Abstract: A defective fuel bundle location system for use with a heavy water moderated nuclear fission reactor having a fueling machine, including a test tool defining an internal volume, the test tool being configured to be received within both the fueling machine and a corresponding fuel channel of the reactor, and a test container defining an internal volume, wherein the test container is configured to be received within the internal volume of the test tool and the internal volume of the test container is configured to receive primary fluid from the reactor when the test tool is disposed within the corresponding fuel channel of the reactor.

Abstract: A method and system for controlling operation of an immersion cooling system to filter a heat transfer fluid having an immersion cooling tank adapted to contain the heat transfer fluid used to immersion cool a heat-generating object contained therein, the method and system comprises: sampling the heat transfer fluid in the tank; measuring at least one property or parameter of the sampled heat transfer fluid; generating and transmitting measurement data to a control unit; comparing measurement data with respective threshold data using the control unit; and filtering the heat transfer fluid with a filter based on the comparison results of the control unit.

Abstract: A sample feed device is provided, including: a body; a sample tray provided on the body; a moving part provided on the body and capable of reciprocating on the body, and the moving part provided with a transfer chamber, the transfer chamber capable of receiving a sample from the sample tray and transferring the sample to an analyzer with the movement of the moving part; a processing system provided on the body, and capable of performing helium gas purging and vacuum processing to the sample. The sample feed device may feed the sample automatically through relay transfer of the sample by the sample tray and the moving part. The processing system may perform the helium gas purging and vacuuming to the sample, which strips adsorbate on the surface of the sample by the helium gas purging, and removes the stripped adsorbate on the surface of the sample by vacuuming.

Abstract: A radiation monitor includes a radiation detection unit detecting radiation, and an optical fiber transmitting photons emitted from a light emitting element of the radiation detection unit, wherein the radiation detection unit includes a first light emitting element generating a photon in response to incident radiation, a chemical compound part having chemical compounds which generate charged particles by nuclear reactions with incident neutrons, and a second light emitting element being located between the first light emitting element and the chemical compound part and generating a photon in response to radiation.

Abstract: A method for detecting a leak in a cladding tube in a nuclear reactor is described. The method is well-suited for use in a reactor having a plurality of cladding tubes housed in a plurality of linearly arranged channels for flowing coolant past the cladding tubes. The method includes monitoring the channels for the occurrence of an increase in radiation above a selected base line indicative of the presence of at least one fission product in the coolant in at least one of the plurality of channels, and monitoring the channels for the occurrence of time dependent changes in the strength of radiation in the coolant above the base line along the length of the at least one of the plurality of channels. The leak location is calculated by triangulating the radiation readings from a fixed linear array of detectors positioned adjacent to the channels to determine the location of the strongest radiation reading and the location along the length of the channel where the increase in radiation occurred.

Abstract: A method and system detects failures in nuclear fuel assemblies (600). A water treatment device degasses/removes fission gases from water used in the canister (500) of a vacuum sipping device (30). A sipping procedure then detects a failure in a fuel assembly in the canister. The degassing improves a signal-to-noise ratio of the detector used during the sipping process, and improves the failure detection sensitivity of the system. Additionally and/or alternatively, gas may be recirculated through the canister water before the vacuum is applied so that fission gas concentration in the recirculating gas reaches a baseline equilibrium with the canister water. The vacuum is thereafter applied and the sipping procedure proceeds such that an increase in detected radioactivity over the baseline equilibrium indicates a leak in the fuel assembly.

Abstract: The invention relates to a device for performing a leak test on a fuel rod capsule, which contains at least one fuel rod and test gas, which device comprises a test container, which is designed to accommodate at least one fuel rod capsule and can be lowered into a pool of a nuclear plant flooded with water. According to the invention, a mass spectrometer is fluidically connected to the interior of the test container in such a way that a gas flow can be fed to the mass spectrometer in order to sense the concentration of the test gas that has diffused into the test container from the fuel rod capsule.

Abstract: Systems and methods for servicing a nuclear reactor module are provided. Such systems include a crane that couples to the reactor module. The crane includes a conduit for routing signals from sensors of the reactor module to sensor receivers. The crane includes a drive mechanism to move the reactor module from a reactor bay to a servicing area. The drive mechanism moves the reactor module in a first direction and a second direction that is orthogonal to the first direction. The crane includes a support bracket for mounting sensor signal receivers that receive the signals from the sensors within the nuclear reactor module. The system includes a display to display representations of the signals from the sensors of the nuclear reactor module in a servicing area. Another display displays representations of the signals from the sensors of the nuclear reactor module in an operator area.

