The second Thorium Energy Conference (ThEC2011) was held at City College in New York from October 10 to 12, 2011, and was hosted by the International Thorium Energy Organization (IThEO).
I had the opportunity to speak on the afternoon of the first day. Fortunately, my presentation was preceded by a very good presentation by Dr. Jess Gehin of Oak Ridge National Laboratory on the subject of molten-salt reactor technology and the history of the different types of MSRs. Jess’s presentation covered a great deal of material that I had reluctantly deleted from my presentation in order to fit it within the allotted time, so it worked out very well.
My presentation basically had two halves. The first half (slides 1-28) focused on how Flibe Energy intends to continue Weinberg’s vision of a “world set free” by clean and abundant nuclear energy from thorium. I highlighted the language in the Department of Energy’s Nuclear Energy division (DOE-NE) that expects industry to lead in the design, development, and implementation of new nuclear energy according to market principles. I described our focus on a portable, modular power source suitable for powering military installations, initially in the United States and later abroad. I described the operation of the LFTR and its safety features. I spent a bit of time talking about the people involved with the company and introducing the Board of Advisors. I closed the first half by describing how an analysis of reactor coolants and fuel cycles leads you to the unique combination of thorium fuel and fluoride coolant that enables long-lived, safe operation of a nuclear power source.
Then I shifted gears for the second half of my presentation (slides 29-55). I anticipated the first question would be the one that I always get in presentations such as these: “why didn’t this happen?” So I attempted to answer that question before it was asked.
Nature gave us three natural nuclear fuels (Th-232, U-235, and U-238) but only one was naturally fissile. It was also the one that was in the shortest supply. Nuclear pioneers saw that we had better get on to one of the abundant fuels (Th-232 or U-238) quickly if we were to sustain the generation of nuclear power. So the question became–which one? The fissile derivative of U-238, plutonium-239, promised sufficient excess neutrons in fast fission to build up a large fissile inventory through breeding gain, so the bulk of nuclear efforts were directly towards the “fast-breeder reactor”, most often cooled by reactive liquid-sodium.
Others saw a compelling possibility in thorium and its fissile derivative, uranium-233. This combination alone had the potential to “breed” in the thermal spectrum, and to avoid the significant complications of the fast spectrum. But the breeding gain would be low, if present at all. There were significant uncertainties, but there would be significant advantages to avoiding the huge fuel inventory of the fast-breeder reactor (some 10 to 20 times greater than the fuel inventory of a thermal reactor for the same power rating).
Despite meltdowns at the EBR-1 reactor and the Fermi 1 reactor, the US Atomic Energy Commission (USAEC) continued to pour hundreds of millions of dollars into fast-breeder reactor development. On June 4, 1971 they gained even more strength when Pres. Richard Nixon made the development of the fast breeder reactor the core of US energy policy. Nixon also saw the fast breeder as a political “treat” that he could dangle in front of audiences and constituents, and he did so both privately and publicly.
Weinberg’s efforts to show the efficacy of a thermal breeder based on molten-salts and thorium was politically doomed. He was fired in late 1972 and the program was cancelled in 1973. Things got worse in 1973. The Arab oil embargo was a blow to the US and caused Nixon to commit even more strongly to the fast breeder.
In 1974, India detonated a nuclear explosive based on plutonium that they had produced in a heavy-water reactor and the issue of proliferation attained far greater prominence in national discussions. It did not curb Nixon’s enthusiasm for the fast breeder nor that of his successor, Gerald Ford. But in the 1976 election proliferation was an issue where Ford felt a disadvantage relative to his opponent Jimmy Carter. Therefore, on October 28, 1976, just five days before the presidential election, Ford announced a ban on the reprocessing of nuclear fuel in an attempt to curb proliferation.
This ban was essentially the death knell for the fast breeder in the United States. Without plutonium recovered from light-water reactors to fuel its large initial fissile inventory, and without the reprocessing of its uranium-plutonium fuel to recover fissile materials, the central concept of the fast breeder was non-viable. Carter went on to win the 1976 election and to continue Ford’s anti-reprocessing strategy (little surprise). He spoke repeatedly about the opportunity costs of the fast breeder and blamed it for slow progress in solar technology. He also said the plutonium fast breeder was unnecessary and that the United States should make greater use of its coal resources.
At no time was there any indication that the decision to kill the molten-salt reactor was ever revisited at a presidential level. In fact, there is little indication that anyone at the executive level even knew what a molten-salt reactor was, or what the potential for thorium could be.
The breeder reactor program was cancelled after the expenditure of billions of dollars, and the Three Mile Island-2 accident in March 1978 ended political interest in exploring advanced nuclear reactor technology.
I summarized my answer to the question “why didn’t this happen” with these observations:
The USAEC saw plutonium as a “sure bet” in a breeder reactor, but thorium was more uncertain (but proven in the end at Shippingport). They invested early and heavily in the liquid-metal fast-breeder reactor (LMFBR) despite failures and meltdowns. Industry got involved with $200M in investment In June 1971, Nixon announced that the fast breeder was US policy, and he saw it as a strategy for energy independence. Weinberg was fired and the MSRP was cancelled. Ford cancelled fuel processing and Carter extended the policy. Without fuel reprocessing and plutonium extraction, the plutonium fast-breeder was non-viable. No one in DC revisited the decision to cancel the MSR program. The team disbanded and dispersed; the knowledge was lost; and MSR technology was wrongly considered a failure for many years.
For those who are interested, here is a copy of the slides I presented at ThEC2011. Many of the videos and audio files related to the Nixon administration nuclear policies are embedded as links in the presentation: