Sunday, December 22, 2013


An Urban Legend

In 1955 I moved from New York with my wife and child to Los Angeles.  On November 15 of that year I started working at a division of one of the aircraft companies, North American Aviation, called Atomics International, often abbreviated as AI.  The purpose of this new division was to establish a foothold for the parent company in the new field of nuclear reactor power.  Nuclear power was touted at the time as being “clean” power.  Nuclear power stations did not emit black soot, oxides of carbon and sulfur, and radioactive material that occurs naturally in coal.

The company secured a number of contracts for developing types of power reactor.  Many of these contracts dealt with portable power units for military use.  These contracts developed information that was classified.  Another government contract was for a prototype reactor in which the coolant was sodium rather than water.  Coolant is the fluid that extracts heat from the fissioning fuel elements and delivers it to a rather conventional power unit through a heat exchanger.  The advantages of sodium rather than water were based on the fact that sodium remains a liquid from its melting point at 97o C to above 1,000o C.  Since it could operate at such a high temperature, the power plant would have a higher Carnot efficiency than one in which water was used to transfer the heat.  In addition to improved thermodynamic efficiency, a sodium cooled reactor had no need for pressure containment.  All parts of the reactor operated at atmospheric pressure.  Only the steam produced in the final heat exchanger operated at high pressure.

The disadvantages of using sodium relate to the chemical and physical properties of the element.  It’s chemically very reactive.  Air, and especially oxygen and water vapor, must be kept away from the liquid sodium.  In addition it has a negative reactivity coefficient with respect to the generation of neutrons.  It absorbs them and the reaction produces radioactive NA24 which decays to magnesium.  Because it absorbs neutrons, any gap or bubble in the sodium in close contact with the uranium fuel produces a slight increase in the efficiency of producing neutrons.  If a sodium cooled reactor suddenly lost all its coolant, the reactor would start a power excursion as well as experiencing an immediate rise in temperature of the fuel.  A different effect occurs with a water-cooled reactor.  Water absorbs few neutrons and also is a good moderator.  Loss of water causes a power reduction in such a reactor.  Of course, the fuel elements get very hot, just as in the case of a sodium reactor with loss of coolant.

Atomics International built the Sodium Reactor Experiment (SRE) at the Rocketdyne-AI Field Test Station in the Simi Hills between Los Angeles and Simi Valley.  The reactor began operation to demonstrate its ability to support a power plant in about 1957.  In 1959 the reactor had an accident that resulted in damage to 13 of the 42 fuel elements.  There are numerous reports written at the time about various aspects of the accident.  These reports state:

From these reports that I have read, I conclude that the accident to the SRE did not rise to the level at which one would say that there was a “melt-down.”  That term has been applied to certain other reactor accidents, particularly at Three Mile Island in Pennsylvania and a Chernobyl in Ukraine.  In those cases the reactor was cooled with water and the water boiled off and left the core with no coolant.  As a result, there was enough heat not only to damage the fuel elements but also the coolant tubes that they were in.  The result was a twisted mass of partly melted tubing, extensive release to the environment of radioactive fission products, and a mess that could only be dealt with by burying it.  None of this happened to the SRE.

In spite of what I’ve just written, there is a persistent belief among some people that there was a melt-down, a large release of radioactive material, and consequent increase in people living within a few miles of the site experiencing cancers.  Since the presumed melt-own is not reported in any official or responsible document, this belief is supported by a presumption that the government and the contractors involved (AI, Department of Energy, Defense Department) are “covering up” the truth.

I have a problem.  How do I go about convincing any of these melt-down believers that there was no melt-down and no cover-up?  

Saturday, December 07, 2013


War with Iran?

A few minutes ago I read an alarming e-mail from a member of  Republicans in the House are putting together legislation that would effectively scuttle President Obama's plans to achieve a diplomatic solution to the problem with Iran.  The law would impose conditions on any settlement that Iran would not accept.  These Republicans would prefer a war with Iran rather than a negotiated settlement.

If this proposed law were enacted by the House, even if the Senate did not concur, it would amount to a vote of no confidence in the President.  It would indicate to the Iranian government that the Americans are not serious about achieving an agreement by negotiation and instead want an imposed settlement.  Our experience with the present regime in Iran indicates that they would simply abandon all negotiations and continue their work toward building their own nuclear weapon.

The American public is tired of war.  Our recent wars have mostly not been successful.  We fought in Viet Nam to prevent that country from becoming ruled by communists.  We failed.  We fought a short war with Iraq over Kuwait and oil.  I  guess we had some limited success with that.  We fought wars in Afghanistan and Iraq and did not achieve our stated objectives in either case.  How can we imagine that we would be successful in Iran?

Realistically the Republican move in the House is not so much a desire to derail any hope of a peaceful settlement with Iran but rather a way of discrediting a President that most Republicans hate with passion.  It's a violation of an ancient rule in American politics: Partisan politics stops at the water's edge.  The Republicans are set on breaking that rule.

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