Shock-absorbing device for fuel assembly and fuel assembly housing container

Patent metadata

Field	Value
Publication number	US-9053831-B2
Application number	US-200913062605-A
Country	US
Kind code	B2
Filing date	Aug 25, 2009
Priority date	Nov 28, 2008
Publication date	Jun 9, 2015
Grant date	Jun 9, 2015

Abstract

A fuel assembly 20 is constituted by combining a plurality of fuel rods 21 , holding the fuel rods 21 by a plurality of support grids 22 , and arranging a lower nozzle 24 and an upper nozzle 23 at opposite ends of the fuel rods 21 . A shock-absorbing device 10 for a fuel assembly is fitted to the lower nozzle 24 and the upper nozzle 23 . The shock-absorbing device 10 for a fuel assembly is constituted a nozzle support 12 fitted to a depression 24 U of the lower nozzle 24 and a depression 23 U of the upper nozzle 23 , and a buffer 11 combined with the nozzle support 12 , with stiffness thereof in a longitudinal direction of the fuel rods 21 being equal to or lower than that of the nozzle support 12.

First claim

The invention claimed is:

1. A shock-absorbing device for a fuel assembly including a plurality of fuel rods, the shock-absorbing device comprising:
a first nozzle and a second nozzle including one surfaces, respectively, by which the plurality of fuel rods are sandwiched, the first and second nozzles including other surfaces having a plurality of legs for defining first and second depressions, respectively;
a nozzle support fitted to a center portion of the first depression of the first nozzle, the nozzle support being comprised of iron, aluminum alloy containing boron)(B 10 ), stainless steel, lead, or concrete so that radiation from the fuel assembly is shielded; and
a buffer combined with the nozzle support, the buffer having stiffness in a longitudinal direction of the fuel rods being equal to or less than that of the nozzle support, wherein
the nozzle support and the buffer are arranged in sequence along the longitudinal direction of the fuel rods as separating from the depressions and wherein
the buffer is either one of the followings (a) to (g):
(a) a buffer including a buffer member including a hydrogen-containing resin so as to shield neutron and a casing holding and surrounding the buffer member;
(b) a buffer including a bottom plate and a plurality of plate materials fitted to the bottom plate;
(c) a buffer including a bottom plate and a plurality of rod members arranged with an axial direction being parallel to the longitudinal direction of the fuel rods;
(d) a buffer including a buffer member including a hydrogen-containing resin so as to shield neutron and a casing holding and surrounding the buffer member, the casing being coupled with a pipe for housing the plurality of fuel rods by a coupling member ( 33 );
(e) a buffer including a first buffer that is provided with a depression and contacts the plurality of legs and a second buffer that is provided on the depression and contacts the nozzle support;
(f) a buffer including a first buffer that contacts the plurality of legs and a second buffer that is provided with a salient and contacts the nozzle support at the salient, the first buffer having stiffness in a compression direction lower than that of the second buffer in the compression direction;
(g) a buffer that has a depression and contacts the nozzle support at the depression, the buffer contacting the plurality of legs.

2. The shock-absorbing device for a fuel assembly according to claim 1 , wherein
the first nozzle is arranged on a bottom side of a fuel assembly housing container for transporting the fuel assembly.

3. The shock-absorbing device for a fuel assembly according to claim 1 , wherein
the second nozzle is arranged at an opening side of a fuel assembly housing container for transporting the fuel assembly.

4. A fuel assembly housing container comprising:
a body that is a container with a bottom and houses a fuel assembly in an internal space thereof; and
the shock-absorbing device for a fuel assembly according to claim 1 , which is arranged at least on a bottom of the body.

5. The fuel assembly housing container according to claim 4 , wherein the shock-absorbing device for a fuel assembly according to claim 1 is arranged on a lid fitted to an opening of the internal space.

