Abstract: A nuclear power plant comprising a primary coolant circuit, a steam-water circuit separated from the primary coolant circuit and a steam generator connected to the primary coolant circuit and the steam-water circuit to transfer heat from the primary coolant circuit into the steam-water circuit has at least one dosing point in the steam-water circuit to inject a reducing agent into the steam-water circuit, wherein the reducing agent is an organic compound consisting of carbon, hydrogen and oxygen. Furthermore, a method for operating said nuclear power plant and the use of the method for downtime preservation of the secondary side of a steam generator of a nuclear power plant are provided.

Abstract: A depressurization and cooling system for steam and/or condensable gases located in a containment. The system contains a steam condenser having an upstream port connected to the containment through an exhaust line and a downstream port connected to the containment through a backfeed line. The backfeed line contains a backfeed compressor. A re-cooling system for re-cooling the steam condenser is provided. The depressurization and cooling system is effective for re-cooling of the steam condenser. Accordingly, this is achieved as the re-cooling system is self-sustainable.

Abstract: The invention relates to a flexible lance for machining or inspecting a tubesheet of a boiler, having a first strip made of a flexible, metallic material and a second strip made of a flexible, metallic material, wherein the second strip is arranged on the first strip in the longitudinal direction, and wherein at least the second strip has a shaped portion extending in the longitudinal direction for receiving a supply line for a machining or inspection head arranged at the free end of the flexible lance, and wherein the first strip is connected to the second strip such that an open side of the shaped portion is covered by the first strip so as to form a guide channel, and wherein at least one edge region of the flexible lance, extending in the longitudinal direction, is formed only by the first strip or the second strip.

Abstract: An electronic device (18) is for managing the display of data to control a nuclear power plant. The data comes from a plurality of electronic control units (16A, 16B, 16C). Each control unit is configured to perform at least one action from among acquiring a value measured by a sensor (12A, 12B, 12C) and controlling an actuator (14A, 14B, 14C), the control units, sensor(s) and/or actuator(s) being according to several different nuclear safety classes. This electronic device (18) is able to be connected to the control units, and includes a set (25) of electronic module(s) (26A, 26B, 26C) for creating overlay(s) (28A, 28B, 28C). Each overlay contains information associated with one or several control units and according to a respective safety class; and a module (30) for generating a page (32) to be displayed, by superposition of several separate overlays.

Abstract: A programmable logic circuit (10) for controlling an electrical facility, in particular a nuclear facility, includes an operating unit (14). The operating unit includes a plurality of types of functional blocks (FB1, FBi, FBN), two distinct types of functional blocks being suitable for executing at least one distinct function, at least one processing module suitable for receiving at least one sequence (46) of functional block(s) to be executed, and at least one internal memory (38) configured to store at least said sequence (46). The programmable logic circuit (10) includes a single functional block of each type, a given functional block being suitable for being called several times, and an execution module (22) configured to execute the called functional block(s) in series, according to said sequence (46).

Abstract: A repair device for underwater repair of a hole in a nuclear reactor part includes a holder (32), a cutting tool (22) held by the holder (32) and having at least one cutting tooth (70) for remachining an inner surface of the hole. The cutting tool (22) has a suction channel (44) extending into the cutting tool (22) between at least one inlet opening (46) and at least one outlet opening (48), a drive shaft (34) for rotating the cutting tool (22), the drive shaft (34) being held by the holder (32), and a suction tube (36) connected to the holder (32) and fluidly connected to the outlet opening (48) of the suction channel (44).

Abstract: A distance sensor unit is also provided. The distance sensor unit includes an array of distance sensors configured to identify surface irregularities deviating from an expected nominal geometry of a surface as the distance sensor unit is moved along the surface and a handheld housing configured for being gripped by an operator. The array of distance sensors is connected to the handheld housing. The distance sensor unit also includes at least one surface irregularity indicator configured for providing an alert to the operator as the distance sensor unit moves over one of the surface irregularities deviating from the expected nominal geometry of the surface.

