talk about about abortion pragmatically too . . .

        The average member of the public has an emotional, visceral reaction to things such as GMO, global warming, nuclear power, et cetera. You might as well be talking about abortion, because Joe Sixpack doesn't understand things like nuclear physics, cost-benefit analysis, risk analysis, et cetera.

        After September 11th, the average American was more worried about being personally harmed by terrorism than bad driving, even though outside of a few major cities, the risk of dying in a terrorist attack was almost non-existent.

        That is why there is such a disconnect between the public and scientists (and the scientifically literate) on these matters. It's easier to scare someone about strangers molesting their children than it is about their children dying or having a worse life because of global warming, even though the former is a remote probability and the later is almost inevitable.

      • the China Syndrome was less about a nuclear disaster and more about cover ups and ignoring of known safety issues. It sorta sounds like we _did_ have a China Syndrome situation here...

      • Re: (Score:2)

        by tomhath ( 637240 )
        The reason this is on /. is because the editors want to still up more traffic with irrational debate

    • Re: (Score:3, Insightful)

      by Anonymous Coward

      Meh, it's an mdsolar submission - so the inference you're expected to draw from it is OMG TEH NUCULAR IS BAD!!ONEONE!

      Tell me again how many people died as a result of radiation leaks at Fukushima.
      And how many died as a result of the tsunami.
      And compare & contrast the relative panic and news coverage of the two.

      Bah.

      • Re:So.. what? (Score:5, Insightful)

        by AmiMoJo ( 196126 ) * on Thursday August 07, 2014 @03:43PM (#47625929) Homepage Journal

        The tsunami continues to be a very big deal in Japan. More so than the nuclear accident at the time, and rivalling it now. The thing is the tsunami happened and that was it. Things are being done to improve safety and rebuild, but for the people left alive there isn't much on-going danger.

        Fukushima, on the other hand, continues to release contaminated material and water into the environment, continues to suck up vast amounts of money with no limit and no end in sight, and continues to prevent full clean-up and re-building in the areas around the plant.

        Both were terrible tragedies, but in the end Fukushima is going to cost more and last a lot longer. It also lead to the discovery of problems at many other plants, and brought into question many of the assumptions that were made about safety. The tsunami raised safety questions too, but the solution is clear: stronger defences, earlier warnings, move away from some areas. The way forward for nuclear is not so clear, so there is still a lot of debating to be done.

        Japanese people have a far better understanding of the issues than you give them credit for, and I'd go as far as to say many of them have a better understanding than you.

        • Re: (Score:2, Interesting)

          by khallow ( 566160 )
          The tsunami continues to release contaminated material and water into the environment too. The debris washed into the sea wasn't all biodegradable and green. And things like lead and mercury have a much longer half life than things like tritium. The two events aren't compared fairly and this just another example of that.

      • Tell me again how many people will die next time a nuke goes rogue close to a 30 million citizens city in California.

        X people will die (X greater 1) in car accidents trying to flee the city.

        And a year later in a /. discussion you will explain us calm wordily: 'there was no death to the accident, the panic amoung the people fleeing, caused more deaths than the radiation! (Erm, no death, more than ... a contradiction)

        You know, we use(d) to say in Germany: "What does concern me nuclear plants or nuclear power?

    • No one's going to actually go in and look at the reactor (or what's left of it) for a long time. What it does tell us is that most of the fuel is in the bottom of the containment vessel, and not hanging in the reactor pressure vessel. While TEPCO how they will use that information today it will affect their decision making process as they move forward.

    • Re: (Score:2)

      by hey! ( 33014 )

      Well, it probably makes no difference to the clean-up, but it does add to the take-away lessons from the disaster. It's an ongoing theme that TEPCO knew less about what was going on at the time than they thought or led us to believe. You have to set that against the overall good news that the failsafe designs of even this relatively primitive reactor mostly contained the accident. The principles of engineering are sound; management, not so much; at least not in a disaster.

