Abstract: A nuclear reactor includes a vessel (1), a support plate (8), arranged in the vessel (1) above the core (2); a plurality of separate dispensing ducts (21); and support members (33) provided to keep the thermocouple ducts (21) in position. Each support member (33) includes a foot (35) rigidly attached to the support plate (8), a head (37) to which the or each thermocouple duct (21) is attached, and a detachable connection (39) from the head (37) to the foot (35).

Abstract: A detection device (18) for detecting the position of a moving object comprises a base (20); an arm (22) that is mounted rotatable to the base (20), wherein the arm (22) is rotatable around a first rotational axis (26) and has a free end (28) for contact with the moving object; and a sensor (24) that is configured to detect rotation of the arm (22) relative to the base (20), wherein the sensor (24) has a first part and a second part, wherein the first part moves with the arm (22), and the second part is attached to the base (20). The first part is a first component of a magnet (40) switch (42) pair, wherein the switch is an electrical switch (42) that is configured to be actuated by the magnetic field of the magnet (40), and the second part is another component of the magnet (40) switch (42) pair.

Abstract: A nuclear fuel powder production plant comprises a conversion installation (2) for the conversion of uranium hexafluoride (UF6) into uranium dioxide (UO2) having a hydrolysis reactor (4) for the conversion of UF6 into uranium oxyfluoride powder (UO2F2) and a pyrohydrolysis furnace (6) for converting the UO2F2 powder into UO2 powder. The nuclear fuel powder production plant also includes a packaging unit (20) for the UO2 powder comprising a filling station (22) having a chamber (26) for receiving a container (24) to be filled, a filling duct (28) supplied from the furnace (6) and a suction system (32) comprising a suction ring (34) disposed at the outlet (30) of the filling duct (28) for sucking an annular air flow (A) around a stream (P) of UO2 powder falling from the outlet (30) from the filling duct (28) into the container (24).

Abstract: An anchoring device (1) for anchoring an equipment to a civil engineering structure includes a support plate (5) for the equipment, with at least two orifices (7); for each orifice (7), a longitudinal dowel (13) intended to be rigidly fastened in the civil engineering structure (3); for each orifice (7), a fastening member (25) mounted around the dowel (13); for each orifice (7), a connection (27) of the fastening member (25) to the plate (5), allowing the fastening member (25) to be placed at any given position in a defined region of the orifice (7) in a plane parallel to the plate (5); and for each orifice (7), a reversible lock (55) for blocking the fastening member (25) with respect to the plate in the given position and for blocking the fastening member in position along the dowel (13).

Abstract: A subrack assembly (1) comprising a subrack (3) comprising two top rails (9), two bottom rails (7) and side elements (5), at least one rigidifying frame (21) comprising a front crossbeam, a rear crossbeam and two side beams; and at least one connector (70) for connecting the rigidifying frame (21) to the top and/or bottom of the subrack (3), comprising at least one movable block movable in translation relative to the rigidifying frame (21) between an insertion position, in which it is spaced away from the subrack (3) and a use position, in which it bears against the subrack (3). The connector (70) is configured for connecting the rigidifying frame (21) to the top and/or bottom of the subrack (3) such that the front and rear crossbeams each extend substantially parallel to a top or bottom rail (7, 9) of the subrack (3) and in alignment therewith along a vertical direction.

Abstract: A self-powered in-core detector arrangement for measuring flux in a nuclear reactor core includes a first in-core detector and a second in-core detector. The first in-core detector includes a first flux detecting material, a first lead wire extending longitudinally from a first axial end of the first flux detecting material, a first insulating material surrounding outer diameters of the first flux detecting material and the first lead wire and a first sheath surrounding the first insulating material. The first sheath includes a first section surrounding the first flux detecting material and a second section surrounding the first lead wire. The first section of the first sheath has a greater outer diameter than the second section of the first sheath.

