US4147938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire resistant nuclear fuel cask
Assignee: United States Department of Energy
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Filing: 1978-02-07
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Granted: 1979-04-03
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Expires: 1998-02-07
Abstract
Abstract The disclosure is directed to a fire resistant nuclear fuel cask employing reversibly thermally expansible bands between adjacent cooling fins such that normal outward flow of heat is not interfered with, but abnormal inward flow of heat is impeded or blocked.
Inventors
- 👤 Richard C. Heckman
- 👤 Marvin Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:22
CPC Classifications
G; G21; G21F; G21F5/00; G21F5/06; G21F5/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
150 words
A fire resistant cask for transportation and storage of radioactive material comprising: an inner container for containing said radioactive material, a layer of gamma and neutron radiation shielding materials surrounding said inner container, an outer container surrounding said layer and inner container, a plurality of spaced apart heat conducting fins projecting outwardly from said outer container, and heat-expansible movable wall means intermediate said spaced apart fins substantially bridging the space between the fins with intermost surfaces at all times having substantial and direct exposure to the atmosphere, disposed closely adjacent to outermost surface of said outer container and the base of said fins during normal dissipation of heat through said fins from the inner container and reversibly movable upon subjection to high exterior temperature to a position adjacent outer extremities of said fins to house the fins against heat flow from the atmosphere through the fins to said outer container.
Claim 2
Dependent Claim
150 words
A fire resistant cask for transportation and storage of radioactive material comprising: an inner container for containing said radioactive material, a layer of gamma and neutron radiation shielding materials surrounding said inner container, an outer container surrounding said layer and inner container, a plurality of spaced apart heat conducting fins projecting outwardly from said outer container, and heat-expansible movable wall means intermediate said spaced apart fins substantially bridging the space between the fins with intermost surfaces at all times having substantial and direct exposure to the atmosphere, disposed closely adjacent to outermost surface of said outer container and the base of said fins during normal dissipation of heat through said fins from the inner container and reversibly movable upon subjection to high exterior temperature to a position adjacent outer extremities of said fins to house the fins against heat flow from the atmosphere through the fins to said outer container.
Claim 3
Dependent Claim
21 words
The fire resistant cask of claim 1 wherein the movable wall means comprises a plurality of bimetallic bands encircling said cask.
Claim 4
Dependent Claim
45 words
The fire resistant cask of claim 2 wherein each bimetallic band is curved and comprises an inner strip of metal having a higher linear coefficient of thermal expansion bonded along a side to an outer strip of metal having a lower coefficient of thermal expansion.
Claim 5
Dependent Claim
36 words
The fire resistant cask of claim 3 wherein the outer strip metal is an iron-nickel-cobalt alloy, the inner strip metal is an iron-chrome-nickel alloy, and said bonding is by spot welding at intervals along said strips.
Claim 6
Dependent Claim
30 words
The fire resistant cask of claim 1 wherein the movable wall means comprises a plurality of metallic bands comprised of an alloy with thermally recoverable and reversible pseudo-plastic strain behavior.
Claim 7
Dependent Claim
20 words
The fire resistant cask of claim 1 wherein means is provided for limiting outward movement of said movable wall means.
Claim 8
Dependent Claim
23 words
The fire resistant cask of claim 6 wherein the limiting means comprises a plurality of pins adjacent the outer extremities of said fins.
Claim 9
Dependent Claim
26 words
The fire resistant cask of claim 6 wherein the limiting means comprises projections adjacent the outer extremities of said fins extending over said movable wall means.
Claim 10
Dependent Claim
37 words
The first resistant cask of claim 1 wherein the cask is characterized by fire survivability of at least about 800° C. fire for about 30 minutes without structural damage and reestablishment of internal cooling without human intervention.
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) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |