Cooling system for stored nuclear fuel

Patent metadata

Field	Value
Publication number	US-2016019990-A1
Application number	US-201414773470-A
Country	US
Kind code	A1
Filing date	Feb 21, 2014
Priority date	Mar 14, 2013
Publication date	Jan 21, 2016
Grant date	—

Abstract

A cooling system for cooling nuclear fuel stored in a pool that can prevent a lowering of water level resulting from evaporation is provided. The cooling system cools the nuclear fuels 3 stored in a bottom of the pool 2 filled with cooling water 4. The cooling water 4 comprises an upper layer formed in a water surface as side in which a density of the cooling water 4 is low, a lower layer formed in the bottom side of the pool 2 in which a density of the cooling water 4 is high, and an intermediate layer in which a density of the cooling water 4 is in between those of the cooling waters 4 in the upper layer and the lower layer. A lower end 5 a of a heat pipe 5 adapted to transport heat in the form of latent heat of working fluid is situated at a site where the heat is exchanged with the cooling water 4, and an upper 5 b end of the heat pipe 5 is exposed to external air. The nuclear fuel 3 is stored within the lower layer.

First claim

1 . A cooling system for cooling nuclear fuel stored in a bottom of a pool filled with solution,
wherein the solution comprises an upper layer formed in a water surface side in which a density of the solution is low, a lower layer formed in the bottom side of the pool in which a density of the solution is high, and an intermediate layer in which a density of the solution is in between those of the solutions in the upper layer and the lower layer, wherein a lower end of a heat pipe adapted to transport heat in the form of latent heat of working fluid is situated at a site where the heat is exchanged with the solution, and an upper end of the heat pipe is exposed to external air, and wherein the nuclear fuel is stored within the lower layer.

2 . The cooling system for cooling nuclear fuel as claimed in claim 1 ,
wherein the solution forming the lower layer includes brine prepared by dissolving salt in water having high concentration; wherein the solution forming the intermediate layer includes brine prepared by dissolving salt in water having concentration lower than that of the brine forming the lower layer; and wherein the solution forming the upper layer includes brine prepared by dissolving salt in water having concentration lower than that of the brine forming the intermediate layer, or by water that does not contain salt.

3 . The cooling system as claimed in claim 1 , wherein the density of the solution forming the lower layer of a case in which a temperature thereof is raised by heat of the nuclear fuel is higher than that of the solution forming the upper layer and having low density.

4 . The cooling system as claimed in claim 1 , wherein the lower end portion of the heat pipe is situated within the lower layer in the pool.

5 . The cooling system as claimed in claim 1 , wherein one of the lower end portion of the heat pipe is situated inside of a frame of the pool.

Assignees

• Fujikura Ltd

Inventors

• Mochizuki Masataka
• Randeep Singh
• Matsuda Masahiro

Classifications

• G21C19/07

  Storage racks; Storage pools · CPC title

• G21C19/08

  Means for heating fuel elements before introduction into the core; Means for heating or cooling fuel elements after removal from the core · CPC title

• F28D2015/0216

  having particular orientation, e.g. slanted, or being orientation-independent · CPC title

• G21F5/10

  Heat-removal systems, e.g. using circulating fluid or cooling fins · CPC title

• G21C19/32 Primary

  Apparatus for removing radioactive objects or materials from the reactor discharge area, e.g. to a storage place; Apparatus for handling radioactive objects or materials within a storage place or removing them therefrom (disposal of waste material G21F9/00) · CPC title