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After Fukushima, Examining Nuclear Power Safety

Interviewee: John Ahearne, Sigma Xi, Executive Director Emeritus and Emeritus Director, Ethics Program
Interviewer: Toni Johnson, Senior Staff Writer, CFR.org
March 31, 2011

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With problems at Japan's Fukushima Daiichi nuclear plant still unfolding following the March 11 earthquake and tsunami, public concern has grown about the safety of nuclear plants. But it is difficult to fully understand what is going on at Fukushima, because the plant operator and emergency workers themselves are still figuring it out, cautions John Ahearne, former head of the U.S. Nuclear Regulatory Commission. He says critics should be careful about making policy and procedure recommendations right now. "After Three Mile Island and after Chernobyl, it took several years of analyzing what happened before one could really reach a conclusion about what could have been done to prevent it, and we are a long way away from having that kind of knowledge about the Japanese systems," he says. However, Ahearne notes countries should proceed with current safety reviews as soon as possible, since "the public in general is uneasy about nuclear power" following the Fukushima catastrophe.

Some international officials have criticized the way the Fukushima crisis has been handled--for instance, the use of seawater in cooling. Could things have been done differently from the emergency management point of view?

My understanding is that the earthquake-resistance systems worked. Of course what didn't work was protection against the huge tsunami. One thing they could have done was to build much higher walls or they could have put their emergency generator systems above ground instead of below ground. But it was a catastrophe, and I'm not sure how much they could have prevented.

The idea of using seawater--they were trying as best as possible to get as much water into the [reactor] system to cool it. They recognized if they used seawater they were essentially saying we are not going to be able to ever restart those reactors. So they were writing off tremendous expense, but they were trying hard to get enough water into the system to cool it down. It's turned out that they also needed to get the [coolant] pumps running, which they have not been able to do yet, so they are a long way away from getting the accident completely under control.

I'm not that familiar with the [emergency] system that Japan has in place. I know that in the United States, [plants] have to do a drill every couple of years on an emergency. That includes at least having a table-top exercise with the local fire, police, emergency systems. For all reactors, there is a set of emergency procedures that is different than the operational procedures. I assume Japan had the same thing, because most countries that have developed nuclear power have ended up using the U.S. regulatory system as their base system.

What is the worst-case scenario? Are we still looking at a potential full meltdown?

It's not only hard to follow for people outside, but from what I gather--I've been reading the TEPCO internal releases--it's very hard for them to follow what's happening because they don't have access to a lot of their systems. They're still trying to figure out what is the condition of the spent-fuel areas, much less what is the condition of the fuel that was in the reactors. We can't say what is the worst case [since it's] not really possible to estimate until you get a better sense of the condition of all those rods.

If the two worst accidents were Three Mile Island and Chernobyl, this is a lot worse than Three Mile Island, much less than Chernobyl. Chernobyl had an explosion that drove a large amount of radioactive debris--parts of the fuel rods-- thirty thousand feet into the air. There is no driving force like that in these reactors, so it's not going to be at that level.

You mentioned that the United States is the regulatory standard for much of the nuclear industry, but one op-ed recently talked about a number of places where known design flaws (NYT) were not addressed, which, if made standard, could have helped prevent some of the problems at Fukushima. What's your take on this?

Any time there is an industrial accident--whether it's chemical, nuclear, airplane--a lot of people say, "If you had only done this, that wouldn't have happened." Some of the ideas are good, [but] a lot of the ideas are not, because you have people who really don't understand the systems saying, "I have a bright idea. You ought to do this." After Three Mile Island and after Chernobyl, it took several years of analyzing what happened before one could really reach a conclusion about what could have been done to prevent it, and we are a long way away from having that kind of knowledge about [the Fukushima Daiichi accident].

Since Chernobyl, the International Atomic Energy Agency (IAEA) has been helping to create a more cogent international safety regime. Could you just talk a little bit about how that regime works?

There were a number of countries interested in getting into nuclear, and they did not have a regulatory system in place; they didn't have a system [to] train the people who could operate the plants. So the IAEA developed a standard guide that could be used by these new entrants. The IAEA can't require that. But what they have been trying to do is put in place a set of guidelines.

