Wednesday, May 5, 2010

Milton Shaw's biggest blunder

We have seen that Milton Shaw's concept of Mature nuclear technology lead him to the mistaken assumption that Light Water power reactors represented a mature technology in the 1960's. A few years later evidence emerged that suggested LWRs to be less safe than Shaw had maintained. This lead to major and expensive revisions of nuclear plants which were already under construction in the early 1970's.

Despite evidence that Shaw's beliefs about Light Water Reactor safety was mistaken, Shaw was to divert funds meant for Light Water Reactor research to LMFBR research in the early 1970's. This Shaw decision, made at a time of rising controversy about nuclear safety, was one of his many errors in judgement concerning the breeder reactor program. However, Shaw was hardly the only person to commit judgement errors with respect to the sodium cooled breeder reactor.

As early as 1945 Harry Soodak and Eugene Wigner published the first design of a sodium-cooled breeder reactor. Wigner realized that the LMFB concept had a number of flaws that would make it expensive. First sodium coolant can be dangerous. Sodium is flammable when it comes into contact with either air or water. This is not a deadly flaw, but preventing sodium contact with air or water is likely to increase reactor costs. A second feature of a sodium moderated breeder is that fast neutron reactors require far more fissile materials than thermal neutron reactors do. Less fissile material means a smaller core, and a smaller core lowers cost means a smaller containment building, and the small size of both means lower costs.

A third flaw of a sodium cooled reactor is that high neutron cross section fission products will build up in the core. The high neutron cross section fission products then capture neutrons creating two undesirable problems. First they can make the reactor more difficult to control. Secondly, captured neutrons are unavailable for breeding.

A fourth flaw of a a sodium cooled breeder is that fuel and blanket rods must be periodically be withdrawn for reprocessing. Fissionable fuel is gradually burned up in fuel rods, while newly produced fissionable fuel in blankets must be recovered and redistributed in the reactor core. In some solid fuel reactors, such fuel recovery requires reactor shut down, sometimes for extended periods of time. The reprocessing of LMFBR fuel rods is complicated if the fuel is in the form of a uranium dioxide ceramic pellet. LMFBR uranium dioxide fuel reprocessing is both complex and expensive. The cost of LMFBR fuel reprocessing adds significantly to the overall cost of LMFBR generated electricity.

The LMFBR of was not a mature design and indeed it is debatable if the classic oxide fuel LMFBRs of 2010 represent a mature design. Even some advocates of liquid sodium cooled fast breeder integral fast reactors would view the earlier LMFBR as being less practical and less safe, and probably more expensive than the IFR. LMFBR developmental programs in France, the United Kingdom, Germany and the United States, were shut down for political and economic reasons. An accident in the Japanese Monju reactor lead to what has amounted to a 15 years setback in the Japanese fast breeder program. Russian, and Indian MFBR programs are still viable, but produce or are expected to produce power at a price that is not competitive with conventional nuclear power plants. The Indian FPR program has grown significantly in expense, while its start up dates has slipped. FBPR problems are allegedly related to site problems, and not due to technology related set backs. But since more Indian FBRs are being ordered the size of the Indian fast Breeder Reactor premium will probably soon become clear. In addition the Indians have a fairly complex plan to transition to production of larger IFR type fast breeders during the next decade. The Russian BN-600 is known to produce electricity at a significantly higher cost than the cost of electricity from conventional reactors.

FBR development programs in Japan, the United States, and France experienced significant setbacks due to reactor accidents. Thus in 2010 it is critics of FBRs can point to reliability issues, and high costs as characteristic of FBR technology. It would be difficult to argue that the operating history of Fast Breeders inspires public confidence in the technology, and their relatively high costs still raise questions about their marketability.

in the case of the IFR we have a track record based on a single prototype. IFB proponents have made conflicting statements about anticipated IFR breeding ratios, optimal size, and power output. While IFR proponents have stated that its capital costs will be lower than the cost of conventional reactors, they have not provided more illumination about anticipated costs, and thus there is little support for the low cost contention. Discussions of the electrochemical fuel reprocessing process, suggests that it does not separate fission products and trans uranium isotopes with high precision. This leaves open the question of how much plutonium goes into the waste stream. Clearly then IFR technology is far from mature.

