Interview: Per Peterson

Thank you for doing this interview with us - um, a lot of your work focuses around the safety and security of nuclear weapons and materials. So what types of measures do you think are needed to create a stable non-proliferation regime? Maybe standards or sanctions?

Well, the truth is that there are no perfect ways to control proliferation - and there’s no silver bullet. And so, it’s really a matter of first becoming familiar with what is the range of methods that are available and have been developed, and then asking the question, how can we further improve them? And then also the question, are there other things that we might be doing that could also be constructive and helpful.



Okay. Do you think the steps that you mentioned can be feasibly carried out in the next generation or so?

Well the truth is, that of course we’ve been doing this now for many years. And what we’ve learned is that we have to work in all of these different areas - uh, use all of these different tools - and that sometimes we discover that they are not working as effectively as they need to. That’s when we need to do work to modify them and to make improvements. So for example, after the first Gulf War it was discovered that a clandestine program to enrich uranium had been ongoing in Iraq using a technology called calutrons. And at that point we began to realize that the nonproliferation regime that we had, had some loopholes in it because the safeguards agreements that the International Atomic Energy Agency had with Iraq (and generally had at the time) did not allow it to investigate facilities that had not been declared.

And so, the program was able to occur or go on in secret. The solution to that is a new protocol, called the Additional Protocol, which provides much more extensive um.. authority to the IAEA to do things which are helpful in verifying that there’s not clandestine activity in addition to verifying that peaceful, civil nuclear energy use is being done in a way that is not diverting material to weapons programs.



Alright. On the topic of nonproliferation as a whole, a large debate has started on whether disarmament is actually the best way to go given today’s geopolitical situation, relationships with Russia… What do you think? Is disarmament even a viable solution at this point?

Well, the… I think that it’s clear that currently the inventories of nuclear weapons in the world are larger than they need to be to provide security, whether or not one goes all the way to disarmament. And I think that, in fact, that one of the reasons there’s a broad consensus that further reductions in nuclear weapons inventories - particularly for the United States and Russia that have larger numbers - uh, that this makes sense in the near term. In the longer term there are some complicated issues that one needs to address to go all the way to zero.

I think that that’s a problem that we will face in the future, but that in the - in the intermediate period there’s a whole set of additional things that are important. As long as nuclear weapons exist in nuclear weapons states, it’s critical that they be provided with adequate security, protection against use and misuse, and that… that they… be kept secure. So those measures are to ensure that as long as weapons exist, that they are kept secure I think is something critical for us to be working on today.



Okay. In our phone call earlier you were talking about horizontal versus vertical proliferation and how the risks for international and national were different. Do you think you could clarify some of those differences?

Well certainly… of course, what we were talking about with disarmament is the idea of vertical proliferation or, let’s say, going down in numbers because we have been systematically seeing the total numbers in nuclear weapons in the world dropping. Uh.. the ability to further reduce these numbers is something we discussed earlier and that would be an element of the vertical proliferation. But the other concern that we are faced with is that there may be horizontal proliferation which is the fact that other countries that currently don’t have weapons might acquire them.

A good example, fairly recently, would be North Korea which has developed and now tested nuclear weapons and therefore is an example of the horizontal proliferation. Now the.. the way that we provide security with respect to horizontal proliferation - it’s really critical to think about what are the incentives that countries face in making decisions as to whether of not to proliferate. So, the regional security environment that countries face can be a very important factor in determining whether or not it makes sense to take on all of the costs, all of the international commendation - commendations… no, it’s not a commendation… you know what I mean *laughs. To take on all of those costs. And rogue countries like North Korea which don't care very much to begin with perhaps require a different strategy than countries which are industrialized and are non-nuclear weapons states such as say Belgium or Japan or South Korea.

In the case of the industrialized countries, the best combination we can come up with is likely to be a combination of rigorous safeguards which provides confidence that the use of nuclear infrastructure and materials in these countries is peaceful. And that there’s not weapons programs underway. Along with regional security arrangements which make it so that there’s no logical reason for the purpose of self defense to acquire weapons. And there’s a wide variety of measures that help to strengthen both of those elements and what we want to do is to continue to try to build those and make them stronger and more robust.



Looking at your amazing lab downstairs, it does look like there are a lot of promising technologies for the future. What new nuclear technologies do you see for the next generation… how they would play out?

