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US4525186A
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Method for producing isotopically enriched helium-4 and use of same as nuclear reactor coolant
Assignee: Southwest Services Inc
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Filing: 1981-09-28
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Granted: 1985-06-25
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Expires: 2001-09-28
Abstract
Abstract Isotopically enriched helium-4, that is, 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 distilling helium-3 therefrom. The coolant is preferably enriched in hydrogen up to about 6 percent by volume to thereby improve the heat transfer characteristics of the coolant, and to reduce the power requirements for circulation of the coolant.
Inventors
- 👤 Leo Garwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:27
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: 10
Claim 1
Independent Claim
30 words
A method of producing isotopically enriched helium-4 which comprises providing a helium feed stock recovered from natural gas, liquefying said feedstock and removing by distillation helium-3 from said liquefied feedstock.
Claim 2
Independent Claim
30 words
A method of producing isotopically enriched helium-4 which comprises providing a helium feed stock recovered from natural gas, liquefying said feedstock and removing by distillation helium-3 from said liquefied feedstock.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein the removal of helium-3 is accomplished at a temperature between about 2.2° K. and about 5.1° K., and at a pressure equal to the equilibrium pressure of the system.
Claim 4
Dependent Claim
35 words
The method of claim 1, wherein the removal of helium-3 is accomplished at a temperature between about 2.3° K. and about 5.0° K., and at a pressure equal to the equilibrium pressure of the system.
Claim 5
Independent Claim
65 words
A method for producing isotopically enriched helium-4 which comprises: providing a helium feedstock recovered from natural gas; liquefying said feedstock; separating by distillation the liquefied feedstock into at least an isotopically enriched helium-4 fraction and an isotopically denuded helium-4 fraction; and passing in heat exchange relation with the liquefied feedstock at least one of said fractions, to recover the refrigeration contained in said one fraction.
Claim 6
Independent Claim
65 words
A method for producing isotopically enriched helium-4 which comprises: providing a helium feedstock recovered from natural gas; liquefying said feedstock; separating by distillation the liquefied feedstock into at least an isotopically enriched helium-4 fraction and an isotopically denuded helium-4 fraction; and passing in heat exchange relation with the liquefied feedstock at least one of said fractions, to recover the refrigeration contained in said one fraction.
Claim 7
Dependent Claim
104 words
A process for cooling a high-temperature gas-cooled nuclear reactor with enhanced safety and efficiency comprising: providing a helium feedstock recovered from natural gas; liquefying said feedstock; separating by distillation the liquefied feedstock into at least an isotopically enriched helium-4 fraction and an isotopically denuded helium-4 fraction; passing in heat exchange relation with the liquefied feedstock at least one of said fractions to recover the refrigeration contained in said one fraction; circulating in said reactor as the coolant, said isotopically enriched helium-4 fraction; and maintaining a concentration of hydrogen gas in said circulating coolant of from about 1 volume percent to about 6 volume percent.
Claim 8
Dependent Claim
104 words
A process for cooling a high-temperature gas-cooled nuclear reactor with enhanced safety and efficiency comprising: providing a helium feedstock recovered from natural gas; liquefying said feedstock; separating by distillation the liquefied feedstock into at least an isotopically enriched helium-4 fraction and an isotopically denuded helium-4 fraction; passing in heat exchange relation with the liquefied feedstock at least one of said fractions to recover the refrigeration contained in said one fraction; circulating in said reactor as the coolant, said isotopically enriched helium-4 fraction; and maintaining a concentration of hydrogen gas in said circulating coolant of from about 1 volume percent to about 6 volume percent.
Claim 9
Independent Claim
30 words
The method comprising: providing a helium feedstock recovered from natural gas, liquefying said feedstock, and producing isotopically enriched helium-4 directly from liquefied feedstock by removal of helium-3 therefrom by distillation.
Claim 10
Independent Claim
30 words
The method comprising: providing a helium feedstock recovered from natural gas, liquefying said feedstock, and producing isotopically enriched helium-4 directly from liquefied feedstock by removal of helium-3 therefrom by distillation.
References Cited (Backward Citations)
US4101375A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |