Fukushima crisis deepens

Written By: - Date published: 10:46 am, March 17th, 2011 - 46 comments
Categories: disaster - Tags: ,

In American football, there’s a move called the ‘Hail Mary pass’ – throw the ball down field and pray. That’s what filling the Fukushima reactors with sea-water has been described as, a Hail Mary pass. It just doesn’t seem to be coming off. Reactor 3 has started emitting more radiation, 4 is on fire, the core may be breached in 2. Even 5 and 6 pose a risk.

Radiation levels are still not immediately dangerous, even close by, but they are preventing workers staying in the vicinity of the reactors for long enough periods to do the work they need to do. In desperation, they tried getting the army to dump water into the spent fuel pond at 4 and the containment building of 3 but that was abandoned due to radiation levels. The plan now is to use police water cannons to get the water in.

The basic problem is that the fuel rods are emitting enough radiation to evaporate the water around them.

Inside the reactor cores, this steam is pumped out, leaving fuel rods exposed to the air. Without the water to absorb the radiation energy they’re putting out, they start to melt through their protective coating. When they touch water, they disassociate it, releasing raw hydrogen and oxygen, which are also pumped out of the core to explode in the outer containment building when they reach combustible levels. Without the water to cool them, the melting continues with the risk that the fuel rods melt through the thick metal casing of the reactor core, or even go critical again, starting the nuclear chain reaction that powers a nuclear plant in operation (the radiation given off at the moment is just the residual level). Reactors 1, 2, and 3 have all had explosions and partial meltdowns. Reactor 2 may also have a breach in its core containment.

In the storage ponds, the spent fuel rods are also putting out a lot of radiation (they’re only ‘spent’ in the sense that their radiation levels have dropped to uneconomic levels and the material can be recycled into useable rods). Again, this is evaporating the water that they’re stored in leaving them exposed and heating themselves. In Reactor 4, a fire, possibly caused by Reactor 3’s explosion has burnt away the building, leaving the spent fuel rods exposed to the air. Temperatures are also rising at Reactors 5 and 6 for the same reason. These three reactors were offline when the tsunami struck, so there’s no heat in the core to worry about.

The one ray of good news today is that the new power line to the plant is nearly complete. This will provide power to the pumping system. In normal operation, the pumping system takes water from the reactor through the turbines to generate electricity and on to a heat exchanger (often the iconic cooling tower, but not a Fukushima), thus cooling the water which then goes back to the core to take away more energy from the fuel rods. But will the pumping systems still be in operational order after all that has happened around them?

And let us not forget that there is still a huge crisis going on due to the earthquake and tsuanmi with over 4,000 confirmed dead and conflicting reports that put the missing at as high as 20,000. There’s also the likelihood of strong (7.0+) aftershocks in the next few days.

In a sign of just how serious this situation is, Emperor Akihito made a televised address to the public asking them to not give up hope. I haven’t been able to find out exactly how rare it is for the Emperor to make a broadcast to the public but the only other time I know of is the first – when Hirohito announced the surrender of Japan in 1945.

46 comments on “Fukushima crisis deepens”

  1. 1945 was the only other time that a Emperor according to the sources I was reading last night.

    The NYT had a very interesting article on the governance issues in Japan at present which explains a large part of the current confusion. I’ll add the link to this comment when I dig it out.

    http://www.nytimes.com/2011/03/17/world/asia/17tokyo.html?_r=1&hp

  2. Lanthanide 2

    “or even go critical again, starting the nuclear chain reaction that powers a nuclear plant in operation (the radiation given off at the moment is just the residual level)”

    Just to highlight this further, it would essentially be a puddle of melted slag at the bottom of the reactor container that would reach criticality. When shut down, the reactors still produce about 7% of their normal operational heat due to ongoing nuclear decay. So if a new reaction started up, it would start producing considerably more heat in the reactor. This would lead to more water boiling off, potentially leading to a runaway scenario where the water can’t be pumped in fast enough to prevent further rods melting, creating a bigger slag resulting in further nuclear reactions taking place. This could melt through the outer steel and concrete containment if it went on for long enough, or potentially explode inside the reactor core from super-heated steam and hydrogen.