Abstract: A batch chemical analyzer is disclosed, the analyzer including a reaction tank (100) in which sample and reagent are mixed, a detector (200), a switching valve (300), a multi-port valve (400), a pump (500) and an air suction/discharge hole (600), and particularly, the switching valve (300) includes a plurality of holes (301˜310) configured to receive sample and reagent and to send the same to the reaction tank (100) and the detector (200) for discharge to the outside, and the rotor (320) formed with a plurality of inlets (321˜325) simultaneously communicating with two adjacent holes of the plurality of holes (301˜310), whereby the two adjacent holes are differently paired to be communicated in two ways by the rotation of the rotor (320).

Abstract: A nuclear reactor fuel integrity monitor includes: a ?-ray detector which detects ?-ray of a specific radionuclide of a subject measurement medium of a nuclear reactor; a sample container which retains the subject measurement medium therein and surrounds the circumference of the ?-ray detector; and a measurement control device which performs a control so that a predetermined amount of the subject measurement medium is introduced into the sample container and calculates a concentration of the specific radionuclide from ?-ray data per each unit time detected by the ?-ray detector and a volume of the subject measurement medium introduced into the sample container.

Abstract: A neutron detector system and method for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. Comparison of the observed neutron count distribution with a Poisson distribution is performed to distinguish fissile material from non-fissile material.

Abstract: Method including: inducing, with antiprotons, nuclear fission in a material, such as depleted uranium; measuring leakage of radioactive byproduct produced by the fission; and producing, responsive to the measuring, a design for the nuclear fuel element. Apparatus, manufactures, and products produced by the method can be encompassed.

Abstract: A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source.

Abstract: Illustrative embodiments provide a nuclear fission reactor, a vented nuclear fission fuel module, methods therefor and a vented nuclear fission fuel module system.

Abstract: Illustrative embodiments provide a nuclear fission reactor, a vented nuclear fission fuel module, methods therefor and a vented nuclear fission fuel module system.

Abstract: Fuel rods of fuel assemblies of a boiling water reactor are tested for leaks. A plurality of fuel assemblies are each arranged adjacent to one another in a cell of the upper core grid of the boiling water reactor. A hood is placed above a plurality of cells A water sample is taken from each of the cells, and the water samples from a plurality of cells forming a group are combined and tested for the presence of radioactive fission products A plurality of groups are analyzed simultaneously in a number, which number corresponds to the number of groups, of measurement channels. Where a result of a group is positive, the cells of the group are tested separately by the measurement channels. Those fuel assemblies of a cell that is found positive are tested individually outside the hood.

Abstract: Methods and apparatus are provided for measuring emissions from radioactive material in a matrix. Consideration is made in the variation in counts observed at different rational positions of the body of material so as to establish the information about the position of the radioactive material within the matrix.

Abstract: Fuel rods of fuel assemblies of a boiling water reactor are tested for leaks. A plurality of fuel assemblies are each arranged adjacent to one another in a cell of the upper core grid of the boiling water reactor. A hood is placed above the fuel assemblies of a plurality of cells, which form a division for simultaneously heating the fuel assemblies of this division. At least one water sample is taken from each cell of this division, and the water samples from a plurality of cells forming a group are combined and tested for the presence of radioactive fission products contained in the water sample. A plurality of groups are analyzed simultaneously and independently of one another in a number, which number corresponds to the number of groups, of measurement channels of an analysis device. Where a result of a group is positive, the water samples from the cells which are located in this group are fed separately to the analysis device and are analyzed separately in a corresponding number of measurement channels.

Abstract: The contents of a container 1 are non-intrusively monitored by probing the container with an ultrasonic signal, and measuring changes in the ultrasound signature of the received signal after the signal has passed through the contents of the container.

