Method for controlling water quality in nuclear reactor and nuclear power plant to which the method is applied

Abstract

A method for controlling water quality in a nuclear reactor comprises a first and second steps. The first step is to make an amount of iron, which is carried into the nuclear reactor and corrosively eluted from structural material within the nuclear reactor into reactor water, at least twice as much as any one of an amount of nickel, which is carried into the nuclear reactor, and an amount of nickel, which is generated in the nuclear reactor. The second step is to limit an upper limit of concentration value of iron in system water supplied into the nuclear reactor to up to 0.10 ppb.

1 - 13 . (canceled)  
   
   
       14 . A nuclear power plant including: 
 piping and equipment made of stainless steel disposed on a nuclear reactor first order system; and    an iron removing device configured to remove iron from system water supplied into a nuclear reactor, said iron removing device configured to remove iron in a form of granules and ions in a case where the system water is condensate having a low temperature, and configured to remove iron mainly in a form of granules in a case where the system water is drain water having a medium or high temperature, said iron removing device used when the system water has the low temperature is a composite removing unit including, 
 a filter having pores with a large filtration area, and  
 an ion exchange resin tower,  
   and said iron removing device used when the system water has the medium or high temperature is a removing unit including a filter having pores and formed of at least one material selected from the group consisting of: heat resistant resin, ceramics, elements forming ceramics through oxidation, carbonization, and nitriding, and carbon material.    
   
   
       15 . The nuclear power plant as claimed in  claim 14 , wherein said nuclear reactor first order system includes a reactor water high-temperature purifying device configured to occlude nickel in a filter medium of any one of ferrite and ferritic alloy.  
   
   
       16 . The nuclear power plant as claimed in  claim 14 , further comprising: 
 a feed water heater and a fuel assembly of the nuclear reactor made of ferrite.    
   
   
       17 . The nuclear power plant as claimed in  claim 14 , further comprising: 
 reactor core structural material of the nuclear reactor having a cobalt content of up to 0.01%.    
   
   
       18 . The nuclear power plant as claimed in  claim 14 , further comprising: 
 turbine blades and large-diameter valves disposed on the nuclear reactor first order system made of nickel-base alloy.    
   
   
       19 . The nuclear power plant as claimed in  claim 14 , wherein: 
 said removing unit has a filter having pores with a diameter of up to 0.45 μm.    
   
   
       20 . The nuclear power plant as claimed in  claim 14 , wherein: 
 an upper limit of concentration value of iron in system water supplied into the nuclear reactor is limited to up to 0.10 ppb.