Abstract: A gripper a fuel element, comprises a housing, an inner part arranged inside the housing, the inner part and the housing being displaceable relative to one another in an axial direction, with the inner part movable between a first end position and a second end position, a catch member movable between a gripping position and a release position, a gripper spring between the housing inner part counteracting movement of the inner part from the second end position, or an intermediate position (Z) between the first and second end position, to the first end position, and a damping system comprising a first and second connecting member for connecting the damping system to the housing, inner part and/or the fuel element loading machine, and a spring member arranged on the first and/or the second connecting member counteracting movement of the inner part from an intermediate position (Z) to the second end position.

Abstract: A method for treating waste water from the decontamination of a metal surface in a primary coolant circuit of a nuclear reactor comprises discharging a predetermined amount of an oxidation solution from the primary coolant circuit into a reduction zone connected to the primary coolant circuit and reacting the oxidation solution with a reducing agent to form a reaction solution that is freed of oxidizing agent, and passing the reaction solution over an ion-exchange resin in order to form a desalinated solution, and returning the desalinated solution to the primary coolant and/or disposing of the desalinated solution. A waste water treatment apparatus for carrying out the method is also provided.

Abstract: An absorber cluster for a nuclear reactor includes at least a first absorber assembly and a second absorber assembly. Each absorber assembly respectively comprises neutron absorbing elements. Absorber elements of each of the first absorber assembly and the second absorber assembly are made from the same material or the same combination of materials selected from the group of neutron absorbing materials consisting of a first europium hafnate, a second europium hafnate, a first samarium hafnate, a second samarium hafnate, hafnium carbide, and samarium hexaboride. The first europium hafnate and the second europium hafnate have different compositions. The first samarium hafnate and the second samarium hafnate have different compositions. The absorber elements of the first absorber assembly have a cross-sectional structure different to that of the absorber elements of the second absorber assembly.

Abstract: A method for sealing an opening extending radially from an outer circumferential surface to an inner circumferential surface of a tubular object in a nuclear power plant includes inserting a stopper from outside of the outer circumferential surface through the opening into the tubular object; and actuating a fastener from the outside of the circumferential surface to force the stopper radially outward to seal the opening. A mechanical seal assembly for plugging an opening in a tubular object by contacting an inner circumferential surface of the tubular object includes a stopper configured for insertion into an interior of the tubular object for plugging the opening. The stopper includes a surface configured for matching the inner circumferential surface of the tubular object.

Abstract: A method of producing a nuclear fuel product includes the steps of providing a core comprising aluminium and low-enriched uranium; and sealing said core in a cladding. The low-enriched uranium has a proportion of U235 below 20 wt %. The step of providing the core including melting low-enriched uranium and aluminium in a furnace to form a melt of uranium-aluminium alloy, producing a powder from the melt of uranium-aluminium alloy, and cold-spraying the powder on a surface of the cladding.

Abstract: A dry FCVS for a nuclear reactor containment is provided. The dry FCVS includes a housing and a round and/or elongated aerosol filter inside the housing for removing contaminant aerosols from gas passing through the housing during venting of the containment. The housing includes at least one inlet portion configured for directing gas into the aerosol filter during the venting of the containment and an outlet portion for gas filtered by the aerosol filter during the venting of the containment. The dry filtered containment venting system is arranged and configured such that when a flow of gas through the outlet portion is closed off at least one of convective, radiant and conductive heat transfer removes decay heat of aerosols captured in the aerosol filter.

Abstract: The invention provides a sintered rare earth metal oxide target for producing a radioisotope in an instrumentation tube of a nuclear power reactor, wherein the sintered target has a density of at least 90 percent of the theoretical density, and wherein the sintered target contains chromium in an amount of from 500 to 2000 ?g/g, and Mg and/or Ca in an amount of from 1000 to 6000 ?g/g. The sintered target is prepared by providing a rare earth metal oxide powder, blending the rare earth metal oxide powder with chromium oxide, dry granulating and consolidating the powder in a mold to form a spheroidal green body, and sintering the green body in solid phase to form a spheroidal ytterbia target.

Abstract: A catalytic recombiner and filter apparatus is especially suited for placement in a containment of a nuclear reactor. The apparatus has a natural convection flow duct with a number of catalytic elements for recombining hydrogen and oxygen contained in a gas flow through the flow duct. The catalytic recombiner and filter apparatus provides for reliable hydrogen reduction and iodine filtering for a gas flow even for a comparatively long period of operation. The catalytic recombiner and filter apparatus includes a number of adsorber elements with iodine adsorbing surfaces and with macroscopic flow channels in between. The iodine adsorbing surfaces are flown over by the gas flow, and the adsorber elements are arranged, when in use, downstream of the catalytic elements in a direction of the gas flow.

Abstract: A method for inspecting a metal surface (12) includes providing a first laser source (14) that is arranged to generate a first laser beam having a first wavelength comprised between 1000 nm and 1100 nm and a power higher than 1 W; providing a second laser source (16) that is arranged to generate a second laser beam having a second wavelength comprised between 1500 nm and 1800 nm and a power higher than 1 W; activating one of the first and second laser sources and transmitting the first or second laser beam to the entrance (22) of an optic (18); scanning the metal surface (12) with the laser beam projected by the optic; and acquiring at least one image of the infrared radiation emitted by the metal surface (12).

Abstract: A nuclear facility includes a fuel element pool which is filled with a cooling liquid. A fuel element rack, which is disposed in the fuel element pool, includes compartments for receiving fuel elements. The fuel elements received in the compartments are in direct contact with the cooling liquid in the fuel element pool. At least one cooling element is disposed in one of the compartments instead of a fuel element. The cooling element acts as a heat exchanger through which a coolant can flow, the cooling element is connected into a cooling circuit and the cooling element is immersed in the cooling liquid.

Abstract: A method of producing radionuclides from irradiation targets in a nuclear reactor uses at least one instrumentation tube system of a commercial nuclear reactor. Irradiation targets and dummy targets are inserted into an instrumentation finger and the irradiation targets are activated by exposing them to neutron flux in the nuclear reactor core to form a radionuclide. The dummy targets hold the irradiation targets at a predetermined axial position in the reactor core corresponding to a pre-calculated neutron flux density sufficient for converting the irradiation targets to the radionuclide. Separating the dummy targets from the activated irradiation targets includes exposure to a magnetic field to retain either the dummy targets or the activated irradiation targets in the instrumentation tube system and release the other one of the activated irradiation target or the dummy target from the instrumentation tube system. An apparatus adapted to the above method is also provided.

Abstract: A method for inspecting a nuclear reactor part includes placing an optical sensor (38) in front of the part to be inspected using a carrier (40); acquiring at least a first image of at least a reference portion of the part using the optical sensor (38), the or each first image being taken with a first magnification; reconstituting a three-dimensional model of said reference portion of the part using the or each first acquired image; calculating the position of an area to be inspected relative to the optical sensor (38) using the three-dimensional model; acquiring at least a second image of the area to be inspected using the optical sensor (38), the or each second image of the area to be inspected being taken with a second magnification higher than the first magnification.

Abstract: The invention provides a method of preparing irradiation targets for radioisotope production in instrumentation tubes of a nuclear power reactor, the method comprising the steps of: providing a powder consisting of an oxide of a rare earth metal having a purity of greater than 99% and, optionally, an organic binder; pelletizing the powder and optionally the organic binder to form a substantially spherical green body having a diameter of from between 1 to 10 mm; and sintering the spherical green body in solid phase at a temperature of at least 70 percent of a solidus temperature of the rare earth metal oxide powder and for a time sufficient to form a round sintered rare earth metal oxide target having a sintered density of at least 80 percent of the theoretical density.