6. A shock-absorbing device for a fuel assembly including a plurality of fuel rods, the shock-absorbing device comprising:
a first nozzle and a second nozzle including one surfaces, respectively, by which the plurality of fuel rods are sandwiched, the first and second nozzles including other surfaces having a plurality of legs for defining first and second depressions, respectively;
a nozzle support fitted to a center portion of the second depression of the second nozzle, the nozzle support being comprised of iron, aluminum alloy containing boron)(B 10 ), stainless steel, lead, or concrete so that radiation from the fuel assembly is shielded; and
a buffer combined with the nozzle support, the buffer having stiffness combined with the first nozzle and the second nozzle in a longitudinal direction of the fuel rods being equal to or less than that of the nozzle support, wherein
the nozzle support and the buffer are arranged in sequence along the longitudinal direction of the fuel rods as separating from the depressions and wherein
the buffer is either one of the followings (a) to (g):
(a) a buffer including a buffer member including a hydrogen-containing resin so as to shield neutron and a casing holding and surrounding the buffer member;
(b) a buffer including a bottom plate and a plurality of plate materials fitted to the bottom plate;
(c) a buffer including a bottom plate and a plurality of rod members arranged with an axial direction being parallel to the longitudinal direction of the fuel rods;
(d) a buffer including a buffer member including a hydrogen-containing resin so as to shield neutron and a casing holding and surrounding the buffer member ( 11 I), the casing being coupled with a pipe for housing the plurality of fuel rods by a coupling member;
(e) a buffer including a first buffer that is provided with a depression and contacts the plurality of legs and a second buffer that is provided on the depression and contacts the nozzle support;
(f) a buffer including a first buffer that contacts the plurality of legs and a second buffer that is provided with a salient and contacts the nozzle support at the salient, the first buffer having stiffness in a compression direction lower than that of the second buffer in the compression direction;
(g) a buffer that has a depression and contacts the nozzle support at the depression, the buffer contacting the plurality of legs.

7. A shock-absorbing device for a fuel assembly including a plurality of fuel rods, the shock-absorbing device comprising:
a first nozzle and a second nozzle, the first and second nozzles including one surfaces, respectively, by which the plurality of fuel rods are sandwiched and the first and second nozzles including other surfaces having a plurality of legs for defining first and second depressions, respectively;
first and second nozzle supports fitted to a center portion of the first depression of the first nozzle and a center portion of the second depression of the second nozzle, respectively, the first and second nozzle supports being comprised of iron, aluminum alloy containing boron (B 10 ), stainless steel, lead, or concrete so that radiation from the fuel assembly is shielded; and
first and second buffers combined with the first and second nozzle supports, respectively, the first and second buffers having stiffness in a longitudinal direction of the fuel rods being equal to or less than that of the first and second nozzle supports, respectively, wherein
the first nozzle support and the first buffer are arranged in sequence along the longitudinal direction of the fuel rods as separating from the first depression and the second nozzle support and the second buffer are arranged in sequence along the longitudinal direction of the fuel rods as separating from the second depression and wherein
the first and second buffers are selected from either one of the followings (a) to (g):
(a) a buffer including a buffer member including a hydrogen-containing resin so as to shield neutron and a casing holding and surrounding the buffer member;
(b) a buffer including a bottom plate and a plurality of plate materials fitted to the bottom plate ( 11 B);
(c) a buffer including a bottom plate and a plurality of rod members arranged with an axial direction being parallel to the longitudinal direction of the fuel rods;
(d) a buffer including a buffer member including a hydrogen-containing resin so as to shield neutron and a casing holding and surrounding the buffer member, the casin

Assignees

• Saito Yoshiyuki
• Yokoyama Takeshi
• Kishimoto Junichi
• Mitsubishi Heavy Ind Ltd

Inventors

• Saito Yoshiyuki
• Yokoyama Takeshi
• Kishimoto Junichi

Classifications

• G21F9/36

  by packaging; by baling · CPC title

• G21F5/08

  Shock-absorbers, e.g. impact buffers for containers · CPC title

• G21F5/012 Primary

  Fuel element racks in the containers · CPC title