System for separating and coupling top nozzle of nuclear fuel assembly

Patent metadata

Field	Value
Publication number	US-11355251-B2
Application number	US-202016870699-A
Country	US
Kind code	B2
Filing date	May 8, 2020
Priority date	Nov 9, 2017
Publication date	Jun 7, 2022
Grant date	Jun 7, 2022

Abstract

Disclosed is a system for separating and coupling a top nozzle of a nuclear fuel assembly. There is provided a lock insert configured to support the top nozzle of the nuclear fuel assembly by being coupled to a guide hole provided in a flow channel plate of the top nozzle, the lock insert including: a body in a hollow shape; and an insertion part provided on a top portion of the body and inserted into the guide hole, wherein a circumference of the insertion part is variable in size, thereby being capable of being inserted into the guide hole. Accordingly, disassembly and reassembly of the top nozzle of the nuclear fuel assembly and the lock insert are simplified, thereby simplifying and reducing the number of processes involved therein. Accordingly, the system is effective for maintenance and repair of the nuclear fuel assembly.

First claim

The invention claimed is:

1. A system for separating and coupling a top nozzle having a flow channel plate with guide holes and a fixing hole formed thereto, from/to a nuclear fuel assembly with guide thimbles, the system comprising:
a lock insert configured to couple the guide thimbles of the nuclear fuel assembly to the flow channel plate of the top nozzle by being inserted into the guide holes provided in the flow channel plate of the top nozzle; and
a separation part configured to separate the lock insert from the flow channel plate of the top nozzle,
wherein the lock insert comprises a body in a hollow shape, and an insertion part provided on a top of the body and configured to be inserted into the guide holes,
the insertion part comprising:
a first latching member having a step, being fixed by being brought into contact with a latching step; and
a second latching member having a projection, being fixed by being brought into contact with a latching groove,

the insertion part being provided with at least one slot at a predetermined interval along a circumference of the insertion part to make the size of the circumference variable,
the guide holes comprising:
the latching step provided at an upper portion of an inner circumferential surface of the guide holes and configured to fix the lock insert; and
the latching groove provided at a predetermined portion of the inner circumferential surface of the guide holes and configured to fix the lock insert,

wherein engagement of the first and second latching members with the latching step and latching groove alone locks the nuclear fuel assembly to the top nozzle,
wherein the separation part comprises a separation member configured to release the coupling of the lock insert and the flow channel plate, and a fixing member configured to be engaged with a bottom surface of the flow channel plate through the fixing hole of the flow channel plate, wherein as the separation part is lowered, the coupling of the lock insert and the flow channel plate is released by the separation member and the fixing member is engaged with the bottom surface of the flow channel plate at the same time; and then as the separation part is lifted, the lock insert remains released from the flow channel plate and the flow channel plate of the top nozzle is lifted in engagement with the fixing member at the same time,
wherein the separation member has a predetermined accommodation space formed therein to accommodate one side of the insertion part of the lock insert, and when the one side of the insertion part of the lock insert is inserted into the predetermined accommodation space, a surface of the separation member defining the accommodation space applies a force to the one side of the insertion part, thereby the size of the circumference of the insertion part is reducibly variable by the force and then the coupling between the lock insert and the flow channel plate is released, and
wherein one end of the fixing member is provided with a fixing latching member having a step to be engaged with the bottom surface of the flow channel plate, thereby the flow channel plate of the top nozzle is lifted as the separation part is lifted.

Assignees

• Chun Joo Hong
• Kim Seong Soo
• Kim Ba Leum
• Ryu Su Pil
• Park Nam Gyu
• Yoo Jong Sung
• Kepco Nuclear Fuel Co Ltd

Inventors

• Chun Joo Hong
• Kim Seong Soo
• Kim Ba Leum
• Ryu Su Pil
• Park Nam Gyu
• Yoo Jong Sung

Classifications

• Y02E30/30

  Nuclear fission reactors · CPC title

• G21C19/105

  with grasping or spreading coupling elements · CPC title

• G21C3/3315 Primary

  Upper nozzle · CPC title

• G21C3/334 Primary

  Assembling {, maintenance or repair of} the bundles {(assembling, maintenance or repair of other reactor components G21C19/207)} · CPC title

• G21C19/10 Primary

  Lifting devices or pulling devices adapted for co-operation with fuel elements or with control elements (manipulators B25J) · CPC title