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David Holcomb’s Interview

Manhattan Project Locations:

David Holcomb is a nuclear engineer who specializes in instrumentation and controls for the molten salt reactors at the Oak Ridge National Laboratory. In this interview, Holcomb discusses his background as a scientist, and recalls his interaction with great minds that worked at Oak Ridge. He explains the differences between molten salt reactors and traditional light-water reactors, and advocates for increased usage of the molten salt reactors in the future. Holcomb closes by promoting nuclear energy on a worldwide scale, discussing the positive benefits it can bring to impoverished nations.

Date of Interview:
April 25, 2018
Location of the Interview:


Cindy Kelly: I’m Cindy Kelly, Atomic Heritage Foundation. I have with me David Holcomb. First question for David is to say his name and spell it.

David Holcomb: My name’s David Holcomb, D-a-v-i-d H-o-l-c-o-m-b.

Kelly: Terrific. Now, I want to know something about yourself—where you’re from, when you were born, and then what sparked your interest in science.

Holcomb: I’m an Army brat, so I’ve kind of lived around the world. I was born in Fort Dix Army Medical Hospital [in New Jersey], so I moved around with my family as my dad changed posts around the world.

I was always interested in science, and my parents sparked that. My dad also has a PhD. When I was zero to three, we lived up at the University of Wisconsin where he was getting his PhD. My mom also has a science bent as well. It’s kind of what the family does there. My brother always described himself as the least educated person—he only has the Master’s from Caltech. It’s a part of the family tradition.

I got interested in energy just from reading as a child. Growing up, I looked at some of the things like Isaac Asimov—he did some estimations of what free energy would do for the world. I got interested in what you really could do if you could lower the prices of energy and saying, “I got to work on something. Why don’t I work on something that I believe in, that I think is important? Providing large quantities of energy to help humanity sounds like a really good thing to work on.” I started this probably in seventh grade, I believe, is when I decided I wanted to start working on energy. This has been what I wanted to do.

Kelly:  That’s fabulous. You got your PhD, and then what happened?

Holcomb: It was the early 1990s. As you might know, nuclear was really in a dark spot at that point. This is just as the nuclear energy research was being killed off in the Department of Energy. In ’97, [President Bill] Clinton had taken it down to zero. I was desperate, trying to find a job and I went into a post-doc in radiology oncology.

Fortunately, the NRC [Nuclear Regulatory Commission] was continuing to fund research, and it turns out ORNL [Oak Ridge National Laboratory] had a spot. They needed someone who could do instrumentation controls for nuclear power, to help them. They posted an opening. I applied. I came here right after—I didn’t actually complete my post-doc. I just was basically out of graduate school straight to ORNL, and have been here since then. They reorganized multiple times, but I have continued to work on nuclear power, instrumentation and controls, advanced reactors.

Molten salt reactors really have become my focus since about 2005. I have to thank the number of people who I’ve worked with. Syd Ball, who was one of the original operators for the MSRE [Molten-Salt Reactor Experiment at ORNL], and you can get his name on a number of the reports on the instrumentation controls for the molten salt reactor. He joined the lab in ’57, and he’s still a casual employee, I believe it’s called. He comes in every once in a while.

Then Charles Forsberg, who’s one of our corporate fellows. He invented the fluoride salt cooled high-temperature reactor, along with Per Peterson and Paul Pickard, from Berkeley and from Sandia [National Laboratories], respectively. He then was our lead for much of the technology. He encouraged us, as he left to go to MIT—he retired to be an MIT professor, so not exactly a low-pressure retirement. But when he left, I then took up a number of his roles. 

Then, because we are here in Oak Ridge, there are so many people who have such history in there. Dave Williams is one our salt chemists, who has extensive knowledge on molten salt reactors, and he has now moved into other areas. We can trace back our history of a number of people. Jim Rushton was my division director, who managed the cleanup activities at MSRE, and encouraged me to become more knowledgeable, to be able to support the DOE [Department of Energy] ongoing activities. It’s just a rich opportunity.

My group leader for almost fifteen years was Gary Mays. When he was first hired here, his job was to run the tritium collection loop. One of the challenges for molten salt reactors is they generate tritium, particularly thermal spectrum reactors which we were running on. That tritium production, we have to prevent that from getting out into the biosphere. His first job in, I believe it was ’74 when he was hired, was to be the engineer running the tritium collection loop.

