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Nuclear Power Regulator Sticks Its Head Further into the Ground

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An ostrich is a clichéd symbol of people making bird-brained decisions that ignore reality. But it’s hard to think of something more apt for the Nuclear Regulatory Commission (NRC) sometimes.

Ostrich

Source: Sven-Kåre Evenseth

Take its most recent decision: The commissioners voted 4 to 1 to end consideration of a plan to accelerate the transfer of the growing stocks of nuclear waste at U.S. nuclear plants from spent fuel pools to safer dry casks. (The lone vote for safety was cast by the NRC Chair—Allison Macfarlane.) Moreover, the Commission said it didn’t want to think about it anymore, ordering that “no further generic assessments be pursued related to possible regulatory actions to require the expedited transfer of spent fuel to dry cask storage.”

That anti-science position is difficult to fathom. Given the potential consequences of an accident or terrorist attack on a spent fuel pool, you would hope the body responsible for ensuring public safety would want to know all it could, and use that information to reduce nuclear risks.

Risks from Spent Fuel Pools

After all, most spent fuel pools at reactors at U.S. plants contain much more nuclear material than the reactor core itself—in many cases more than 5 times as much. And as I noted in an earlier post, even the NRC believes that poses a huge risk. A recent study by NRC staff considered an accident scenario at the Peach Bottom nuclear plant in Pennsylvania that resulted in a fire of the spent fuel rods and the release of radioactivity that, on average, would lead to more than 17,000 cancer deaths, 9,400 square miles of evacuated territory—an area the size of New Hampshire—and more than 4 million people displaced long-term.

So everyone agrees the consequences of such an accident are potentially huge. And in such a case, transferring spent fuel out of the pools and putting it in dry casks would make an astounding difference.

In particular, the same NRC staff study compared the consequences of an unmitigated spent fuel fire in the Peach Bottom pool today with the consequences assuming all spent fuel that had been in the pool longer than 5 years had been moved to dry casks. It found that after the transfer, the number of cancer deaths would be 10 times smaller and the amount of evacuated territory and number of long-term displaced people would both be 50 times smaller.

The NRC’s “Flawed and Incomplete Analysis”

So, what was behind the Commission’s decision?

It decided that while the consequences of such an event might be horrific, the probability of it happening was so low that it didn’t need to take additional steps to lessen those consequences. You would think it must have pretty convincing evidence of that fact to make such a decision and decree that it was time to stop looking at it further.

You would be wrong.

People—including staffers at the NRC itself—have identified a lot of problems with the analysis that backs up the NRC’s conclusion (see, eg, here and here). My colleague Ed Lyman calls the analysis “flawed and incomplete.”

But you don’t need to get into the details of the study to find a glaring omission that undermines its conclusions: The analysis did not include the possibility of a terrorist attack on a spent fuel pool. Even if a nuclear plant is operating perfectly, such an attack could lead to exactly the kind of “loss of coolant” accident described above. And in a 2006 study, the National Academy of Sciences calls out spent fuel pools as something “knowledgeable terrorists might choose to attack.”

So the crucial piece of logic leading to the NRC’s wrong-headed decision is completely unconvincing—certainly not something you should bet the safety of tens of thousands of Americans on.

Ostriches sticking their heads in the ground appeals to our sense of absurdity—the idea that it thinks it can be safe by refusing to look at whatever risk is at hand. That absurdity becomes tragic when the NRC does the same thing, and people’s lives are at stake.

Posted in: Nuclear Power Tags: , , ,

About the author: David Wright is a physicist and the co-director of the Global Security Program. He is a nationally known expert on the technical aspects of missile defense systems, missile proliferation, and space weapons. See David's full bio.

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  • Rod Adams

    David:

    You wrote: “People—including staffers at the NRC itself—have identified a lot of problems with the analysis that backs up the NRC’s conclusion…” However, all of the links you provided are to documents created by staff members of your own organization.

    Can you provide a reference that supports your statement that “staffers at the NRC itself” have identified analytical problems?

    • David Wright
      • Rod Adams

        David:

        Thank you for the prompt and useful reply.

        It is worth reading both the non-concurrence and the responses to the non-concurrence to recognize that it is a matter of well-reasoned judgement to decide that there are more cost effective and important ways to reduce risk than to force the early movement of used fuel from spent fuel pools into dry cask storage containers.

        There will never be unanimous agreement on answers to the question “How safe is safe enough.”

      • Rod Adams

        I also think it is worth noting that Mr. Helton, in particular, uses circular logic by stating that “these events are known to be low likelihood/high consequence events.”

        Unless one accepts the assertion that a slight increase in an already high risk of developing cancer at some time is a “high consequence” event, it can be argued that even a very low probability spent fuel pool fire that results in releases of some radioactive material is a low consequence event.

        Sure, there were about a hundred thousand people evacuated from areas around Fukushima, but most of those evacuations were forced by conservative government edicts designed to avoid doses that are within the variations in natural background radiation in inhabited areas around the world.

