Abstract: A reactor internals component having a sensor insert for monitoring reactor internals components, supported within the reactor internals. The sensor insert has a hollow internal cavity that houses a number of compartmentalized, self-contained, passive environmental sensors. The sensor inserts are provided with a tracking code that can be employed to identify their location and orientation.

Abstract: An improved support apparatus is structured to support a dosimetry system within an interior region of a containment apparatus. The dosimetry system is supported in a region between an interior surface of the containment apparatus and an exterior surface of a reactor apparatus that is disposed within the interior of the containment apparatus. The support apparatus includes a retention apparatus having a plurality of brace elements that each have a receptacle formed therein. The receptacles are aligned with one another when installed within the interior of the containment apparatus. The support apparatus further includes a tube apparatus that includes a plurality of tube segments that are connectable together. The dosimetry system is situated within an elongated cavity formed in the tube apparatus. The tube apparatus is situated in the receptacles and thereby supports the dosimetry system on the containment apparatus.

Abstract: An improved support apparatus is structured to support a dosimetry system within an interior region of a containment apparatus. The dosimetry system is supported in a region between an interior surface of the containment apparatus and an exterior surface of a reactor apparatus that is disposed within the interior of the containment apparatus. The support apparatus includes a retention apparatus having a plurality of brace elements that each have a receptacle formed therein. The receptacles are aligned with one another when installed within the interior of the containment apparatus. The support apparatus further includes a tube apparatus that includes a plurality of tube segments that are connectable together. The dosimetry system is situated within an elongated cavity formed in the tube apparatus. The tube apparatus is situated in the receptacles and thereby supports the dosimetry system on the containment apparatus.

Abstract: The present invention relates to a computational system and method to analyze a radiation field in a light water nuclear reactor. The system and method include a radiation transport module for performing a neutron and gamma transport calculation of a reactor geometry model of the light water nuclear reactor for at least one fuel cycle; a material analysis module for analyzing flux data calculated by the radiation transport module for materials and/or components within the light water nuclear reactor; and a mobile component tracking module for calculating radiation exposure for components within the light water nuclear reactor which have more than one different location during or between the at least one fuel cycle.

Abstract: Detectors are used to monitor the status of spent nuclear fuel storage containers non-invasively while they remain in storage casks. The detectors measure neutron flux and &ggr;-ray flux and may also measure temperature variations of the spent nuclear fuel. The measurements can be accomplished actively or passively, with minimal exposure of individuals to radiation fields or other hazardous conditions. Preferred neutron and &ggr;-ray detectors have a semiconductor active region that is resistant to neutron damage. Incipient structural failures may also be detected using measurements based on electrical continuity, with data being transmitted to an external pickup coil.

Abstract: Prompt Gamma Neuteon Activation Analysis (PGNAA) is employed to determined in situ the content of nickel, copper, or other embrittlement-enhancing elements within the weld metal joints of nuclear reactor pressure vessels.

Abstract: The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor.

Abstract: An integrated temperature monitor (ITM) is placed in a protective carrier and the carrier is placed in a base. Thermally conductive adhesive is injected around the carrier. A cover is placed on the base, forming a container around the ITM. The adhesive holds the carrier in the container holding the base and cover together. Two screws also hold the base and cover together as the adhesive cures. The base has slots for seizing wire. The container is attached to a device with thermally conductive adhesive and the seizing wire. A bar code label is placed on the container. The end of the container is cut to expose the carrier and monitor and create an opening to remove the ITM from the container.

Abstract: An apparatus is provided for determining the thermal history of an environment for purposes of monitoring thermal aging in equipment or the extent to which a process has proceeded. The apparatus comprises a plurality of solid state track recorders, and the range of activation energy values among the solid state track recorders encompasses the activation energy of the thermal aging process of the equipment to be monitored. Using Arrhenius functions, data obtained from the apparatus can be used to determine an equivalent average temperature which is combined with the equipment life data to determine the extent of thermal aging.

Abstract: Apparatus for monitoring an object piece of qualified equipment in a nuclear power plant includes passive means for detecting a total integrated dose of radiation received by the object piece, means for determining a thermal history of the object piece, and means for housing the passive detection means and determining means in close proximity to the object piece. In order to generate and maintain evidence to assure that qualified equipment used in such stations will operate on demand, the passive detection means and determining means mounted in close proximity to the object piece are exposed to the environment of a normally operating power plant and periodically analyzed to determine whether the qualified life of the object piece may be extended.

Abstract: Apparatus for monitoring an object piece of qualified equipment in a nuclear power plant includes first passive means for memicking the effect of radiation received by the object piece, second means for mimicking hte effect of a thermal history of the object piece, and means for mounting the first and second mimic means in close proximity to the object piece in the nuclear power plant. In order to generate and maintain evidence to assure that qualified equipment used in such stations will operate on demand, the first and second mimic means, mounted in close proximity to the object piece, are exposed to the environment of a normally operating power plant and periodically analyzed to determine whether the qualified life of the object piece may be extended.

Abstract: Disclosed is a method and apparatus for measuring the burnup of nuclear fuel. A curve giving the calculated relationship between the fast neutron emission rate and the burnup of fuel is prepared. The fast neutron counting rate from a sample of nuclear fuel of known burnup is measured and the proportionality ratio between that measurement and the fast neutron emission given by the curve for the same burnup is determined. The fast neutron counting rate of nuclear fuel of unknown burnup is then measured and multiplied by the proportionality ratio to determine the fast neutron emission rate, from which the unknown burnup is then determined by means of the curve.

Abstract: Apparatus for monitoring an object piece of qualified equipment in a nuclear power plant includes passive means for detecting a total integrated dose of radiation received by the object piece, means for determining a thermal history of the object piece, and means for housing the passive detection means and determining means in close proximity to the object piece. In order to generate and maintain evidence to assure that qualified equipment used in such stations will operate on demand, the passive detection means and determining means mounted in close proximity to the object piece are exposed to the environment of a normally operating power plant and periodically analyzed to determine whether the qualified life of the object piece may be extended.

Abstract: A reactor cavity dosimetry system and method in a nuclear power plant having a reactor vessel and a primary biological shield substantially surrounding the reactor vessel thereby forming a reactor cavity between the vessel and the shield, the system and method providing for remotely and repeatedly positioning a plurality of neutron dosimeters at preselected locations within the cavity, and for withdrawing the dosimeters for analysis thereof and replacing them at the same preselected positions. Assessment of the long-term effects of neutron irradiation on the vessel is enhanced by accurate and repetitive placement of the dosimeters.

Abstract: A reactor cavity dosimetry system and method for deploying the system which includes a top access support stand. Having a generally rectangular frame assembly formed by a pair of cross members and a pair of frame tubes, the support stand holds the dosimetry in place as part of a continuous loop. The continuous loop is first fed through a U-shaped tube situated beneath the support stand, and coupled together by a chain support plug which is adapted for insertion within a hole formed in an upper one of the cross members to fix the position of the dosimetry axially with respect to the core of a nuclear power plant within which the system is deployed. Each of the frame tubes has mounted thereon a pivotable arm assembly with a spring-loaded slide. After insertion within the cavity, the arm assemblies are pivoted out from the plane of the frame assembly, and disposed locked in place perpendicularly across the cavity.