  • and the real bad news is... (Score:4, Informative)

    by Cardoor ( 3488091 ) on Thursday August 07, 2014 @02:56PM (#47625577)
    considering that the recently passed 'state secrets' law in japan effectively gags anyone from talking about fukushima in an honest way, the fact that this is being released at all probably means it's just to warm up the public for the real shoe to drop..

    oh, and in case you don't know the law... here it is. [npr.org]

    • Re: (Score:3)

      by jd ( 1658 )

      I wouldn't worry too much about Fukushima, per se.

      It's the fact that the State Secret law passed days after the abandonment of the pacifist sections of the Constitution, at a time Japan desperately needs to get rid of masses of deadly radioactive material, that you need to concern yourself with.

  • Is anybody surprised? (Score:5, Insightful)

    by thsths ( 31372 ) on Thursday August 07, 2014 @03:02PM (#47625625)

    In case of a nuclear accident, the industry will always downplay and deny everything that is not perfectly obvious. Has always been, and probably will always be. This is the main reason I do not trust nuclear power that is run for profit.

    • Re: (Score:2)

      by Minwee ( 522556 )

      In case of a nuclear accident, the industry will always downplay and deny everything that is not perfectly obvious. Has always been, and probably will always be. This is the main reason I do not trust nuclear power that is run for profit.

      Whereas non-nuclear power that is run for profit has always been quite trustworthy.

      • Re: (Score:2)

        by thsths ( 31372 )

        Non-nuclear power has well known consequences. An important one for coal is the release of mercury, lead and radon (!) into the atmosphere. Of course industry has downplayed it, but it is very easy to verify.

        As for state owned power - it depends on whether you trust the system. If it is totalitarian, so is the management of power plants.

        • Non-nuclear power has well known consequences. An important one for coal is the release of mercury, lead and radon (!) into the atmosphere.

          Oh, and enough radioactive carbon-14 to make nuclear power look safe by comparison.

    • In case of a nuclear accident, the industry will always downplay and deny everything that is not perfectly obvious. Has always been, and probably will always be. This is the main reason I do not trust nuclear power that is run for profit.

      Right, because coal is working out so safely for us.
      http://en.wikipedia.org/wiki/K... [wikipedia.org]

    • Re: (Score:3)

      by TheSync ( 5291 )

      I do not trust nuclear power that is run for profit.

      Uh, was Chernobyl run for profit?

    • In case of a nuclear accident, the industry will always downplay and deny everything that is not perfectly obvious. Has always been, and probably will always be. This is the main reason I do not trust nuclear power that is run for profit.

      So Chernobyl was ok with you? Yikes, you might want to rethink that..

  • I think this means (Score:2, Interesting)

    by MobyDisk ( 75490 )

    fuel at the No. 3 reactor began melting at 5:30 a.m. on March 13

    I think this confirms that that they should not have flooded the reactor with seawater because the meltdown had already happened by the time they made that decision. They flooded the reactor on March 15th, as a last ditch attempt to prevent a meltdown. But it was too late to save the reactor since the fuel was already completely melted. So all the seawater did was let more nuclear material escape.

    Or, alternatively, they should have flooded it with seawater days ahead of time. The tsunami was March 11th,

    • Re: (Score:2)

      by AmiMoJo ( 196126 ) *

      Consider that we are only realizing this now though, years later. Lack of information was a huge problem at the time. When the plant was in crisis and people couldn't get near the reactors to check them there was a lot of guesswork.

      The reason they didn't flood with seawater earlier was that they were pumping water in with fire engines. That was an established emergency procedure but failed to work because the cooling system was damaged and once again a lack of information lead to much of the water being syp

      • Re: (Score:2)

        by thsths ( 31372 )

        Consider that we are only realizing this now though, years later. Lack of information was a huge problem at the time.

