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US4491540A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of preparing spent nuclear fuel rods for long-term storage

Assignee: ABB Norden Holding AB
•
Filing: 1982-03-17
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Granted: 1985-01-01
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Expires: 2002-03-17
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Abstract

Abstract Spent fuel rods from a nuclear reactor are enclosed in a body of copper, the fuel rods being embedded in copper powder in a copper container provided with a copper lid. The container with its contents and lid are then subjected to isostatic compression at a pressure and temperature sufficient to form a coherent dense mass unit of the powder, the container and the lid which embeds the fuel rods. The container can be enclosed in a sealed gas-tight capsule prior to the isostatic compression. A preliminary isostatic compression may be conducted at a lower temperature to effect creep deformation of the container, the lid and the powder.

Inventors

  • 👤 Hans Larker
  • 👤 Ragnar Tegman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 18:37
CPC Classifications
G; G21; G21F; G21F5/00; G21F5/005; G21F9/00; G21F9/28; G21F9/34; G21F9/36

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 79 words
A method of preparing spent nuclear fuel rods from a nuclear reactor for long-term storage in a copper container, which method comprises the steps of: embedding the fuel rods in copper powder within the container, closing the container with a copper lid, and subjecting the closed container to hot isostatic compression at a pressure and a temperature sufficient to form the container, the powder and the lid into a coherent mass in which the spent fuel rods are embedded.
Claim 2
Independent Claim 79 words
A method of preparing spent nuclear fuel rods from a nuclear reactor for long-term storage in a copper container, which method comprises the steps of: embedding the fuel rods in copper powder within the container, closing the container with a copper lid, and subjecting the closed container to hot isostatic compression at a pressure and a temperature sufficient to form the container, the powder and the lid into a coherent mass in which the spent fuel rods are embedded.
Claim 3
Dependent Claim 31 words
A method as claimed in claim 1 which includes the further step of enclosing the lidded container in a capsule which is evacuated and sealed prior to effecting the isostatic compression.
Claim 4
Dependent Claim 13 words
A method according to claim 2, in which the capsule is of copper.
Claim 5
Dependent Claim 36 words
A method according to claim 1 or claim 2, in which the hot isostatic compression is carried out at a pressure of at least 10 MPa and at a temperature in the range of 500°-800° C.
Claim 6
Dependent Claim 27 words
A method according to claim 1 or claim 2, in which the fuel rods are spaced-apart from each other in the container by means of spacing elements.
Claim 7
Dependent Claim 25 words
A method according to claim 5, in which the spacing elements consist of the spacers supporting the fuel rods in bundles in the nuclear reactor.
Claim 8
Dependent Claim 14 words
A method according to claim 5, in which the spacing elements are of copper.
Claim 9
Dependent Claim 42 words
A method according to claim 1 or claim 2, in which a region of one of said container and said lid which makes contact, respectively, with one of said lid and said container, comprises a cylindrical surface and an intersecting annular surface.
Claim 10
Dependent Claim 17 words
A method according to claim 8, in which said cylindrical and annular surfaces intersect at right angles.
Claim 11
Dependent Claim 27 words
A method according to claim 1 or claim 2, in which the lid is provided with a part which extends into the container and fits closely therein.
Claim 12
Dependent Claim 37 words
A method according to claim 1 or claim 2, in which surfaces of the lid which confront surfaces of the container, when the lid is closing the container, are textured to improve the seal between these surfaces.
Claim 13
Dependent Claim 22 words
A method according to claim 1, in which said surfaces are textured by an operation selected from grooving, scratching and surface patterning.
Claim 14
Dependent Claim 70 words
A method according to claim 1, in which prior to the isostatic pressing of the container, its contents and the lid at a pressure and a temperature sufficient for forming a coherent mass thereof, the container with its contents and its lid gas-tightly joined to the container, is subjected to an isostatic pressing at a lower temperature for achieving a creep deformation of the container, its contents and the lid.
Claim 15
Dependent Claim 62 words
A method according to claim 2, in which prior to isostatic pressing of the capsule and its contents at a pressure and temperature to form a coherent mass of the container, the powder and the lid, the gas-tight capsule is subjected to an isostatic pressing at a lower temperature for achieving a creep deformation of the container, its contents and the lid.
Claim 16
Dependent Claim 39 words
A method according to claim 13 or claim 14, in which the isostatic pressing for achieving creep deformation is carried out at a pressure of at least 10 MPa and at a temperature in the range of 300°-500° C.

References Cited (Backward Citations)

US3235958A Cited
US4090873A Cited
FR2375695A1 Cited
US4209420A Cited
GB1590108A Cited
JPS54130798A Cited
FR2432752A1 Cited
US4300056A Cited
JPS57960A Cited
GB2076582A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-01-01 1988-07-02 1989-01-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-01-01 1992-07-02 1993-01-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-01-01 1996-07-02 1997-01-01 $7700.00 Window Closed / Lapsed

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