Kraftwerk Union Aktiengesellschaft

Gerhard Ulrych

Peter Suchy

Leonhard Irion

Gustav Fromel

Jurgen Tautz

Nuclear reactor with a radiation-emitting core including a container for conducting a coolant, the radiation-emitting container having a wall formed with a plurality of slots disposed parallel to one another, the slots having a depth within the wall equal to at least one-fourth the thickness of the wall, the slots being spaced from one another a distance which is at most as great as the depth thereof.

Nuclear reactor

A nuclear reactor-fuel element with cylindrical fuel rods and a fuel element skeleton formed of a head and foot member and cylindrical control rod-guide tubes connecting the members includes a plurality of mesh-forming spacing holder-grids for the fuel rods fastened to the guide tubes, the control rod-guide tubes being received respectively in the mesh formed by the spacing holder-grids, and flow guide means in vicinity of at least one of the spacing holder-grids largely closing, from a flow-technology standpoint, the cross section of the respective mesh surrounding the guide tube received therein.

Nuclear reactor-fuel element

A pressurized-water reactor pressure vessel has a plurality of inlet openings through which coolant is introduced from the cold legs of a plurality of main coolant loops, into an annular descent space of restricted radial extent and formed between the inside of the vessel's side wall and the outside of a core barrel on the inside of the vessel. To prevent outward loss of coolant from the vessel in the event of a break in any of the cold legs, the vessel is internally provided with a check valve assembly for each of the inlet openings, and to avoid restriction of the normal inlet coolant flow rate, each assembly comprises a plurality or series of flap valves which are each individually of small dimensions so that they can be fitted into the descent space. Therefore, these flap valves are normally held open by the inlet coolant flow but can snap shut to outward coolant flow. Due to their small dimensions, they are very sensitive to coolant flow in the descent space through the vessel's various inlet openings making it possible for some of these valves to flutter between fully open and partially closed or fully closed positions in regions of low coolant flow velocity. To prevent this fluttering possibility, each valve assembly comprises means for forming a flow-confining chamber extending downwardly from the coolant inlet opening involved, and having an open lower end substantially conforming in contour to a segment of the annular descent space, the flap valves being mounted in the form of a row in this open lower end of the chamber. In this way, the flow is directed in a predeterminable manner also in case of a break, so that the flap valves associated with the broken pipe defenitely close and are prevented from fluttering.

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Tennenlohe, Germany

Gerhard Ulrych