        Yes, but that is a well known problem. In every core meltdown, lack of information has been a serious issue. Guess why? Because the sensors melt, too. An expert may be able to guess what is going on, but it is beyond the skill of a typical operator.

        • Re: (Score:2)

          by khallow ( 566160 )
          Hmmm, I wonder what sort of remote sensors could be used in the situation? I guess if neutron and gamma ray detectors could be built with decent spatial resolution, then that might work. A nuclear plant undergoing a meltdown is no doubt a high noise environment, but you still might be able to image its interior with infrasound.

      • Re: (Score:2)

        by jd ( 1658 )

        I can accept that, but with reservations.

        A lack of timely information lies at the heart of all nuclear accidents, large and small. It would seem to follow that to improve safety, you'd want to improve on sensors - the number, resilience and backups.

        They were using helicopters, IIRC, which raises the question of what cameras and other sensors could have been used on those helicopters to fill in the gaps in their knowledge.

        Did they try firing simple rockets into the reactor core? Something capable of carrying

      • I was about 100 km from Fukushima when it happened, the reason they didn't flood the reactors with seawater right away was that the president of TEPCO, who before the earthquake was famous for being a cost cutter, wanted to save the reactor because if they flooded it it would never produce power again. He only reluctantly agreed to have it flooded after it was clear not doing so would result in an even bigger catastrophe. The dude should be hung for what he did.

    • Re: (Score:3)

      by tp1024 ( 2409684 )

      Cooling down a molten core to the point where it solidfies reduces emissions quite enormously, especially when the containment (such as a Mark I BWR containment), wasn't designed to stay fully sealed after a meltdown. Otherwise, when the hot molten core just sits there, more aerosols (maiinly Caesium) are created and eventually scattered in the environment.

      When this containment was designed, back in 1958-1962, it was sufficient to ensure that there would be no catastrophic numbers of casualties after any po

      • Re: (Score:2)

        by AmiMoJo ( 196126 ) *

        The containment buildings were supposed to contain everything, but they were damaged by hydrogen explosions. The hydrogen gas was supposed to have been vented, but the battery powered venting system stopped working after the disaster. Some consideration was given to venting into the atmosphere, but it was decided not to. A bad choice in hindsight, but they thought that their emergency cooling measures would work.

        • The containment buildings were supposed to contain everything, but they were damaged by hydrogen explosions. The hydrogen gas was supposed to have been vented, but the battery powered venting system stopped working after the disaster. Some consideration was given to venting into the atmosphere, but it was decided not to. A bad choice in hindsight, but they thought that their emergency cooling measures would work.

          I don't know much about Japan... but in the US most plant upgrades have been denied permits by the feds because of work done by organizations like Greenpeace. If I didn't know better, I'd think they were intentionally trying to cause accidents to further their anti-nuclear agenda.

          • Re: (Score:3)

            by sphealey ( 2855 )

            - - - - - but in the US most plant upgrades have been denied permits by the feds because of work done by organizations like [organization parent poster doesn't like] - - - -

            Nuclear power plants in the United States with operating licenses undergo a continuous process of upgrade and modification, will continue to do so throughout their operating life, and in some cases continue to receive upgrades after retirement if in safestore mode. Over the last 20 years enormous effort has gone into simplifying and

    • fuel at the No. 3 reactor began melting at 5:30 a.m. on March 13

      I think this confirms that that they should not have flooded the reactor with seawater because the meltdown had already happened by the time they made that decision. They flooded the reactor on March 15th, as a last ditch attempt to prevent a meltdown. But it was too late to save the reactor since the fuel was already completely melted. So all the seawater did was let more nuclear material escape.

      Or, alternatively, they should have flooded it with seawater days ahead of time. The tsunami was March 11th, so perhaps had they made that decision on March 12th it would have been in time to prevent the worst of it? Ehh... maybe not.... the reactor foundation was probably already damaged by that point. :-(

      Armchair quarterbacking something this complex is a tad ridiculous don't you think? This reactor survived one of the worst natural disasters ever recorded. People were freaking out, the government was threatening to take over the plant, and worst of all they feared the earthquake was so strong that it had broken the containment vessel. Thank God it survived mostly unscathed.

