Abstract: This invention applies optical sensing technology with an ultrasound inspection system to associate encoded position data with the inspection data. The compact electronics of the optical system can be attached to the inspection assembly to allow fully encoded position information to be associated with the ultrasonic, eddy current, or other nondestructive examination data without substantially impacting the overall envelope of the NDE inspection equipment. Moreover, because of the small size, the optical system can be used in tandem to monitor skew or twist of the inspection equipment with respect to the normal rectilinear transducer orientation. The inspection equipment position information is then coupled to the inspection data to provide data outputs equivalent to fully encoded multi-axis manipulator automated scans, but with less setup burden and equipment expense.

Abstract: A method is provided for operating a nuclear reactor. The method includes operating the nuclear reactor for an initial cycle during which a core contains initial nuclear fuel assemblies; then operating the nuclear reactor for transition cycles, at least some of the initial nuclear fuel assemblies being progressively replaced, during the replacement steps preceding the transition cycles, with transition nuclear fuel assemblies or with plutonium-equilibrium nuclear fuel assemblies; and then operating the nuclear reactor for at least one plutonium equilibrium cycle during which the core contains only plutonium-equilibrium nuclear fuel assemblies.

Abstract: A method of evaluating at least one quantity relating to the distortion of a nuclear fuel assembly, the method including the following steps: the nuclear fuel assembly is placed in a volume of water bounded by an upper free surface; a camera is placed outside the volume of water, above the free surface; at least one image of at least one lateral face of the nuclear fuel assembly is taken; the at least one image is analyzed graphically and the at least one quantity relating to the distortion of the nuclear fuel assembly is deduced therefrom.

Abstract: The method comprises the steps of: partitioning the core in cubes to constitute nodes of a grid for computer implemented calculation, splitting the cubes into a first category and a second category, each cube of the first category being adjacent only to cubes from the second category so that the first category and second category of cubes constitute a checkerboard-like pattern, ordering the cubes of the first category and then the cubes of the second category, calculating neutron flux and/or thermohydraulics parameters by using an iterative solving procedure of at least one linear system and/or an eigensystem, the components of an iterant of the linear system and/or the eigensystem constituting the neutron flux and/or thermohydraulics parameters to be calculated, wherein, during the iterative solving procedure, calculations are conducted on the cubes of the first category then on the cubes of the second category.

Abstract: A computer implemented method for modelizing a nuclear reactor core, including the steps of: partitioning the core in cubes to constitute nodes of a grid for computer implemented calculation, calculating neutron flux by using an iterative solving procedure of at least one eigensystem, the components of an iterant of the eigensystem corresponding either to a neutron flux, to a neutron outcurrent or to a neutron incurrent, for a respective cube to be calculated. A control parameter is varied to impact a neutron eigenvalue ? through a perturbed interface current equation and drive the neutron eigenvalue ? towards 1.

Abstract: A method for installing industrial components in an environment is provided, in which, with the aid of a computer-assisted design model representing the theoretical layout of the industrial components in the environment, various measuring points of the theoretical positioning of the supports of each component are determined, those theoretical measuring points are codified with values, parameterisable model measuring ranges are parameterized by the codified values, and at least one measuring device is controlled with the aid of the codified values by application of the corresponding range in order to compare the actual positioning points in the environment as a function of theoretical positioning points of the supports of each component. The method is applicable to the installation of the components of the loops of the primary circuits of nuclear power stations.

Abstract: A nuclear fuel assembly bottom nozzle, of the type including a perforated plate to allow water to pass through it, the nozzle having lateral faces, and at least one anti-debris element positioned on a lateral face to block out debris likely to infiltrate between the bottom nozzle and another adjacent bottom nozzle, characterized in that, in the free state, the or each anti-debris element permanently projects from the lateral face on which it is positioned, the or each anti-debris element being elastically deformable so as to retract towards the lateral face in the event of a force being exerted on the anti-debris element towards the lateral face.

Abstract: The invention relates to a method of determining at least one technological uncertainty factor in respect of nuclear fuel elements (23) as a function of variations in the production parameters of the elements (23) in relation to nominal values. The inventive method comprises a step involving the use, for at least one production parameter, of a collective variation in said parameter in relation to the nominal value within a batch of produced elements (23). The invention can be used, for example, to design, produce and check pellets for light water reactors.

Abstract: A jet pump stabilizer is disclosed and claimed. The stabilizer includes a clamp body that is affixed about the riser pipe. Two U-clamps are connected to the clamp body, each U-clamp positioned about a jet pump mixer section. A wedge assembly is positioned between the clamp body and each mixer pipe, cooperating with the clamp body and U-clamps to laterally restrain the mixer sections. A clamp ring is positioned about each mixer section and retained in place by the U-clamps, wedge assemblies, and clamp body. A sealing ring is moveably connected to the clamp ring such that it is biased toward engagement with the jet pump diffuser. Seals provided on the stabilizer engage the jet pump assembly above and below the slip joint, preventing vibration-inducing leakage through the slip joint.

Abstract: The strip is of the type comprising a wall portion for delimiting a cell for receiving a fuel rod and allowing flow of a coolant upwardly through the spacer grid, a spring provided on the wall portion for biasing a fuel rod extending through the cell away from the wall portion, the spring being cut out in the strip and delimited by a slot and a motion limiter formed in the strip on the wall portion to limit motion of a fuel rod received in the cell towards the wall portion against action of the spring. According to one aspect of the invention, the motion limiter is located on an edge of the slot opposite the spring and defines a risen portion on the edge.

