Zirconium-alloy clad fuel rods containing metal oxide for mitigation of secondary hydriding

Abstract

Method of fabricating a fuel rod, comprising providing an effective amount of a metal oxide in the fuel rod to generate steam and mitigate the tendency for secondary hydriding. Fuel rods fabricated according to the method of the invention are also provided.

What is claimed is:  
     
         1 . A method of fabricating a fuel rod, comprising the step of providing an effective amount of a metal oxide in the fuel rod to cause generation of steam and mitigate secondary hydriding.  
     
     
         2 . A method according to  claim 1 , wherein the composition of the metal oxide is such that if hydrogen fraction is above the equilibrium condition for the metal/metal oxide couple, a back reaction occurs between the hydrogen and the metal oxide to generate steam.  
     
     
         3 . A method according to  claim 1 , wherein the metal oxide is selected from oxides of iron, nickel, tin, bismuth, copper, colbalt, chromium, manganese and combinations of such oxides.  
     
     
         4 . A method according to  claim 3 , wherein the metal oxide is bismuth oxide.  
     
     
         5 . A method according to  claim 1 , wherein the metal oxide is present in an amount ranging from up to 10 grams per fuel rod.  
     
     
         6 . A method according to  claim 1 , wherein the metal oxide is present as a coating on an interior surface of cladding of the fuel rod.  
     
     
         7 . A method according to  claim 1 , wherein the metal oxide is present as a coating on fuel pellet surfaces.  
     
     
         8 . A method according to  claim 1 , wherein the metal oxide is present as individual pellets as a fuel pellet stack, or as wafers.  
     
     
         9 . A method according to  claim 8 , wherein the individual pellets or wafers are between fuel pellets.  
     
     
         10 . A method according to  claim 8 , wherein the individual pellets or wafers are at the top of the fuel pellet stack.  
     
     
         11 . A method according to  claim 8 , wherein the individual pellets or wafers are at the bottom of the fuel pellet stack.  
     
     
         12 . A method according to  claim 8 , wherein the individual pellets or wafers are at the top and bottom of the fuel pellet stack.  
     
     
         13 . A method according to  claim 1 , wherein the metal oxide is within a container.  
     
     
         14 . A method according to  claim 13 , wherein the metal oxide is present as a powder or pellet within said container.  
     
     
         15 . A method according to  claim 13 , wherein said container is at the bottom of a fuel pellet stack.  
     
     
         16 . A method according to  claim 13 , wherein said container is at the top of a fuel pellet stack.  
     
     
         17 . A method according to  claim 13 , wherein said container is at the top and bottom of a fuel pellet stack.  
     
     
         18 . A method according to  claim 1 , wherein the metal oxide is distributed intermittently along the fuel rod.  
     
     
         19 . A fuel rod fabricated according to the method of  claim 1.