Sherrell Greene on Liquid Chloride Reactors, "Business as Usual," and a second Manhattan Project

The third part of my interview Q&A with Sherrell Green focused on questions concerning the future of nuclear technology. My father had been a pioneer in research on Liquid Chloride Reactor technology in the 1950's. Sherrell Greene mention LCR development during out preinterview, so I wanted to ask him some follow up questions. The LCR is a potential competitor to the Liquid Metal Fast Breeder Reactor, but it is not clear if itsadvantages would out wight its potential costs. Sherrell notes that,

The environment in today’s nuclear energy enterprise is hostile to innovation.

This is undoubtedly the case, and the consequence of our unwillingness to take risks on new concepts in nuclear power are ominous. for our country are ominous. Continuing a business as usual pattern is likely to bring national economic and environmental failure, but it is not clear what it is we should be doing.

30. You view the development of a Liquid Chloride Reactor (LCR) as an important path to Generation V nuclear technology. What do you view as the most important contribution of LCR development to improving nuclear technology?
No I don’t. I’m actually very much on the fence with regard to LCRs. They are potentially attractive fast-spectrum systems and could offer some innovative options for burn/breed fuel cycles. But they also face much more daunting chemical compatibility challenges than fluoride salt-cooled concepts. I don’t consider LCRs to be in the same category of feasibility as liquid fluoride reactors.

31. Would a LCR have significant advantages over Liquid Metal Fast Breeders (LMFBR).
I don’t think we know enough about LCRs to answer the question.

32. Would a LCR have safety advantages in comparison to LMFBRs?
Theoretically, they should have because the coolant wouldn’t interact as energetically with air and water. But again, we know more about LMFBRs than LCRs.

33. Would a LCR have any notable safety problems, in comparison to LMFBRs?
I don’t think we know enough to answer the question. They two reactors have very different shutdown mechanisms. Again, until one has a specific mechanical design in front of them, it’s mostly speculation.

34. Do any Liquid Chloride Salt formulas hold potential advantages in comparison to Flibe (The lithium fluoride (LiF) and beryllium fluoride (BeF2) mixture, often referred to as the preferred carrier/coolant salt formula for MSRs?
Most of the chloride-based salts don’t perform well in the thermal spectrum. Corrosion management is more demanding than the fluoride salts. LiF-BeF2 (FLiBe) mixtures are very attractive from the nuclear, thermal, chemical, and thermo-mechanical standpoint. But with you have a tritium production issue, a lithium enrichment cost issue, and a beryllium occupational exposure issue to deal with. All of that drives up the cost. George Flanagan and David Holcomb at ORNL have recently evaluated some of these issues. They conducted an initial screening of LCR salt options, and developed a pre-pre- conceptual concept for a LCR. MIT and a few others have also done work in this area.

35. Do any Liquid Chloride Salt formulas have the potential of being technically competitive with Flibe, but at a lower cost?
Again, I think you will want to consider chloride salts for harder-spectrum systems. So it’s a different application. That’s said, I don’t think we know enough to answer the question. I am pessimistic there is a chloride salt that can match FLiBe from an integrated performance perspective.

36. What changes would you view as desirable in the current business-as-usual pattern of the nuclear technology industry?
This is probably the most important question we’ve discussed! I don’t pretend to have many answers. But I’m thinking a lot about this issue.

I’ve been privileged to work in one of the world’s premier energy research laboratories for over three decades. I’ve seen the ins and outs of the Department of Energy, and its national laboratories. I’ve been involved in major long-term international collaborations. I’ve supported the NRC. I worked with the nuclear industry. All of these venues are populated with extraordinarily bright, committed people with noble motives. Yet “business-as-usual” doesn’t seem to be working very well in the US.

The environment in today’s nuclear energy enterprise is hostile to innovation. Not by intent, but in reality nevertheless. The industry is highly regulated. It is very costly to do research, development, and demonstration. It’s a very capital-intensive business. The barriers to entry are incredibly high. The down-side risks of innovation are more easily rendered in practical terms than the upside gains. Often it seems everyone in the enterprise (federal and private sectors) are so risk-averse that innovation is the last thing on anyone’s mind. In this environment, “good-enough” is the enemy of “better”. Humans learn by failing. It’s the way we learn to walk, talk, and ride a bicycle. Our environment today has little tolerance for failures at any level. There’s no room for Thomas Edison’s approach to innovation in today’s world. On top of all of this, or perhaps because of it, the nuclear industry invests less on R&D, as a percentage of gross revenues, than practically every other major industry you might name.

We can and must change this paradigm if the 3-4 billion people on this earth who are in dire need of electricity are to ever have it. I view this as both a moral imperative and a practical necessity if global peace and stability are to be sustained throughout this century.

