Light water reactor uranium fuel assembly and operation method of nuclear fuel cycle

Patent metadata

Field	Value
Publication number	US-2022328204-A1
Application number	US-202217587315-A
Country	US
Kind code	A1
Filing date	Jan 28, 2022
Priority date	Mar 23, 2021
Publication date	Oct 13, 2022
Grant date	—

Abstract

According to embodiments, a light water reactor uranium fuel assembly is capable of reducing heating values of both Am-241 and Cm-244, to reduce the amount of generated vitrified waste without using fast reactors. The light water reactor uranium fuel assembly is a light water reactor uranium fuel assembly to be used in a nuclear fuel cycle that extracts. An americium isotope is extracted at the time of reprocessing of spent fuel to be added to a fuel, in which a weight fraction W (unit: wt %) of americium 241 to be added to a fuel heavy metal is in ranges of W<−0.006e2+0.12e−0.43 (enrichment: 5 wt % or more), W<−0.000356e+0.00357 (enrichment: 4.2 wt % or more and less than 5.0 wt %) with respect to an average enrichment of uranium 235 e (unit: wt %) of the fuel assembly.

First claim

What is claimed is:

1 . A light water reactor uranium fuel assembly including a plurality of fuel rods bundled together and is used in a nuclear fuel cycle that extracts an americium isotope at the time of reprocessing of spent fuel to add the extracted americium isotope to a fuel, wherein
a weight fraction W (unit: wt %) of americium 241 to be added to a fuel heavy metal is in ranges of
W<−0.006e 2 +0.12e−0.43 (enrichment: 5 wt % or more),
W<−0.000356e+0.00357 (enrichment: 4.2 wt % or more and less than 5.0 wt %) with respect to an average enrichment of uranium 235 e (unit: wt %) of the fuel assembly.

2 . The light water reactor uranium fuel assembly according to claim 1 , wherein a range of a burnup is 45 GWd/t or more and 60 GWd/t or less.

3 . The light water reactor uranium fuel assembly according to claim 1 , wherein
the light water reactor uranium fuel assembly includes uranium fuel rods containing, as a nuclear fissile material, a uranium isotope and not containing poison and poison rods containing both a uranium isotope and poison, and added americium is contained only in each of the uranium fuel rods.

4 . An operation method of a nuclear fuel cycle that discharges a used fuel assembly obtained by burning a light water reactor uranium fuel assembly including a plurality of fuel rods bundled together in a reactor core to a certain burnup to reprocess the used fuel assembly, the method comprising:
extracting an americium isotope from the used fuel assembly at the time of reprocessing and adding the americium isotope to the light water reactor uranium fuel assembly, wherein a weight fraction W (unit: wt %) of americium 241 to be added to a fuel heavy metal is in ranges of
W<−0.006e 2 +0.12e−0.43 (enrichment of 5 wt % or more),
W<−0.000356e+0.00357 (enrichment of 4.2 wt % or more and less than 5.0 wt %) with respect to an average enrichment of uranium 235 e (unit: wt %) of the fuel assembly.

Assignees

• Toshiba Kk
• Toshiba Energy Systems & Solutions Corp

Inventors

• Hiraiwa Kouji
• Yoshioka Kenichi
• Kimura Rei
• Wada Satoshi
• Sugita Tsukasa

Classifications

• G21C3/32 Primary

  Bundles of parallel pin-, rod-, or tube-shaped fuel elements · CPC title

• G21C19/44 Primary

  of irradiated solid fuel · CPC title

• G21G1/02

  in nuclear reactors (by thermonuclear reactions G21B; conversion of nuclear fuel G21C) · CPC title

• G21C3/326 Primary

  comprising fuel elements of different composition; comprising, in addition to the fuel elements, other pin-, rod-, or tube-shaped elements, e.g. control rods, grid support rods, fertile rods, poison rods or dummy rods · CPC title

• G21C3/30

  Assemblies of a number of fuel elements in the form of a rigid unit · CPC title