Abstract: Disclosed is a nuclear reactor system for use with a power grid. The nuclear reactor system comprising a nuclear reactor, an energy storage system coupled to the nuclear reactor, and a control circuit coupled to the nuclear reactor and the energy storage system. The control circuit is configured to monitor a power demand of the power grid, monitor a power output generated from the nuclear reactor, detect a change in the power demand, cause the energy storage system to temporarily compensate for the change in the power demand, and adjust the power output based on the change in the power demand.

Abstract: A sensor system for a fuel rod including a fuel pellet stack, the sensor system including a wireless interrogator disposed outside the fuel rod and a passive sensor component disposed within the fuel rod. The passive sensor component includes a receiver structured to receive an interrogation signal and output an excitation signal in response to receiving the interrogation signal, a reference transmitter structured to output a reference signal to the reference receiver in response to the excitation signal, a sensing transmitter structured to output a sensing signal to the sensing receiver in response to the excitation signal, and a core at least partially disposed within the sensing transmitter and coupled to move in conjunction with expansion or contraction of the fuel pellet stack, to move based on changes in pressure within the fuel rod, or to change temperature based on temperature changes within the fuel rod.

Abstract: The present disclosure is generally related to methods, devices and systems for improving the performances of a Rod Cluster Control Assembly (RCCA) and/or a Control Element Assembly (CEA) to mitigate clad strain, especially in the high fluence region, during normal operation conditions and accident conditions. One method may include incorporating a device such as a powder collection and blockage device between the ceramic upper and ceramic lower absorber materials of the RCCA and/or CEA. Another method may include increasing the plenum volume by incorporating an axial hole into the top end plug extension. Another method may include increasing the plenum volume by incorporating an axial hole into the bottom end plug and optionally incorporating radial grooves in the bottom of the lower absorber material to provide a flow channel for gas expansion or generation to ensure that the lower absorber does not block the opening in the bottom end plug.

Abstract: A passive venting arrangement for use in venting gases produced by radioactive materials. The arrangement includes a source gas region for receiving the gases and a filter ullage region disposed above the source gas region and segregated therefrom. A removable lid includes the filter ullage region and a plurality of bore holes. Each bore hole extends between, and fluidly couples, the source gas region and the filter ullage region. The arrangement also includes a plurality of filters disposed in contact with the filter ullage region. Each filter is structured to provide for an exchange of gases from the filter ullage region through the filter to an ambient environment.

Abstract: A system for measuring radiation activity of a target radioisotope being produced in a reactor core is disclosed. The system includes a cable assembly and a radiation detector. The cable assembly includes a housing, a target cable configured to position the housing, and a drive cable couplable and decouplable with the target cable. The target radioisotope is positioned within the housing. The drive cable is configured to drive the target cable. The radiation detector is configured to periodically measure the radiation activity of the target radioisotope being produced.

Abstract: A system for measuring gamma spectroscopy of a neutron irradiated material includes a plurality of semiconductor sensors. Each of the semiconductor sensors includes a gamma ray receiving surface disposed above a Schottky layer in contact with an n-doped active layer. The receiving surface is configured to emit electrons upon irradiation by gamma rays. The receiving surface contacts an adjustable telescoping mount configured to adjust the distance between the receiving surface and the Schottky layer. The n-doped layer is fabricated to have a thickness designed to pass through electrons having greater than a defined energy. The combination of adjustable receiving surface and active layer thickness define a minimum and maximum energy response of each of the sensors. Multiple sensors may be integrated in an array in which each sensor has its own energy response. An array of such sensors can measure the gamma spectrum of a material irradiated with neutrons.

Abstract: An enclosure for producing a radioisotope from an irradiation target material in a thimble guide tube of a nuclear reactor core is provided. The enclosure is comprised of an enriched material and defines a cavity therein. The cavity of the enclosure is configured to house the irradiation target material. A target assembly for producing synthetic radioisotopes and a method for producing pharmaceutical radioisotopes with a target assembly are also provided.

Abstract: Devices, systems, and methods for delivering delta radiation using prompt neutron capture gamma radiation are disclosed herein. In one aspect, a device for delivering delta radiation can include a neutron generator, an electron emitter, and an irradiation target. The neutron generator may be configured to generate a neutron flux field. The an irradiation target can include an irradiation target material having a high thermal neutron cross section and can be configured to emit gamma radiation in response to exposure to the neutron flux field. The electron emitter can be configured to emit delta radiation in response to exposure to the gamma radiation. In some aspects, the irradiation target and the electron emitter can be configured to be positioned between the neutron generator and a surface of an object to deliver the delta radiation to a target region within the object.

Abstract: A target assembly for producing synthetic radioisotopes of Cobalt is provided. The target assembly comprises an enclosure and an irradiation target material. The enclosure defines a cavity therein and is comprised of an enriched material configured to have a short half-life upon being exposed to a neutron flux. The irradiation target material is comprised of a precursor to Cobalt-60. A method for producing a target assembly is also provided.

