Abstract: An in-core neutron monitor that employs vacuum microelectronic devices to configure an in-core instrument thimble assembly that monitors and wirelessly transmits a number of reactor parameters directly from the core of a nuclear reactor without the use of external cabling. The in-core instrument thimble assembly is substantially wholly contained within an instrument guide tube within a nuclear fuel assembly.

Abstract: An in-core neutron monitor that employs vacuum microelectronic devices to configure an in-core instrument thimble assembly that monitors and wirelessly transmits a number of reactor parameters directly from the core of a nuclear reactor without the use of external cabling. The in-core instrument thimble assembly is substantially wholly contained within an instrument guide tube within a nuclear fuel assembly.

Abstract: A method and associated apparatus for detecting concealed fissile, fissionable or special nuclear material in an article, such as a shipping container, is provided. The article is irradiated with a source of fast neutrons, and fast neutrons released by the fissile or fissionable material, if present, are detected between source neutron pulses. The method uses a neutron detector that can detect and discriminate fast neutrons in the presence of thermal neutrons and gamma radiation. The detector is able to process high count rates and is resistant to radiation damage, and is preferably a solid state neutron detector comprised of silicon carbide.

Abstract: A method of monitoring a nuclear reactor includes monitoring the nuclear reactor with a plurality of radiation sensors having spaced apart attachments to a radiation hard cable; providing signal processing equipment at each end of the cable for processing signals from the radiation sensors; establishing signal time intervals based upon differences in time of arrival of signals from the radiation sensors to the signal processing equipment at each end of the cable; producing a plurality of output signals each of which has an amplitude proportional to a difference in time of arrival of a signal to the signal processing equipment at each end of the cable; and rejecting output signals which have a difference in time of arrival outside of the signal time intervals.

Abstract: A solid state semiconductor neutron detector that automatically varies its sensitivity to provide a pulsed output over the entire range of operation of a nuclear reactor. The sensitivity is varied by changing the thickness or makeup of a converter layer that emits charged particles to the active region of the semiconductor surface.

Abstract: A solid state semiconductor neutron detector that automatically varies its sensitivity to provide a pulsed output over the entire range of operation of a nuclear reactor. The sensitivity is varied by changing the thickness or makeup of a converter layer that emits charged particles to the active region of the semiconductor surface.

Abstract: A method of monitoring a nuclear reactor includes monitoring the nuclear reactor with a plurality of radiation sensors having spaced apart attachments to a radiation hard cable; providing signal processing equipment at each end of the cable for processing signals from the radiation sensors; establishing signal time intervals based upon differences in time of arrival of signals from the radiation sensors to the signal processing equipment at each end of the cable; producing a plurality of output signals each of which has an amplitude proportional to a difference in time of arrival of a signal to the signal processing equipment at each end of the cable; and rejecting output signals which have a difference in time of arrival outside of the signal time intervals.

Abstract: A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

Abstract: A system for determining depth profiles of concentrations of hazardous elements in soils comprises a neutron source for generating neutrons of a first energy level and irradiating a volume of soil with the neutrons. Nuclear reactions are effected within the soil and gamma radiation is emitted from the soil. The system also includes an array of gamma detectors for detecting gamma radiation emitted from the soil; source electronics for controlling the width of regularly repeated pulses of neutrons generated by the neutron source; detector electronics associated with the gamma detectors for amplifying and digitalizing signals generated by the gamma detectors and storing data representing the digitalized signals; spectral analysis software for analyzing the data and determining the concentrations of selected target elements in the soil; and an acquisition interface module (AIM).

Abstract: A method for determining the depth of a gamma emitting element beneath the surface of a volume of soil is disclosed. The disclosed method includes the steps of detecting gamma rays at a first height h.sub.1 above the surface; detecting gamma rays at a second height h.sub.2 above the surface; determining a ratio R representative of the ratio of the number of gamma rays detected at h.sub.2 to the number of gamma rays detected at h.sub.1, or vice versa; and inferring, on the basis of the ratio R, an estimate of the depth of the gamma emitting element beneath the surface.

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: The finely-divided particles of a selected phosphor material are combined with an aqueous solution of a suitable binder material to form an emulsion which is spread uniformly on the smooth surface of a support member. The wet coating is then heated to remove the water and the resulting film is sintered to produce a strong, continuous film. The film is then peeled from the support member resulting in a uniformly thick sheet of phosphor and binder from which dosimeters can be cut or stamped to any desired size.

Abstract: A thin film radiation dosimeter is secured to a plate member exhibiting sufficient mechanical strength to function as a dosimeter support member and electrical resistance characteristics which permit the plate member to function as a heating element during the readout process of the radiation dosimeter.

Abstract: In a radiation dosimeter assembly consisting of a wafer-like radiation dosimeter in combination with a mechanical support member the radiation dosimeter is secured within an aperture of the support member by disposing a protective film on either side of the dosimeter and securing the film to the support member via a high temperature adhesive or high temperature adhesive film. This assembly technique permits the annealing of the combination of the dosimeter and the support member to a temperature of about 300.degree. C. which is the typical process for "erasing" extraneous radiation dosage stored in the dosimeter prior to the use of the radiation dosimeter/support combination for radiation measurements. The capability of annealing the total combination permits stock piling of preassembled radiation dosimeter/support member combinations for extended periods of time.

Abstract: The heating element in a conventional radiation dosimeter reading apparatus which functions to both physically support a dosimeter as well as heat the dosimeter to a temperature of luminescence, is modified to include a dished portion, or recessed portion, having a flat bottom and sufficient dimensions to receive the radiation dosimeter and allow for the positioning of a transparent retainer, i.e., a glass plate, in contact with the dosimeter to physically retain the dosimeter in the recess to avoid deformation of the dosimeter when heated, and transmit light emanating from the dosimeter when heated.

Abstract: An improved thermoluminescent dosimeter system and apparatus for sensing alpha particle emission. A thermoluminescent body is sealed between a pair of metallized plastic films. The dosimeter is mounted within a protective inverted cup or a tube closed at one end, which is disposed in a test hole for exposure to radioactive radon gas which is indicative of uranium deposits.