A new look at spent nuclear fuel

Recent statements by Shizuoka Gov. Heita Kawakatsu concerning the stalled plan to use plutonium-uranium mixed-oxide (MOX) fuel at Chubu Electric Power Co.’s Hamaoka nuclear power plant in Omaezaki, Shizuoka Prefecture, highlight various contradictions in the central government’s continuing pursuit of a nuclear fuel-cycle policy.

In an interview with Kyodo News and at a subsequent news conference in April, the governor said his prefecture’s approval of the utility’s plan to use MOX fuel at the Hamaoka No. 4 reactor — given before nuclear power safety was thrown into doubt by the March 2011 meltdowns at Tokyo Electric Power Co.’s Fukushima No. 1 plant — should be considered invalid.

Kawakatsu is suggesting that Chubu Electric will need to obtain the consent of the prefecture and host municipalities all over again if it plans to push ahead with using the plutonium-uranium fuel at Hamaoka.

Kawakatsu also urged Chubu Electric to shift from the practice of storing spent nuclear fuel in water pools at the power plant to the alternative “dry cask storage.”

He went on to say that the Hamaoka plant would be able to store spent fuel in dry casks on-site even if the used fuel currently kept at a reprocessing plant in Rokkasho, Aomori Prefecture, is returned to the plan in the event the reprocessing program goes nowhere.

For decades, the central government has pursued a policy of recycling fuel used at nuclear power plants by reprocessing it into MOX fuel, to be used again both at fast-breeder reactors — which are designed to produce more plutonium than they consume — and at light-water reactors. It was meant to be a dream program for resource-scarce Japan.

However, Monju, the nation’s sole prototype fast-breeder reactor in Tsuruga, Fukui Prefecture, has been inoperative for nearly two decades now because of a series of accidents and problems with its operator.

Use of MOX fuel began at several light-water reactors at nuclear power plants around the country, but all of them are offline today, and the tightened safety requirements on restarting nuclear power plants following the Fukushima disasters raise doubts about whether the prospect of having 16 to 18 reactors nationwide consume the nation’s plutonium stockpiles — already reaching 44 tons — is realistic.

Completion of the Rokkasho reprocessing plant has been delayed for years due to a raft of technical glitches, but starting the plant’s operation could end up producing more separated plutonium whose consumption is uncertain.

Nevertheless, the nation’s Basic Energy Plan, adopted by the Abe administration last month, keeps up the quest for a nuclear fuel-cycle policy — even though doubts about the validity of the program have become widespread because of the realities surrounding it.

One logic that proponents use in pushing the policy, despite all the doubts, is that a halt to the reprocessing plan could put the nation’s nuclear power generation itself in jeopardy. Spent fuel from nuclear power plants around the country that has been shipped to Rokkasho, waiting to be reprocessed, will need to be returned to each plant if the reprocessing program is canceled. This will lead eventually to the filling to capacity of spent nuclear fuel pools at the plants, effectively making it impossible for the utilities to operate their nuclear reactors.

This problem could be resolved if, as Kawakatsu says, the nuclear power plant operators kept their spent nuclear fuel — including fuel that might be returned from Rokkasho — on the premises of their plants in dry cask storage.

With this method, spent fuel already cooled in the pool for at least one year would be surrounded by inert gas inside a container called a cask — typically steel cylinders that provide leak-tight confinement of spent fuel — and further surrounded by additional materials including steel and concrete for radiation shielding.

While dry cask storage is becoming more common at American and European nuclear power plants, it has so far been used at only a few Japanese plants. The method is believed to be technically more stable than storage in pools, where temperatures can rise if the cooling system fails because of the loss of water or power.

Spent fuel today occupies about 70 percent of the total storage pool capacity at the nation’s nuclear power plants and the Rokkasho facility combined, raising alarms that the capacity would be used up within years if power plants are restarted without the reprocessing of used fuel at the Rokkasho plant.

Kawakatsu said that typical nuclear power plant sites should have enough surplus space for dry cask storage of spent fuel, noting that at least the Hamaoka plant does.

Dry cask storage does not provide a permanent solution to the problem of what to do with spent nuclear fuel. Still, it could provide some leeway for reviewing the government’s rigid pursuit of the nuclear fuel cycle policy.

The Hamaoka plant has five reactors, including two aging ones that Chubu Electric decided in 2008 to decommission. In 2011, the utility shut down two operating reactors and held off restarting another that was down for maintenance at the urging of the government following the Fukushima meltdowns.

In February, Chubu Electric applied to the Nuclear Regulation Authority for safety screening of its plan to restart the No. 4 reactor, hoping to resume operations upon the completion of the extra anti-earthquake and tsunami measures by the end of September 2015.

Kawakatsu said he would seek to hold a plebiscite to get local residents’s views if the government and the utility decide to restart the Hamaoka plant. His retraction of Shizuoka’s go-ahead for the MOX fuel use at the plant may also influence other prefectures and municipalities that had had MOX plans approved for the nuclear power plants they host — before the Fukushima nuclear crisis.

The governor’s remark that it is rational for nuclear waste to be kept where it has been produced speaks volumes about another problem with nuclear power generation in Japan — the imbalance between the direct beneficiaries of nuclear power and those who bear the biggest burdens of it.

Tokyo, for example, is the nation’s largest consumer of electricity, but nuclear power plants that serve its needs are built hundreds of kilometers away. Shizuoka, however, happens to be both a producer and consumer of nuclear power.

The government has been unable for years to find candidate sites for the final storage of high-level radioactive waste from power generation. The lack of clear answers to this question is symbolic of the shaky nature of nuclear power in Japan.

  • lokay5

    MOX? No problem. The explosion of MOX-fueled reactor #3 at Fukushima was jus a fluke…

    • Starviking

      And yet the non-MOX fueled reactors 1 and 3 also suffered hydrogen explosions…

      • lokay5

        The explosion of Reactor #3 was NOT a hydrogen explosion. It was an uncontrolled nuclear detonation.

      • Starviking

        Please correct me if I’m wrong, but are you saying the the explosion in reactor 3 was a nuclear explosion, as in ‘nuclear bomb’?

      • lokay5

        Some have speculated it could have been a nuclear explosion — just like Chernobyl. ‘I watched video of the Reactor 3 explosion,’ said veteran Japanese nuclear-reactor designer Setsuo Fujiwara. ‘There was an orange flash, which suggests the temperature must have been thousands of degrees centigrade before the explosion. Then there was black smoke.’ Fujiwara insisted to me that a hydrogen explosion created white smoke and steam, as witnessed after the Reactor 1 building was torn apart. He continued, ‘The second piece of evidence is that plutonium was scattered about after this blast. Plutonium is consistent with the mixed oxide fuel [used in Reactor 3]. The third point is that the Reactor 3 building was bent like candy, unlike the Reactor 1 building, where the steel framework remained intact. So this could only mean it was a nuclear explosion.’

      • Sam Gilman

        Some may have speculated that, but they’d be wrong, simple as that. Chernobyl was also not a nuclear explosion, but a steam explosion.

        I don’t mean to be rude, but for anyone interested in what happened either in Fukushima or Chernobyl, these are fairly basic facts of the cases. Civilian reactors, even of the flawed type at Chernobyl, can’t explode like a nuclear device.

      • lokay5

        The explosion of R3 at Fukushima was clearly NOT a hydrogen explosion but a prompt criticality CAUSED by the hydrogen explosion.
        Anyone who thinks that the huge explosion of reactor 3 was simply hydrogen is deluded.

      • Sam Gilman

        You’re calling an awful lot of rather well-qualified people deluded. Is your source for all this Arnie Gundersen, by any chance?

      • lokay5

        Are you implying that Gunderson, a nuclear engineer, is not ” well qualified”?

      • Sam Gilman

        I wouldn’t use the word “well”.

        I’ll go beyond implying. I’m stating directly that he has a track record of making false statements, many backed up with ridiculously flimsy evidence or decades-old rejected science, of making outlandish statements on all manner of nuclear issues for which he has no qualification at all, and that he is financially dependent on the anti-nuclear lobby. He calls himself “chief engineer” of his money-making consultancy outfit. He’s the only “engineer”.

        He survives on a hilariously padded CV that needs a critical and informed reading to realise that the only reactor he’s ever been “in charge of” was a 100W reactor in a college lab that probably wasn’t even switched on, that he was moved out of engineering work into admin within two years of becoming an engineer, that he was fired from his last industry job a couple of decades ago, and that he is more intelligibly described as a retired high school physics teacher and media personality.

        So I can go to the expertise of trained experienced engineers and scientists who enjoy the high esteem of their peers, or I can go to Arnie Gundersen, who doesn’t. They love him at Russia Today, though.

        What you have to do is stop selecting your experts based on them supporting what you want to believe. You’ve got to choose them independent of what they say. Look at their qualifications, their publications, their reputations, awards and appointments within their field of expertise. If that’s all good, then look at what they (and what others like them say) and adjust your beliefs accordingly.

      • Starviking

        OK, a few points.

        Point 1: You are being deceived. There are plenty of people out there willing to peddle conspiracy theories, and twist what people say to achieve that. How can I say that? That’s…

        Point 2: Plenty of ‘evidence’ can be easily debunked. Look at the evidence of Mr Fujiwara, which rests on orange flashes and dark smoke. Consider the most photographed hydrogen explosion in history, the Challenger Disaster. What do we see when the hydrogen and oxygen in the external tank mix and explode? Orange flash. Evidence one for a nuclear explosion gets nixed. Now, the black smoke. A hydrogen explosion produces water – not smoke as Fujiwara insists. Now this should be as white as steam – under perfect lighting conditions. However, when we look at clouds in the sky, often they are not white – due to lighting. Additionally, debris and burnable material will also be released into the atmosphere in a hydrogen explosion – adding more masking to any whiteness from the water vapor.

        Point 3: Reports concerning massive amounts of Plutonium being released come from sources like ENEnews. A search of the scientific literature shows that Plutonium release is hundreds of thousands less than Chernobyl, and not an environmental concern. Additionally, Plutonium is found in any reactor core, as a byproduct, so any environmental Plutonium can come from any Uranium-fueled reactor.

        I hope these points are of use to you.

      • lokay5

        Study: Plutonium found 120 km from plant; “Pu and non-natural uranium certainly increased in environment” – (ENENEWS)

        Study: High plutonium-241 activity detected over 30 kilometers from Fukushima plant — Additional research suggests “long-distance transport” of plutonium – (Environmental Science & Technology (American Chemical Society)

        “Plutonium release is hundreds of thousands less than Chernobyl, and not an environmental concern.”
        So you’re admitting that Plutonium WAS released ?
        Plutonium – not an environmental concern?

        “…so any environmental Plutonium can come from any Uranium-fueled reactor.”
        That’s reassuring seeing as how Plutonium is the deadliest radioactive substance known to man.

        Anyone who believes that the huge explosion of R3 @ Fukushima was simply hydrogen is delusional.

      • Sam Gilman

        Why are you relying on ENEnews?

        Do you know who runs it? Do you know who is responsible for the fact checking on it?

        For science journals I can always answer this question. What about ENEnews?

  • Richard Werkhoven

    This is so funny. You are all comparing apples & space aliens.

    Admittedly this is fairly common with this issue.

    Q: Was the cause of the explosion the hydrogen buildup in the building around the reactor?

    A: Well when the reactor well cover moves – not likely.

    Q: Was the explosion the result of hydrogen in the reactor exploding? Or the result of a nuclear reaction resulting in rapid expansion? (deliberately not using the nuclear terminology)

    A: Well I’m not sure why it matters in the greater scheme of things. It could have been either really from the evidence given here. Experts give both opinions. Those employed in nuclear industry or suporting it claim it was impossible and character assasinate those who say otherwise.

    The point is that either was possible actually and both are seriously dangerous due to the damage caused.

    What we do know is that the whole core nor even a significant part of the core did not explode in a fission event. If it had there would be no doubt about it.

    Reactor suffered destructive explosion. Result is massive mess and spread of radioactive material. According to the nuclear industry it wasn’t the big event we are worried about. That may be the next one then.

    • Starviking

      If it were a criticality in the reactor that caused the explosion, then there would be a lot more reactor debris around. This is not seen. Also, as pointed out by one of locay5’s ENEnews referenced authors – the released isotopes are consistent with hydrogen explosions.

      • Richard Werkhoven

        That is entirely consistant with what I just said isn’t it?

        We actually don’t know 100% really but not a significant criticality or there would be no doubt.

        Isotope release is being judged on data supplied by people who keep failing to accurately collect and report it.

        The debate has become about the wrong issue. The issue is did it blow up inside? Yes it seems that way.

        The other issue is: Was it bad? Yes it was.

        The third issue should then be: Could it have been worse? Seems that way since this was apparently just a hydrogen explosion and not a criticality.

        Now do you understand my points?

      • Starviking

        Sort of – you think a minor criticality was possible?