US 4,788,027 A · Method and means for remote removal of guide balls from nuclear reactor control rods

Abstract

A punch mechanism for remote removal of guide balls from nuclear reactor control rods, includes attachment means for attaching the punch mechanism to means for reversibly lowering the punch mechanism over the top of one of the control rods. The mechanism includes a die and cylinder means operatively connected to the die for axially moving the die in a back-and-forth direction, a die block cooperating with the die, and guide means for self-aligning the punch mechanism so that the die and the die block are automatically aligned with one of the guide balls therebetween when the punch mechanism is lowered over the top of the control rod. When the punch mechanism is lowered into aligned position, activation of the cylinder means will cause the die to advance into the die block, thereby removing the guide ball from the control rod. The punch mechanism is then remotely raised above the control rod, rotated 90 degrees, and lowered to repeat the ball removal procedure. Two more repetitions effect removal of all four balls from the control rod. The procedure may be carried out while the control rod is positioned in a spent fuel pool. The rod may then be removed for crushing.

Claims18

Dependent claims

A punch mechanism for remote removal of guide balls from nuclear reactor control rods, comprising:

(a) attachment means for attaching said punch mechanism to means for reversibly lowering said punch mechanism over the top of one of said control rods;
(b) a die;
(c) cylinder means operatively connected to said die for axially moving said die in a back-and-forth direction;
(d) a die block cooperating with said die;
and
(e) guide means for self-aligning said punch mechanism so that said die and said die block are automatically aligned with one of said guide balls when said punch mechanism is lowered over the top of said control rod;
whereby, when said punch mechanism is lowered over the top of said control rod and said die and said die block are aligned with said guide ball therebetween, activation of said cylinder means will cause said die to advance into said die block thereby removing said guide ball from said control rod.

4 more elements

A method of remotely removing guide balls from nuclear reactor control rods using a punch mechanism, comprising:

(a) providing attachment means in said punch mechanism for attaching said punch mechanism to means for reversibly lowering said punch mechanism over the top of one of said control rods;
(b) providing a die within said punch mechanism;
(c) providing cylinder means within said punch mechanism operatively connected to said die for axially moving said die in a back-and-forth direction;
(d) providing a die block within said punch mechanism cooperating with said die;
(e) providing guide means within said punch mechanism for self-aligning said punch mechanism so that said die and said die block are automatically aligned with a first one of said guide balls therebetween when said punch mechanism is lowered over the top of said control rod;
(f) lowering said punch mechanism over said control rod so that said die, said die block, and said first guide ball are in alignment;
and
(g) then operating said cylinder means so that said die advances into said die block, thereby removing said first guide ball from said control rod.

5 more elements

Dependencies are inferred from the claim text.

Method and means for remote removal of guide balls from nuclear reactor control rods

Life of this patent

Method and means for remote removal of guide balls from nuclear reactor control rods

Life of this patent

Abstract

Claims18