Thermal load reducing system for nuclear reactor vessel

Abstract

In a reactor vessel thermal load reducing system near the surface level of a coolant, the present invention is characterized in that a heat conductive member is installed not contacting the reactor vessel ( 1 ) wall in an area above and below the coolant liquid surface, and the heat conducting member is a guard vessel ( 2 ) made of good heat conductivity, or a heat conductive plate ( 20 ) made of good heat conductivity.

1 . A reactor vessel thermal load reducing system for a reactor vessel having walls and being partially filled with liquid coolant up to a coolant liquid surface level, wherein a vertical portion of the reactor vessel wall has contact with liquid coolant and a vertical portion of the reactor wall does not have contact with liquid coolant, comprising: 
 a heat conductive member attached either to the reactor vessel wall or to a wall adjacent to the reactor vessel wall, and adapted to thermally conduct heat from the liquid coolant,    wherein said heat conductive member located outside the reactor vessel wall and not contacting the reactor vessel wall;    wherein said heat conductive member is horizontally adjacent to the liquid coolant surface level,    wherein said heat conductive member is horizontally adjacent to less than all of the vertical portion of the reactor vessel wall having contact with the liquid coolant,    and wherein said heat conductive member is horizontally adjacent to less than all of the vertical portion of the reactor wall not having contact with the liquid coolant.    
   
   
       2 . The reactor vessel thermal load reducing system according to  claim 1 , characterized in that the aforementioned heat conductive member is a plate supported by the guard vessel.  
   
   
       3 . The reactor vessel thermal load reducing system according to  claim 1 , characterized in that said heat conductive member is a guard vessel wall.  
   
   
       4 . The reactor vessel thermal load reducing system according to  claim 1 , characterized in that the material of said heat conductive member has a higher heat conduction coefficient than the reactor vessel walls.  
   
   
       5 . The reactor vessel thermal load reducing system according to  claim 4 , characterized in that the material of said heat conductive member is high chrome steel.  
   
   
       6 . The reactor vessel thermal load reducing system according to  claim 4 , characterized in that the material of the aforementioned good heat conductive member is graphite.