Abstract: A method for testing whether fuel rods of fuel assemblies resting on a working base and under water, of a nuclear reactor are leaking is disclosed. The method includes heating at least one first fuel assembly of a first division of fuel assemblies for driving radioactive fission products out of a defective fuel rod contained in the first fuel assembly. The first fuel assembly is continuously tested by extracting samples of water and continuously degassing the water removed from an area around the first fuel assembly even during the heating resulting in gas. A radioactivity of gaseous fission products released in the gas is continuously recorded. A fuel assembly belonging to a second division of fuel assemblies is heated only if the first fuel assembly belonging to the first division of fuel assemblies has been tested. An apparatus for implementing the method is also disclosed.

Abstract: A fuel assembly mechanical flow restriction apparatus for detecting failure in situ of nuclear fuel rods in a fuel assembly during reactor shutdown.

Abstract: A combination of a master machine and a plurality of slave machines communicate wireless with each other. In case of a radiation leak accident, multitudes of inhabitants or workers dealing with the accident are made to carry the slave machines. The slave machine measure the degree of radiation exposure in real time, and notifies this measured result automatically to the master machine by wireless communication. The master machine recognizes the accurate radiation dose of the exposure and determines the degree of danger. The master machine notifies in real time the determined result individually to people carrying the slave machine, who are exposed victims or people that have a possibility of being exposed, according to the danger degree. The master machine is made to extract true radiation measurement data from the measurement signal data sent by the slave machine, by discriminating noise.

Abstract: A method for testing whether fuel rods of fuel assemblies resting on a working base and under water, of a nuclear reactor are leaking is disclosed. The method includes heating at least one first fuel assembly of a first division of fuel assemblies for driving radioactive fission products out of a defective fuel rod contained in the first fuel assembly. The first fuel assembly is continuously tested by extracting samples of water and continuously degassing the water removed from an area around the first fuel assembly even during the heating resulting in gas. A radioactivity of gaseous fission products released in the gas is continuously recorded. A fuel assembly belonging to a second division of fuel assemblies is heated only if the first fuel assembly belonging to the first division of fuel assemblies has been tested. An apparatus for implementing the method is also disclosed.

Abstract: A fuel assembly mechanical flow restriction apparatus for detecting failure in situ of nuclear fuel rods in a fuel assembly during reactor shutdown.

Abstract: An apparatus and a method for detecting and locating leaks in a nuclear plant, in particular a pipeline in a nuclear plant, include a collection line which is permeable to a substance to be detected and which communicates with a pump and with a sensor for the substance. The sensor has a detector for detecting the radioactivity of the substance or a branch line which communicates with a detector for detecting radioactivity branches off upstream of the sensor. If a radioactive substance reaches the collection line and penetrates it, then the location of the leak can be determined from the instant at which the radioactive substance reaches the detector.

Abstract: A multiple-sheathed sodium leakage detection apparatus capable of detecting a small amount of leakage of sodium due to a breakage of a well for temperature measurement at an early stage of the leakage. The apparatus is a combination of a multiple-sheathed sodium leakage detector having a sheathed thermocouple and sodium leakage detection element wires, which are disposed in an insulating material filled in a multiple sheath; a sodium leakage judgment device which judges whether or not there is a leakage of sodium by a signal from the multiple-sheathed sodium leakage detector; an alarm device which gives an alarm when it is judged that there is a leakage of sodium; and signal lines which connect these devices. The multiple-sheathed sodium leakage detector is designed in conformity to the sheath outer diameter so that it can be inserted into a well which has already been installed on an existing piping without changing the well.

Abstract: Methods and apparatus for moving fuel bundles in a reactor pressure vessel (RPV) of a nuclear reactor are described. In one embodiment of the apparatus, a support tube facilitates the positioning of a multiple channeled magazine within the RPV, especially at locations adjacent fuel bundles. In the one embodiment, the support tube extends in the reactor pressure vessel into the area above the top guide. A magazine assembly is coupled to the support tube, and includes a magazine having a plurality of fuel bundle receiving channels. The magazine extends from the support tube so that it is adjacent the fuel bundles and the top guide. Grapples extend through the magazine channels, engage the fuel bundles, and retract the bundles into the magazine channels. The magazine and support tube, and thus the bundles, are then moved.

Abstract: An apparatus for testing a nuclear fuel assembly for leaks by sweeping a fluid along the fuel assembly while the fuel assembly is disposed in a pool. The apparatus includes a bridge overlying the pool and a mast assembly depending from the bridge. The mast assembly includes an outer, stationary mast and an inner, movable mast adapted to hold the fuel assembly and to position the fuel assembly in the interior channel between the upper and lower ends. The apparatus includes an injection assembly including an injection conduit, a nozzle and a clamp system for securing the nozzle to the outer mast. The apparatus also includes a suction conduit having an inlet disposed in fluid communication with the interior channel for collecting the fluid after the fluid sweeps the fuel assembly.

Abstract: A refueling machine for refueling a pressurized water reactor has a trolley which travels on rails mounted on a transversely movable bridge. The trolley supports a refueling mast which includes an outer mast and two horizontally spaced apart, vertically movable gripper masts disposed within the outer mast. This design permits the machine to safely handle two fuel assemblies simultaneously in order to substantially reduce refueling critical path time. The two gripper masts can be raised, lowered and otherwise operated independently of each other. A partition plate extending through the stationary mast between the two movable gripper masts permits each fuel assembly held in the refueling mast to be independently leak tested.

Abstract: The present invention provides a method for identifying failed fuel elements and the scale of damage accurately, quickly and at low cost without disassembling a fuel assembly and without discharging radioactive waste. Radiation detector(s) for measurement of gamma radiation emitted from surface of the irradiated fuel assembly and the fuel assembly are rotated and translated relative to each other, the dectected data of the radiation emitted from the surface of the fuel assembly is acquired, processed, a tomographic image is constructed from the radiation intensity distribution and is prepared and displayed, and a failed fuel element is finally confirmed from the tomographic image of the fuel assembly cross-section.

Abstract: A method and system for providing a tag gas identifier to a nuclear fuel rod and analyze escaped tag gas to identify a particular failed nuclear fuel rod. The method and system include disposing a unique tag gas composition into a plenum of a nuclear fuel rod, monitoring gamma ray activity, analyzing gamma ray signals to assess whether a nuclear fuel rod has failed and is emitting tag gas, activating a tag gas sampling and analysis system upon sensing tag gas emission from a failed nuclear rod and evaluating the escaped tag gas to identify the particular failed nuclear fuel rod.

Abstract: For use in the manufacture of gas tags employed in a gas tagging failure detection system for a nuclear reactor, a plurality of commercial feed gases each having a respective noble gas isotopic composition are blended under computer control to provide various tag gas mixtures having selected isotopic ratios which are optimized for specified defined conditions such as cost. Using a new approach employing a discrete variable structure rather than the known continuous-variable optimization problem, the computer controlled gas tag manufacturing process employs an analytical formalism from condensed matter physics known as stochastic relaxation, which is a special case of simulated annealing, for input feed gas selection.

Abstract: A gamma-rays measurement method of radionucludes (iodine-131, cobalt-60, etc.) coexisting with radionuclides (nitrogen-13, fluorine-18, cobalt-58, etc.) each emitting a pair of annihilation gamma-rays, particularly in primary water of a nuclear reactor by the use of a gamma-ray spectrometric system which includes a primary detector for detecting the gamma-rays and the one annihilation gamma-rays as pulses, a secondary detector for detecting the other annihilation gamma-rays as pulses, and shield detector for detecting gamma-rays Compton-scattered and escaped from the primary to shield detectors as pulses. The method comprises counting the pulses of the secondary detector in anticoincidence with the pulses of the primary detector, thereby to reject the recording of the annihilation gamma-rays from the primary detector, thus minimizing the annihilation gamma-rays disturbing to the measurement, followed by determining count numbers of the gamma-rays.

Abstract: An on-line sipping air delivery system that propels bubbles across the entire surface of the fuel assembly. A pump delivers liquid through an aspirator located near the bottom of the fuel handling mast. Liquid flow through a venturi in the aspirator causes a drop in pressure inside the aspirator and pulls air into the aspirator through an ambient air line that extends above the surface of the liquid. The air is mixed with liquid as it flows through the aspirator and the mixture is injected under the fuel assembly through nozzles positioned at the bottom of the assembly. Suction nozzles above the liquid level at the top of the fuel assembly are used in a conventional manner to capture and deliver the released air and gases to appropriate testing equipment.

