Siemens Aktiengesellschaft

Areva Np Gmbh

Framatome Anp Gmbh

Areva Gmbh

Siemens Aktiengsellschaft

Werner Meier

Hans-Joachim Lippert

Peter Rau

Erhard Friedrich

Gerhard Hau

Dirk Blavius

Hans Lettau

Pramod Batheja

Michael Liebler

Roland Rink

Anton Kautetzky

Dietrich Alter

Hartmut Lelickens

Kurt Kraus

Heinrich Dressel

Rudolf Schmidt

Helmut Moldaschl

Jorg Tschemernjak

Lothar Koerner

Stefan Linden

Reazul Huq

Stefan Drecker

Dieter Menges

David Barkhurst

Jochen Heinecke

Knut Emmert

Martin Kraft

Walter Droscher

Kurt Winter

Rainer Huber

A lower nozzle for use in a nuclear fuel assembly provided. The lower nozzle is of the type having an axis and comprising a transverse lower tie plate for channeling the coolant through the lower tie plate and a tubular skirt extending axially from the periphery of the lower tie plate, the skirt delimiting an axial housing closed at one end by the lower tie plate and open at the opposite end, a debris filter configured for axial insertion in the housing and snap-fit springs for retaining the debris filter in the housing after insertion. The springs are configured to shift the debris filter axially towards the lower tie plate.

Lower nozzle for use in nuclear fuel assembly

The strip is of the type comprising a wall portion for delimiting a cell for receiving a fuel rod and allowing flow of a coolant upwardly through the spacer grid, a spring provided on the wall portion for biasing a fuel rod extending through the cell away from the wall portion, the spring being cut out in the strip and delimited by a slot and a motion limiter formed in the strip on the wall portion to limit motion of a fuel rod received in the cell towards the wall portion against action of the spring. According to one aspect of the invention, the motion limiter is located on an edge of the slot opposite the spring and defines a risen portion on the edge.

Strip for a nuclear fuel assembly spacer grid

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.

Device for removing solid particles from the cooling medium which circulates in the primary circuit of a nuclear reactor

A fuel element for a nuclear reactor has fuel rods with nuclear fuel guided through spacers. The spacers are equipped with devices that exert a swirling impulse upon a coolant flowing along the fuel rods. In order to present as little flow resistance as possible for the coolant, these swirl-introducing devices have the form of a vane with a spoonlike or bladelike shape and they extend into the coolant flow. Owing to the shape&#x2014;here the vane is curved in the longitudinal and in the transverse directions&#x2014;practically all cross sections of the vane have such a high geometrical moment of inertia that even a vane made of a thin sheet metal is sufficiently rigid. Fuel elements configured according to the invention are particularly suitable for use in boiling water nuclear reactors.

Fuel assembly

In order to reduce the flow resistance of a coolant flowing through a passage in a support plate of a boiling water reactor and entering a transition piece at a lower end of a fuel assembly resting on the support plate, a lower rim of the transition piece forms a conically tapered surface which fits into a corresponding conical counter-surface at an upper edge of the passage. The lower rim of the transition piece forms a circular inlet which is concentric with the passage and has a size equal to or slightly larger than the passage. Fingers protruding laterally into the passage and extending down into the passage are used to center the lower rim within the passage. Additionally, end caps of the fuel rods may be stream-lined and the lower tie plate of the fuel assembly may be spaced apart from an inner surface of a fuel channel by a plurality of ribs which form a plurality of peripheral through holes on each of the four inner surfaces of the rectangular-shaped fuel channel.

Nuclear fuel assembly having a transition piece providing a reduced flow

A nuclear reactor fuel assembly includes a fuel assembly base, a fuel assembly head and mutually parallel fuel rods containing nuclear fuel and extending between the fuel assembly head and the fuel assembly base. A water tube having first and second open ends extends parallel to the fuel rods. The first end of the water tube grips and is held at the fuel assembly base. An elongated extension body has first and second ends. The second end of the extension body grips and is held at the fuel assembly head. The second end of the water tube is screwed into the first end of the elongated extension body, or the first end of the elongated extension body is screwed into the second end of the water tube. The elongated extension body has two mutually coaxially disposed partial bodies. One of the partial bodies has the second end of the extension body and the other of the partial bodies has the first end of the extension body. One of the partial bodies is screwed into the other of the partial bodies. A check nut may be seated on the one partial body which is screwed into the other partial body and the check nut is braced against the other partial body.

Nuclear reactor fuel assembly

In a foot of a fuel assembly of a boiling water reactor, an upper edge of a transition member is tight against a lower edge of a fuel assembly casing to substantially prevent bypass flow between them. Rather, bypass apertures are provided therefor over all sides of the fuel assembly casing. In a first position of a base plate lying on the transition member, the bypass apertures on some sides are blocked by lateral surfaces of the base plate, while in a second position of the base plate, the bypass apertures of other sides are blocked. The direction of the bypass flow can thus be predetermined regardless of the position of the fuel assembly casing.