Well, I think there is a number of areas where further improvement of nuclear reactors and fuel cycle technologies is clearly possible. While we’re making these improvements we need to recognize that we have a lot of existing infrastructure - both reactors and fuel cycle facilities - and that we need to make sure that that existing infrastructure continues to be operated safely, that physical security is maintained, and that uh, effective safeguards are being applied to all of this existing infrastructure.

We’re quite interested in a number of areas of opportunity where we could make significant improvements. So one of the things that we’ve been working on are reactor designs, both near-term that would use water as a coolant similar to what current reactors use as well as some longer-term alternative coolants… My personal interest in terms of research involves the use of molten salts as coolants for reactors. The idea behind implementing passive safety in these reactors is that you can eliminate the need to have electrical power or an external heat sink to remove decay heat when you shut the reactor down. And, the two principle things that we do to prevent uh.. radioactive releases from reactors involved, first of all, assuring that we can control the reactivity or essentially the rate of the chain reaction. And that that’s done primarily by passive feedback. If the fuel heats up, the chain reaction should slow down naturally.

The ability to shut the reactor down and terminate those reactions is also important, and we have highly reliable systems that can essentially put in so much neutron poison that no chain reaction is possible. But even after you shut down, the main safety issue is that the radioactive products from the fission process continue to undergo radioactive decay… these fission products. And they release heat. If that heat is not removed, the temperature of the fuel will climb and at some point the fuel will pass the threshold where it will begin to suffer damage and release radioactive material, as occurred in, say, the Fukushima accident.

So, if we can develop systems that are capable of removing that heat reliably without needing external sources of electrical power, that can enhance the safety of reactors. And this is something that we work on here in our laboratory. And we have developed approaches to essentially verify that under a wide variety of conditions, these passive mechanisms can be effective in removing decay heat. I think that this would have benefits that would go beyond safety and also would allow us to further improve the physical security of reactors. And that’s one important dimension of making these systems safe and secure.

The other major areas where we should be devoting effort relate to the fuel cycle infrastructure… uh, that provides fuel and handles waste generated by nuclear reactors. And this is the area of technology where we face very important questions also around nonproliferation, because this is the area of technology where we have, for example, the enrichment of uranium as a necessary element of the nuclear energy system. And then we also have the potential issues and benefits of taking the spent nuclear fuel that comes from reactors and reprocessing or separating constituents from it. I think that there’s ways on both of those ends of the fuel cycle where further improvement can be made, both to improve the proliferation resistance and to improve our capability to provide effective safeguards as well as to provide physical security of these materials and to make sure that materials that might be attractive for use in explosives - nuclear explosives - are difficult to steal. Because the… on the fuel cycle side, the question of physical security in preventing theft of the materials is another important dimension and we want to make sure that the systems are robust and that they’re not attractive places for criminals or terrorist groups to acquire materials that they could make crude bombs with.



So after Fukushima, as you talked about, we saw a lot of countries such as France and Germany start to take down their nuclear energy programs. What role do you see nuclear energy playing in the future of America’s energy portfolio? And around the world as a whole?

That’s a really good question and in order for nuclear energy to play a substantive role going forward, we need to address some key issues, one of them being that we need to develop a better capability to build reactors, in particular, on a predictable schedule for a reasonable cost. And in that area, first of all, the development of passive safety has been very helpful. It actually reduces significantly the complexity of the reactor systems. You have far fewer pumps and valves and other equipment which is needed for the active safety systems to remove decay heat.

The other dimension of construction is to implement and use more extensively modular construction methods where a far greater degree of the construction work or fabrication occurs in a factory environment, and what happens at the… the difference between, you know, Ikea furniture and building your own table with saws and nails and hammers. So, so… the modular construction methods are now being used on AP1000 reactors which were designed in the United States and are being constructed in China and there’s actually four of them in construction now here in the United States and likely to be built… more built, here and worldwide. The AP1000, even the reactor buildings, are prefab, and are assembled at the site using something called steel plate concrete composite constructions. The benefit of doing that is that… that you're far less sensitive to the site labor, and I think it does make these reactors also more attractive for export and probably we’ll see AP1000 and similar reactors deployed extensively in the next couple of decades worldwide simply because they’ll be easier to build, can be built on a more reliable, predictable schedule, and uh, will be safe and secure.

Um, beyond that, other really important questions relate to what will happen in the development of the fuel cycle. And this will relate, in particular, to whether we start to see countries choosing to procure enrichment services from international organizations or multinational companies which actually can produce these services at the lowest cost, rather than developing national programs for enrichment.


And on the back end of the fuel cycle another critical element is to develop the capability to place uh… residual waste or nuclear waste into deep geologic disposal. The… intrinsically with fission energy we do produce wastes that uh… will require very long term isolation. The thing that makes nuclear energy better than fossil is the fact that - we prefer that the carbon dioxide from burning fossil fuels also be placed into geologic sequestration, it’s called carbon capture and storage - the thing that makes it very difficult and likely impractical is the massive volumes. So instead we use the biosphere as our principal disposal location for fossil energy waste just due to the huge volumes. With nuclear waste, the quantities are much smaller. And what we know is that if we identify… um… geologic repositories or develop geologic repositories in media which is geologically stable, that the conditions that we find when we’re hundreds of meters underground can remain remarkably stable for hundreds of millions or even billions of years in many cases.

And, that… therefore the likely transport and retention of radioactive waste actually is scientifically and technically predictable. That… uh… that is, that means that today there is a substantial scientific consensus that deep geologic isolation can work and that it is a socially and technically appropriate technology to use for the disposal of waste. There’s not a consensus on whether we should use it for spent fuel or whether we should reprocess spent fuel. But even with reprocessing and even with advanced reactors (like fast spectrum reactors) there will always be residual waste that will inevitably require this type of disposal.

So there’s a lot that also the world needs to do on the back end of the fuel cycle. Particularly because we have a large fraction of countries that now operate nuclear reactors only have a tiny number. For the majority of those countries, it’s not really credible that they individually can develop the capability to manage spent fuel and do it safely and place it in a geologic disposal. So ultimately, on way or another, we need to develop international facilities that will accept nuclear waste and provide for its safe processing and disposal. And that’s a lot of work that needs to be done.

One interesting point, though, is that it really does have to be done whether or not nuclear energy expands. We already have plenty of waste and so we have to solve these problems one way or another and that means that um.. there’s a lot of work to be done



For this work, do you think that the solutions are likely to take place internationally in the form of maybe… international mandates similar to the NPT, or do you think it’ll be a more decentralized process, country by country? Maybe even science labs are involved… how do you see it playing out practically?

The… I think that of course, when you look at how the public perception of risks associated with nuclear technologies, they’re heavily flavored (I think) by the Cold War. And it’s - I think it’s difficult today to really fully comprehend and grasp how terrifying the situation was back during the height of the Cold War from the perspective of the potential to have cataclysmic conflict occur. That risk has actually not fully disappeared by any means. On the other hand, the public perception and concern about it certainly has, has reduced a lot. We worry a lot more about other security issues these days if you look at the news. But the, the perception of risk related to things such as exposure to radiation, radioactive materials, nuclear accidents… those, those perceptions have been colored, I think, significantly by this history and furthermore these are technologies that if they’re not implemented properly are risky and can cause environmental problems.

So, the question of how we make constructive steps towards better fuel cycle technologies, towards the capability to place waste into geologic disposal, and to manage these materials properly and to see these practices used widely, I think is going to be incremental. And initially what we really need to have is individual countries sort of demonstrating that you can do it well, and that you can accomplish this safely. If you look at some elements of the back end of the fuel cycle where there’s already extensive activity, one of those areas, for example, is transportation of the spent fuel from reactors to centralized storage or reprocessing facilities. There’s a lot of concern in the United States about transportation of spent fuel. In Europe, transportation of spent fuel has been conducted routinely, in large quantities, for several decades. And the safety record that has been achieved is quite impressive. The key point, though, is that because it’s a complicated activity, it’s important to demonstrate through practice and through learning that this can be done safely. And with the transportation of spent fuel, we still have quite a lot of work to do because we have more limited experience here in the United States.

