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US4101375A
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Isotopically enriched helium-4
Assignee: Individual
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Filing: 1975-11-17
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Granted: 1978-07-18
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Expires: 1995-11-17
Abstract
Abstract Isotopically enriched helium-4, that is to say, helium-4 which is low in helium-3, is useful as a nuclear reactor coolant. It is produced from liquefied natural gas source helium by removing helium-3 therefrom.
Inventors
- 👤 Leo Garwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:36
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0228; F25J3/028; F25J3/029; B; B01; B01D; B01D59/00; B01D59/02; B01D59/04; C; C01; C01B; C01B23/00; F25J1/00; F25J1/006; F25J1/0062; F25J1/0065; F25J1/02; F25J1/0243; F25J1/0244; F25J1/0245; F25J1/0249; F25J1/025; F25J3/0204; F25J3/0209; F25J3/08; G; G21; G21C; G21C15/00; G21C15/28; F25J2200/00; F25J2200/02; F25J2200/50; F25J2215/00; F25J2215/30; F25J2220/00; F25J2220/90; Y; Y02; Y02E; Y02E30/00; Y02E30/30; Y10; Y10S; Y10S376/00; Y10S376/90; Y10S376/904; Y10S62/00; Y10S62/919
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
46 words
A method of producing isotopically enriched helium-4 which comprises removing by distillation helium-3 from liquefied natural gas source helium, said removal being accomplished at a temperature between about 4.2° K and about 5.1° K, and at a pressure equal to the equilibrium pressure of the system.
Claim 2
Independent Claim
46 words
A method of producing isotopically enriched helium-4 which comprises removing by distillation helium-3 from liquefied natural gas source helium, said removal being accomplished at a temperature between about 4.2° K and about 5.1° K, and at a pressure equal to the equilibrium pressure of the system.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein the removal of helium-3 is accomplished at a temperature between about 4.3° K and about 5.0° K, and at a pressure equal to the equilibrium pressure of the system.
Claim 4
Independent Claim
128 words
A method for more safely and efficiently cooling a high-temperature, gas-cooled nuclear reactor comprising: liquefying natural gas source helium; subjecting the liquefied natural gas source helium to distillation carried out at a temperature of between about 4.2° K and about 5.1° K, and at a pressure equal to the equilibrium pressure of the system, to separate, by such distillation, and through the removal of the helium-3 isotope in the course of the distillation, the liquefied natural gas source helium into an isotopically enriched helium-4 fraction containing less than about 0.17 ppm of helium-3, and an isotopically denuded helium-4 fraction; and circulating at least a portion of the isotopically enriched helium-4 fraction through the high-temperature, gas-cooled nuclear reactor to provide at least a portion of the coolant gas therefor.
Claim 5
Independent Claim
128 words
A method for more safely and efficiently cooling a high-temperature, gas-cooled nuclear reactor comprising: liquefying natural gas source helium; subjecting the liquefied natural gas source helium to distillation carried out at a temperature of between about 4.2° K and about 5.1° K, and at a pressure equal to the equilibrium pressure of the system, to separate, by such distillation, and through the removal of the helium-3 isotope in the course of the distillation, the liquefied natural gas source helium into an isotopically enriched helium-4 fraction containing less than about 0.17 ppm of helium-3, and an isotopically denuded helium-4 fraction; and circulating at least a portion of the isotopically enriched helium-4 fraction through the high-temperature, gas-cooled nuclear reactor to provide at least a portion of the coolant gas therefor.
Claim 6
Dependent Claim
39 words
The process defined in claim 3 wherein the separation is carried out at a temperature between about 4.3° K and about 5.0° K and the helium-3 content of the separated isotopically enriched helium-4 fraction is below about 0.06 ppm.
Claim 7
Independent Claim
132 words
A method for more safely and efficiently cooling a high-temperature, gas-cooled nuclear reactor comprising: subjecting liquefied natural gas source helium to distillation carried out at a temperature of from about 4.2° to a temperature less than the critical temperature of the liquefied natural gas source helium, and at a pressure equal to the equilibrium pressure of the system, to separate, by such distillation, and through the removal of the helium-3 isotope in the course of the distillation, the liquefied natural gas source helium into an isotopically enriched helium-4 fraction containing less than about 0.17 ppm of helium-3 and an isotopically denuded helium-4 fraction; and circulating at least a portion of the isotopically enriched helium-4 fraction through the high-temperature gas-cooled nuclear reactor to provide at least a portion of the coolant gas therefor.
Claim 8
Independent Claim
132 words
A method for more safely and efficiently cooling a high-temperature, gas-cooled nuclear reactor comprising: subjecting liquefied natural gas source helium to distillation carried out at a temperature of from about 4.2° to a temperature less than the critical temperature of the liquefied natural gas source helium, and at a pressure equal to the equilibrium pressure of the system, to separate, by such distillation, and through the removal of the helium-3 isotope in the course of the distillation, the liquefied natural gas source helium into an isotopically enriched helium-4 fraction containing less than about 0.17 ppm of helium-3 and an isotopically denuded helium-4 fraction; and circulating at least a portion of the isotopically enriched helium-4 fraction through the high-temperature gas-cooled nuclear reactor to provide at least a portion of the coolant gas therefor.
Claim 9
Dependent Claim
40 words
The process defined in claim 5 wherein the separation is carried out at a temperature of between about 4.3° K and about 5.0° K, and the helium-3 content of the separated isotopically enriched helium-4 fraction is below about 0.06 ppm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |