Abstract: A method and a device depressurize a nuclear power plant. A depressurization flow is conducted out of a containment shell into the atmosphere via a depressurization line having a filter system. The filter system contains a filter chamber having an inlet, an outlet, and a sorbent filter. The depressurization flow is first conducted in a high-pressure section, then is depressurized by expansion at a throttle device, then conducted through the filter chamber having the sorbent filter, and finally blown out. To enable an effective retention of activity carriers contained in the depressurization flow, including organic compounds containing iodine, the depressurization flow depressurized by the throttle device is conducted through a superheating section before the depressurization flow enters the filter chamber, in which superheating section the depressurization flow is heated from the not yet depressurized depressurization flow to a temperature that is at least 10° C. above the dew point temperature.

Abstract: A boiling water reactor assembly includes a bayonet plate closure between a control rod guide tube and a drive housing pipe. The bayonet plate closure has a bayonet plate constructed in two parts including a central bayonet ring mounted rotatably about its longitudinal axis and an outer ring completely surrounding the bayonet ring. The outer ring is mounted on the periphery of the bayonet ring and reaches inwards under the bayonet ring periphery. The ring is furthermore permanently supported in the axial direction on the drive housing pipe by spring pressure acting on the control rod guide tube, in order to produce a frictional connection. The spring pressure can be released unhindered from the reactor side by tools.

Abstract: A pencil-shaped electrical heating element, in particular for application in a device for measuring filling level in a liquid container, in particular in a reactor chamber of a nuclear plant, contains an electrically-conducting sleeve and at least one electric line embedded therein which is in conducting contact with the sleeve. The electrical line has at least two line sections with differing electrical properties and/or thermal conductivities.

Abstract: A method for producing a uranium oxide catalyst body includes the following steps: UO2+x powder, with x?0.7, having a purity of at least 50% is sintered in a first sintering process to obtain a UO2+y intermediate, where y?0.25. Then the UO2+y intermediate is oxidized with oxygen and converted in the process into a U3O8?z powder, with z?1. The U3O8?z powder is pressed to form a blank having a shape that corresponds with the catalyst body to be produced. The blank is sintered in a second sintering process at a temperature of at least 900° C. in an oxygen-containing sintering atmosphere.

Abstract: A method produces a welded connection between first and second components each having inner and outer sides interconnected by an end face. The first component has a ferritic basic body carrying a plating at the inside and having an end face with a buffer layer of Ni-based alloy. The second component is of austenitic material. The end faces of the components enclose a weld groove. An austenitic root, connecting the plating to the end face of the second component, is welded in the weld groove. An intermediate layer of a nickel alloy having at least 90% nickel is welded onto the root. The intermediate layer is connected to the end faces of the plating and the second component. A weld seam is then produced in the remaining weld groove using a nickel-based welding additive. A method for repairing a welded connection between first and second components is also provided.

Abstract: The geometric dimensions and shape of a device for removing solid particles from the cooling medium that is circulated in the primary circuit of a nuclear reactor, in particular a boiling water nuclear reactor, are such that the device can be inserted in lieu of a fuel element or fuel assembly into an empty fuel element or assembly position of the reactor core of the nuclear reactor.

Abstract: A method for decontaminating nuclear plant surfaces, which have been contaminated with alpha emitters, is carried out subsequently to a decontamination process which is aimed at the removal of oxide layers. The surfaces are treated with an aqueous solution which contains a cationic or zwitterionic surfactant and oxalic acid. At least a part of the solution, after having acted on a surface, is conducted across an ion exchanger.

Abstract: A method for conditioning the circulatory system (1) of a power plant is especially suited for a nuclear power plant. An amine, which is a film-forming agent, is metered into the working medium circulating in the circulatory system. The film-forming agent forms a hydrophobic film on the surfaces of the circulatory system. During the process, the concentration of the film-forming agent is monitored in at least one measuring point by way of measurement, and metering of the film-forming agent is stopped once its concentration in the working medium has reached a value of 1 ppm to 2 ppm in at least one measuring point M1.

Abstract: A method for cleaning and conditioning the water-steam circuit of a power plant, especially of a nuclear power plant, uses an amine as a film-forming agent. The amine is metered into the working medium circulating in the water-steam circuit. The film-forming agent forms a hydrophobic film on the surfaces of the circuit. During the process, the concentration of at least one impurity contained in the water and the concentration of the film-forming agent in at least in the feed water of the steam generator are measured and monitored. The concentration of the film-forming agent is varied, as needed, subject to the concentration of the impurity.

Abstract: A device separates a fluid mass flow in a nuclear plant. The device contains a primary end piece for conducting the fluid mass flow and a plurality of secondary end pieces for conducting a plurality of separate partial flows of the fluid mass flow. A number of separating elements is provided in the area within the primary end piece, and each of the partial areas defined by the separating element or the separating elements opens in a secondary end piece clearly assigned to the partial area.

Abstract: An anchoring system for forming a non-releasable connection between a concrete component, has a reinforcement containing at least one steel bar mesh, and a steel component. At least one anchoring element formed of an anchor strip is cast into the concrete component in such a way that at least one connecting surface projects at least partially from the concrete component. This improves the loadability of the anchoring. For this purpose, the anchor strip has a number of recesses which extend at least partially into the concrete component and which are each traversed by at least one steel bar of the steel bar mesh.

Abstract: A nuclear plant has a containment shell and a pressure relief pipe connected thereto in which a blowing device and a Venturi washer placed in a container with a washing liquid are connected in series. Even the finest particles or aerosols carried by air are held in the Venturi washer with a very high degree of reliability and the release thereof in environment is excluded in a particularly reliable manner in the case of decompression even associated with seal failures. For this purpose, the size of the blowing device and the Venturi washer are selected in such a way that during the operation of the blowing device a flow rate of liquid in the Venturi washer flowing to the decompressing pipe is higher than 130 m/sec, preferably higher than 180 m/sec.

Abstract: An apparatus for detecting a magnetically conductive object in a detection area has an electrical coil and at least one sensor element. The apparatus is intended to be as free of degradation processes as possible and thus requires little maintenance and is configured and set up with the highest possible degree of redundancy and measurement reliability. For this purpose, the coil is set up to form a magnetic field in the detection area and the sensor element is configured to detect a magnetic field with a field strength, the magnitude of which is greater than a predefined threshold value. The threshold value is set to be higher than the field strength present in the detection area when the magnetically conductive object is absent and lower than the field strength present therein when the object is present.

Abstract: A wall module is configured as a concrete prefabricated building element for building a structure and can be connected to further wall modules to form a structure and is configured to withstand improbable extreme loads. The wall module has a wall body with multiple edges, a plurality of reinforcement rods which all together form a regular reinforcement grid, and each extend parallel to the edges, and which are cast into the wall body. The reinforcement rods each penetrate the wall body substantially from edge to edge, and provided at their ends with connecting elements configured to establish a connection with complementary connecting elements of an immediately adjacent wall element. Each of the connecting elements is connected with clearance to the associated reinforcement rod such that it can be moved in a plane which is perpendicular to the longitudinal direction on all sides by at least 2 mm.

Abstract: A method for producing a uranium oxide catalyst body includes the following steps: UO2+x powder, with x?0.7, having a purity of at least 50% is sintered in a first sintering process to obtain a UO2+y intermediate, where y?0.25. Then the UO2+y intermediate is oxidized with oxygen and converted in the process into a U3O8?z powder, with z?1. The U3O8?z powder is pressed to form a blank having a shape that corresponds with the catalyst body to be produced. The blank is sintered in a second sintering process at a temperature of at least 900° C. in an oxygen-containing sintering atmosphere.

Abstract: A method for monitoring the fill level of a liquid in a liquid container, in particular for monitoring the coolant fill level in a reactor pressure vessel of a pressurized water reactor system, wherein a determination is made about the drop in the liquid level below the installed height of a heated thermal element by way of the temperature difference measured between said heated thermal element and an unheated thermal element associated therewith, both of said elements being disposed in the liquid container, said method comprising the especially reliable triggering of an alarm with a short response time while maintaining a low level of physical and controls engineering complexity when the liquid level to be monitored falls below a critical value.

Abstract: The invention relates to a sealing element fastening system for at least one sealing element of a pressure vessel, which has at least one opening and a sealing part, in particular a cover, provided for the opening. In the operating state of the pressure vessel each sealing element is at least partially inserted in an accommodating groove in the sealing part and corresponding sealing element fastening devices are positioned in each case in an indentation in the sealing part. The indentations are in each case sealed by a fill element in the operating state of the pressure vessel.

Abstract: A fuel assembly for a light water reactor contains a fuel rod cluster and a spacer that has a number of cells, bounded by webs for laterally holding fuel rods. A damaged region including at least one damaged cell is present in an edge region of a spacer. There being fastened above or below the damaged region on the spacer with the aid of at least one connecting part is a replacement assembly that contains at least a number of cells that corresponds to the number of the damaged cells, at least a portion of the cells being traversed by fuel rods. A method for repairing the light water reactor fuel assembly in the case of which fixed above or below the damaged region on the spacer is a replacement assembly that takes over the holding function at least of one defective cell.

Abstract: A method for machining a sealing seat of a shut-off valve in a power generating or industrial plant. An upper valve part and the internal housing fittings are removed from the housing of the shut-off valve to thereby expose a housing opening. A clamping device with a counter-bearing is introduced through the housing opening into the connection pipe and fastened to its inner wall. A machine tool with a bearing is introduced through the housing opening and mounted with its bearing on the counter-bearing. A machining step is carried out with the machine tool on the sealing seat. Then the machine tool is detached and removed through the housing opening. The clamping device is detached from the connection pipe and removed through the housing opening. Then, the upper valve part and the internal fittings are reattached to the housing.

Abstract: A nuclear engineering plant has a containment, whose interior chamber is subdivided by a wall into a systems chamber and an operating chamber which is accessible during normal operation. The containment ensures a particularly high operational reliability, in particular also in incident situations, in which hydrogen is released in the systems chamber. For this purpose, a number of overflow openings are provided in the partition wall, the respective overflow opening is closed by a closure element of a closure apparatus which opens automatically when a trigger condition associated with the respective overflow opening is reached. Closure apparatuses are provided which open both as a function of pressure and independently of pressure. The closure apparatus furthermore has a closure element containing a bursting film or a bursting diaphragm. The closure apparatus is configured such that it frees the overflow opening automatically when a predetermined environment-side trigger temperature is reached.