 You are tied to such a rich collection of people here. Day one of being hired here, I had people who were at—one of my close colleagues, Dick Fox, was at the Chicago Pile. His name is on the Chianti bottle [signed by witnesses of the Chicago Pile-1 going critical]. You just don’t get that very many other places.

Kelly:  That’s very exciting. Talking about history, why don’t you tell us, what is the history of the molten salt reactors?

Holcomb: There were a couple of people, actually. It kind of helps, you have two Nobel Laureates, Eugene Wigner and Harold Urey, who really thought initially that you always should have had a liquid fuel. These are basically a chemical reactor, and we add the nuclear to it. Other people thought that these were really mechanical systems. But we always had a couple of people in the Manhattan Project from day one who thought it really should be a liquid system, because we really want to be able to take the fission products out and manipulate what the fuel is. We’ve just been building from the beginning of the nuclear era on, “How do we go ahead and make a reactor?”

Initially, in the Manhattan Project, of course, they were trying to make weapons. They had their production here, that was the graphite pile and such that was going on. Following this, the U.S. then was trying to initially come up with a way of keeping its nuclear deterrence alive. They didn’t have ICBMs [intercontinental ballistic missiles] back then, and so they were trying to keep the aircraft up flying. We had the nuclear bomber program that existed until ’59, when we had developed ICBMs. We were trying to create reactors which could fly and would stay aloft, and be able to deliver a nuclear weapons payload. That paid for a lot of the original technical developments.

Frankly, if you read all of [Alvin M.] Weinberg’s notes from there—he was the lab director at the time, who was really the person who pushed molten salt reactors. We knew this was probably not going to be the best way of doing that, because the requirements for shielding just are not really well-compatible with flying. On the other hand, the Air Force had an awful lot of money and was very interested in pursuing the technology, and so we were pushing it forward.

In 1957, there was the Fluid Fuel Reactors Task Force, which really tried to look at, “Okay, if we’re going to look beyond the light-water reactors,” which were already going forward, “What are some of the options and what would be the best thing?” The molten salt reactors were selected as the most technologically useful option on there in ’57. The U.S. program largely grew out of that, their decisions.

I think it continued in small phases until ’61, with the aircraft reactor program. It really had transitioned into, by the early ‘60s, a civilian program. We got authorization to build the MSRE, I believe it was ’61. Between ’61 and ’63, they’re doing the design. Then in ’64, construction is going. By June of ’65, they have first criticality.

Now, while that’s very impressive in any case, just from the rate on there, to understand how much the aircraft reactor program provided is a tale, of its help on this. We ran the aircraft reactor experiments, I believe it was ’54. We ran a number of hot criticals and cold criticals as part of the aircraft reactor experiments. There was a very large program. I believe we ran twenty-five pumped loops. We ran a number of loops within test reactors. The materials test reactor at Idaho, we ran a number of different loops, different materials, different salts. It was an extensive program.

I can find natural circulation loops numbered, and the numberings go over a thousand. Now, unfortunately, I can’t find all the paperwork, so I don’t know whether this is a continuous numbering on there. But I would not be surprised if we did not have over a thousand natural circulation loops run in the ‘50s and ‘60s.

There’s a huge history on this. Many of the things, like the advanced nickel-based alloys, have much of their origin in these salts. Because the chemical compatibility of the nickel-based alloys with the halide salts is a key technology to allow you to contain the salts and for them not to corrode extensively. Largely, by the early ‘70s with the MSRE, we had mostly mastered the technologies. The MSRE was an incredibly successful operating test reactor.

We generally understand the physics and the chemistry of running a test reactor. Today’s challenges are, how do we go ahead and take this from this small test reactor that ran it from a limited period, and get something which is economically competitive, and can be run for a long time at a large scale? That wasn’t done, and that’s what we need to do. Frankly, we’re a capitalist society, and if somebody can’t run this and make money, we’re not going to do it.

Kelly: And that’s what happened?

Holcomb: We had a couple of times things stopped. We really thought we were running out of uranium in the ‘60s. We really did not appreciate how much uranium there is in the world. We were really trying to breed more uranium to create more fissile material. That was the focus of the molten salt reactor program, trying to use thorium, and breed it into uranium-233. We were focused on that technology. 