I’m an advocate of “Design Thinking”, which is a multi-disciplinary, human-centered approach to innovation pioneered by Tim Brown and others. One of the things I hope to do in the post-ORNL phase of my career is to integrate the Design Thinking paradigm with my experience in the nuclear energy enterprise to find ways to accelerate the rate of innovation and deployment of improved nuclear energy technologies and systems. This basically begins with questioning (notice I did not say attacking) everything about the status quo - assumptions, approaches, frameworks, paradigms, systems, etc. at all levels. It means re-visiting all constraints and asking a lot of “What if” and “How might” questions. All of this while maintaining a zealous adherence to scientific and technical integrity and engineering discipline. It means looking to both natural and man-made analogs for inspiration. (As an example, I believe the nuclear industry can learn a lot by emulating the petroleum industry’s approach technology deployment.) A fresh look at government – private sector partneships for research, development, and demonstration (RD&D) is in order. Realistic and practical methods for risk / reward sharing must be developed.
I’m a dedicated free-market guy. But it is clear to me the free market is not currently serving the long-range interests of our nation and our globe in terms of strategic energy resource development. There are policy, regulatory, business system, and other issues, but it’s clear to our current processes for policy and regulatory framework synthesis, and energy technology development and deployment do not capture all of the essential feedback loops required to drive us to good long-term decisions.

37. Would the Anthropogenic Global Warming problem justify a new Manhattan Project?
Well, this may surprise you, but I’m not sure I know what a “new” Manhattan Project looks like. If your definition is simply a focus of enormous federal resources on the problem, my answer is that’s a necessary, but not sufficient action.

In my mind, the achievement of the atomic bomb, the moon landing, and the Interstate Highway system are three of the greatest achievements of the US federal government. But the context and circumstances surrounding each of these accomplishments were unique to each. R&D investment in the Manhattan Project spawned a second generation of scientists and engineers who achieved the moon landing. Investment in the space program inspired and enabled a third generation of scientists and engineers whose talents and creations have benefited society in a plethora of ways during the past few decades. The interstate highway system is a trophy of perseverance. The Manhattan Project was done in response to an imminent threat to our existence. The lunar landing was motivated out of national pride and our desire to outshine the Russians during the cold war era. The interstate highway system was created out of recognition of the need for America to be “one nation” in culture and commerce.

The problem with global climate change is that it’s everybody’s problem. Which too often in this world means it’s no one’s responsibility to address. I’m reminded of both anecdotal and experimental studies showing that a large group of witnesses are less inclined to intercede to aid someone being attacked on the street, than is a individual who witnesses the event. When everyone owns a problem, no one owns the solution. It’s also a perfect “frog in the kettle” problem - big change in small steps over a long (in human lifespan terms) timeframe. Another issue is that the challenge is made so complex and so enormous by many who discuss it, that the average person surrenders in confusion or hopelessness. Climate change in many ways is the ultimate test of the “think globally, act locally” mentality. Finally, the “dirty little secret” of climate change is that if it occurs as many predict, there will be winners and losers in terms of countries, cultures, and populations. Massive population shifts would occur, but the story is not all bad. Large regions of land that are currently un-inhabitable could become prime real estate.

I feel we need to approach the global climate change problem with a hefty dose of humility. This beautiful blue planet we inhabit is a wonder of complexity and balance. We need a revolution in understanding of natural systems, their interactions, and their feedback loops. Understanding the natural system leads to predictive capability. Predictive capability enables us to examine the value of various interventions. This, in turn, allows us to gauge the value of various technologies. When we understand the value of various intervention technologies, we can prioritize our technology RD&D options. One thing is pretty clear: more carbon in the atmosphere is not a good thing. So reducing our carbon emissions and exploring ways to terraform or remove carbon from the atmosphere would be a critical element of a major attack on the problem. But we are talking about massive amounts of carbon. Nuclear energy could play an important enabling role in both of these endeavors.

Lastly, I believe our great scientific and technical institutions would have to be refocused in many ways to be successful in a “new Manhattan Project.” One challenge we face is that for too long the federal sector has tended to focus on “basic science” to the detriment of use-focused R&D. We’ve avoided the what Donald Stokes called “Pasteur’s Quadrant” of RD&D. After all, how many people can point to a single innovation from our national laboratory system in the past twenty years that has had a major impact on the lives of ordinary people? What grand problem have we actually solved? I’m not disrespecting the national labs. I love them. But in fact, there’s been an aversion in many quarters of the federal government to pursing research that has near-term payback or impact. I think it is time for us to rethink the value propositions for federally-funded R&D. Often, many of the challenges are in technology development and systems integration phases of development – not in the very fundamental basic research. This (technology development and systems integration) is the so-called “valley of death” between discovery and impact. It is precisely this type of RD&D that has been out of favor for too long in the federal sector, and where the interface between the federal and private sectors is broken.

38. Should the AHTR and/or the SmAHTR be targeted for development by a second Manhattan Project?
I feel that FHRs (SmATHR, AHTR, PB-AHTR) and MSRs warrant consideration for future development and deployment. I do feel the nation would be well served by a balanced program of FHR and MSR system concept development and enabling technology development. Such work is necessary to enable us to sufficiently mature system concepts and technologies to the point required to inform downselect decisons. We’re not there yet.

39. What other nuclear technologies would you see as candidates for rapid development by a Second Manhattan project? (If you view that a second Manhattan Project is desirable.)
Let me broaden your question.... I feel there are cluster of key technologies, working in harmony, that could revolutionize our planet: high temperature nuclear energy systems; carbon capture and sequestration to enable use of fossil fuels; ultra-high density electrical energy storage for individuals, vehicles, homes, and the grid; and “retrofitable” residential and commercial “super insulation” to reduce building energy consumption in existing buildings. These four technologies, along with a fortified and modernized electrical transmission and distribution grid, could revolutionize our future.