Abstract: The invention relates to an arrangement for carrying out leak detection of a fuel assembly for a pressurized-water nuclear reactor. A substantially vertical hollow mast means open in both ends houses the fuel assembly to be examined. The fuel assembly is drawn to the inside of the mast means from its lower side. The part of the mast means housing the fuel assembly is lifted to a position in which the fuel assembly is provided near but below the water surface of water inside the nuclear reactor. Water is sucked from a position inside the mast means above the fuel assembly. A gas separating means separates gases present in water sucked from the inside of the mast means. The separated gas is analyzed in a gas analyzing means regarding its amount of gaseous fission products.

Abstract: A process and a system for detecting defective nuclear fuel assemblies in situ. The system includes two basic subsystems. The first subsystem is a sample collection system consisting of a hood placed over the fuel. A technique whereby a vacuum is drawn across a submerged nozzle of a degas tank is used to draw up the sample of fluid out of a fuel assembly. The second subsystem determines the amount of Kr-85 radioisotope contained in the fluid sample. This information is used to determine whether the fuel assembly contains a defective, i.e., leaking, fuel rod. The measurement values for Kr-85 in the fluid sample extracted from the fuel assembly are compared to the measurement values for Kr-85 in fluid samples taken from the reactor pool prior to fuel assembly testing and fluid samples taken from non-leaking control cells, the latter values representing the background to which the subject fuel assembly is compared.

Abstract: Failed fuel cladding in light water reactors can lead to premature reactor shutdown for removal of the failed fuel bundles from the core. The lost power and associated fuel replacement costs are astronomically high, approaching a million dollars per day in near term costs. Additionally, the long term affect on an operating plant are the release and distribution around the plant of long-lived fission products which increase radiation levels and impose increased radiological protection procedures. A method has been developed which allows for on-line early detection of failed fuel elements while the plant is operating through flowing off-gas through a conduit to a gamma spectrograph with a time delay to allow interfering short lived isotopes to decay and then analyzing for gamma radiation from at least one of the nuclides Kr-85m, Kr-87, Kr-88, Xe-133, Xe-135, Xe-135m and Xe-138.

Abstract: The length of an object, particularly a spent fuel rod, is measured by taking an optical image of a support surface and then taking an optical image of a fuel rod when placed on the support surface. The two optical images are digitised, stored and then processed to obtain a difference in grey level values between the two stored images. The two images are stored as a plurality of columns each containing pixels having a grey level value. Using an algorithm, the difference between these values in corresponding columns of the two images are determined as root mean square values. The columns are processed in turn to determine which have a root mean square value above a threshold value, these being representative of the presence of a fuel rod. The number of such columns is a measure of the fuel rod length.

Abstract: A process and system for the rapid concentration, separation and measurement of Kr-85 and Xe-133. By measuring the amount of Kr-85 radioisotope which is present, false positive signals for the vacuum sipping process can be eliminated. The fission gases are trapped by passing the recirculating gas stream through an adsorbing media. During this process, a known mixture of nonradioactive krypton and xenon is added to the gas stream which enters a thermal conductivity (TC) detector to calibrate the latter. The trapped gases are desorbed and injected into the inlet of a separating column. The column discharges into the TC detector. The TC detector discharge is diverted for counting to an evacuated beta detector chamber during the time that krypton is sensed by the TC detector. Any minute amount of Kr-85 is captured in the chamber, free of Xe-133. The detector discharge is diverted for counting to another evacuated beta detector chamber during the time that xenon is sensed by the TC detector.

Abstract: For use in the manufacture of gas tags such as employed in a nuclear reactor gas tagging failure detection system, a method for designing gas tagging compositions utilizes an analytical approach wherein the final composition of a first canister of tag gas as measured by a mass spectrometer is designated as node #1. Lattice locations of tag nodes in multi-dimensional space are then used in calculating the compositions of a node #2 and each subsequent node so as to maximize the distance of each node from any combination of tag components which might be indistinguishable from another tag composition in a reactor fuel assembly. Alternatively, the measured compositions of tag gas numbers 1 and 2 may be used to fix the locations of nodes 1 and 2, with the locations of nodes 3-N then calculated for optimum tag gas composition.

