US3909617A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radioisotopic heat source
Assignee: United States Department of Energy
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Filing: 1974-05-30
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Granted: 1975-09-30
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Expires: 1994-05-30
Abstract
Abstract A radioisotopic heat source and method for a long life electrical generator. The source includes a mixture of plutonium dioxide shards and yttrium or hafnium enclosed within a container of a particular tantalum-tungsten-hafnium alloy, all being enclosed in a nickel alloy outer container, and subjected to a heat treatment of from about 1570K to about 1720K for about 1 hour.
Inventors
- 👤 Gary J Jones
- 👤 James E Selle
- 👤 Paul E Teaney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:56
CPC Classifications
G; G21; G21H; G21H1/00; G21H1/10; G21H1/103; G21G; G21G4/00; G21G4/04; G21G4/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
107 words
Method for producing a radioisotopic heat source comprising mixing from about 96.8 to 92.9 w/o plutonium dioxide shards of from about 50 to 500 micrometers in size with from about 3.2 to 7.1 w/o of yttrium getter material; sealingly enclosing said mixture in a first container comprising about 90 w/o Ta, 8 w/o W, 2 w/o Hf alloy; heating said first sealed container and mixture to a temperature of from about 1570K to about 1720K for about one hour; and thereafter nesting and sealingly enclosing said first container in a second container comprising about 55% Ni, 16% Cr, 16% Mo, 4% W, 5% Fe, 2.5% Co alloy.
Claim 2
Dependent Claim
107 words
Method for producing a radioisotopic heat source comprising mixing from about 96.8 to 92.9 w/o plutonium dioxide shards of from about 50 to 500 micrometers in size with from about 3.2 to 7.1 w/o of yttrium getter material; sealingly enclosing said mixture in a first container comprising about 90 w/o Ta, 8 w/o W, 2 w/o Hf alloy; heating said first sealed container and mixture to a temperature of from about 1570K to about 1720K for about one hour; and thereafter nesting and sealingly enclosing said first container in a second container comprising about 55% Ni, 16% Cr, 16% Mo, 4% W, 5% Fe, 2.5% Co alloy.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said getter material comprises chips of about 3 by 3 by .25 mm in size.
Claim 4
Dependent Claim
46 words
The method of claim 1 including, nesting said first container in an additional container of the same alloy as said first container, and subjecting both said first and additional containers to said heating, and nesting and sealingly enclosing said additional container concomitantly with said first containers.
Claim 5
Dependent Claim
55 words
The method of claim 1 including, subsequent to inserting said fuel mixture into said first container, inserting an interfitting retainer member of said first container alloy into said first container to wipe said fuel mixture from interior surfaces of the first container and retain the same therein, and provide a void above said retainer member.
Claim 6
Dependent Claim
98 words
A RADIOISOTOPE HEAT SOURCE COMPRISING AN OUTER SEALED CONTAINER OF ABOUT 55 NI, 26% MO, 4% W, 5% FE, 2.5% CO ALLOY AN INNER CONTAINER OF ABOUT 90 W/O TA, 8 W/O HF ALLOY NESTED INSIDE SAIDOUTER CONTAINER AND A MIXTURE OF FROM ABOUT 96.9 W/O PLUTONIUM DIOXIDE SHARDS WITH A YTTRIUM GETTING AT LEAST PARTIALLY FILLING SAID INNER CONTAINERR, INNER WALLS OF SAID INNER CONTAINER EMBODYING THE ENHANCED CHARACTERISTICS RESULTING FROM SUBJECTION OF SAID INNER CONTAINER AND SAID MIXTURE TO HEATING TO TEMPERATURE OF FROM ABOUT 1570K TO ABOUT 1720K FOR A PERIOD OF ABOUT 1 HOUR
Claim 7
Dependent Claim
98 words
A RADIOISOTOPE HEAT SOURCE COMPRISING AN OUTER SEALED CONTAINER OF ABOUT 55 NI, 26% MO, 4% W, 5% FE, 2.5% CO ALLOY AN INNER CONTAINER OF ABOUT 90 W/O TA, 8 W/O HF ALLOY NESTED INSIDE SAIDOUTER CONTAINER AND A MIXTURE OF FROM ABOUT 96.9 W/O PLUTONIUM DIOXIDE SHARDS WITH A YTTRIUM GETTING AT LEAST PARTIALLY FILLING SAID INNER CONTAINERR, INNER WALLS OF SAID INNER CONTAINER EMBODYING THE ENHANCED CHARACTERISTICS RESULTING FROM SUBJECTION OF SAID INNER CONTAINER AND SAID MIXTURE TO HEATING TO TEMPERATURE OF FROM ABOUT 1570K TO ABOUT 1720K FOR A PERIOD OF ABOUT 1 HOUR
Claim 8
Dependent Claim
29 words
The heat source of claim 5 wherein said containers include a hollow cylindrical portion terminating in an arcuate shaped end and a planar end welded to said cylindrical portion.
Claim 9
Dependent Claim
33 words
The heat source of claim 5 including an additional container of about 90 w/o Ta, 8 w/o W, 2 w/o Hf alloy nested inside said outer container intermediate said inner and outer containers.
Claim 10
Dependent Claim
50 words
The heat source of claim 7 wherein said mixture fills all of the arcuate shaped end and part of said cylindrical portion of said inner container and includes a retainer member of 90 w/o Ta, 8 w/o W, 2 w/o Hf alloy interfitting into said cylindrical portion against said mixture.
Claim 11
Dependent Claim
62 words
The heat source of claim 8 for use in a thermoelectric generator having a lifetime of about 16 years wherein said mixture includes about 12 grams of plutonium, said outer container has a wall thickness of about .5 mm, said intermediate container has a wall thickness of about 1.0 mm, and said inner container has a wall thickness of about .5 mm.
Claim 12
Dependent Claim
23 words
The heat source of claim 5 wherein said getter material comprises chips of about 3 mm by 3mm by .25 mm in size.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |