Abstract:
A method and system detects failures in nuclear fuel assemblies. A water treatment device degasses/removes fission gases from water used in the canister of a vacuum sipping device. 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:
A cam is immersed in water at an elevated temperature and/or pressure. A reciprocating cam follower also immersed in the water contacts a surface of the cam. The cam follower includes a permanent magnet. An electrically conductive coil is magnetically coupled with the permanent magnet such that movement of the cam follower induces an electrical signal in the electrically conductive coil. A sealed housing also immersed in the water contains the electrically conductive coil and seals it from contact with the water. Leads of the coil are electrically accessible from outside the sealed housing and from outside the water. Alternatively, the cam includes magnetic inserts, the cam follower is replaced by a sensor arm of magnetic material, and the sensor arm and/or the inserts are magnetized whereby rotation of the rotary element causes time modulation of the magnetic coupling and induces coil voltage.
Abstract:
L'installation comprend une caméra (9) suspendue à un pont roulant (6) en même temps qu'un palan (7) porteur de l'élément de combustible (8) à descendre ou monter. Elle indique la position du pont roulant (6) par rapport à l'alvéole (2) à occuper, et un mouvement déterminé du pont roulant (6) place l'élément de combustible (8) au-dessus de l'alvéole. Un avaloir (10) à l'entrée de l'alvéole (2), porteur d'une paire de caméras (13, 14), effectue une seconde mesure de la position de l'élément de combustible (8) en même temps qu'un guidage sans frottement. Application au chargement ou au déchargement d'éléments de combustible nucléaire dans des emballages de transport.
Abstract:
A welding system (10) for welding a pipe (18) within a confined space includes a motor housing (11), a weld head assembly (12) remote from the motor housing and an insertion tube (13) extending between the motor housing and the weld head assembly. The motor housing is supported on a platform (17) for rotational and translational movement of the weld head assembly and houses a motor for positioning the weld head assembly relative to the pipe. The weld head assembly includes a clamp assembly (31) for attaching to the pipe and a weld tool assembly (30) mounted adjacent the clamp assembly for welding the pipe. An arc length gear (33) and a travel gear (34) adjust the distance between a torch assembly (38) and the pipe, and adjust the location of the torch assembly around the pipe when the weld head assembly is attached to the pipe.
Abstract:
Eine Brennelement-Lademaschine (2) mit einer einen Führungsmast (12) und einen teleskopartig aus dem Führungsmast (12) ausfahrbaren Brennelementgreifer (16) umfassenden Hebevorrichtung (8) soll eine besonders sichere und einfache Handhabung von Brennelementen (10) ermöglichen. Zu diesem Zweck ist erfindungsgemäß an der Hebevorrichtung (8) eine datenseitig mit einem Leitstand (34) verbundene Videokamera (32) angeordnet, deren Blickrichtung nach unten gerichtet ist.
Abstract:
The invention relates to a nondistuctive eddy-current test of materials and products. The inventive method and device are based on comparison of test results on the same cross section of a fuel element by means of two measuring systems. Said systems comprise transmission transducers through which a tested fuel element is displaced, and compensation converters provided with reference samples inserted therein. In the first system, the test is carried out when an external constant magnetic field formed by constant magnets is superimposed. In the second system, the test is carried out outside of magnetic field. The thus obtained results are used for computing the gadolinium content in each pellet taking into account the interference produces by ferromagnetic inclusions and the deviation of the conductivity and geometrical dimensions of the tested fuel element claddings from the reference sample claddings, and also the axial offset of the tested fuel element with respect to the axes of the transducers. The inventive method and device ensure a more accurate gadolinium determination in the presence of the ferromagnetic inclusions in the pallets.
Abstract:
Ce paravent de protection est constitué d'une paroi frontale (1) associée à une paroi latérale (2) s'étendant à l'équerre ou sensiblement à l'équerre à partir de ladite paroi frontale (1), lesquelles parois (1, 2) comportent des panneaux transparents (8, 10) sur une partie au moins de leur hauteur. La partie supérieure (8) de la paroi frontale (1), d'une part est inclinée vers l'avant, formant surplomb, pour permettre à l'opérateur de se rapprocher de la zone d'intervention, et d'autre part, est munie de deux orifices (11, 12) pour le passage des bras dudit opérateur.
Abstract:
The invention concerns a method which consists in: moving a measuring head (8a) of the probe (8) along the length of a gap (12) between two rows of pencils (4) and in its extension on either side of the passage gap (12) and of the pipe provers, in an outgoing direction and in a return direction opposite to the outgoing direction; collecting and transmitting the probe signal in digital form to a computing unit (18) comprising a software for processing the signal and for determining the thickness of an oxide layer on the outer surfaces of the pencils (4); determining the minima of the probe (8) signal during its displacement in the passage gap between the rows of pencils (4); adjusting a calibration curve based on the minima values of the signal of the probe in contact with the calibration pencils; determining the thickness values of the oxide layer corresponding to the signal minima, based on the calibration curve; verifying the coherence of the thickness values obtained for each of the pencils of the row of pencils in the outgoing direction and in the return direction of the probe (8) displacement and recording and displaying the coherent thickness values of the oxide layer for each of the pencils (4).
Abstract:
The invention relates to the nuclear power industry and more particularly to technologies for controlling leak tightness of fuel elements at the stage of production thereof as well as to the creation of fully automated control equipment. The inventive method of controlling fuel elements comprises the following steps: placing the items of interest in a chamber linked to a leak detector; creating a vacuum inside such chamber; connecting the leak detector; and recording signals emitted by the latter. The leak tightness of the items of interest is judged according to signals exceeding a background value. According to the inventive method, abutted fuel elements are continually moved along the axis thereof and sequentially pass through areas where there is a gradual drop in residual pressure, through the control chamber connected to the mass spectrometry leak detector and through areas where there is a gradual rise in residual pressure.
Abstract:
A bracelet (14) for moving sensors (12) along a straight or elbow pipe. The bracelet (14) has a number of side-by-side positionable supports (10) for removably holding the sensors (12) respectively. A flexible attachment, such as a string (20), is provided for holding the supports (10) in a pliant side-by-side series arrangement (22). The string (20) has opposite ends (24) extending beyond the supports (10) at opposite ends (26) of the series arrangement (22). The bracelet (14) further has a frame (28) having an inner circular opened surface (30) for installation around the pipe, and a longitudinal circular side receiving surface (32) along which the series arrangement (22) of the supports (10) is mounted. The side receiving surface (32) is provided with fastening members (34) projecting at both ends (26) of the series arrangement (22) of the supports (10). The ends (24) of the string (20) is supported by the fastening members (34).