    If a slag puddle did start reacting, there’s very little they can do to stop it. In regular operations the fuel rods are interspersed with neutron-absorbing carbon control rods. The control rods can be moved in or out of the fuel rods, sort of like interlocking combs (this happened automatically as soon as the quake struck). In a pool of slag, there would be no such moderating rods available, the best they could do would be to pump boric acid around the slag, but with aforementioned heat problems that may not achieve much.

    This scenario would be a true “meltdown” situation.

    • What happens then L – I just don’t know much about it.

      • Colonial Viper 2.1.1

        An unmoderated criticality incident will mean a giant uncontrolled release of heat and energy which will burn through and vapourise all containment walls, and lead to a massive release of both direct radiation and radioactive particles.

        In a criticality incident, no nuclear explosion would occur as the shape and configuration of the fissile material would be incorrect, but an ongoing fission reaction would occur.

        Worst case scenario would lead to a large portion of central Japan (thousands or tens of thousands of square km’s) to be uninhabitable for several hundred years, similar to the area around Chernobyl today.

      • Bright Red 2.1.2

        It is imporant to note that there cannot be a nuclear explosion, the nuclear material is not pure enough to go supercritical.

        The spread of radiation from a meltdown would depend also on where the molten slag ends up. At Chernobyl, fires carried long-lived radioactive particles aloft to settle over a wide area.

  3. todd 3

    In the event of a core on the floor, does anybody know what measures can be taken to limit the amount of radiation released?

    • lprent 3.2

      The Russian solution. Put in a concrete base and the drop concrete and anything else available on top to form a sarcophagus.

      • Colonial Viper 3.2.1

        Sucks to be the helicopter pilots.

        Wish they had some good old fashioned catapults or ballistas. That’ll get’m covered quick, from a hundred metres away. On second thoughts that’s a bit of a crazy idea, ah well.

      • Bright Red 3.2.2

        it took the USSR 6 months to complete theirs – they had to use robot bulldozers and welders/riveters because the buildings were too radioactive to touch – and it’s leaking to the point where it’s now being replaced.

        Hopefully the Japanese are already planning how to build one. Basically, it’s just a bigger and very very thick version of the containment systems that would have already failed to get to that point. There would be no way to decontaminate the materials inside once it was complete, and the highly radioactive isotopes have half-lives varying from a few days to tens of thousands of years

        • Lanthanide 3.2.2.1

          Yeah, with the potential crack in reactor #2, they need to be considering it. I’m sure someone somewhere in Japan is already.

          They might even end up putting them over reactors 1, 3 and 4 as well, for PR reasons. I wonder if they’ll continue to run 5 and 6.

          • Marty G 3.2.2.1.1

            five and six aare located a little way of from the others, so hopefully they’ll be okf from the others, so hopefully they’ll remain ok

        • Richard 3.2.2.2

          Also the USSR cycled workers from all over their territory to do the construction work — the theory apparently being that as individual workers were only there for a short time, they would all get a small dose of radiation rather than fewer workers receiving larger doses each.

          Also it meant that, as the workers came from all over the USSR, those with radiation exposure were spread throughout the entire population. Rather than having a small population (one city or something) forced to carry a large proportion of its population with exposure related cancers and so forth, the damage was dilluted through-out a larger population.

          Quite a cold calculation somebody did to think that through. But really very clever and sensible.

          • Colonial Viper 3.2.2.2.1

            Quite a cold calculation somebody did to think that through. But really very clever and sensible.

            That’s central state planning for you.