At that point, essentially the weapon states were us and Russia. Then China came in and India, the UK and France. But we weren’t nearly as concerned about rogue actors on this. It’s just a different world today. It was President [Gerald] Ford who gave the big speech on plutonium, the plutonium economy, and his decision not to pursue the plutonium economy. We just weren’t in the President’s 1977 budget, because molten salt reactors were perceived to be too high of a proliferation risk.

What we were trying to pursue at the time was called the Molten Salt Breeder Reactor program. We were very much trying to breed more fissile material on site. That is very much not the case today. We recognize the environment that we live in, and the risks that the world has. Frankly, we also realize the world’s got an enormous amount more uranium than we thought. We can’t come up with any scenario—particularly now that we can get uranium at a reasonable price from seawater—that we’re ever going to run out of uranium. In these reactors, it’s not necessary to have a breeding system. We don’t include that in the reactor design.

Some of these reactor companies are trying to even get rid of the enrichment part and say, “We can feed natural uranium in, and get rid of all of the centrifuges.” Which are currently one of our most vulnerable parts for proliferation is the enrichment part. If you can get a reactor which allows you to breed but not separate the fissile materials, you can get rid of the most vulnerable part of the proliferation.

We’re trying to become a positive force on proliferation instead of a negative one. Historically, there are risks if you create separated streams of fissile materials. We think that largely they are –– some of this is perception, because of the extreme radiation environments and the particulars of the details of the reactors –– that they would be very difficult to use for weapons production. But it’s not impossible, and that’s the type of decisions that political people make, whether we pursue actions or not.

Following the closure of the program in 1977, there were a couple of reactors that were developed. Largely, I have to give credit to a few of the folks like Dick Engel, who was one of the inventors of what’s called a denatured molten salt reactor. Essentially what they’ve done is taken the breeding part out of it and just said, “We’ll just allow the fission products to build up. We never separate them out, we never separate out protactinium. We’re not trying to be a reactor which creates separated fissile material. Can we still run as a useful reactor?” It certainly seems so.

Several of the current companies are trying to make businesses out of that. Whether it’s Terrestrial Energy or Thorcon, there are a number of companies that are private companies that are trying to make a business out of what’s largely the denatured molten salt reactors. I’m actually very thankful they credit Oak Ridge very publicly about the ideas on this as, “Yeah, we probably can turn this in.” Terra Power is also building on some of the history with fast-spectrum molten salt reactors and their own version of not having fissile material separations.

Kelly: For the elementary school watchers, can you describe the difference between your molten salt reactor and let’s say, the light-water reactor?

Holcomb: In a light-water reactor, the fuel is in rods. It’s a solid object in the rods, and it’s cooled by water flowing through it.

In our reactor, the fuel is already a liquid. The nice thing about our liquid is that the liquid doesn’t boil until very, very high temperatures, in our case, typically around 1400 C [Celsius], very hot. Essentially, the reactor vessel softens and melts about the same time that the salt would boil. Not being at boiling means that our fluid is at very low pressure, meaning atmospheric pressure or less. The advantage of atmospheric pressure is that there’s no real force to cause radionuclides to leave.

Unlike a light-water reactor, which has a reactor vessel about six inches thick, it has a number of safety systems to really make sure that the water stays over the reactor core, and that you always keep it covered. These safety systems end up making the reactor expensive. It also has very thick-walled containments. The modern light-water reactors have ended up being a very safe system, but they’re ending up being more and more expensive to generate power.

What we’re trying to realize is that if you get something which is a liquid and at low pressure, we can’t come up with a way of having a large accident. I don’t need to have safety systems to prevent accidents that we haven’t been able to come up yet. As long as we can’t come up with any serious accidents, we think it should be a much cheaper system. Our real big difference is, our fuel is a liquid and the fuel moves along with the coolant. In a light-water reactor, the fuel and the coolant are separate and only the coolant moves.

Kelly: In a reactor, you have a containment vessel that contains this, but interior to that, inside, is just heterogeneous liquid.

Holcomb: In our system, there are two general parts in a molten salt reactor, two classes. One of them is a fast-spectrum reactor, and that means that it stays critical on neutrons which have high energies. That allows you to use U-238, essentially, allows you to have positive breeding gain from natural uranium. In that, essentially, it’s just the liquid inside.

Then what you have is the liquid. There’s fissions that happen in there, it heats the liquid up. The liquid is pumped around, it goes through a heat exchanger. In the heat exchanger, your primary coolant salt then absorbs the heat. The coolant just continues, and the fuel salt just recirculates back into the reactor core.

In a thermal-spectrum reactor, you also have to have a moderator. In most cases, that’s graphite. The graphite goes ahead and brings down the neutron energy to where you don’t have to use a fast fission and you just have much higher cross-sections, which means you need a lot less fuel in there. It’s uranium-235. It looks an awful lot like compositions of the uranium content in the light-water reactor. You bring that in, and you cause the fissions with a thermal spectrum. But otherwise, the fuel itself is a liquid. Most of the core in a thermal-spectrum reactor, if you look at it, is essentially graphite blocks with holes in them so the liquid will flow through it.

Essentially right now, light-water reactors are mostly a mature technology. We’re in the process of making them better, and I will say, the Gen-III-plus have some substantial improvements over the earlier ones. On the other hand, the early reactors worked pretty well as well.

What our problem comes out to is, they cost too much right now. People can make very strong claims that the U.S. market is broken on the price and that’s why we are closing down so many reactors in the non-regulated markets. But fundamentally, we’re trying to get to the point as an industry, we’d like to be able to be the cost-competitive option on this. That’s always the drive is, how do you lower the price? If you are continuing to be burdened by more safety regulation and more procedural requirements, it is very difficult to win, because those aren’t engineering things where I can engineer and make a better thing. Because every time I do something for engineering, it costs more money.

What we’re trying to do is, you change the game, something where we can’t come up with having the big accidents. If we don’t have the big accidents, I don’t need to put in a safety system to prevent them. That really is the focus. We need to be able to make the next generation of nuclear entrepreneurs successful, to say, “Hey, we’re going to generate large quantities of electricity.” We also need to do it a way that is highly proliferation-resistant, so that the U.S. would be supportive of deploying this around the world.

As we look at what’s going to the happen when the rest of the world reaches our level of development, the amount of energy in there—if we do this with fossil fuels, we are going to be sending so much unpleasantness up into the atmosphere. Whether it’s CO2 [carbon dioxide], or particulates, or SOx [sulfur oxides], or NOx [nitrogen oxides], we really don’t want to run that experiment to find out the details of what’s going to happen with that.

Nuclear is the clean-air energy that doesn’t take massive quantities of land and massive quantities of concrete. If you look at the solar and the wind, there’s some real challenges with dense societies and dense industrial areas. You also just look at the physical infrastructure, because you’ve got a diffuse energy source, and how much concrete it takes to build this system. Nuclear has the advantage that it’s a very compact energy source. You have a very small area that produces an enormous quantity of electricity.

We want to take advantage of that and be able to help all these people, and help them bring up their standards of living. There’s higher correlations with available energy than about anything else with the wellbeing of society. If you look at healthcare or in food availability, apart from just the basic nourishments, energy availability tracks so well with the helping of humanity. It’s such an important thing for us to do.

Kelly: That’s true. Well said. You’re involved in looking even further with the Generation IV International ––

Holcomb: This was part of President [George W.] Bush’s initiatives. We’re trying to see, how can we cooperate around the world? The Generation IV, we were trying to look at — sorry, the second Bush, not the first. He was trying to look at, “How can the world cooperate on nuclear power, and what are the mechanisms?” 

We looked at, “What are the classes of advanced reactors that might be done in the future?” There were six reactor classes identified, one of which is the molten salt reactor. There are a number of countries that have had molten salt reactor programs. But because it takes a fair amount of engineering effort to go ahead and take a reactor class from essentially PowerPoint today into a real system, everyone was running these sort of sub-critical effort levels. We’re never going to get to an actual deployment, from a government push perspective.

We’re trying to say, “Can we combine some efforts, and see whether we can’t get further?” Also, to some extent, there are a number of things that—as far as safety, the proliferation resistance—that the advanced countries all agree on. Can we take a common approach to this? We have a number of the efforts—the Russians are a major player in molten salt reactors, the Chinese have got a fairly large program. We don’t ordinarily cooperate extensively, except in basic sciences. But for some of these things, like reactor safety, we’d very much like to make sure that we have common approaches to these types of things. We want to cooperate where we can.

The Generation IV International Forum provides that vehicle. Because the U.S. Senate has approved the framework agreement for the Generation IV International Forum, it provides us a vehicle so that we can cooperate on the specific technology developments internationally. Of course, DOE is the implementing agent for this, so it’s under the guidance of the Department of Energy on what we would cooperate with, with other countries.