I think the same thing applies to the development of deep geologic repositories. As we see more examples where this has been done successfully - and the Swedes and the Finns, for example, have been successful and are siting and are constructing geologic repositories… the French are very close behind… in the United States we have, frankly our situation is disastrous. Everything has shut down and is at a standstill, and we need, we need to restart a functional waste program, hopefully in the fairly near future ‘cause right now we’re setting a very bad example. But as we make progress toward developing these capabilities, I think we can - we can begin to see countries who may be willing to step forward and also offer services for disposal of waste, at least to those countries that clearly are not going to be able to do it on their own. And we may see some more internationalization of the back end of the fuel cycle. It has to happen in the longer term and frankly it would be worthwhile for people who are interested in improving nuclear security in the future to see what they might do, to influence this process that gets us towards more of an international approach to the back end of the fuel cycle.



So you said the situation in the U.S. is pretty disastrous but you remember the Blue Ribbon Commission under President Obama. Could you tell us a little bit about what that’s trying to do?

Well the… the Blue Ribbon Commission was formed in January of 2010 and it was asked to review US policy for managing nuclear waste. Uh, it was a real privilege to actually serve as a member of the commission. The commission was comprised mainly of people who have expertise across a wide range of different uh, areas of policy: former senators, former congressmen, chief executive officers, people from the environmental NGO community, some academics, I was one of a very small fraction that were actually technical experts, because when you begin to look at what are the most important problems we face with the development of the capability to manage spent fuel and to place it, to place those elements that deserve to be treated as waste uh, into disposal… those challenges are no longer really the technical and scientific challenges. They’re really policy challenges. And the commission looked at what’s going on in the United States and we found a number of significant problems. In fact, it’s not a surprise that the entire effort to develop geologic repository in the United States, had stumbled forward and has been so difficult and, in fact, at this point has ground completely to a halt.

And the other thing that was interesting was that in the process of conducting its business, the commission used an approach which we ended up recommending be used in the development siting of these types of facilities which is what we would call a consent-based approach. And the most important element of it involves a lot of consultation with stakeholders and members of the public. The commission held a lot of public meetings. It reviewed and took in a lot of public comment as well as comments from stakeholders. And, I have to say that when I entered into the process to be a commissioner, I thought I knew what the answers were. I thought I knew how the United States was going to have to solve this problem, this impasse. Listening to what the public thought about it changed my perceptions. In fact, it gave me greater confidence that a consent-based process can work, because what I discovered is that if you go out and listen to what people think, you can actually identify a number of areas where there’s a broad consensus among NGOs, among members of the public, about things we need to do.

There’s also areas where there’s disagreement. Consensus, for example - there is a strong consensus in this country that our generation has a responsibility to develop effective solutions for the disposal of these wastes. It’s not something that we should kick on down the road to future generations. We really need to do this. There’s a strong consensus there…. You find other areas of consensus. In particular, the way that the fee… the government - federal government - collects a nuclear waste fund fee from utilities that today with interest totals about thirty-four billion dollars that you would think would be sitting in the bank. In fact, what has happened, was that early on congress in previous administrations used budget classification tools so that they could actually take that money and spend it for other purposes.

To ever spend the money in the future for the… the… the contractually obligated purpose will require actually cutting future discretionary spending on other programs. Which, when people learn that essentially the money has been - it’s not quite stolen, but it has been misappropriated and used for purposes, then they get angry. In fact, I think the only organizations in the United States that like the current system are the OMB (Office of Management and Budget) and the Congressional Budget Office, because it allows them to… look like they’re balancing the books. I think that’s - that’s - I, I am ashamed every time I see that.

The other thing that has, that you will find there’s a broad consensus about is that the Department of Energy has really struggled to implement the geologic waste program, and that we’d be better off if we were to transfer those responsibilities to some type of new entity where that will be their primary obligation. There’s various different possible models. It could be an executive branch agency focused on this purpose. It could be a federally-chartered corporation. That’s another area where there’s significant consensus.

There’s also significant disagreement on some things. In this country there’s no consensus about whether we should use nuclear energy or not - very strongly held opinions on both sides. There’s no consensus about whether we should ever develop a repository at Yucca Mountain - very strongly held opinions on both sides. Uh, there’s actually no consensus on whether we should reprocess spent fuel or not - very strongly held opinions on both sides. So how do you move forward? Well, these days you just don’t, right? I mean that’s - that’s… I think this is the largest failure of our political system in general is that umm… we, we just cannot reach consensus on anything. Pretty much.