            • Colonial Viper 3.2.2.2.1.1

              Yuli Andreyev, former head of the agency tasked with cleaning up after Chernobyl, told the Guardian that the Japanese had failed to grasp the scale of the disaster. He also said the authorities had to be willing to sacrifice nuclear response workers for the good of the greater public, and should not only be deploying a skeleton staff. “They don’t know what to do,” he said. “The personnel have been removed and those that remain are stretched.”

              From the Guardian online. Told you the Ruskies know how to do this shit.

              • todd

                You know CV, a catapult would be a good idea if radiation levels were too high to fly in a bombardment. A problem exists of the projectile causing further damage when it lands. I was initially thinking of a graphite foam but I’m unsure of the combustion point. Fully sealing the site when there are pressures still unreleased might cause further issues. So some sort of powder or sand consistency might be best. Getting enough of whatever that substance might be could also be an issue. Using too much water might just spread the radiation around. A sarcophagus for such a large facility is going to take a long time to build.

  4. joe90 4

    Spent fuel rods exposed.

    Spent fuel rods in Unit 4 of Japan’s stricken Fukushima Daiichi nuclear plant have been exposed, resulting in the emission of “extremely high” levels of radiation, the head of the U.S. Nuclear Regulatory Commission said Wednesday

    • Lanthanide 4.1

      Thanks for that. Reading the entire article, it’s not really clear if they are clarifying what has appeared to have happened at reactor #2 and #4 on Monday through early Wednesday, or if they are now talking about further developments since then. For example the mention the 400 millisieverts /hour rate which I believe was recorded on Monday or Tuesday.

      The statement that there is “no water” in the #4 spent fuel pool is quite worrying.

      The article does however indicate that the increased radiation output from #2 may not have been from containment breach, but from it’s spend fuel pool. A lesser of two evils, but not by much.

  5. ianmac 5

    Marty (and Lanthanide): Great to read some credible factual information. It seems in summary that if they can wet down and cool off, the situation will not worsen.
    There is some pretty strange ill-informed stuff floating out of TV. They seem to be trying to make a bad situation worse by mis-speaking stuff. Deliberate or just ignorant?

    • Colonial Viper 5.1

      Western news services seem to want to dramatise the whole thing even further. As crazy as it sounds, its not Hollywood enough for them.

      • todd 5.1.1

        3 News continues to think Dai-ichi is located where the dot on the map for Fukushima is, in the middle of the country. Not on the coast where the reactors are actually located. I wonder if they can tie their own shoelaces?

        Apparently the Americans have just provided Japan with some really big water pumps to help douse the reactors. With the new power line hopefully being completed, let’s hope they get there in time. I’ve also read that the Japanese have told the Americans to stay away from Dai-ichi, but who knows what to believe. Unfortunately no news is not always good news in these kinds of situations.

  6. Jenny 8

    A small crew of technicians, braving radiation and fire, became the only people remaining at the Fukushima Daiichi Nuclear Power Station on Tuesday – and perhaps Japan’s last chance of preventing a broader nuclear catastrophe.
    They crawl through labyrinths of equipment in utter darkness pierced only by their flashlights, listening for periodic explosions as hydrogen gas escaping from crippled reactors ignites on contact with air.

    They breathe through uncomfortable respirators or carry heavy oxygen tanks on their backs. They wear white, full-body jumpsuits with snug-fitting hoods that provide scant protection from the invisible radiation sleeting through their bodies.

    They are the faceless 50, the unnamed operators who stayed behind. They have volunteered, or been assigned, to pump seawater on dangerously exposed nuclear fuel, already thought to be partly melting and spewing radioactive material, to prevent full meltdowns that could throw thousands of tons of radioactive dust high into the air and imperil millions of their compatriots.

    Fukushima plant workers brave explosions and fire and deadly radiation in a bid to stop the meltdown

    While workers risk their lives, the authorities and the nuclear company are downplaying the seriousness of the crisis.

    But it’s not what they say.

    It is what they don’t say.