This is, again, an indication that much of the world can see that this is an important subject. But they can also see that there are technological challenges in this. In some ways, everyone refers back to Oak Ridge, because this was the only place that’s ever actually operated a molten salt reactor.

Again, the other reactor classes are also going forward in the Generation IV International Forum. Our real thing that we think molten salt reactors, the effort is to try to get them to be economically competitive. We hope that we have that advantage as a low-pressure system that provides high temperature—the technical term is high-exergy energy, because of the high availability ability to do work with the energy, which is a distinctive characteristic of the reactor class.

Kelly: How does the molten salt reactor address the nuclear waste generation issue?

Holcomb: If you look at this, the fuel doesn’t actually build up any radiation damage. If you look at what’s going on in the fuel, essentially, you can keep using the fuel. Even in the next reactor, where did you get the fuel from? In the breeder reactors, the concept is that you produce the fuel in the prior generation reactor, and so that largely the waste is the fuel to allow you to create an expanding program. You don’t actually end up with any of the fuel waste until somebody decides the molten salt reactors are no longer an energy source that we’re going to be using for the world. We’re hoping that’s a very long time from now. There is not a substantial high-level waste program, because essentially, the fuel is used in the next reactor and the next reactor and the next reactor.

It somewhat sidesteps it. Because it does mean that at some point if fusion is ever working, or if we ever have some other very large transition, then all of sudden, all of the fuel salt in all of the reactors then becomes waste. There is some advantage. We happen to know almost all of our fuel-processing technologies are based upon the molten salts, so it’s one of the easier ones. If someone had to create a waste-processing system, our reactor would be one of the ones that would be the easiest to do that with.

But again, mostly the vision is just avoid needing to. Our challenge is going to be creating the initial fuel, and saying that the next reactor is largely going to get its fuel from the prior one. Once it’s irradiated the reactor vessel and the materials within it so much that they need to be replaced, well, we just put a new one in. It’s a liquid, you pump it from one to the other, and move it on to the next generation.

Kelly: You mean, you have a succession of ––

Holcomb: Yes, and hopefully a growing one. The breeder reactors are really trying to feed—how many years does it take to generate enough new fuel to feed a daughter, and then the two of them working together to feed another daughter? Then the three reactors to feed the next and the next, and you keep producing more and more.

On the ones that are burners, which are the thermal spectrums on there, they would still need to be fed with somewhat low-enriched uranium, so they would continue rely upon this. But you could still use much of the fuel that was in the prior generation and feed it into the next one. It doesn’t stop being good fuel, just because I have now irradiated the graphite so much that it’s no longer mechanically useful. It was still good fuel at the end of the other reactor, well, it’s still good fuel in the new one.

Some of the challenges that we’re still looking for, one of the things is that we are now in a light-water reactor environment in this country, because those are the only reactors we’ve deployed commercially. One of our challenges right now is helping the NRC [Nuclear Regulatory Commission] develop a licensing framework, which is reflective of the safety characteristics of the reactor class.

Because light-water reactors have the potential, while it’s remote, of having these large accidents, all of the regulatory structure is based upon, “What do you have to do to show that you’ve adequately prevented that?” If you go ahead and you pile all those requirements on something which doesn’t need that, because it doesn’t have the accident possibilities, you make your reactor so expensive that you don’t build it. That’s one of our big challenges today.

Another one of our big challenges is that we’ve lost the supplier base in this country. I can’t buy, if I need, twenty tons of salt reactor fuel –– there’s nobody who sells that in the quality that I need. There’s nobody who sells the reactor vessel in the form, all these things. We’re having to essentially bootstrap the industry up.

There’s a lot of challenges today, which are really being born by these first-of-a-kind developers trying to say, “I have to have a reactor vessel, I have to have a pump, I have to have this heat exchanger. I only need one of them right now.” People charge them for one-of-a-kind specialty items, and it makes these things very expensive.

They have an uncertain licensing path, because we don’t know how much time or money it’s going to take for the NRC to change into a performance-based, risk-informed licensing path instead of its current prescriptive, “You must do it this way, because that’s an acceptable way for a light-water reactor.” It would be acceptable for us, it would just be so expensive that would make the technology unfeasible.

Our big challenges are both get the licensing aligned with the risks of the real technology, and then get a supplier base developed so that people can see, “If I invest money is this, it may be a very expensive thing. But there’s a lot of capital in this society. Look at how much the oil industry spends on something like a refinery or a new gas field. We’re at the same type of timeframes for payoffs and the same amounts of money.” The problem is the lack of certainty that they’re going to get the payoff. They’re very certain on if they go to a gas field or they do a new refinery, in ten years, this is going to turn around and it’s going to start pumping money back out.

Unfortunately, with it being a regulatory hurdle, we’re in the spot where, “We don’t know how long it’s going to take. We don’t know how much money it’s going to cost. And, by the way, we can’t buy the pieces, so I can’t tell you how much it’s going to cost to construct this, either.”

So right now, we’re caught in an uncertainty hurdle, and that’s where the DOE efforts are trying to help. We’re saying, “How can we support the NRC, to provide the technical evidence, so they can adjust their rules?” They are dedicated to protecting the environment and the people. We have to have the evidence for them to say, “This is what the rules really should be.” You have to have high-quality evidence all the way through every accident scenario, every piece. That’s part of what the DOE campaign is doing, is developing the evidence.

We’re also trying to provide the evidence of, “How can you apply modern manufacturing techniques? How you can apply modern designs?” One of the things that we have is, we know that some of the components in the system are not going to last the life of the plant. The reactor vessels probably are going to need to be replaced several times. This is an extremely radioactive environment, and we’re just not going to have workers in there. That means we’re going to need to do this all automated.

Sixty years ago, when we were building these things, we didn’t have automation. We didn’t have the advanced robotics. We have to use very specialized advanced robotics, because of the extreme radiation environments. But things like, just up the hill, the Spallation Neutron Source, its target exchange capability is extreme radiation environments advanced robotic system. That’s something that was done in 2006. That’s much more recent, but we can apply those technologies and try to help the industry understand, “What does it really take to do this? 

To some extent, there is private industry leadership. But right now, it’s all at the very risky end of venture capital. It’s also not as commonly known. There just aren’t that many people in the advanced nuclear power business, so it’s harder to get the set of venture capitalists to say, “Yeah, this is where I need to go.” Because they know the IT industry, and they know, “In eighteen months, this is our timeframe.”

 We are in the fifteen years, this is our timeframe, a time when you’re going to start making money. You might be able to put a test reactor online in a much shorter date, but when you say, “When I start to have to make multiples of these to make money,” your payback windows are longer.

I have to say we still are in a high-risk area. We’re hoping through the DOE program to buy down some of that risk, to allow the private industry to be able to be successful.

Kelly: So you know from conversations with the private sector, there are companies who want to get in this game?

Holcomb: There are, there always are. Some of that is the nature of the U.S., that we have all these bright startups. The challenge on some of this is getting that combination of enough experience and enough engineering depth to say, “This is a large, complicated endeavor, along with enough capital to keep going for a while.”

There are multiple companies. Some of them are at various stages, and some of them are backed by very wealthy individuals. It’s an interesting time. Don’t know whether anyone is going to be successful, but I don’t see any fundamental technology reasons why they can’t be.

Kelly: Since it’s all about pricing, we don’t know what’s going to happen to natural gas, it’s gone up and down. It’s low now, but ––

Holcomb:  That also sets a target for us. They still have to pay for fuel. We still are a high-temperature energy source. Most of the economic models that you see from these companies say we should still be able to be competitive, even with low-price natural gas. I’m not going to just give up on beating natural gas.

On the other hand, you’re correct, it’s a very low price. On the other hand, if you look at most of the models, they tell you in thirty-five or forty years, even with the fracking revolution, we will still have a lot of natural gas available, but the price is going to go up.

That’s part of the reason I think I see some interest, because the oil majors want to stay in business. They know in thirty-five or forty years they’re going to still have to be providing energy. They’re going to say, “We need to start investing now if we’re going to have—what are we going to do next? If we’re going to run out of hydrocarbon resources, or at least the hydrocarbon resources are going to become markedly more expensive, that’s not an indication of, ‘Don’t invest.’ Because long-term, our companies are in the energy business.”

I don’t think that low-price natural gas is the death knell of this, both from the basic economics on our fuel is very low-cost. The price of the uranium in the nuclear power today is like .1 cents per kilowatt hour. It’s a very small amount of the price. If we can make the most of the rest of this, because we’re a low-pressure system where you’ve paid some capital costs upfront. But we’ve radically reduced them, because we have very much lower amounts of materials, because we’re low-pressure, we’re high-temperature.

