Written by guest blogger Dr. Stephen Boyd
Stephen Boyd PhD spent a week recently touring New Mexico, where he visited the famed Los Alamos laboratory and spoke at a space energy conference in nearby Albuquerque. He’s still buzzing with observations on unwise reactor designs, heroic scientists, flimsy U.S. energy policy, the enormous potential of molten salt and on how things aren’t always as they appear. He treated us to this trip report…
Appearances are quite often deceiving. My recent participation in a leading space technologies conference in Albuquerque, and my subsequent meetings with fellow researchers at the nearby Los Alamos National Laboratories affirmed this observation over and over again. Let me explain…
My colleagues and I have written a paper questioning the use of silicon carbide as a material in fluoride molten salt reactors (MSRs) and in other high temperature reactors. Many space experts have a keen interest in MSRs, which could potentially power spacecraft and provide energy on “off-earth” places such as Mars and the Moon. I was thus pleased when our paper earned me an invitation to speak at the recent Nuclear and Emerging Technologies for Space (NETS) conference, which tackled the challenges of energy in space head on. The paper is up for peer review in the NETS conference publication.
A quick review for those of you new to the subject: It’s not just the space community that is interested in MSRs. Chemists, physicists and engineers in the U.S. and around the globe have a rekindled interest in them as a safe, efficient, environmentally friendly, CO2-free power source. This type of nuclear reactor, studied extensively (and nearly exclusively) in the U.S. from the 1950s-1970s, differs dramatically from conventional, solid-fuel nuclear reactors. In a molten salt reactor the nuclear fuel is the salt; the salt is molten (due to the high heat) and used as the working fluid, so the fuel acts as its own coolant. The fluid design provides safety and operational advantages of conventional solid fuel reactors.
China and India are conducting considerable research and development into liquid-fueled MSRs. By comparison, the U.S. Department of Energy is only timidly pursuing the concept. It has helped to fund a handful of projects at universities, and these projects are not exploring full-on molten-fueled reactors. Rather, they are examining molten salts as coolants, while keeping the fuel in a solid form.
BEWARE SILICON CARBIDE
Across the world, government and private initiatives are considering using silicon carbide (SiC) as a structural material for pipes that contain the molten, circulating salts. Others are proposing it as cladding to coat specialized solid-fuel pellets commonly referred to as “pebbles” in proposed “pebble bed reactors” that would use solid pebble-shaped fuel cooled by molten salt.
Our contention is that SiC is a poor material. In our paper we cite experimental evidence collected over the decades that, we assert, demonstrate this point. Normally, SiC is an excellent refractory material (a material that retains its structural strength even at high temperatures).
At issue here is the combination of high heat and aggressive molten fluorinating salts. SiC, and silicon-based compounds in general do not perform well at all even at room temperature with fluoride-based compounds. They tend to dissolve, much like salt in water. At a macroscopic level, some reports have demonstrated no effect. But remember – appearances are sometimes very deceiving. We assert and cite evidence that if you look at the microscopic level, you will see substantive dissolution of the SiC, reflected in both the disappearance of the SiC, as well as the appearance silicon-based residues in post-facto studies.
Anyone who heard me speak in Albuquerque will hopefully now understand the considerable risks of SiC in an MSR, and will hopefully care enough to act on what may, indeed, prove to be a major design flaw of an all-important reactor.
Certainly, there were plenty of impassioned people gathered at NETS who could make a difference in pushing forward a clean and sustainable energy future with innovative MSRs playing a big role.
But to the casual onlooker, the fervent nature of these individuals might not have been obvious. These avid believers were, after all scientists. For any of you who have attended such a conference, the scene was typical: attendees milling about with staid tones and conversations.
There’s that deception again. I had a chance to sit in on many of the talks, where one could not help but conclude: Scientists must be some of the most passionate people on the planet (myself included). We investigate the fundamentals of matter and energy and we use the Three Laws of Thermodynamics, Quantum Mechanics and applications thereof to do so. We explored NETS’ bold theme of conceiving novel forms of energy production for extended human off-world occupation.
Talk after talk thrust robust skill sets to the fore: intense chemistry, nuclear physics, engineering and materials science that could deal with the extremes of space, lunar or Martian environments. We debated how to handle unfamiliar pressures, temperatures, and the prolonged absence of maintenance and how to deploy technologies with as few moving parts as possible and build clever nuclear batteries and propulsion.
My three-day stop at NETS at the end of February was just the first half of a trip that was populated all along the way by ardent big thinkers.
I remain grateful and honored to have been invited by an excellent staff scientist at the nearby Los Alamos National Laboratories (LANL) to give a talk and meet with scientists there. This was truly a dream come true. I was humbled to be there at LANL, where I was standing on the shoulders of true giants: Feynman, Born, Dirac, Oppenheimer, Teller, Seaborg – to name just a few.
My host (a density-functional theorist by training) was the consummate docent. He arranged meetings for me with a slew of world-class researchers in my fields of interest: materials science, nuclear power-plant design, metallurgy, crystallography, synthetic chemistry.
You see, several goals motivate me. As an entrepreneur, I remain keen on building an energy company focused on making molten salt nuclear reactors a reality – be they terrestrial or off-world. I would prefer using thorium as my fuel, However, I am fine with an “interim” fuel such as low-enriched uranium-235, which is available on the world market and well-known as far as its nuclear chemistry and physics profiles are concerned.
THE PRIVATE PUBLIC CHALLENGE
I have free-market concepts in mind, but as a researcher, some experiments with “hot” materials like uranium-235 are simply not feasible in my start-up laboratory – it costs millions of dollars for a combination of reasons including licensing and waste disposal. I was hopeful that LANL – a U.S. Department of Energy lab – might be able to play a role. They have world-class scientists who specialize in a range of materials and coatings that could be safely used within the brutal environment of a molten salt system. Unfortunately, in my discussions with representative from the LANL Technology Transfer Division, I was told that no federal funding at all is available.
I was frustrated, but I quickly realized that I wasn’t the only one.
On my trip to New Mexico, scientists’ consternation with the illusion of Washington’s energy commitment was palpable. On more than a few instances they voiced their frustration with funding limitations, inconsistent rhetoric and a lack of vision on the part of the U.S. Department of Energy and Congress.
Several scientists were stunned at the comparative advances many nations are making in molten-salt reactor research and development. Canada, Russia, China, the Czech Republic, Australia and India are conclusively ahead of the U.S. and pull further ahead with every Congressional slash, every DoE diversion.
So, what have I gleaned by my interactions with LANL and NETS scientists? Where are we, as a nation, as Americans, relative to the world? Scientists possess some of the greatest ideas, creativity and sheer gumption with respect to emerging technologies and cutting-edge innovation, as well as what they believe should be studied: sexy science and math problems which simply are not being funded, and for vague and nebulous reasons. Those seemingly staid individuals have the passion, really to save the planet.
Ironically, however, the politicians in Washington who are given to more flamboyance, and to loud “rescue the planet” proclamations, are not as interested. If they were, they would be paying more attention to possibilities of nuclear research and development such as molten salt reactors. That is the flip side of the deceiving appearance: just like those who seem uninspired are full of zeal, those in Washington who appear rhetorically impassioned are actually less interested.
I remain optimistic – bolstered by the enthusiasm of the world-class researchers who welcomed me, my ideas, and my chemistry. I remain cautiously confident that the right mix of American entrepreneurial spirit, investment capital, and collaboration with LANL and other government laboratories and maybe even international efforts will foment the momentum so desperately needed to bring humanity’s energy needs (both on this planet and off-world) into the 21st Century and beyond. I am truly hoping that appearances really are deceiving, as many chemists and physicists view Washington with such abject disappointment.
I truly hope we are wrong about Washington and that the ostensible apathy and lack of direction are, in fact, false, and that the U.S. (with its 22 national laboratories leading the way), again demonstrates the practices that once placed us at the forefront of the world for cutting-edge research.
And, of course, I hope my optimism is not deceiving me.
Dr. Stephen Boyd is CEO of Havelide Systems Inc. and CTO of Aufbau Laboratories, LLC, both energy IP companies in Blue Point, Long Island, New York. He is also a post-doctoral fellow in the Physics/Astronomy Department of Hunter College in New York City, focusing on chemical energy retrieval and storage. Dr. Body is developing technologies to advance molten salt reactors. He has a PhD in solid state chemistry/chemical physics and degrees in international finance and political science. You can reach him at firstname.lastname@example.org or email@example.com.