Abstract: During leak detection of fuel assemblies (10) for a boiling water nuclear reactor, water is sucked from an area (12) located above an outlet (11) for water from the fuel assembly and around a gripper (8) for a loading machine (1) for fuel assemblies, which gripper is secured to the fuel assembly above the outlet, while the fuel assembly is lifted in the water (6) in which the fuel assembly is immersed or while the fuel assembly, after having been lifted in the water, is maintained in its lifted position or relowered in the water and while maintaining a flow of the water through the fuel assembly and around the gripper. The sucked-off water is subjected to an analysis with respect to the presence of fission products which, during operation of the reactor, have been formed of the fuel in the fuel assembly.

Abstract: A method and apparatus for measuring radioactivity associated with nuclear reactor coolant leaks. The method includes providing a delay tank in a gas sampling line upstream of a radiation particulate monitor, the delay tank allowing radioactive noble gases from the leak to decay to radioactive daughter particulates that are monitored by the radiation particulate monitor. The apparatus includes the delay tank as well as a background delay tank and a valve sequencer for comparing radiation associated with the delay tank to radiation associated with the background delay tank.

Abstract: Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wave length shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event.

Abstract: The fuel element is inserted into a cell, under water, in a pool. Compressed air is injected into the cell so as to drain it of water. A pressure lower than atmospheric pressure is established in the cell and then the gases contained in the cell are subjected to a stream of scavenging air and are collected in a fission product detecting unit. Water is introduced into the cell, the water in the cell is sampled, fission products in the water sample are detected and the fuel element is extracted from the cell if the possible presence of a leak from this fuel element is determined. The detection device comprises a cell having an elongate body delimiting a central housing for a fuel element and end parts. One of the end parts, traversed by a channel in the extension of the housing, receives a cap for opening and closing the channel associated with a remotely controllable opening and closing arrangement.

Abstract: The present invention is directed to a nuclide separation precipitator system in which noble gas nuclear fission products are introduced into a gas reservoir and generate charged daughter nuclides in the gas reservoir. A collector collects three detectable charged daughter nuclides. A detector detects the energy distributions of beta-rays and gamma-rays emitted from the daughter nuclides collected in the collector and outputs signals indicative of the detected beta-rays and gamma-rays. Three pulse height discriminators discriminate the signals output from the detector into three respective energy levels of a low energy range, a middle energy range, and a high energy range. A first order simultaneous equation of three unknowns obtained by utilizing a fact that counting ratios of the three energy ranges vary for each daughter nuclide is then solved.

Abstract: Water testing apparatus for monitoring circulating water coolant in service within a water cooled nuclear reactor system is disclosed. The invention is an improvement in such water testing apparatus and comprises filtering and a preconditioning of selected sample specimens of the coolant water with a pH adjustment for inhibiting unbalancing an equilibrium in solution of water coolant with ion solutes.

Abstract: The invention makes it possible to measure the degree of radioactive radiation emitted by large pieces. It includes two large gamma ray detectors (12A, 12B) placed opposite each other and whose spacing is adjustable. They are completed by a photoelectron multiplier (14A, 14B). The piece (2) to be measured is suspended so as to be brought between the two detectors (12A, 12B). The positioning of these detectors is obtained with the aid of a computer and a system (22) for recognizing the shape of the piece (2) functioning with the aid of optical clip-on lenses. The fact that the two detectors are position-adjustable makes it possible to take account of the shape of the piece to be measured. An application is the recovery of materials originating from nuclear installations with the view to re-using the materials.

Abstract: In order to detect leaky rods inside a nuclear fuel assembly (24), this assembly is placed inside a pool (36) so that the gases contained inside the rods (10) escape from the leaky rods. By heating the upper part of the assembly by means of a heated sleeve (42) the gases contained inside the leaky rods are expanded. Monitoring the diameter change of the rods (10) at the base of the assembly by means of a measuring device (44) makes it possible to distinguish the sealed rods whose sheaths elastically get out of shape from the leaky rods whose sheaths hardly warp at all.

Abstract: An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

Abstract: An inspection apparatus and method for testing nuclear fuel rods for helium leaks includes the basic operative steps of constantly leaking helium at a predetermined known value into a test chamber containing a fuel rod to be tested, and sampling the atmosphere within the chamber and measuring the helium in the atmosphere. A measured helium value below a preset minimum helium value indicates a malfunction in the inspection apparatus, whereas a measured helium value above a preset maximum helium value indicates the existence of a helium leak from the fuel rods. On the other hand, a measured helium value between the minimum and maximum helium values indicates the absence of a helium leak from the fuel rod.