Abstract: A heat exchanger for cooling a nuclear reactor core is disclosed herein. The heat exchanger can include a first stage including an input configured to receive a working fluid from an external source into the heat exchanger, and a first plenum configured to envelope a moderator heat pipe extending from the nuclear reactor core. The heat exchanger can further include a second stage including an output configured to remove a working fluid from the heat exchanger to the external source, and a second plenum configured to envelope a power heat pipe extending from the nuclear reactor core, wherein the first plenum and the second plenum are in fluid communication and configured such that the external fluid must traverse the first plenum and over the moderator heat pipe before entering the second plenum and traversing over the power heat pipe.

Abstract: Arrangements and devices for reducing and/or preventing wear of a thermal sleeve in a nuclear reactor are disclosed. Arrangements include a first structure provided on or in one the thermal sleeve and a second structure provided on or in the head penetration adapter. At least a portion of the first structure and at least another portion of the second structure interact to resist, reduce, and/or prevent rotation of the thermal sleeve about its central axis relative to the head penetration adapter. Devices include a base for coupling to a guide tube of the reactor and a plurality of protruding members extending upward from the base. Each member having a portion for engaging a corresponding portion of a guide funnel of the thermal sleeve.

Abstract: A coating for protecting a Zirconium alloy based layer of a nuclear fuel rod cladding is provided. The coating comprises a primary layer. A microstructure of the primary layer is comprised of a number of grains and is randomized. The primary layer is configured with a density of about 94.5% or greater. A cladding for a nuclear fuel rod and a method for producing a cladding for a nuclear fuel rod are also provided.

Abstract: A method is described herein that produces UN from UF6 in at most two steps comprising UF6?intermediate?UN. The principle of the reaction is that in a first step, UF6 would be reduced to UxNy, where x may be an integer selected from 1 and 3, and y is an integer selected from 1 and 2. Reduction occurs at or near the surface of a gaseous membrane electrode where it is also in contact with a nitrogen bearing salt. In a second step, UxNy decomposes to UN and N2 gas, either in the same reactor as the first step or after removal to a separate unit for further processing.

Abstract: A calibration system is disclosed. The calibration system includes a waveform generator configured to generate a periodic waveform and a control circuit in signal communication with the waveform generator. The control circuit includes an analog-to-digital converter configured to convert the periodic waveform to digital values and an electronic device in signal communication with the analog-to-digital converter. The electronic device is configured to verify calibration of (1) timing of the control circuit and (2) voltage levels of the control circuit based on the periodic waveform.

Abstract: Disclosed is a passively cooled nuclear reactor, comprising a heat exchanger and a nuclear reactor core disposed proximal to the heat exchanger. The nuclear reactor core comprising a fuel rod, a heat pipe located proximate to the fuel rod and extending from the nuclear reactor core into the heat exchanger, a moderator monolith configured to house and space the fuel rod and the heat pipe, and a thermal bond material disposed internally throughout the moderator monolith to surround the fuel rod and the heat pipe with the thermal bond material and to facilitate heat transfer from the nuclear reactor core to the heat exchanger.

Abstract: A housing assembly configured to house a reactor is disclosed. The housing assembly includes a plurality of modular walls configured to surround the reactor and a passive temperature control system. The plurality of modular walls includes a first modular wall. The passive temperature control system is coupled to the first modular wall. The passive temperature control system is configured to transfer heat between the reactor and an area around the housing assembly.

Abstract: Devices, systems, and methods for power generation using irradiators and other gamma ray sources are disclosed herein. In various aspects, an irradiator-based power generation device is disclosed. The power generation device can include a radiator layer configured to at least partially surround an irradiator, wherein the radiator layer comprises a radiator material configured to emit delta radiation in response to exposure to gamma radiation; an electrical insulation layer configured to surround the radiator layer, wherein the electrical insulation layer comprises an electrical insulation material configured to allow delta radiation to penetrate therethrough; and a collector layer configured to surround the electrical insulation layer, wherein the collector layer comprises a collector material configured to collect delta radiation.

Abstract: A power sensor system for monitoring a subcritical neutron generator is provided. The power sensor system comprises a self-powered sensor insert. The self-powered sensor insert comprises an insert thimble and a detector assembly. The insert thimble includes an outer housing, a power generator configured to produce an electrical power based on an incident radiation and a first electrical interface electrically connected to the power generator. The detector assembly includes a solid state radiation detector able to provide a detector signal directly proportional to a neutron flux level, a transmitter configured to wirelessly output a transmitter signal based on the detector signal and a second electrical interface configured to electrically couple to the first electrical interface. A power monitor system comprising a power sensor system and a control system and a method for optimizing a subcritical neutron generator are also provided.

Abstract: A cladding for housing enriched nuclear fuel in a nuclear fuel assembly is provided. The cladding comprises a base layer comprised of Zirconium alloy and a coating for the base layer. The base layer has a wall thickness of less than 1 millimeter. The coating comprises a primary layer comprised of Chromium or a Chromium alloy. The primary layer has a thickness in the range of about 5 to about 50 microns. A fuel rod for a nuclear reactor core and a method for producing a fuel rod are also provided.

Abstract: A target assembly for producing synthetic radioisotopes of Cobalt is provided. The target assembly comprises an enclosure and an irradiation target material. The enclosure defines a cavity therein and is comprised of an enriched material configured to have a short half-life upon being exposed to a neutron flux. The irradiation target material is comprised of a precursor to Cobalt-60. A method for producing a target assembly is also provided.