Thus retrospectively we must judge Milton Shaw's belief that LMFBR technology was mature. Nor can a case be made that the public held great confidence in LMFBR technology at the time of WASH-1126, WASH-1184, and WASH-1222, critical documents that advanced the public confidence claim. The Fermi I commercial fast breeder prototype suffered a partial core meltdown in 1966. During a repair attempt, the Fermi I reactor experienced a coolant fire, and despite continued repair attempts, that reactor was never fully operational again. The AEC denied Fermi I's license renewal application in 1972. Eventually the Fermi I experience became the topic for an anti-nuclear potboiler, "We Almost Lost Detroit." The argument that in 1972 the history of sodium cooled fast reactors would inspire public confidence in their safety is extraordinarily obtuse.

Alvin Weinberg argues that the Molten Salt Reactor lost the breeder race because it was late to the gate. It was, Weinberg and ORNL did not begin to inform the AEC and the scientific community about the breeding potential of the MSR reactor until about 1959. In adition, for much of the 1950's ORNL research efforts were going into another potential breeder technology. the Aqueous Homogeneous Reactor. It was only after an AEC committee reported that the MSR was a more promising route to breeding that ORNL terminated Aqueous Homogeneous Reactor research. Yet by the late 1960's ORNL Researchers had produced evidence that the Molten Salt Breeder Reactor might be a formidable competitor for the LMFBR. Indeed, the safety issues related to the use of metalic sodium as a fast breeder coolant, were completely absence in the Molten Salt Reactor. When the molten salt reactor coolant leaked it froze preventing further leakage. then LMFBR coolant leaked, it burned, creating instant staff panic. ORNL also provided some evidence that MSBR costs would be competitive with conventional nuclear power plants. Far from being an immature technology, MSR technology had matured at ORNL between 1960 and 1969 to the extent that in many respects its potential compared favorably with that of the LMFBR. Why then did Milton Shaw and the AEC prefer he LMFBR? Alvin Weinberg states that Milton Shaw was following orders. But who did shaw perceive giving orders directing him to favor the LMFBR over the MSBR? In the past I have suggested it was Hyman Rickover. But AEC Chairman Glen Seaborg may be a better candidate. Seaborg had played a major role in developing chemical processes to recover plutonium from production reactor fuel during the World War Ii Manhattan Project. Seaborg was a chemist, not a reactor specialist. The LMFBR would produce a lot of plutonium, and Seaborg felt comfortable with plutonium.

Susan M. Stacy notes,
Glenn Seaborg, a Nobel laureate chemist who as part of the Manhattan Project had made the world’s first plutonium, became chairman of the AEC in 1961. Seaborg was completely committed to the “plutonium economy” of the breed- er reactor. He told President Kennedy in 1962 that the way for the United States to maintain nuclear reactor tech- nological preeminence in the world was to perfect the breeder reactor as a safe and commercially viable source of energy. He even suggested that plutoni- um would eventually replace gold as the standard of the monetary system.
From the start of Shaw's AEC career, he must have been aware hat promoting his boss Glen Seaborg wanted him to promote the LMFBR. Stacey reports,
Shaw spent 1965 considering how best to redirect the AEC’s breeder program and then decided, with AEC approval, to manage it directly from his own office.
Thus a case can be made that Glen Seaborg long standing attachment to plutonium was behind Shaw's decision to favor the LMFBR over the MSBR. Yet it was an extremely bad decision. In 1972 not enough was known about either the MSBR or the LMFBR reactor to justify a choice to focus on it to the exclusion of the other, but enough was known to justify the argument that the LMFBR might be the less desirable of the two breeder concepts. Potentially the MSBR might well to be the lower cost and technologically more desirable of the two potions. And by 1972, the fact that the MSBR did not produce plutonium might turn out to be a plus rather than a minus, but by that time, Milton Shaw had already placed his bet.

From the end of World War II to 2009 the United States government spent about 25 billion 2009 dollars on LMFBR research. In contrast, it spent less than 1 billion 2009 dollars on MSR research. The United States has no commercial product to show for the $25 billion it spent on lMFBR research. Had that much money been spent on MSBR research would this have been the case?

Shaw's choice of the LMFBR was an expensive mistake, one which haunts our energy choices to this day. Had American nuclear research focus been placed on the MSBR, rather than the LMFBR, it is quite possible that the world would have an energy solution it needs today. In terms of its consequence for the human future, Milton Shaw's choice to back the LMFBR had serious and highly undesirable consequences that are still being plaid out.

1 comment:

Alex P. said...

" A second feature of a sodium moderated breeder is that fast neutron reactors require far more fissile materials than thermal neutron reactors do. "

I think it's sodium *cooled* breeder...


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