    If you wanted to know how serious the nuclear disaster in Japan really is -then you would need to know what measures the government have taken to protect the families of the nuclear workers engaged in the suicide mission to save the plant.

    Nuclear reactor operators say that their profession is typified by the same kind of esprit de corps found among firefighters and elite military units. Lunchroom conversations at reactors frequently turn to what operators would do in a severe emergency.
    The consensus is always that they would warn their families to flee before staying at their posts to the end, said Michael Friedlander, a former senior operator at three U.S. power plants for 13 years.

    As a condition of selling their lives, what measures have the nuclear company and the government agreed to take on behalf of these workers’ families?

    Have private planes or special government vehicles been laid on, to move their families to a place of safety?

    How far is that from Fukushima?

    Is it further than Tokyo?

    Tens of thousands are said to be leaving Tokyo, Yet no official statement has yet been issued to say that people should stay, that they are over reacting and needn’t leave – Why?

  7. RedLogix 9

    With heavy heart I’m at the point of conceding that this crisis will now need a miracle. In the old fashioned Biblical sense of the word.

    The US Nuclear Regulatory Commission announcement that the #4 Spent Fuel Pool is empty, has now been confirmed by TEPCO officials. This means this building is too dangerous to approach at all.

    The #3 Reactor and Spent Fuel Pool are assumed to be rapidly approaching the same condition.

    I think it is now a race against time. The only thing that can prevent the entire site from becoming too radioactive to survive (even for short periods) is a substantive amount of water into these pools. The only way to achieve this is with the large pumps on site. The only way to run them is with the new cable being run into the Fukushima Daiichi site.

    But the existing pump motors are probably electrically terminated into switchboards that have been under seawater in the basements and cannot ever be used again. This means that massive cables have to be somehow re-terminated into new temporary boards… under the worst conditions imaginable. I know that I’m lacking critical information here, but piecing together what I’ve been able to read so far, I’m not at all confident this can be done in time. And even if it could, it assumes the pipework exists undamaged and can be used for the task.

    This has to be the most unreal and possibly monumental battle to be fought in our lifetimes. It’s an odd sensation, the magical blips and blops of the internet unfold it all in a confusing welter of roller-coater information, ups and downs. Yet at the same time we are so remote; there is no way to reach through this computer screen and offer these desperate humans the aid and comfort they must so need at this moment.

    • Lanthanide 9.1

      I can see why they’re bringing in the helicopters now.

      This really is a terrible situation. Frankly it was entirely predictable as well. The biggest risk to these types of plants has always been the loss of water reticulation, and having pools that aren’t properly shielded from the atmosphere that also require water reticulation for safety is simply madness.

      • Jenny 9.1.1

        It all has the sad air of inevitability.

        The same scenario that unfolded in Chernobyl is being repeated.

        Only a day ago, the authorities declared the use of helicopters was too dangerous because of the danger of radiation to the pilots.

        Now they are using helicopters.

        In Chernobyl all the helicopter pilots died of radiation poisoning.

  8. Jenny 10

    .
    “Chernobyl on steroids”

    “The Fukushima Daiichi plant has seven pools dedicated to spent fuel rods. These are located at the top of six reactor buildings – or were until explosions and fires ravaged the plant. On the ground level there is a common pool in a separate building that was critically damaged by the tsunami. Each reactor building pool holds 3,450 fuel rod assemblies and the common pool holds 6,291 fuel rod assemblies. Each assembly holds sixty-three fuel rods. In short, the Fukushima Daiichi plant contains over 600,000 spent fuel rods – a massive amount of radiation that will soon be released into the atmosphere.”

    “In November 2010 there were 1760 TONS of Uranium fuel rods stored on site.”

    If you do the math that works out to 24.51 lbs / 11.14 Kg of Uranium per square mile of Japanese countryside.

    • Colonial Viper 10.1

      11kg per square mile isn’t so bad when you consider that it works out to only 4.3kg of spent fuel per square kilometre.

