General Electric Company

Barry M Gordon

James H Terhune

Gerald M Gordon

Carl P Ruiz

Randall N Robinson

George E Petersen

William J Marble

A technique for reducing the shadow corrosion effect in zirconium-based alloys caused by .beta.-particles emitted by adjacent components containing one or more elements that emit .beta.-particle flux when activated by neutron capture. The technique entails providing a coating capable of absorbing .beta.-particles, so as to mitigate the adverse effect of .beta.-particle bombardment of a zirconium-based alloy. Preferred coating materials include beryllia, beryllium, tin, zinc, chromium and cadmium. The coatings can be applied to various nuclear reactor structural alloys, such as stainless steel and nickel, platinum, copper, hafnium and yttrium-based alloys containing 0.2 weight percent manganese or more.

Coating for reducing corrosion of zirconium-based alloys induced by      .

A stand-alone low-voltage direct current power supply, for use as a battery, which is energized by the decay of a radioactive isotope in response to neutron capture. During this decay, either .alpha.- or .beta.-particles are emitted. The emitting radioactive isotope should have adequate half-life and no .gamma.-emission. The preferred .beta.-emitting radioisotope is thallium, which decays directly to the ground state of Pb.sup.204 by 763-keV .beta.-decay with no .gamma.-emission. The resulting .beta.-particles are collected to form a current which can be used for various purposes inside a reactor. The preferred .alpha.-emitting radioisotope is americium.

Stand-alone power supply energized by decay of radioactive iostope

A method and an apparatus for electrically suppressing electrochemical potential near highly susceptible components of a boiling water reactor. A small self-powered, electrical device is affixed to the metal area to be protected, which device has the capacity to locally suppress electrochemical potential automatically and continuously without provision for external power supplies, cables, penetrations, or other paraphernalia usually associated with electrical and electronic systems. The result is that components susceptible to intergranular stress corrosion cracking are not as sensitive to the details of the water chemistry flowing over them and do not crack as much, or as rapidly, as presently. The new technique is based on the concept of supplying electrons directly and locally to the sensitized zone(s) of the metal, thereby inhibiting intergranular stress corrosion cracking. The source of the electrons is .beta.-emitting material which is contained in a housing attached to the metal. The electron source is electrically connected to the sensitized zone of the metal. The current of electrons has a magnitude sufficient to compensate for the electrons lost by the metal to electron-accepting fluid in contact with the metal.

Method and apparatus for electro-protection of piping systems and

Deposition of radioactive cobalt on the interior surfaces of a water-cooled nuclear reactor and intergranular stress corrosion cracking are inhibited or substantially prevented by the continuous injection of zinc oxide to the reactor water. The zinc oxide may be prepared in the form of a paste, a slurry, or a preformed aqueous solution.

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Monte Sereno, CA, United States of America

Barry M Gordon