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EP0065697A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Fuel assembly

Assignee: Hitachi Ltd
•
Filing: 1982-05-11
•
Granted: —
•
Expires: 2002-05-11
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Abstract

Abstract In an atomic reactor, gaps are defined between fuel assemblies so that moderators can be inserted. Hence, the nuclear characteristics vary between the central portion and periphery of the fuel assembly so that the local output peaking becomes greater on the periphery of the fuel assembly. The present invention contemplates to make this local output peaking flat by reducing the loading quantity of a nuclear fuel material per fuel rod on the outermost layer of the fuel assembly to be smaller than the loading quantity of the fuel material per fuel rod at the central portion of the fuel assembly. Anyone of the following three constructions can be used for accomplishing this object: (1) The theoretical density of the nuclear fuel material pellets to be inserted into the fuel rod is reduced. (2) The nuclear fuel material pellets to be inserted into the fuel rod is made hollow. (3) The diameter of the fuel rod is reduced.

Inventors

  • 👤 Motoo Aoyama
  • 👤 Kunitoshi Kurihara

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-04 08:20
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/30; G21C3/32; G21C3/326; G21C3/328; G21C7/00; Y; Y02; Y02E; Y02E30/00; Y02E30/30

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 66 words
In a fuel assembly for a reactor having a group of fuel rods aggregated in a predetermined range and loaded into a coolant at the core of the reactor, the improvement wherein the mean value of the loading quantity of the nuclear fuel material per' fuel rod of the fuel rods on the outermost layer is lower than that of the fuel rods at other portions.
Claim 2
Dependent Claim 66 words
In a fuel assembly for a reactor having a group of fuel rods aggregated in a predetermined range and loaded into a coolant at the core of the reactor, the improvement wherein the mean value of the loading quantity of the nuclear fuel material per' fuel rod of the fuel rods on the outermost layer is lower than that of the fuel rods at other portions.
Claim 3
Dependent Claim 43 words
The fuel assembly as defined in claim 1 wherein among the fuel rods on the outermost layer, the enrichment of the fuel rods to be placed at the corners of the fuel assembly is lower than the enrichment of the other fuel rods.
Claim 4
Dependent Claim 33 words
The fuel assembly as defined in claims 1 and 2 wherein the mean enrichment of the fuel rods on the outermost layer is lower than the mean enrichment of the other fuel rods.
Claim 5
Dependent Claim 39 words
The fuel assembly as defined in claims 1, 2 and 3 wherein the loading quantity of the nuclear fuel material per fuel rod is adjusted in accordance with the density of pellets to be inserted into the fuel rod.
Claim 6
Dependent Claim 35 words
The fuel assembly as defined in claims 1, 2 and 3 wherein the loading quantity of the nuclear fuel material per fuel rod is adjusted in accordance with the transverse sectional area of the pellet.
Claim 7
Dependent Claim 25 words
The fuel assembly as defined in claim 5 wherein the transverse sectional area of the pellet is adjusted by the hollow diameter of the pellet.

References Cited (Backward Citations)

FR1312193A Cited
DE1814641A1 Cited
US3844886A Cited
US3652744A Cited
JPS529792A Cited
DE2742940A1 Cited
DE2742939A1 Cited
JPS53109089A Cited

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