Reactor internal structure and method of manufacturing the same

Abstract

A coating of niobium oxide, zirconium titanate, or nickel titanate is formed on at least a part of a surface of a jet pump member constituting a jet pump serving as a reactor internal structure of a boiling water reactor. Further, a solution containing, e.g., a niobium compound is applied to at least a part of the surface of the jet pump member constituting the jet pump, and the jet pump member coated with the solution is heat-treated to form a coating of, e.g., niobium oxide. With this configuration, the jet pump member constituting the jet pump of the boiling water reactor is provided such that deposition of crud can be sufficiently suppressed on the jet pump member.

1 . A reactor internal structure constituting a boiling water reactor, the reactor internal structure having a surface at least partially coated with niobium oxide, zirconium titanate, or nickel titanate. 
     
     
         2 . The reactor internal structure according to  claim 1 , wherein the zirconium titanate has a one-to-one atomic ratio of titanium to zirconium. 
     
     
         3 . The reactor internal structure according to  claim 1 , wherein the nickel titanate has a one-to-one atomic ratio of titanium to nickel. 
     
     
         4 . The reactor internal structure according to  claim 1 , wherein the coating has a thickness of 0.01 μm to 10 μm. 
     
     
         5 . The reactor internal structure according to  claim 1 , wherein the reactor internal structure is a jet pump member constituting an inlet mixer. 
     
     
         6 . A method of manufacturing a reactor internal structure, comprising the steps of:
 applying a solution containing a niobium compound to at least a part of a surface of the reactor internal structure constituting a boiling water reactor; and   forming a coating of niobium oxide by heat-treating the surface of the reactor internal structure coated with the solution.   
     
     
         7 . A method of manufacturing a reactor internal structure, comprising the steps of:
 applying a titanium-zirconium compound solution to at least a part of a surface of the reactor internal structure constituting a boiling water reactor; and   forming a coating of zirconium titanate by heat-treating the surface of the reactor internal structure coated with the solution.   
     
     
         8 . The method of manufacturing a reactor internal structure according to  claim 7 , wherein the titanium-zirconium compound solution has a one-to-one atomic ratio of titanium to zirconium. 
     
     
         9 . A method of manufacturing a reactor internal structure, comprising the steps of:
 applying a titanium-nickel compound solution to at least a part of a surface of the reactor internal structure constituting a boiling water reactor; and   forming a coating of nickel titanate by heat-treating the surface of the reactor internal structure coated with the solution.   
     
     
         10 . The method of manufacturing a reactor internal structure according to  claim 9 , wherein the titanium-nickel compound solution has a one-to-one atomic ratio of titanium to nickel. 
     
     
         11 . The method of manufacturing a reactor internal structure according to any one of  claims 6 ,  7 , and  9 , wherein the heat treatment is performed at 80° C. to 600° C. 
     
     
         12 . The method of manufacturing a reactor internal structure according to any one of  claims 6 ,  7 , and  9 , wherein the coating has a thickness of 0.01 μm to 10 μm.