Abstract: A resin removal tooling system for electric generator parallel rings including: a non-rotating sheath; a shaft mounted in the non-rotating sheath; a cleaning ball attached to the shaft, the non-rotating sheath positioning the cleaning ball; a high speed motor coupled to the shaft for rotating the shaft; a variable power supply connected to the high speed motor; and a tachometer for measuring a rotational speed of the high speed motor and the cleaning ball. A process of cleaning resin out of an electrical generator parallel ring including the following steps: inserting a cleaning ball mounted on a shaft into the parallel ring; verifying a location of the cleaning ball; rotating the shaft; measuring a rotational speed of the cleaning ball with a tachometer; and removing resin with the cleaning ball.

Abstract: A lower nozzle for use in a nuclear fuel assembly provided. The lower nozzle is of the type having an axis and comprising a transverse lower tie plate for channelling the coolant through the lower tie plate and a tubular skirt extending axially from the periphery of the lower tie plate, the skirt delimiting an axial housing closed at one end by the lower tie plate and open at the opposite end, a debris filter configured for axial insertion in the housing and snap-fit springs for retaining the debris filter in the housing after insertion. The springs are configured to shift the debris filter axially towards the lower tie plate.

Abstract: A nuclear fuel assembly for boiling water reactor is provided. The nuclear fuel assembly includes a base, a head, a bundle of fuel rods extending longitudinally between the base and the head, a tubular fuel channel encasing the bundle of fuel rods, and at least one fuel channel spacer for transversely spacing the fuel assembly from an adjacent element. The or each fuel channel spacer includes a support having at least one plate and at least one corresponding leaf spring supported by the corresponding plate, the or each plate being fixed to a corresponding sidewall of the fuel channel.

Abstract: A process of incorporating technetium into an electroless deposit, forming an alloy that is extremely resistant to corrosion and reduces the mobility of technetium on a geologic time scale is disclosed and claimed. The process includes providing a liquid containing technetium, such as an aqueous waste stream generated during the used nuclear fuel reprocessing activities. The technetium is collected and concentrated, and provided into an electroless deposition bath. A substrate, such as suitably prepared zero valent iron or stainless steel, is introduced into the bath to initiate autocatalytic electroless deposition of the technetium onto the substrate due to the difference in electrochemical potential between the plating bath and ti metals in solution. This causes a layer of technetium metal to form on the substrate.

Abstract: The inventive viscous damping tube stabilizer includes modules or capsules containing a viscous material. Adjacent capsules are linked end to end by a flexible cable, allowing the device o pass through curves such as the U-bend regions of steam generator tubes. The weight of the entire assembly will keep it essentially connected to the tube inner diameter such that any tube vibration is transmitted to the stabilizer. The viscous material may only partially fill the capsules such that even under small motion the material can slip and slide past each other, and/or bump into walls, each microscopically absorbing some of the tube energy. By creating multiple cells inside the capsule, the capsule then have good operating characteristics no matter to what angle the individual capsule is oriented as it rests on the full U-bend. The viscous material may completely fill the capsules, which also have a perforated member positioned therein.

Abstract: A debris filter for a nuclear reactor installation is provided. The debris filter comprises a plurality of plates arranged side-by-side in a spaced relationship and delimiting between them flow passages extending through the debris filter from a lower inlet face to an upper outlet face of the debris filter, each passage having an intermediate section offset with respect to an inlet section and an outlet section. At least one of the plates is formed with debris catching features distributed along the plate and protruding into at least one passage delimited by the plate.

Abstract: The strip is of the type comprising a wall portion for delimiting a cell with interlaced strips, a spring formed in the strip and provided on the wall portion for biasing a fuel rod extending through the cell away from the wall portion, the spring comprising a cantilevered tab formed in the strip and a contact portion formed at least partially in the tab and protruding from the tab for contacting a fuel rod received in the cell.

Abstract: The invention relates to a nuclear reactor primary circuit comprising a primary pipeline (30), which defines an internal volume (32) and in which a primary nuclear reactor coolant downwardly runs, an additional pipeline (26) which is branched to the primary pipeline (30) and defines an internal volume communicating with the internal volume (32) of the primary pipeline (30) and a cuff (36) whose first end (50) is connected to the additional pipeline (26) and the second free end (52) is positioned in the internal volume (32) of the primary pipeline (30). According to said invention, the second end (52) is delimited by a free peripherial edge (53) comprising at least one upstream and downstream sections (56, 58) which are oriented towards the upstream, wherein the upstream section (56) penetrates into the internal volume (32) deeper from the primary pipeline (30) than the downstream section (58).

Abstract: A method for working on a defective heating element of a pressuriser comprising a tank lying flat along a longitudinal axis and elongate heating elements extending within the tank, and at least one spacer plate through which the heating elements pass and which is capable of maintaining a transverse spacing between the heating elements is provided. The method includes cutting at least one spacer plate around the heating element so as to detach said heating element from said spacer plate, and then extracting the heating element from the tank in one single piece.

Abstract: The invention relates to a method for regulation of operational parameters of the core of a pressurised water nuclear reactor comprising: a step of acquisition of values (FH, FB, TBC, TBF, Q) which are representative of the conditions of operating of the core of the reactor; a step of evaluation of the actual values (Tmoye, AOe, {circumflex over (P)} maxe) of the operational parameters at least according to the values acquired (FH, FB, TBC, TBF, Q); a step of selection of a control law for the concentration of a neutron-absorbent component ([B]) and for the positions of insertion (Z1 to Z5) of the groups (P1 to P5) of rods selected from at least the first and second control laws which are different from one another; and a step of regulation of the operational parameters by means of the control law selected, according to set points (Tmoyc, AOc, {circumflex over (P)} maxc) relative to the said parameters and to the actual values (Tmoye, AOe, {circumflex over (P)} maxe) evaluated.