      Since its dense stuff it won’t actually be that much.

      A bit of rain etc and it will be all gone, good as new. 😐

    • wtl 10.2

      Presumably that figure (1760 tons) is of the entire mass of the fuel rods, and the fuel rods are not entirely made of radioactive material – does anyone know what the actual amount of this material is present at the site?

      • Colonial Viper 10.2.1

        wtl – I’ll suggest that it doesn’t quite work like that. A used fuel rod has NO non-radioactive components to it. Any microscopic particle released from any part of the fuel rod is going to be dangerously radioactive.

        Meanwhile this is a heartstopping presentation by the Tokyo Electric Power Company. Delivered late 2010.

        Its like reading the menu on the last Air NZ flight to Antarctica.

        http://www.nirs.org/reactorwatch/accidents/6-1_powerpoint.pdf

        • Colonial Viper 10.2.1.1

          Just worked out that 1760 short tons of spent fuel rods stored on site is the same mass of material as that in ~930 new Ford Falcons.

          That’s a shit load of radioactivity. Stored in a pretty small car park.

        • Lanthanide 10.2.1.2

          Interesting, thanks for the link. They seem quite interested in the new casket technology, but when you look at the capacity of them (few hundred) vs the pool which can hold 6000, and then the cooling times: 19 months for the pool, >5 or >7 years for the caskets, it’s no wonder they went with the pool system.

          Still doesn’t excuse the pools not being encased in a proper steel/concrete containment vessel, or at least something a bit more sturdy than the big empty secondary containment buildings that exploded due to hydrogen from the reactor.

          • Colonial Viper 10.2.1.2.1

            Over time the US NCR has permitted these storage facilities to re-rack and reconfigure their spent fuel storage pools, to pack more and more rods into the same space.

            Why?

            As a cost saving measure for private industry power operators. And yes, the utilities preferred not to use the dry cask system, putting extra rods into existing pools instead. Each dry cask is about US$1M in cost.

            Some frakin regulation.

      • Lanthanide 10.2.2

        CV is correct, once a rod is spent, the entire thing is radioactive due to neutrons and gamma rays etc produced in the reaction being absorbed by the remaining materials.

        The wikipedia article on nuclear fuel is unfortunately quite poor, but I can say from articles I’ve gleaned over the last week, that these rods start with a uranium oxide ceramic that is 3% U235 which is the fissile material (‘enriched uranium’, weapons grade is > 95%). I’m sure there would be at least some amount further of U238 (much more stable) in there as well. So when a fuel rod is ‘spent’, it is still capable of reacting but is economically infeasible, so they ‘reprocess’ the rods to get the remaining useful U235 out. Reactors will have variations as to what point it is considered economically infeasible to continue using the rods, so (a complete guess I just made up on the top of my head) I think you might expect ‘spent’ rods to generally have 1-2% U235 left?

        The U238 is also radioactive of course, but it has a significantly longer half life and so is less dangerous in and of itself. Having said that however, naturally occurring (‘yellowcake’) ores of it will be in much lower in concentration that what you get in a fuel rod, so probably the concentrated U238 in a fuel rod all by itself would still be at least somewhat hazardous to your health (if not “very” hazardous, I don’t really know).

        In short, the levels of radioactive isotopes being dealt with in ‘spent’ rods is still significantly high enough to be a real concern. Furthermore, the spent rods are sheathed in a different manner to help prevent criticality occurring within the pool, mainly as a precaution I would imagine but it also means that the meltdown scenario I outlined in #2 is still a real threat.

  9. Colonial Viper 12

    Terrifyingly, Japan appears to have a recent history of fatal nuclear accidents at its facilities.

    Here, workers **accidentally** started a nuclear chain reaction 😯

    http://en.wikipedia.org/wiki/Tokaimura_nuclear_accident

    • joe90 12.1

      Not a lot to be confident about when the industry is described as scandal-ridden.