It remains to be seen how effective that is going to be. So far, the countries that are building nuclear power plants, such as China, are not ones that didn't have any experience. There are a lot of small countries that have decided that they want to get into the nuclear power world, and the IAEA is concerned that they develop the fundamental infrastructure to be able to do that safely. I've been concerned that a regulatory system is not easy to develop, and to some in the industry a regulatory system always looks like an unnecessary burden.

For these new entries, it's critical that they start developing their regulatory systems, develop people who understand how to monitor construction, how to test operator skills and watch over the reactor when it's built and running. That will take five to ten years to develop.

Many countries, including the United States, are retesting nuclear plants for issues like seismic activity, power loss, and flooding. What does a nuclear plant risk analysis look like? And how do you weigh safety versus cost of safety measures?

[In the United States], nuclear plants have a system of regulatory requirements based on locale. What has to be done is to periodically review those requirements. [For example,] do we now know more about the seismic hazards of an area; do we have better information about the likelihood of wind damage? The climate change issue has come to the front: One has to now review whether the weather patterns that have been used in the past for the design requirements are still accurate and appropriate.

Nuclear Energy Guide

Those kinds of reviews should be done, and certainly they are going to have to be done now because the public in general is uneasy about nuclear power. They had been getting more comfortable with it, but this Japanese catastrophe has made the public once again get very uneasy. So it's absolutely necessary that the plants go through a review of all their design requirements and how well they were developed and how well are they being maintained.

Ten, fifteen years ago, the argument was that stressing safety would make a plant inefficient, but it finally got across to the utilities that safety actually makes a plant run more efficiently. I don't think there has been much of a debate over the last ten years about whether safety regulations interfere with the operation of the plant.

Can you talk a little bit about the debate over long-term storage (Beacon) at a facility like Yucca Mountain in Nevada and the discussion over reviving reprocessing in the United States?

They're separate issues. Reprocessing basically means to take the fuel and go through a chemical reduction process to extract the plutonium and the uranium to reuse it. Once you do that and put it through the reactor, you now have spent fuel again, so you haven't really solved the problem of what to do with spent fuel. It does enable you to reuse some of that material, so that's really separate from where do you put the spent fuel.

So far, the only countries that have come close to having a way of putting away the spent fuel is Sweden, [which] is well on its way toward developing a site, as is Finland. Countries like the United States, France, Japan, China, with large numbers of nuclear power plants, do not have a system in place.

Technical people end up saying, the best thing to do is to build a depository. The problem with that is it is an engineering answer to a political problem. Finding a place to put it has turned out to be extraordinarily difficult, as the Yucca Mountain case points out. So I'm not sure how that's going to be resolved. My own personal preference for years has been to have monitored surface storage; that is, to build a facility somewhere where you can put a lot of the fuel and just keep monitoring it for maybe a century. But that still requires finding a place to build it, which hasn't been possible. The Achilles' heel of nuclear power is the waste problem.

The industry is touting the safety of newer reactors, but there are many reactors in operation using older technologies that are expected to operate for decades to come. What has Fukushima taught us about safety and preparedness, and what do you expect to see going forward?

There has always been an open question about whether the type of pools that exists in some of the [plants] was a safe way of storing the spent fuel. That's going to be revisited.

As far as what lessons are readily learned, there are facetious answers: Don't build a reactor where you can have a thirty-foot tsunami wash over it. But, realistically, countries like Japan, which is laced with fault lines, don't have much of an option about where to build the reactors. They have to try to make sure that they are seismically safe, and I believe these reactors were, and [it was] the tsunami that wiped them out.

There's clearly going to be a revisiting of nuclear power worldwide. We've already seen it happening in Germany [which has shutdown some reactors and is considering phasing out nuclear power entirely], and I expect something similar in Sweden. I don't expect to have a revisiting in South Korea or China or India, which are other countries that are going forward with nuclear power. The United States is a little uncertain. Certainly the big question always in the United States is can you afford to build a plant. It's a little too soon to tell what's going to happen with respect to the loan guarantee offers and congressional offers.

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