      If there's one thing we can say in hindsight it's that there would have been almost no release of dangerous materials if there had been

      • Re:I think this means (Score:5, Insightful)

        by angel'o'sphere ( 80593 ) <angelo.schneider@nOSpam.oomentor.de> on Thursday August 07, 2014 @05:23PM (#47626617) Journal

        That is incorrect.
        The mag 9.5 quake was 450 miles away.
        Ar the place of the reactor the quake was not even mag 6 ... the surrounding power pillions failed, shutting off the plant from external power.
        The plant itself was damaged by far enough to be unable to produce its own power and cool itself.
        And then the Tsunami hi tits emergency power.

        So, claiming the 'plant survived' a '.... how was your words? Ah: "This reactor survived one of the worst natural disasters ever recorded." '

        No, it certainly did not. It is smoldering in its ashes.

        Not only was it NOT EVEN HIT, by the 'worst natural disaster', but it got destroyed by its wake (1 thousand times weaker than the a actual disaster/quake)!! Or actually as wake implies by the water of the tsunami.

        Even if there had not been a tsunami, the plant was destroyed. What is so fucking difficult in accepting that? Sure, the emergency diesel power likely had prevented a 'disaster'.
        But the plant never would have gone online again.
        Claiming 'it survived the biggest catastrophe in mankind' is bullshit, and is a disrespect to the dead of Nagasaki and Hiroshima, or the simple earth quakes of the last 100 years.

        Google/Wikipedia for it. The official death toll is never even close to the 'unofficial' one. And all those quakes certainly qualify your brain dead definition of 'biggest disasters naturally recorded' ... Fukushima was no such thing yet. It will be in 30 or 50 years when the radiation death will start piling up.

        • You are right that the Tsunami was the issue here, not the earthquake, which the plant survived largely in one piece.

          However, I take exception to you description of the plant as being "smoldering in its ashes". Not exactly...

          The plant survived largely in one piece, sans the emergency generators and stuff that the sea water fouled. They have had some difficulties with keeping the reactors cooled and we have seen significant releases of radioactive materials into the environment because of the core(s) tha

      • Design a system to be idiot proof, and they will simply design a better idiot.

    • Communications and knowledge were a problem (Score:5, Informative)

      by ChumpusRex2003 ( 726306 ) on Thursday August 07, 2014 @07:17PM (#47627119)
      This is the crux of the problem. No one knew what was going on and what to do. Investigations over the last few years have shown that typical TEPCO safety drills were very limited and basic; there was little planning or rehearsal of complex accident scenarios, just basic minor incidents.

      There were poor decisions and communication between various designers and operators. Take for example, the situation at reactor 1. After the generators started, the emergency reactor cooling condensers should have switched on to provide cooling. However, operators had found that they were very effective and being unfamiliar with their use were concerned that they would cause thermal shock to the reactor. Not familiar with the operation of this system, the operators decided to manually switch off the condenser system to arrest the temperature drop. They would then switch them on again manually as reactor temp rose again. This worked fine, until the generators failed, removing control and monitoring from this system.

      Operators at emergency control, in a separate quake-proof building asked for confirmation of operation, but the control room could not give it. So,workers went out to inspect the reactor building for steam rising from the condenser stacks. They reported some steam rising, and it was assumed that the system was operational. However, the condenser system had never been used or tested since the plants were constructed 40 years ago. No one knew how they worked and how quickly they could cool the reactor, no one knew how much steam was produced during operation. It turns out that the workers sent out for reconnaissance saw only faint steam trickling from the stacks, consistent with the system having been switched off for many minutes, but still containing some residual heat. Had the system been switched on, the clouds of steam would have been so profuse and so dense that the it would have been impossible even to see the reactor building, let alone identify the condenser stacks.