Abstract: A method regulates operating parameters comprising at least the mean temperature of the core (Tm), and the axial power (AO) imbalance. The method includes development of a vector (US) of control values of the nuclear reactor by a supervisor (31) implementing a predictive control algorithm; development of a vector (uK) of corrective values of the nuclear reactor controls by a regulator (33) implementing a sequenced gain control algorithm; development of a vector (U) of corrected values of the commands of the nuclear reactor, by using the vector (US) of the values of the commands produced by the supervisor (31) and the vector (uK) of the corrective values of the commands produced by the regulator (33); and regulation of the operating parameters of the nuclear reactor, by controlling actuators using the vector (U) of the corrected values of the controls.

Abstract: A ventilation and air conditioning system (6) is for a room (2) containing a heat source and the ventilation and air conditioning system (6) comprising a cooled air supply (12) and a ventilation duct (10). The ventilation duct (10) includes a primary inlet (24) connected to the cooled air supply (12) and an outlet (14) leading into the room (2). A number of heat storage elements (30) is arranged inside the ventilation duct (10) between the primary inlet (24) and the outlet (14), such that during operation of the cooled air supply (12) there is a forced stream of cooled air through the ventilation duct (10), thereby cooling and preferably freezing the heat storage elements (30). A secondary inlet (36) into the ventilation duct (10) is in flow communication with the room (2) and during operation of the cooled air supply (12) is closed by a damper (40).

Abstract: A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

Abstract: A nuclear reactor includes guide tubes; and vessel head penetrations each comprising a tubular adapter fixed in one of the openings and defining an inner passage. Each vessel head penetration also includes a tubular sleeve engaged in the inner passage and axially extending in line with one of the guide tubes. Each sleeve is suspended by an upper axial sleeve end lying on an upper range on the corresponding adapter. A lower axial end of the sleeve projects axially into the vessel beyond the adapter and is separated from an upper axial end of the corresponding guide tube by an axial gap having an axial height of less than 50 millimeters.

Abstract: A passive oscillation damper (8), in particular for a switch cabinet (2), includes a supporting structure (12) having a longitudinal direction (y) and a transverse direction (x) and with a central oscillating mass (14) mounted by means of spring elements (20, 22, 24, 26) so as to be able to oscillate in the longitudinal direction (y) and in the transverse direction (x). At least one peripheral oscillating mass (40, 42) is mounted on the central oscillating mass (14) so as to be slidable in the longitudinal direction (y) and to be movable relative to the central oscillating mass (14). At least one peripheral oscillating mass (44, 46) is mounted on the central oscillating mass (14) so as to be slidable in the transverse direction (x) and to be movable relative to central oscillating mass (14).

Abstract: A method for peening an obstructed region of a metal assembly that is obstructed by an obstructing part of the metal assembly is provided. The method includes determining an optimal peening path for treating the obstructed region irrespective of the obstructing part; identifying a portion of the obstructing part within the optimal peening path; determining a section of the portion of the obstructing part that is removable without affecting a mechanical integrity and functionality of the obstructing part; removing, by machining, the section so as to create additional space along the optimal peening path; and peening the obstructed region, a path of the peening at least partially crossing through the additional space. A method for peening a nuclear reactor pressure vessel is also provided.

Abstract: A method for determining at least one threshold value of at least one operating parameter of a nuclear reactor is implemented by an electronic determination system and includes the steps of determining a first threshold value of a respective operating parameter for an operation of the reactor at a first power; and determining a second threshold value of said parameter for an operation of the reactor at a second power. The operation at the lower power of the first and second powers is an operation continued for a duration of at least 8 hours over a 24-hour sliding window. The method also includes determining a third threshold value of said parameter for an operation of the reactor at a third power between the first power and the second power.

Abstract: A method for intervention in a radioactive zone includes production of a digital model representing the three-dimensional topography of the radioactive zone (1); and intervention of the at least one operator in the radioactive zone (1). The intervention step includes repeated measurement of the radioactive radiation intensity by a portable detector (3), and determination of the spatial coordinates of the portable detector (3) at the time of the measurement; recording of a plurality of said measurements and the corresponding spatial coordinates in the digital model; materialisation of the recorded measurements in an augmented reality device (5) worn by the at least one operator, by a plurality of discrete holographie symbols (7).

