Water jet peening apparatus and water jet peening method

Patent metadata

Field	Value
Publication number	US-9728285-B2
Application number	US-201414762217-A
Country	US
Kind code	B2
Filing date	Jan 23, 2014
Priority date	Jan 25, 2013
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Provided is a water jet peening apparatus and a water jet peening method including: a clamping cylinder ( 201 ) which is able to be disposed at the outer peripheral side of an instrumentation nozzle ( 83 ) with a predetermined gap therebetween; a clamping piece ( 210 ) which is able to fix the clamping cylinder ( 201 ) to the instrumentation nozzle ( 83 ); a nozzle guide ( 221 ) which has a cylindrical shape, is provided inside the clamping cylinder ( 201 ), and is positioned to a position adjacent to the upper end of the instrumentation nozzle ( 83 ); an inner surface WJP nozzle ( 105 ) which is movable upward and downward inside the nozzle guide ( 221 ); and a drainage hole ( 224 ) which radially penetrates the nozzle guide ( 221 ). Accordingly, it is possible to improve the safety of the operation by preventing a thimble tube from being popped out due to a water jet peening operation.

First claim

The invention claimed is:

1. A water jet peening (WJP) method for a nuclear reactor vessel comprising:
disposing a clamping cylinder at the outer peripheral side of an instrumentation nozzle with a predetermined gap therebetween;
fixing a positioning member provided in the clamping cylinder to the instrumentation nozzle at a position adjacent to the upper end of the instrumentation nozzle;
moving an inner surface WJP nozzle downward to the instrumentation nozzle through the clamping cylinder;
jetting high-pressure water to an inner surface of the instrumentation nozzle by moving the inner surface WJP nozzle downward in a rotation state while the high-pressure water including cavitation air bubbles is jetted from the inner surface WJP nozzle; and
discharging the high-pressure water jetted from the inner surface WJP nozzle to an outside of the instrumentation nozzle through a drainage hole provided in the positioning member.

2. The water jet peening method according to claim 1 ,
wherein the high-pressure water is jetted from the inner surface WJP nozzle while a thimble tube drawn to an outside of the reactor vessel from the instrumentation nozzle through a conduit tube is not movable.

3. The water jet peening method according to claim 2 ,
wherein a fixed state of the thimble tube and the conduit tube is monitored when the high-pressure water is jetted from the inner surface WJP nozzle to the inner surface of the instrumentation nozzle.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Minamiyama Akio
• Nishitsuji Yutaka
• Okimura Koji
• Hinami Kazuyuki
• Hamamoto Tomochika
• Konno Takao

Classifications

• G21C17/017

  Inspection or maintenance of pipe-lines or tubes in nuclear installations · CPC title

• B24C1/003 Primary

  using material which dissolves or changes phase after the treatment, e.g. ice, CO2 · CPC title

• G21C19/28 Primary

  Arrangements for introducing fluent material into the reactor core; Arrangements for removing fluent material from the reactor core (pumping coolant G21D) · CPC title

• B24C3/325

  for internal surfaces, e.g. of tubes · CPC title

• G21C17/01

  Inspection of the inner surfaces of vessels · CPC title