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Title: Weld monitor and failure detector for nuclear reactor system

Abstract

Critical but inaccessible welds in a nuclear reactor system are monitored throughout the life of the reactor by providing small aperture means projecting completely through the reactor vessel wall and also through the weld or welds to be monitored. The aperture means is normally sealed from the atmosphere within the reactor. Any incipient failure or cracking of the weld will cause the environment contained within the reactor to pass into the aperture means and thence to the outer surface of the reactor vessel where its presence is readily detected.

Inventors:
 [1]
  1. (Mt. Lebanon, PA)
Publication Date:
Research Org.:
WESTINGHOUSE ELECTRIC CORP
OSTI Identifier:
866291
Patent Number(s):
US 4675146
Assignee:
United States of America as represented by United States (Washington, DC) OSTI
DOE Contract Number:
AC76-76CL02395
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
weld; monitor; failure; detector; nuclear; reactor; critical; inaccessible; welds; monitored; throughout; life; providing; aperture; means; projecting; completely; vessel; wall; normally; sealed; atmosphere; incipient; cracking; environment; contained; pass; thence; outer; surface; presence; readily; detected; readily detected; aperture means; vessel wall; reactor vessel; nuclear reactor; outer surface; accessible welds; weld monitor; /376/976/

Citation Formats

Sutton, Jr., Harry G. Weld monitor and failure detector for nuclear reactor system. United States: N. p., 1987. Web.
Sutton, Jr., Harry G. Weld monitor and failure detector for nuclear reactor system. United States.
Sutton, Jr., Harry G. Thu . "Weld monitor and failure detector for nuclear reactor system". United States. doi:. https://www.osti.gov/servlets/purl/866291.
@article{osti_866291,
title = {Weld monitor and failure detector for nuclear reactor system},
author = {Sutton, Jr., Harry G.},
abstractNote = {Critical but inaccessible welds in a nuclear reactor system are monitored throughout the life of the reactor by providing small aperture means projecting completely through the reactor vessel wall and also through the weld or welds to be monitored. The aperture means is normally sealed from the atmosphere within the reactor. Any incipient failure or cracking of the weld will cause the environment contained within the reactor to pass into the aperture means and thence to the outer surface of the reactor vessel where its presence is readily detected.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1987},
month = {Thu Jan 01 00:00:00 EST 1987}
}

Patent:

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  • This patent describes a detection system for monitoring the integrity of inaccessible weld means throughout the life of a reactor system and providing a responsive signal indicative of weld failure. The nuclear reactor system includes a steel nuclear reactor vessel having an outer wall surface and an inner wall surface and reactor vessel structural support means projecting inwardly from the vessel inner wall surface. Reactor core means is retained within the reactor vessel. Heat transfer coolant means which during reactor operation flows upwardly through the reactor core means under pressure is greater than the pressure of the atmosphere exteriorly ofmore » the reactor vessel. A steel reactor core support structure supports the reactor core within the reactor vessel, and circumferential weld means affixing the reactor core support structure to the reactor vessel structural support means. The detection system comprises: weld integrity monitor means comprising small aperture means opening from the outer wall surface of the reactor vessel and extending through the wall of the reactor vessel and through the inwardly projecting reactor vessel structural support means and completely through the circumferential weld means. All portions of the aperture means are normally sealed from the coolant-means-containing environment within the reactor vessel; and detecting means positioned exteriorly of the reactor vessel detects the egress of any of the coolant means from the reactor vessel via the aperture means. Coolant means egress is indicative of the failure of the circumferential weld means.« less
  • A self-powered gamma monitor for placement near the core of a nuclear reactor comprises a lead prism surrounded by a coaxial thin nickel sheet, the combination forming a collector. A coaxial polyethylene electron barrier encloses the collector and is separated from the nickel sheet by a vacuum region. The electron barrier is enclosed by a coaxial stainless steel emitter which, in turn, is enclosed within a lead casing. When the detector is placed in a flux of gamma rays, a measure of the current flow in an external circuit between emitter and collector provides a measure of the power levelmore » of the reactor.« less
  • A self-powered gamma monitor for placement near the core of a nuclear reactor comprises a lead prism surrounded by a coaxial thin nickel sheet, the combination forming a collector. A coaxial polyethylene electron barrier encloses the collector and is separated from the nickel sheet by a vacuum region. The electron barrier is enclosed by a coaxial stainless steel emitter which, in turn, is enclosed within a lead casing. When the detector is placed in a flux of gamma rays, a measure of the current flow in an external circuit between emitter and collector provides a measure of the power levelmore » of the reactor.« less
  • A system for detecting the failure of a nuclear fuel rod in a nuclear reactor comprises sampling a coolant in a nuclear reactor, cooling the sampled coolant to permit 135/sub I/ in the coolant to be adsorbed on an iodine adsorption device, moving 135m/sub Xe/ produced by the 135/sub I/ decay into a cover gas at the upper space of a gas-liquid separator, and introducing the 135m/sub Xe/ entrained cover gas into a radioactivity detector where the radioactivity of 135m/sub Xe/ is counted.