We also try to very much improve our security parts, that there isn’t anything for anybody to go blow up. I don’t need to have the security force that other places have. The technical term is, “We have no vital areas that are accessible.” We’re hoping to rely upon the local police to provide our defense, just like other industrial plants, instead of having to have your own security force, which is what we have to have in today’s plants. That’s another major cost. 

Again and again, what we come back to is, we have to lower the price of power if we’re going to be competitive in the market.

Kelly: Well, it sounds promising.

Holcomb: We’re in an interesting time. I hope that we are successful. I—as all the nuclear engineers probably since the last light-water reactor eras—am worried that your career is going to be a failure in that right now, no one’s built an advanced reactor. There are no molten salt reactors on the grid generating power. I really want that to change. Otherwise, you have these possibilities of negative results of all these years of effort of so many people, which is why so many people are interested in this.

We very much want to see success, and not just success in the government. Because we built and ran the MSRE as a government institution. It worked exceptionally well. It’s the best-run test reactor I’ve ever heard of on its performance characteristics. Yet, it didn’t go out on the market. That says our purely government solution is not the answer. Our answer now is, we need to get the private industry into this, building these, making a profit, and selling power to the people.

Kelly: I certainly hope that works.

Holcomb: As do I.

Kelly: From all I hear, we just can’t make it in terms of meeting the world’s energy needs, and probably not the nation’s energy needs, without having some form of nuclear energy in the mix.

Holcomb: These are societal choices. We can become a much less industrial society, and that is an option. I don’t think most people want that. I certainly would like to continue to have advantages, the advantages of a lot of the industrial components on this. And yes, a rich society, which the U.S. is a rich society, can make a number of choices. We would become somewhat less rich, but we’re still a rich society. We’re not probably necessary, it’s just really useful.

For other parts of the world, I think it is necessary. And for me, necessary is. there are so many people who are going to live such horrible lives that we can make better. We can make the U.S. better. But there are some great advantages to living in a wealthy society. Without nuclear – okay, we’re either going to have a much higher carbon footprint or much less energy-intensive lives.

Energy is such an enabler here. Being able to travel, to be able to have the lights and have the heating and the air conditioning. I live in the South here. I have a hard time imagining not being able to have air conditioning when I want it. I’ve lived in the North. Not having central heating when I want it is—both of those places are uninhabitable without central heating or air conditioning. I can’t imagine much of the coastal parts of this country, Houston or New Orleans, without air conditioning. They would revert to swamps.

I’m hoping that the next generation of people continue to build upon the good ideas of the prior generations. It’s probably one of the young generation who’s going to have their hand on the switch when the first electrons hit the grid from the advanced reactors. Because we’re still not on the grid yet, and it’s still a few years. The folks who are probably in the schools learning their science and learning their engineering disciplines are going to be the ones that set the course for the future. I hope that you guys can participate.

Again, I want to have a successful career. But my goals, my threshold on this at the end of the day is, I want to see an advanced reactor put power on the grid. It has not happened yet here. I think that most of the folks who are in the nuclear enterprise, in the advanced nuclear enterprise, have that similar goal. You’re worried about, “Are our careers a failure?” Because eventually the only metric is, “Did we actually produce power?” Because that’s what the purpose for this is.

I’ve worked and helped the NRC, and helped to see what we can do to maintain the current fleet and help to make it safe, or keep it safe more than make it safe. But to me, that is unsatisfying on this. I think our next generation really needs to push for, “How do we improve upon where we are now?”

Kelly:  Well, that’s a worthy goal, important goal. Thank you very much. This has really been terrific. You said a lot. 

Holcomb:  You are more than welcome. Hopefully you found most of this is useful.

Kelly:  Oh, very, absolutely. I don’t think we have anybody talking about this. Reactors are one of the big outcomes of the Manhattan Project. This clearly connects the dots with what started back in the ‘40s.

Holcomb: The technologies are similar; the goals are very different on there. Essentially, yes, you can use the energy out of fission for very creative and useful things, whether it’s nuclear medicine or power production. Or you can use them as very destructive things, where our nation maintains a stockpile of nuclear weapons and we still live in a world that has adversaries and unpleasant things. Both aspects of the power of the atom continue to be important today.

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