US4175002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear fuel pellet with oppositely bottomed holes
Assignee: Toshiba Corp
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Filing: 1977-09-02
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Granted: 1979-11-20
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Expires: 1997-09-02
Abstract
Abstract A nuclear fuel pellet is made of a sintered, ceramic nuclear fuel mass and has a cylindrical configuration with a pair of opposite bottomed holes centrally provided one at each end. The bottomed holes are convergent toward their bottoms and each have a U-shaped cross-section. A ratio of the diameter of the opening to the depth of the bottom hole is smaller than unity. The nuclear fuel element is free from defects such as cracks, easy to manufacture and capable of reducing a PCMI (a pellet-clad casing mechanical interaction).
Inventors
- 👤 Toyoji Wada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:15
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/02; G21C3/28; G21C3/04; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
65 words
A nuclear fuel pellet made of a sintered ceramic nuclear fuel mass and having a cylindrical configuration with a pair of opposite bottomed holes centrally provided one at each end, said bottomed holes being convergent toward their bottoms and each having a U-shaped cross-section, in which a ratio of the diameter of the opening to the depth of the bottomed holes is smaller than unity.
Claim 2
Dependent Claim
65 words
A nuclear fuel pellet made of a sintered ceramic nuclear fuel mass and having a cylindrical configuration with a pair of opposite bottomed holes centrally provided one at each end, said bottomed holes being convergent toward their bottoms and each having a U-shaped cross-section, in which a ratio of the diameter of the opening to the depth of the bottomed holes is smaller than unity.
Claim 3
Dependent Claim
35 words
The nuclear fuel pellet according to claim 1, in which said sintered mass has shallow plate-like dimples provided one at each end, said convergent bottomed holes being provided at the central portions of the recesses.
Claim 4
Dependent Claim
42 words
The nuclear fuel pellet according to claim 2, in which each of said convergent bottomed holes includes and edge portion located at the intersection of said convergent bottomed hole and said shallow plate-like dimple and wherein said edge portion is curvilinearly formed.
Claim 5
Dependent Claim
20 words
The nuclear fuel pellet according to claim 1, in which the peripheral end edges of the sintered mass are chamfered.
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) | 1982-11-19 | 1983-05-21 | 1983-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-19 | 1987-05-21 | 1987-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-19 | 1991-05-21 | 1991-11-20 | $7700.00 | Window Closed / Lapsed |