Part including vibration mitigation device(s), nuclear reactor pressure vessel assembly including the part, and methods of manufacturing thereof

Patent metadata

Field	Value
Publication number	US-2016379724-A1
Application number	US-201514751690-A
Country	US
Kind code	A1
Filing date	Jun 26, 2015
Priority date	Jun 26, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

A nuclear reactor pressure vessel assembly includes a part in a reactor housing structure. The part includes a body a vibration absorber. The body includes an internal surface. The internal surface of the body defines at least one cavity that is not exposed to an environment external to the body. The vibration absorber includes at least one of a harmonic oscillator connected to the internal surface of the body or an external surface of the body, a shear multiplier in the at least one cavity, a hybrid mass-viscoelastic structure in the at least one cavity and not secured to the internal surface of the body, and a distributed damping structure incorporated into the body.

First claim

1 . A nuclear reactor pressure vessel assembly, comprising:
a reactor housing structure; and a part in the reactor housing structure, the part including a body and a vibration absorber, the body including an internal surface, the internal surface of the body defining at least one cavity that is not exposed to an environment external to the body, and the vibration absorber including at least one of,
a harmonic oscillator connected to the internal surface of the body or an external surface of the body,
a shear multiplier in the at least one cavity,
a hybrid mass-viscoelastic structure in the at least one cavity and not secured to the internal surface of the body, and
a distributed damping structure incorporated into the body.

2 . The nuclear reactor pressure vessel assembly of claim 1 , further comprising:
at least one of a shroud, a support plate, a chimney assembly, a core plate, a top guide, a nozzle, a sparger, a fluid separator, a stand pipe, and a dryer, wherein the part is one of the at least one of the shroud, the support plate, the chimney assembly, the core plate, the top guide, the tubular structure, the nozzle, the sparger, the steam separator, the stand pipe, and the dryer.

3 . The nuclear reactor pressure vessel assembly of claim 1 , wherein the part is embedded in the reactor housing structure.

4 . The nuclear reactor pressure vessel assembly of claim 1 , wherein
the vibration absorber includes the harmonic oscillator, and the harmonic oscillator includes at least one spring-mass structure.

5 . The nuclear reactor pressure vessel assembly of claim 1 , wherein
the vibration absorber includes the shear multiplier structure, the shear multiplier structure includes a viscoelastic damping material between two layers, and at least one end of the shear multiplier structure is connected to the inner surface of the body.

6 . The nuclear reactor pressure vessel assembly of claim 1 , wherein
the vibration absorber includes the hybrid mass-viscoelastic structure, and the hybrid mass-viscoelastic structure includes a viscoelastic damping material surrounding a mass.

7 . The nuclear reactor pressure vessel assembly of claim 1 , wherein
the vibration absorber includes the distributed damping structure incorporated into the body, a grain microstructure of the distributed damping structure includes a first material dispersed in a second material, and a damping coefficient of the first material is greater than a damping coefficient of the second material.

8 . The nuclear reactor pressure vessel assembly of claim 7 , wherein
an outer portion of the body includes the second material and not the first material, the outer portion of the body surrounds the distributed damping structure such that the distributed damping structure is not exposed to the environment external to the body, and the first material includes magnesium.

9 . The nuclear reactor pressure vessel assembly of claim 1 , wherein a material of the body includes one of a low alloy steel, a stainless steel, a nickel-based alloy, and a combination thereof.

10 . The nuclear reactor pressure vessel assembly of claim 1 , wherein the body is a unibody structure.

11 . The nuclear reactor pressure vessel assembly of claim 1 , further comprising:
a plurality of parts, wherein the plurality of parts include the part in the reactor housing structure, and the plurality of parts are in the reactor housing structure.

12 . A part comprising:
a body including an internal surface, the internal surface of the body defining at least one cavity that is not exposed to an environment external to the body; and a vibration absorber including at least one of, a harmonic oscillator connected to the internal surface of the body or an external surface of the body, a shear multiplier structure in the at least one cavity, a hybrid mass-viscoelastic structure in the at least one cavity and not secured to the internal surface of the body, and a distributed damping structure incorporated into the body.

13 . The part of claim 12 , wherein
the vibration absorber includes the distributed damping structure incorporated into the housing, a grain microstructure of the distributed damping structure includes a first material dispersed in a second material, and a damping coefficient of the first material is greater than a damping coefficient of the second material.

14 . The part of claim 12 , wherein a material of the body includes one of a low alloy steel, a stainless steel, a nickel-based alloy, and a combination thereof.

15 . The part of claim 12 , wherein
the part is configured to have a natural frequency that is different than a natural frequency of a reference part, and the reference part does not include a vibration absorber.

16 . The part of claim 12 , wherein the vibration absorber includes the harmonic oscillator.

17 . A method of manufacturing a modified nuclear-reactor part based on a reference part, comprising:
forming a body of the modified nuclear-reactor part based on a body of the reference part, the body of the modified nuclear-reactor part having a different structure than the body of the reference part at least because an internal surface of the body of the modified nuclear-reactor part defines at least one cavity that is not exposed to an environment external to the body of the modified nuclear-reactor part; and forming a vibration absorber in the modified nuclear-reactor part, the vibration absorber including at least one of, a harmonic oscillator connected to the internal surface of the body or an external surface of the body, a shear multiplier structure in the at least one cavity, a hybrid mass-viscoelastic structure in the at least one cavity and not secured to the internal surface of the body, and a distributed damping structure incorporated into the body.

18 . A method of manufacturing a modified part based on a reference part, comprising:
forming a body of the modified part based on a body of the reference part, the body of the modified part having a different structure than the body of the reference part at least because an internal surface of the body of the modified part defines at least one cavity that is not exposed to an environment external to the body of the modified part; and forming a vibration absorber in the modified part, the vibration absorber including at least one of,
a harmonic oscillator connected to the internal surface of the body,
a shear multiplier structure in the at least one cavity,
a hybrid mass-viscoelastic structure in the at least one cavity and not secured to the internal surface of the body, and
a distributed damping structure incorporated into the body.

19 . The method of claim 18 , wherein the forming the vibration absorber in the modified part includes at least one of:
changing a natural frequency of the modified part relative to a natural frequency of the reference part, and changing a damping level of the modified part relative to a damping level of the reference part such that the damping level of the modified part is greater than the damping level of the reference part.

20 . The method of claim 18 , wherein the changing the natural frequency of the modified part relative the natural frequency of the reference part includes one of:
adding a mass into the at least one cavity of the modified part, and increasing a stiffness of the modified part such that the stiffness of the modified part is greater than a stiffness of t

Assignees

• Carneal James P
• Davis William P
• Connor Myles L
• Webber David W
• Ge Hitachi Nuclear Energy Americas Llc

Inventors

• Carneal James P
• Davis William P
• Connor Myles L
• Webber David W

Classifications

• G21C13/02 Primary

  Details · CPC title

• G21C21/00

  Apparatus or processes specially adapted to the manufacture of reactors or parts thereof (in general section B, e.g. B23) · CPC title

• Y02E30/00

  Energy generation of nuclear origin · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title

• F16F7/104

  the inertia member being resiliently mounted {(F16F7/1022 takes precedence)} · CPC title