      Behind Japan’s escalating nuclear crisis sits a scandal-ridden energy industry in a comfy relationship with government regulators often willing to overlook safety lapses.
      Leaks of radioactive steam and workers contaminated with radiation are just part of the disturbing catalog of accidents that have occurred over the years and been belatedly reported to the public, if at all.

      In one case, workers hand-mixed uranium in stainless steel buckets, instead of processing by machine, so the fuel could be reused, exposing hundreds of workers to radiation. Two later died

  10. todd 13

    Desperation at Fukushima

    http://thejackalman.blogspot.com/2011/03/desperation-at-fukushima.html

    By late Tuesday, the water meant to cool spent fuel rods in Unit 4 was boiling and by Wednesday, the fuel pond had caught fire and was leaking radiation directly into the atmosphere.

  11. looks like i finally get to make sense of my poem and grafik done ages ago…

    http://pollywannacracka.blogspot.com/2006/08/red-sky-at-nightshepherds-delight_29.html

  12. Jenny 15

    The worst possible scenario is now underway….

    Without actually saying that meltdown is occurring, authorities all but admit that this is the case for three of the Fukushima Daiichi reactors.

    Japan admits: “Nuclear rods melting”

    Continuing their policy of minimising this disaster, the authorities claim:

    “any meltdown can be contained by the various safety structures in place at each reactor”

    • RedLogix 15.1

      Jenny,

      The article linked to is dated the 14th which is a tad out of date. On the other hand there seems to be a relative lack of new up-to-date info around at the moment.

      It would appear as I surmised above that just getting power to the site was the least of the problems, the real challenge would be laying new cables to the existing pump motors and either re-terminating or splicing them in. In ideal conditions this is never easy work; with the plant a radioactive wreck it is a nightmare. My deepest respect goes out to the poor sods who are trying to pull this off.

      The next question as I indicated will be if the pumps and pipework are still intact and capable of achieving the desired flows and pressures into the desired locations. Again we have no information about any of this.

      And even then if the water can be made to flow what of the condition of the reactors and pools themselves? As the article you linked to implies it’s highly likely that Reactors #1, 2, & 3 are at least partially melted. Will just circulating water be enough to halt the process of meltdown? One has to hope it will be, but again very little information.

      Probably the no-one actually knows the answers yet. It’s my gut feeling that we’ve had a miracle; that they’ve succeeded in turning the corner on this… but there is weeks if not months of hard, dangerous work ahead of the operators, before there is any confidence about the stability of this site.

      • Jenny 15.1.1

        Jenny,

        The article linked to is dated the 14th which is a tad out of date. On the other hand there seems to be a relative lack of new up-to-date info around at the moment.

        Strangely the capcha word for my above comment was “quiet”.

        • RedLogix 15.1.1.1

          I’ve been following the Guardian .. it’s seems to have been as good as any.

          http://www.guardian.co.uk/world/2011/mar/19/japan-survivor-found-kesennuma-tsunami

          Anyone know of a more specialised and up-to-date analysis?

        • RedLogix 15.1.1.2

          Again from the Graniad… which rather backs up my wild-assed guessing above:

          A spokesman for Tokyo Electric, which owns and runs the complex, said it was protected against tsunamis of up to five metres (16ft) but a six-metre wave of water struck Fukushima on 11 March.

          Plant operators said they would reconnect four of the plant’s six reactor units to a power grid on Saturday. Workers have to methodically work through badly damaged and deeply complex electrical systems to make the final linkups without setting off a spark and potentially an explosion.

          “Most of the motors and switchboards were submerged by the tsunami and they cannot be used,” Nishiyama said.

          Even once the power is reconnected, it is not clear if the cooling systems will still work.

          These few paras really understate the complexity of the task; so many things could go wrong. Part of me (a very small part I’ll admit) wishes I was there; this is the kind of geeky techo-battle the stuff dreams, or nightmares, are made of.

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