Fuel assembly for a boiling water reactor with adjustable by-pass

A fuel assembly includes a cluster of mutually parallel fuel rods. A fuel assembly channel laterally surrounds the cluster of fuel rods and has a substantially rectangular cross section and flat channel walls. Grid-like spacers having meshes formed therein each receive a respective one of the fuel rods for guiding the fuel rods in a plurality of axial positions. At least one support spring laterally supports each respective one of the fuel rods in the mesh guiding the fuel rod. Each of the spacers have inner ribs being aligned parallel to the fuel rods and outer peripheral ribs opposite the channel walls. At least some of the inner ribs are fastened to the peripheral ribs, and the outer peripheral ribs are joined together only by the inner ribs.

Fuel assembly with a flow-aiding spacer

A fuel assembly for a boiling water reactor includes a cluster of mutually parallel fuel rods. A fuel assembly channel laterally surrounds the cluster of fuel rods and has open upper and lower ends. A top plate covers the upper open end of the fuel assembly channel and has coolant outlets formed therein. A foot part is assembled from a plurality of individual parts and includes a cast transitional piece having a lower end with an inlet opening formed therein and an upper edge inserted into the open lower end of the fuel assembly channel. The transitional piece defines and surrounds a flow channel widening upward in funnel-like fashion from the inlet opening. The foot part also includes a base plate being disposed at and welded to the upper edge of the transitional piece. The base plate covers the open lower end of the fuel assembly channel and has coolant inlets formed therein. A foot part for a fuel assembly of a boiling water reactor includes a transitional piece defining and surrounding a flow channel widening in funnel-like fashion upward along a center axis. The transitional piece has a lower end with at least one inlet opening formed therein and an upper end with an edge. A one-piece base plate is welded to the edge, covers the flow channel at the top and has coolant inlets formed therein for a flow of coolant through the fuel assembly.

Fuel assembly for a boiling water reactor, with a foot assembled from

In a fuel assembly, lower end pieces of fuel rods, guide tubes and coolant pipes, etc., are inserted and/or screwed into a base plate and secured against lifting by a bolt. In the case of fuel rods, in particular fuel rods which do not extend over the entire length of normal rods, the bolt is screwed onto connecting parts in such a way that a releasable bayonet closure is produced. In the case of coolant pipes of boiling water reactors, there is provided in particular a screw connection which is irreleasably secured against torsion by the bolt.

Fuel assembly with secured rod ends at the foot

A fuel assembly for a boiling water reactor includes approximately mutually parallel fuel rods in a bundle having upper and lower ends. A skeleton holding the bundle has a handle, an upper tie plate retained on the handle at the upper end of the bundle, a lower tie plate at the lower end of the bundle, and at least one support element joining together the lower tie plate and the upper tie plate. The skeleton and the bundle are inserted in a fuel assembly case. A redundant support device holds the lower tie plate, the fuel assembly case and the upper tie plate together, when the handle is lifted.

Fuel assembly for a boiling water reactor with a redundant support

In order to obviate the use of supporting rods, an upper end piece of a coolant tube penetrates a fuel assembly head of a nuclear reactor fuel assembly and is supported on the fuel assembly head. A lower end piece of the coolant tube is fastened to and supported by a fuel assembly foot, in particular with rods of partial lengths. A supporting skeleton therefore includes the foot and the coolant tube with spacers. The fuel assembly head and a handle are placed on the skeleton and screwed onto the coolant tube after fuel rods are pushed into meshes of the spacer.

Nuclear reactor fuel assembly with a supporting coolant tube

A gap between a foot part and a channel of a boiling water fuel assembly is sealed against a coolant flow by a spring being supported by a central part thereof against the channel and by sides thereof against the foot part and being clipped and/or clamped on at that location even when all of the fuel rods are removed. For this purpose, the upper edge can extend around the foot part edge or the spring may be constructed as a spring band running entirely around the foot part and being fitted into a lateral groove.

Fuel assembly for a boiling water reactor with a sealing spring between

A hydraulic control rod drive for a nuclear reactor, with a a reactor plenum enclosing the drive, comprises first and second hollow bodies together forming a cylinder and a hollow piston. Working fluid is supplied through one of the hollow bodies. The first hollow body is stationary and the second hollow body is disposed coaxially around the first hollow body. The two hollow bodies define an annular gap therebetween so as to allow axial reciprocating movement of the second hollow body, which forms a carrier body for control elements of the control rod. The second hollow body can be lifted, lowered or suspended by feeding working fluid. A portion of the fluid is removed from the inner space via a throttle passage. A positional measurement system determines the relative displacement of the second hollow body by measuring an ultrasonic measurement path. The system includes an ultrasound reflector and an ultrasonic transducer rigidly mounted remote from the ultrasound reflector. Provisions are made for venting the inner space through venting channels which open into the reactor plenum at a security distance from the measurement path so as not to adversely affect the ultrasonic measurement.

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Kunreuth, Germany

Werner Meier