Stabilized in-vessel direct current source
AssigneeGeneral Electric Company
InventorJames Howard Terhune
Life of this patent
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AssigneeGeneral Electric Company
InventorJames Howard Terhune
Estimating the term…
A method for stabilizing direct current generated by neutron activation of a plurality of interconnected .beta.-emitter (nuclear decay electron) cells, which are placed in a specific position in the out-of-core region of a light water nuclear reactor. The method entails a synergistic combination of neutron-absorbing isotopes, in specific relationship to each other, the amount of each absorber and their respective locations in the neutron flux field being chosen to render the total current-time characteristic substantially constant over a significant number of reactor full-power-years. The method enhances the current output and lifetime of the current generator by greatly deferring burn-up of the neutron absorbers. If configured as a DC voltage source for powering radiation-hardened, high-temperature integrated circuitry contained in the reactor pressure vessel, voltage regulation circuitry is not necessary. Typically, the useful lifetime is rendered independent of output current and can be extended indefinitely, thereby greatly reducing replacement costs.
A neutron-activatable current source comprising:
A neutron-activatable current source comprising a multiplicity of current-generating cells arranged as layers in a pack and a metallic collector structure surrounding each of said cells and separated therefrom by electrically insulating material, wherein each of a first predetermined number of successive cells in said pack comprises a first stable isotope material, each of a second predetermined number of successive cells in said pack comprises a second stable isotope material different than said first stable isotope material, and each of a third predetermined number of successive cells in said pack comprises a third stable isotope material different than said first and second stable isotope materials, wherein said first stable isotope material has a first property of capturing neutrons from a neutron flux and being activated by neutron capture to a radioactive state having a subsequent decay chain during which at least a first .beta.-particle is emitted to produce a current having a first current-time characteristic, said second stable isotope material has a second property of capturing neutrons from a neutron flux and being activated by neutron capture to a radioactive state having a subsequent decay chain during which at least a second .beta.-particle is emitted to produce a current having a second current-time characteristic, and said third stable isotope material has a third property of capturing neutrons from a neutron flux and being activated by neutron capture to a radioactive state having a subsequent decay chain during which at least a third .beta.-particle is emitted to produce a current having a third current-time characteristic, wherein said first, second and third current-time characteristics are such that the sum of said first, second and third currents over time has greater stability than any one of said first, second and third currents alone.
Dependencies are inferred from the claim text.