      On the assumption that the system was operational, other attempts to provide emergency cooling were suspended or delayed. A steam/battery powered pump system was available to deliver fresh water to the reactor, but without a heatsink (condenser) available, the reactor temperature rapidly rose and so did reactor pressure, eventually overcoming the maximum discharge pressure of the coolant injection system. After a few hours, the UPS controlling this system discharged and it also failed.

      After 24 hours, reactor pressure unexpectedly dropped. Operators realised that this might permit external coolant injection and fire engines were called in. There was a huge delay, as the fire engines were unable to reach the site due to debris and some had been destroyed by the tsunami. Subsequent investigation showed that despite massive coolant injection, coolant did not rise in the reactor. The cause was thought to be due to damage to the reactor vessel or a pipe. In retrospect, it probably indicated damage to the reactor following meltdown of the fuel.

      There were also design oversights in the emergency systems for the plants. One of the final backup schemes for reactor cooling was the ability to connect fire engines to the reactor to inject coolant. It subsequently became apparent that in units 2 and 3, this water didn't reach the reactor, and collected in a condenser unit instead. This was always going to happen, due to the way in which the water pipes were connected. There was a pump connected between the storage tank and the injection flow pipe. Under normal injection conditions, the pump would have been running, and any additional water from the fire engine would likely have gone towards the reactor, and this presumably was the assumption under which the water injection protocol was developed. However, under power failure conditions, the pump was unpowered. Due to the design of the pump - a rotodynamic (impeller) pump. this pump would have offered little or no resistance to reverse flow when unpowered.

    • The media had a hayday trying to cover an event in deep coverup. What they reported revealed volumes.

      They reported the Hydrogen Explosion. This was the first indicator to the public a major event happened. What the media does not know.

      1 The fuel pellets are held in rods made of Zirconium. This is because it is transparant to the reaction and does not slow the reaction so it can be controlled by control rods.

      2 Zirconium is flamable, even in water. It burns even better in water than in air. It breaks do

  • As if asahi.com wasn't already borked from the canal story, we link to them again?

  • The man who saved Onagawa (Score:5, Insightful)

    by Old VMS Junkie ( 739626 ) on Thursday August 07, 2014 @04:03PM (#47626123)
    It could have been worse except for one determined engineer, Yanosuke Hirai, who insisted on a higher seawall for the Onagawa plant. A good article can be found at http://www.oregonlive.com/opin... [oregonlive.com]. I have a quote on my wall from Tatsuji Oshima, one of his proteges. "Corporate ethics and compliance may be similar, but their cores are different. From the perspective of corporate social responsibility, we cannot say that there is no need to question a company's actions just because they are not a crime under the law."

  • This is why we need NEW reactors (Score:4, Interesting)

    by WindBourne ( 631190 ) on Thursday August 07, 2014 @04:53PM (#47626437) Journal
    Seriously, the mistake that everybody is making is stopping new ultra-safe reactors from replacing these old second gen reactors. Companies like Transatomic can make it so that the reactor can not fail.

    • can not fail (Score:5, Insightful)

      by mdsolar ( 1045926 ) on Thursday August 07, 2014 @05:04PM (#47626501) Homepage Journal
      Isn't that what they said about these reactors?
      • When you have the laws of physics on your side, it is hard NOT to fail.
        The old reactors required ACTIVE work to stop them from melting down.
        OTOH, the molten salt requires an ACTIVE system to keep it going and a simple passive one to shut it down.

        BIG difference.
  • "The estimated start of the fuel melting is roughly consistent with when neutrons were detected near the front gate of the nuclear plant, according to the officials."
  • Everything that could have gone wrong, did go wrong. They were in deep shit, and they knew it.
    Here [youtube.com] is a very good documentary on how things played out.

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