A. Alvin Weinberg

Reversing the Tragedy of Alvin Weinberg’s firing as Director of the Oak Ridge National Laboratory

.. if weakness in other [reactor] systems are revealed, I hope that in the second nuclear era, the molten-salt technology will be resurrected.
Alvin M Weinberg: The First Nuclear Era

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The Manhattan Project, was initiated to develop an atomic bomb before the Germans did. The famous physicist, Enrico Fermi, built the first atomic reactor, the Chicago Pile-1, under the Stagg Stadium at the University of Chicago. On December 2,1942, this reactor went critical producing a self-sustaining reaction and demonstrating that it was possible to safely control the energy produced by nuclear fission by raising and lowering graphite rods that adsorbed the excess neutrons in the chain reaction. This event initiated the beginning of the Atomic Age. After the atomic bomb was developed, bringing an end to WWII, attention turned to peaceful uses of atomic energy.

Two types of reactors were in development. The first was the well­ known Light Water Reactor (LWR). This is light water as opposed to heavy water or deuterium. An LWR employs circulating water to keep the reactor from over heating and producing the much feared “melt down.” The second was the less well known Molten Salt Reactor (MSR) developed by Alvin Weinberg, then head of the Oak Ridge National Laboratory (ORNL).

LWRs got a major head start because Admiral Hyman Rickover was pushing this design. He wanted a reactor that could be used in submarines and did not trust having molten salt in a submarine. Once the LWR demonstrated its usefulness in submarines, it became the go-to model for land-based reactors for producing electricity. Enthusiasm for atomic energy generated electricity was running so high that in a 1954 speech Lewis Strauss, then chairman of the United States Atomic Energy Commission said, ”Our children will enjoy in their homes electrical energy too cheap to meter... “ Unfortunately, for reasons outlined below, this never happened.

Now, 5O years plus years later, the disadvantages of the LWRs have become apparent. They include the following list.

  1. Enormously expensive. The typical industrial sized LWR costs about 9-10 billion dollars to build. Nuclear power now, instead of being too cheap to meter is too expensive to finance. The first generation of nuclear power plants proved so costly to build that half of them were abandoned during construction. Those that were completed saw huge cost overruns, which were passed on to utility customers in the form of rate increases. By 1985, Forbes had labeled U.S. nuclear power “the largest managerial disaster in history.”
  2. Long licensing time. The following is an estimate of the time needed to build a LWR in the US: Licensing from the Nuclear Regulatory Commission (NRC) 4 years; Site Prep: 1 year; Construction: 4 or more years, Startup: 6 months Total: 9 years or more years.
  3. Susceptible to disastrous meltdowns. Meltdowns may be due to operator error (Chernobyl, Three Mile Island) or natural disasters such as earthquakes and tsunamis (Fukushima). The achilles heal of LWRs is the requirement of cooling the reactor with water. Since this water has to be circulated weak points include the loss of electrical power for the pumps, pump failure, operator failure by incorrect use the pumps, not to mention massive facility failure as with an earthquake or tsunami.
  4. Radioactive Waste Nuclear reactor waste, mostly spent fuel rods, contains fission products that emit beta and gamma radiation, and actinides that emit alpha particles, some of which have very long half-lives. For example the half life of uranium-234 is 245 thousand years), and neptunium-237 is 2.144 million years). These and other waste products represent a major problem for LWRs. In addition, they only burn a small fraction of the total fuel, further contributing to the problem.
  5. Terrorism. One of the popular reactors was a fast breeder so named because it generated more fissionable material, in the form of plutonium, than it started with. If taken over by a country bent on terrorism and/or the development of its own bomb, this would clearly be a major problem. Even with a reactor that was not a fast reactor, flying a plane or a missile into the reactor would also pose a major danger. In the late 1940’s Enrico Fermi said the following about fast reactors, “It is not clear that the public will accept an energy source that produces this much radioactivity and that can be subject to diversion of material for bombs.” He was correct.

The second type of reactor, the MSR, has NONE of these disadvantages. The details of MSR are given in a separate section: See Molten Salt Reactors.
  1. Expense. A major proposal for MSRs is that they can be produced in small modular sections costing millions rather than billions of dollars. It is also proposed that they can be produced on an assembly line basis similar the that for producing airplanes, with the potential for average construction times of weeks instead of many years.
  2. Long licensing time. It is proposed that since the technology is so different that a separate regulatory commission will be formed and utilized. The smaller size, simpler design, lack of need for a containment dome, minimal radioactive waste and other features the licensing times will be considerably shortened.
  3. Meltdowns. As outlined in the detailed section on MSRs, they are uniquely resistant to meltdowns because they are already in a constant meltdown state - i.e. a Molten Salt Reactor. If there is a loss of electricity or man power or other calamity, a frozen salt plug in the bottom of the reactor melts, allowing molten salt to drain into a buried container, immediately stopping the reactor without requiring any human input.
  4. Radioactive waste. One of the great advantages of MSRs is that they use up 95 plus percent of the fuel and thus leave little radioactive waste, as opposed to LWRs that use less than 5% of the fuel. MSRs can even be used to process and thus eliminate radioactive waste from LWRs.
  5. Terrorism. Since LWRs do not produce materials that can be used in an atomic bomb they eliminate this terrorism aspect. In addition, they are small and housed underground, greatly minimizing the problem of being a target of airplanes or missiles.

The second type of reactor, the MSR, has NONE of these disadvantages. The details of MSR are given in a separate section: See
Molten Salt Reactors. So what was the tragedy referred to above?

Under Weinberg’s leadership the ORNL shifted its focus to the meltdown-proof MSR. A MSR was built and set a record of several years for continuous operation. It was known as the "chemist's reactor" because it was proposed mainly by chemists and used a chemical solution of melted salts containing the uranium, thorium, and/or plutonium. The MSR also afforded the opportunity to change the chemistry of the molten salt while the reactor was operating to remove fission products and add new fuel or change the fuel, all of which is called "online processing”.
Weinberg pushed the MSR because he was concerned with safety issues of the LWR. Tragically, Weinberg was fired by the Nixon administration from ORNL in 1973 after 18 years as the laboratory's director, because he continued to advocate increased nuclear safety and MSRs, instead of the Administration's chosen Fast Breeder Reactors. Weinberg’s firing effectively halted development of the MSR, as it was virtually unknown by other nuclear laboratories and specialists.
(There was a brief revival of MSR research at ORNL as part of the Carter administration's nonproliferation interests, culminating in ORNL-TM-7207, "Conceptual Design Characteristics of a Denatured Molten-Salt Reactor with Once-Through Fueling", by Engel, et al., which is still considered by many to be the "reference design" for commercial molten salt reactors.

Unfortunately for the world, Weinberg’s concern about the safety of LWRs was correct. Because of these problems (see above) the use of atomic energy was limited to a small proportion of the world’s electricity generation. Three Mile Island and Fukushima brought further reactor development to a virtual halt and in some countries, such as Germany, resulted in shutting down the current reactors. If the MSR had been the prevailing reactor, it is likely that it would have replaced coal generated, and later gas generated, production of electricity. This could have prevented many of the problems with global warming and its current and eventual trillions of dollars of damage to the world. The goal of The Comings Foundation is to aid in the reversal of this tragedy.

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