But in this case, if at least you were to build a policy on those areas where we know everybody agrees and then figure out where… how it is we reach some point of compromise on those where we don’t, then you may have a path forward. And I think that the set of recommendations that the commission generate (there’s eight major recommendations) and legislation has actually been drafted in the Senate (there’s four senators: Feinstein, Murkowski, Alexander, and Wyden, who submitted a bill that would implement - I think in an amazingly effective way - the major recommendations of the commission). The interesting point about that bill is it leaves a lot of flexibility. It doesn’t say whether we should reprocess or not. That’s a decision that could easily be deferred to the future. It doesn’t say whether or not we should develop a repository at Yucca Mountain. It does say that we should move forward to develop another repository - statute actually requires that we have at least two. And… it makes a lot of sense, frankly, to look at additional options in addition to Yucca Mountain regardless of whether we ever develop Yucca Mountain. It solves the funding problem. It does a whole bunch of great things.

Right now it’s very difficult to move forward because the politics around whether or not to proceed with Yucca Mountain has trumped everything else. And so, this area where there’s actually a perfectly fine compromise which is, why not get started locating and building - and deciding and building - the second repository which the Nuclear Waste Policy Act requires, leave Yucca Mountain pretty much as it is, which is… a lot of work has been done and it could be restarted in the future if it proved to be necessary… There’s a path forward. We just need to get moving, that’s all.



That’s very exciting. Um, well as you’re saying there does seem to be a disconnect between this generation and the risks associated with nuclear issues and weapons. But as a professor - Berkeley Engineering tee-shirt, I’ve seen them all over campus - how do you think we could engage young people in the issues and take action and hopefully like, help the process move forward?

Well, I think that one of the things we need to do is to step back a bit and to look more broadly at this question of energy that we face. If you look at what goes on in the world, there’s pretty much arguably two major human activities that have enormous impact on our environment and on ecological systems. One of them is agriculture. We have managed to modify the natural nitrogen cycle with very large impacts on how things grow in the environment. We’re also in the process, of course, of modifying the um, climate which ties into the other major element of what we do, which is the production of energy and our continuing growth in our reliance on fossil fuels. If you look at consumption of coal, for example, it has just been continuing to climb worldwide. This - as a world, we have not engaged effectively in any perceptible way to reduce emissions of carbon dioxide and, in fact, they’re continuing to climb.

When we look at the potential consequences not just in a hundred years, but put your nuclear waste mindset on and ask: a hundred years from now, in all of our projects for climate, temperatures are going up, correct? So where are we going to be in two, three hundred mill- uh, thousand years? Ten thousand years? In terms of the impacts… recognizing that over half of this carbon dioxide actually is being absorbed into the oceans and ultimately the majority of it is likely to go into the ocean at rates that dwarf any previous rates and which will change the chemistry of the ocean in ways that make it potentially fundamentally impossible for major elements of those ecosystems to survive. Right?

This is - this is actually pretty scary stuff, so we’d want to step back and say, what can we do that could potentially improve the situation? Now, when we look at technologies which are capable of producing energy without burning significant amounts of fossil fuel, or at least without releasing carbon dioxide into the atmosphere, we have carbon capture and sequestration (that’s very challenging), we have wind and solar (which are the most practical renewables to expand to a large extent although there’s other options as well), and we have nuclear. All of these different sources have different issues and risks. I think that for us to have some confidence that we can manage, or at least, plateau and begin to bring the consumption of fossil fuels down, that we really have to work seriously with nuclear.

The principle reason for that is if we look at wind and solar, I think that we will get better at managing their daily intermittency. You know, the fact that the sun goes down while electricity demand is still climbing and uh, that there’s variability in weather. The thing that makes me nervous about those technologies is that they have very large amount of their variability which is monthly, seasonal, and annual. The total production of wind, for example, in the United States, averaged across the country, varies by a factor of two between seasons, right? And so, we don’t have any viable technologies to store energy that long. Batteries - other things which are efficient (pumped hydro worked really well if they’re cycled every day*). We have no options that are good for the longer-term variability. We might generate some, but in the meantime, having non-fossil… non-emitting technology that is dispatchable, which is what nuclear is, I think is something which is really vital for us to try to improve. I don’t want to understate the challenges associated with making nuclear energy work well, but it behooves us to work to try to solve those challenges and that’s something that I’ve been trying to do.



Okay, well thank you. I love ending on a happy note. So thank you very much for your time.