  • Rod Adams

    David:

    Thank you for providing a link to the NRC analysis. It is helpful to be able to read the original work and realize that the staff’s conclusions are not as scary as your interpretation of the numbers.

    “The study also showed that the risk of an individual dying from cancer from the radioactive release is very low. When including the very low likelihood of a release, the risk in the analyzed scenarios that an average individual within 10 miles receives a fatal latent cancer is between about two in a trillion and five in a hundred billion per year.”

    With all of the risks in the world, is it really worth spending tens of millions of dollars to try to reduce a risk that is already on the order of 5 in a hundred billion years? Based on the precision with which such risks can be estimated, does it really make any substantive difference at all?

    How many angels really can dance on the head of a pin?

    • David wright

      Yes, the study is written in a way that suggests very low
      risk. But, as I note, the study also discusses a scenario that results in
      significant casualties. Second, the “very low likelihood of release” the study
      mentions results because the NRC’s study was performed in response to Fukushima
      and looked at only one scenario – an earthquake larger than the “safe shutdown”
      earthquake for the reactor. Our point is that there are other scenarios that
      lead to a different conclusion, which is that it makes sense to accelerate the transfer from pools to reduce the potential consequences.

      • Rod Adams

        David:

        Though the study was specifically designed to investigate spent fuel pool earthquake vulnerability, it is disingenuous to dismiss the consequences portion of the study on that basis.

        Once a leak occurs in a spent fuel pool, it makes no difference what caused the leak; the event progression is essentially the same.

        Here is another quote from the Executive Summary that is worth emphasizing:

        “In the unlikely situation that a leak occurs, this study shows that for the scenarios and spent fuel pool studied, spent fuel is only susceptible to a radiological release within a few months after the fuel is moved from the reactor into the spent fuel pool.”

        There is only a narrow window of vulnerability that is caused by having very freshly removed fuel. A program of expedited transfers does not significantly alter the probability of release in that scenario.

        Most of the scary numbers associated with the consequences change dramatically if you avoid the bad practice of multiplying tiny risks by very large numbers of exposed people. Numerous international radiation protection speciality bodies have advised against using “collective dose” to estimate consequences, yet the only way this study produces scary numbers for latent cancer fatalities is do ignore that advice and use collective dose anyway.

      • David Wright

        My guess is that we could essentially write each other’s
        side of this debate. The time after fuel discharge when ignition can happen remains controversial. Ed Lyman discusses this in his January testimony to the NRC (a transcript is available at http://www.nrc.gov/reading-rm/doc-collections/commission/tr/2014/20140106a.pdf). For example, the NRC study only looks at a complete draining of water from the pool, which allows convective air cooling. The NRC has not released its calculations assuming a partial draining. And the NRC only calculates heating out to 3 days, assuming cooling will be reestablished by then, even though there are scenarios where it could be longer. For these and other reasons, we aren’t convinced the window is so short.

        The current standard model for radiation effects is the linear no-threshold model, which leads to the numbers I cite based on the radiation doses from the NRC report. Even if you dismiss this number, the size of the evacuated area and the number of people affected is based on individual doses, not collective doses.

      • David Wright

        The transcript link above doesn’t seem to work; here it is again:
        http://www.nrc.gov/reading-rm/doc-collections/commission/tr/2014/20140106a.pdf

      • Rod Adams

        Perhaps we could write each other’s side of the debate.

        My “arrow analysis” understanding of the effect of a partial pool drain is that the presence of some remaining water would be a greater ability to cool the rods. The latent heat of vaporization of water is about 500 times the specific heat capacity of air. As remaining water boils off into steam, it carries away at least as much heat, but probably considerably more heat, than would be removed by circulating air.

        I’m not sure I understand the mechanism by which you think that fuel assemblies that have not overheated in 3 days would somehow overheat if left uncovered for a longer period of time. The air flow continues and decay heat production continues to gradually slow down over time. I wish that the modelers would have let their models run for a longer period of time, but I suspect that no matter how long they ran they would still not indicate any significant risk of rapid corrosion (aka fire.)

      • David Wright

        If the pool drains completely, there is an air space below the racks that hold the spent fuel and you can get convective air currents that circulate and cool the fuel by the air passing over them. A partial draining cause the remaining water to fill the space below the fuel racks and stop the cooling convective airflow. But since the water would only be in contact with the very bottom of the fuel rods it could not provide cooling along most of the length of the rods.

  • Richard Solomon

    Thanks for talking about what is a distressing decision made by the majority of the Commissioners on the NRC. In a recent hearing Senator Barbara Boxer attempted to explore this decision making by the Commission. While Director Macfarlane agreed with the concerns that Senator Boxer expressed, the other Commissioners stood by their decision.

    I wrote the Senator to encourage her not to give up in her efforts to get the industry to move its spent fuel into dry casks. I hope other UCS members will do similarly with their Senators and Reps in the House.

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