Abstract: A process for recovering uranium from components contaminated with uranium oxide includes providing a cleaning apparatus with a cleaning solution for dissolving the uranium oxide of the components, carrying out a cleaning process by introducing a batch of components into the cleaning apparatus, and carrying out a measurement for determining the uranium content of the components. The cleaning and the measuring are repeated if a limit value for the uranium content is exceeded. The components are discharged from the process if the uranium content falls below a limit value. The cleaning is carried out on a plurality of successive batches of components until a control measurement indicates an unsatisfactory cleaning action of the cleaning solution. The uranium oxide dissolved in the cleaning solution is recovered after indication of the unsatisfactory cleaning action.

Abstract: A photometric method for determination of a concentration of a film forming amine in a liquid, including providing a buffer solution of a weak acid having a pKa?4.5 and a strong acid having a pKa?1; diluting an aliquot of the buffer solution with water, and determining the pH of the diluted buffer solution; adding reagent to the diluted buffer solution and measuring an initial absorbance of the diluted buffer/reagent solution; preparing a sample solution by adding liquid containing the film forming amine to an aliquot of the buffer solution and measuring the pH of the sample solution; adjusting the pH of the sample solution to match the pH of the diluted buffer solution by adding strong acid; and adding the reagent to the pH adjusted sample solution to form a colored complex, and measuring the absorbance of the resulting solution in a photometer.

Abstract: A method for simulating an ultrasonic response of a metal part is carried out by an electronic simulating device. The method includes computing a first distribution of ultrasonic waves for the part without defect, in response to an ultrasonic excitation toward said part computing a second distribution of ultrasonic waves for a predefined zone (S3k) of the part, including a defect (20), in response to an ultrasonic excitation toward said zone (S3k), with the computation of elementary distributions, each corresponding to an ultrasonic response received by a receiver located at a border (F) of said zone; and determining a resultant distribution of ultrasonic waves for the part with defect, from the first and second computed distributions, the resultant distribution forming a simulation of an ultrasonic response received from the part including the defect (20), in response to an ultrasonic excitation toward said part.

Abstract: A method for decontaminating a metal surface exposed to radioactive liquid or gas during operation of a nuclear facility comprises an oxidation step wherein a metal oxide layer on the metal surface is contacted with an aqueous oxidation solution comprising a permanganate oxidant for converting chromium into a Cr(VI) compound and dissolving the Cr(VI) compound in the oxidation solution; and a first cleaning step wherein the oxidation solution containing the Cr(VI) compound is directly passed over an anion exchange material and the Cr(VI) compound is immobilized on the anion exchange material. The method provides for substantial savings of radioactive waste and produces chelate-free waste.

Abstract: An analysis device for detecting fission products by measurement of a radioactivity includes a first line for carrying a liquid sample, a first detector connected to the first line and designed for measuring the radioactivity of fission products contained in the liquid sample, a second line for carrying a gas sample and a second detector connected to the second line and designed for measuring the radioactivity of fission products contained in the gas sample. The analysis device includes a separation device for separating gas from the first line carrying the liquid sample, which line has an outlet opening into the second line for gas separated from the liquid sample. The outlet opening fluidly connected to the second lines in such a manner that the gas separated from the liquid sample is suppliable as a gas sample to the second detector for measuring the radioactivity of fission products contained therein.

Abstract: A method for a multielement analysis via neutron activation. The method includes generating fast neutrons with an energy in the range of 10 keV to 20 MeV and moderating the neutrons, irradiating the sample with the neutrons, and measuring the gamma radiation emitted by the irradiated sample using a detector to determine at least one element of the sample. The sample continuously irradiated in a non-pulsed fashion. The measurement is implemented during the irradiation. The determination of the at least one element includes an evaluation of the measured gamma radiation. The sample is subdivided into individual partitions and the measurement is implemented using a collimator. The evaluation includes a spatially resolved and energy-resolved determination of the neutron flux within the respective partition of the sample and calculation of energy-dependent photopeak efficiencies and neutron flux and neutron spectrum within a single partition of the sample by an approximation method.