Rack for underwater storage of spent nuclear fuel

Abstract

A fuel rack for nuclear fuel assemblies includes a base plate and an array of cells for holding fuel assemblies. The array of cells includes: a plurality of first slotted plates slidably interlocked with one another to form a top portion of the array of cells, the plurality of first slotted plates formed of a first material; a plurality of second slotted plates slidably interlocked with one another to form a middle portion of the array of cells, the plurality of second slotted plates formed of a second material, the first and second materials being metallurgically incompatible; and a plurality of third slotted plates slidably interlocked with one another to form a bottom portion of the array of cells, the plurality of third slotted plates formed of the first material and connected to a top surface of the base plate.

What is claimed is: 
     
         1 . A fuel rack for nuclear fuel assemblies, the fuel rack comprising:
 a base plate; and   an array of cells for holding fuel assemblies, the array of cells comprising:
 a plurality of first slotted plates slidably interlocked with one another to form a top portion of the array of cells, the plurality of first slotted plates formed of a first material; 
 a plurality of second slotted plates slidably interlocked with one another to form a middle portion of the array of cells, the plurality of second slotted plates formed of a second material, the first and second materials being metallurgically incompatible; and 
 a plurality of third slotted plates slidably interlocked with one another to form a bottom portion of the array of cells, the plurality of third slotted plates formed of the first material and connected to a top surface of the base plate. 
   
     
     
         2 . The fuel rack according to  claim 1 , further comprising a plurality of tie members, each tie member affixed to each of the top and bottom portions of the array of cells. 
     
     
         3 . The fuel rack according to  claim 2 , wherein each tie member is welded to the top and bottom portions of the array of cells. 
     
     
         4 . The fuel rack according to  claim 2 , wherein each tie member is located on an external surface of the array of cells. 
     
     
         5 . The fuel rack according to  claim 1 , wherein the plurality of third slotted plates are welded to a top surface of the base plate. 
     
     
         6 . The fuel rack according to  claim 1 , wherein the plurality of second slotted plates are constructed of a metal matrix composite material. 
     
     
         7 . The fuel rack according to  claim 1 , wherein the plurality of second slotted plates are welded together. 
     
     
         8 . The fuel rack according to  claim 1 , wherein the plurality of first and third slotted plates are constructed of stainless steel. 
     
     
         9 . The fuel rack according to  claim 1 , wherein the plurality of first slotted plates are welded together and the plurality of third slotted plates are welded together. 
     
     
         10 . The fuel rack according to  claim 1 , wherein the plurality of second slotted plates are interlocked with one another to form flux traps between adjacent cells in the array of cells. 
     
     
         11 . A nuclear fuel storage apparatus comprising:
 a fuel assembly having a top section, a middle section, and a bottom section, nuclear fuel being stored within the middle section; and   a fuel rack comprising:
 a base plate; and 
 an array of cells, the fuel assembly located in a first cell of the array of cells, the array of cells comprising:
 a plurality of first slotted plates slidably interlocked with one another to form a top portion of the array of cells, the plurality of first slotted plates formed of a first material; 
 a plurality of second slotted plates slidably interlocked with one another to form a middle portion of the array of cells, the plurality of second slotted plates formed of a second material, the first and second materials being metallurgically incompatible, and the middle section of the fuel assembly located entirely within the middle portion of the first cell of the array of cells; and 
 a plurality of third slotted plates slidably interlocked with one another to form a bottom portion of the array of cells, the plurality of third slotted plates formed of the first material and connected to a top surface of the base plate. 
 
   
     
     
         12 . The apparatus according to  claim 11 , further comprising a plurality of tie members, each tie member affixed to each of the top and bottom portions of the array of cells. 
     
     
         13 . The apparatus according to  claim 12 , wherein each tie member is welded to the top and bottom portions of the array of cells. 
     
     
         14 . The apparatus according to  claim 12 , wherein each tie member is located on an external surface of the array of cells. 
     
     
         15 . The apparatus according to  claim 11 , wherein the plurality of third slotted plates are welded to a top surface of the base plate. 
     
     
         16 . The apparatus according to  claim 11 , wherein the plurality of second slotted plates are constructed of a metal matrix composite material. 
     
     
         17 . The apparatus according to  claim 11 , wherein the plurality of second slotted plates are welded together. 
     
     
         18 . The apparatus according to  claim 11 , wherein the plurality of first and third slotted plates are constructed of stainless steel. 
     
     
         19 . The apparatus according to  claim 11 , wherein the plurality of first slotted plates are welded together and the plurality of third slotted plates are welded together. 
     
     
         20 . The apparatus according to  claim 11 , wherein the plurality of second slotted plates are interlocked with one another to form flux traps between adjacent cells in the array of cells. 
     
     
         21 . A fuel rack for nuclear fuel assemblies, the fuel rack comprising:
 a base plate;   an array of cells for holding fuel assemblies, the array of cells comprising:
 a plurality of first slotted plates slidably interlocked with one another to form a top portion of the array of cells, the plurality of first slotted plates welded together and formed of a first material; 
 a plurality of second slotted plates slidably interlocked with one another to form a middle portion of the array of cells, the plurality of second slotted plates formed of a second material, the first and second materials being metallurgically incompatible; and 
 a plurality of third slotted plates slidably interlocked with one another to form a bottom portion of the array of cells, the plurality of third slotted plates formed of the first material and welded to a top surface of the base plate; and 
   a plurality of tie members, each tie member welded to each of the top and bottom portions of the array of cells.   
     
     
         22 . The fuel rack according to  claim 21 , wherein each tie member is located on an external surface of the array of cells. 
     
     
         23 . The fuel rack according to  claim 21 , wherein the plurality of second slotted plates are constructed of a metal matrix composite material. 
     
     
         24 . The fuel rack according to  claim 21 , wherein the plurality of second slotted plates are welded together. 
     
     
         25 . The fuel rack according to  claim 21 , wherein the plurality of first and third slotted plates are constructed of stainless steel. 
     
     
         26 . The fuel rack according to  claim 21 , wherein the plurality of second slotted plates are interlocked with one another to form flux traps between adjacent cells in the array of cells.