Control rod guide tube cleaning apparatus in nuclear reactor

A control rod guide tube cleaning apparatus in a nuclear reactor comprising:

• a main body which is generally cylindrical and able to be inserted in a housing of control rod drive mechanism provided on a lower side of a nuclear reactor pressure container;
• a rod member for pressing up a control rod, held by said main body so as to be movable in a vertical direction;
• a slit-shaped nozzle containing portion formed in the vicinity of a head portion of said rod member;
• and
• a suction nozzle supported by a shaft at one end so as to be rotatable between a vertical direction and a horizontal direction inside said nozzle containing portion, said suction nozzle having a nozzle opening and passage opening, said nozzle opening facing the bottom of said control rod guide tube and said passage opening communicating with a water passage formed in said rod member when said suction nozzle is generally horizontal.

A control rod guide tube cleaning apparatus for a nuclear reactor having a housing of a control rod drive mechanism secured to a pressure vessel at an upper end portion thereof and a control rod guide tube disposed in said pressure vessel and having a lower end portion connected to an upper end of said control rod guide tube to provide a connecting portion, said housing and said lower portion of said control rod guide tube having an inner through hole, said control rod guide tube cleaning apparatus comprising:

• a rod member having inside a water passage and disposed in said inner through hole so as to be axially movable so that one end of said rod member is shiftable from a position at or below a bottom of said control rod guide tube into the inside of said control rod guide tube through said connecting portion;
• a suction nozzle having a nozzle opening and a passage opening, and rotatably mounted on an upper portion of said rod member at one end thereof, said suction nozzle being disposed so that said nozzle opening and passage opening are inside said inner through hole under the condition that said upper portion of said rod member is disposed at or below the bottom of said control rod guide tube, and said nozzle opening faces the bottom of said control rod guide tube and said passage portion faces an upper end of said water passage of said rod member under condition that said one end of said nozzle rod member is disposed inside said control rod guide tube;
• a suction pump fluidly connected to said water passage of said rod member;
• and
• a rotating device fixed to said rod member so as to rotate said suction nozzle.