Harold “Hal” Feiveson, is a Senior Research Scientist, Emeritus, at the School of Public and International Affairs. He was co-founder, and until 2006, co-director of the Program on Science and Global Security, where he remains a member, and is also a member of the International Panel on Fissile Materials. He was one of the founders of the international journal, Science & Global Security, and Editor for the journal’s first twenty-one years (1989–2010). He is a Fellow of the American Association for the Advancement of Science. Feiveson received an M.S. in Theoretical Physics from the University of California Los Angeles in 1959; and a Ph.D. in Public Affairs from Princeton University in 1972. Date of interview: July 22, 2020 Interviewed by: Jessica Lambert Citation: Harold Feiveson, "Harold Feiveson’s Interview" interview by Jessica Lambert, Nuclear Princeton Project, Princeton University (2020) https://nuclearprinceton.princeton.edu/harold-feivesons-interview. Video Recording Transcription JL: I just sort of want to give you the platform to talk about what you’d like to talk about and I have a few guiding questions but having you lead the conversation I feel like is my main priority. So I guess, some things I was thinking about, and then I can let you talk, are that your work seems to talk a lot about decoupling nuclear power and nuclear weapons, and I’d like to hear more about why you see that as important and necessary. A couple other things are whether or not you see nuclear power as a viable energy source that can help us combat the climate crisis or if there are sort of too many issues with it. The third thing is that our project does a lot of work with communities and aspects that nuclear things bring about that are often hidden. We talk a lot about how nuclear weapons testing and uranium mining and other nuclear endeavors have impacted Indigenous communities in ways that aren’t blatantly obvious and that aren’t talked about a lot about when you’re talking about the history of these projects so hearing your perspectives on that and if there’s anything you think would be interesting to include in our project that we might have not thought of already. HF: Ok, that’s quite a bit. You know, I don’t think I have anything really very relevant to say about the impact on Indigenous communities and so on of nuclear testing. There have people who have looked at it and what the impact of - say, the Nevada testing was on Indigenous communities - but I don’t really know anything first hand about any of that. On the nuclear power question, of course that is something I have looked at. So why is it important? It’s important because even though nuclear power - civilian nuclear power - has slowed pretty drastically in the last decade. There is still a lot of it and I think it's important to make sure that it becomes as little a platform for nuclear weapons as possible. So I may be saying some things, Jessica, that you already know and are obvious so just tell me to shut up and I’ll skip over it. But there are two routes to nuclear weapons. One is highly enriched uranium. Uranium, natural uranium, is 99.3% Uranium-23 but to get a bomb, you wanna get 80% or more of Uranium-235 which is the other isotope of uranium. So that’s one route - enrichment. The second route is plutonium. Plutonium is produced in a nuclear reactor, including in a civilian nuclear reactor. But before the plutonium is used it has to be separated in something called a reprocessing plant. So the trick - trick’s not exactly the right word but you know - the goal I think is, with civilian nuclear power, is to make sure there’s not a route that allows enrichment - uranium enrichment - to become a path to nuclear weapons and to make sure the plutonium is never separated from the spent fuel. Much of the civilian nuclear power, almost all of it, is based now on light water reactors such as the US has or in the case of Canada, for example, natural uranium reactors and the plutonium is not separated for civilian uses. So that’s the first thing, to be sure that to the extent possible you do not try to separate the plutonium. The French have done it to some extent and that is somewhat bothersome. The Japanese have done it to some extent. But as long as nuclear reactors are based on the light water reactor or the natural uranium reactor there’s no reason to separate the plutonium. When I first started looking at this, people thought the future of nuclear power was something called breeder reactors. And with breeder reactors you do separate the plutonium and make nuclear fuel from the plutonium and you just recycle it so that reprocessing - you’re separating the plutonium - became critical to the breeder reactor feature. And that was the prediction in the middle 1970s when I first started looking at this. And that is now, fortunately, pretty much given up around the world. That people are not talking about breeder reactors. Now the second route - uranium enrichment. As I said, natural uranium is seven-tenths percent - less than one percent - uranium-235. The light water reactors that the US and most other countries use is three or four percent uranium-235 - so there is some enrichment that's necessary. It used to be done by something called gaseous diffusion where you take a uranium gas and push it through kind of porous walls and if you do it enough times - like a thousand times - you can get enrichment. More recently, it's been done by centrifuges where you just spin the gas at very high speed and the lighter uranium gets slightly separated from the heavier uranium isotopes. And unlike gaseous diffusion, the centrifuges is a more - what’s the word i’m looking for - a more dangerous technology, I guess, from the point of view of nuclear proliferation because you could, from a plant that's designed to produce 4% uranium-235, rejigger the whole thing so that instead of 4% you can get up to 80%. So centrifuge technology is more problematic from that point of view. You can safeguard it so that you have, for example, International inspectors in a centrifuge plant to make sure that it's not regiggerd to make 80% instead of 4% but still, it’s possible. That was a concern with the Iranian effort a few years ago where the US was concerned that their enrichment could be used to - not that they've done it - but that it could be used to make more highly enriched uranium. So the two big safeguards, I think on nuclear power to proliferation is 1) to make sure you don't separate the plutonium, so you don't have a reprocessing plant and 2) that if you have a centrifuge plant making the 4% enriched uranium that you have safeguards in place - international inspectors - to make sure that it's not being converted to make to make 80% or 90%. So that's sort of - that's my that's my short abbreviated statement about nuclear power. JL: I think that something that comes to my mind - I wrote a paper on depleted uranium. Do you have any knowledge about that, that you’d like to contribute to this. HF: No not really. When you do the enrichment, you get an enriched product and then you get depleted uranium too. And the depleted uranium can't be used for weapons so it's not in itself any real concern. Well, the other part of your question is nuclear power necessary for climate change. So, there is some of a controversy about this. My own sense is that nuclear power is not necessary and is probably not even the most direct way to get climate change relief. If you replace, for example, if you replace a coal plant by a nuclear power plant, the coal plant will produce a lot of carbon carbon dioxide - a greenhouse gas. The nuclear power plant will produce zero, basically. So that's good. However, it takes maybe 10 years to build the nuclear power plant, and a lot of money. And instead of doing that - if you replace the coal plant with a natural gas plant - you can do it much more quickly and it wouldn't reduce the carbon to zero, but it reduces by about half. So for the kind of immediate relaxation or reduction of greenhouse gases - you're probably better off replacing the coal plants by natural gas plants and then ultimately by renewable energy - solar and wind- which also produces essentially no carbon. So that's my sense - that in the short-term, the natural gas revolution, which replaces coal is good and probably would do more per dollar invested than would nuclear. In the somewhat longer-term, renewables - solar and wind - look as effective as nuclear and a lot safer from the point of view from nuclear proliferation. JL: Yeah, that's all really interesting! HF: It's true with solar and wind that - which are both variable sources - you kind of need some backup and that's an argument for nuclear I guess. Right now the backup is based on coal mostly, and natural gas to some extent. But, in the long run, if you want to get away from carbon, nuclear would be the non-variable source. But again, in the somewhat longer-term if you can get storage - good storage technology - which is being developed, then even an economy based mostly on renewables like solar and wind could work. Because, if you could store it during the day then when the wind stops blowing - you have some electricity you can draw from. So that's my sort of, more long-term view of what's going on.