Kraftwerk Union Aktiengesellschaft

Josef Steven

Alexander Steinke

Helmut Bezold

Friedrich-Wilhelm Aisch

Diethelm Knodler

Hans Peter Fuchs

Karl Hassfurther

In a nuclear reactor fuel element for receiving mutually parallel rods, the improvement includes a rectangular grid-shaped spacer including planar webs crossing and facing the rods defining grid mesh openings receiving the rods, the webs including two outer webs forming an outer corner of the spacer and defining a corner grid mesh opening at the outer corner, the outer corner having an outward curve being curved in a direction parallel to the longitudinal direction of the rods, the outer webs having edges at the curve transverse to the rods being drawn inward toward the rods in the corner grid mesh opening forming a bevel in longitudinal direction of the rod.

Nuclear reactor fuel element

Device for measuring the spring-force of resilient spacer projections set into spacer grids of nuclear reactor fuel assemblies to push fuel rods surrounded by spacer meshes against at least two oppositely disposed rigid spacer projections, including a force measuring plug having a diameter equal to the diameter of a fuel rod to be fixed in the spacer grid, and a flexible beam integral with the force measuring plug, the flexible beam having a free end in contact with a first resilient spacer projection to be measured, and another end firmly connected to the force measuring plug and having at least one wire strain gage disposed thereon.

Spring-force measuring device

A nuclear reactor fuel rod formed of a cladding tube, end caps hermetically sealing the tube at both ends thereof, the tube being divided transversely into two longitudinal zones one of which is for receiving a charge of nuclear fuel and the other of which is for receiving gas-adsorbing material free of nuclear fuel, includes means received in the second zone for simultaneously supporting the tube and for containing gas-adsorbing material therein, the means having a capsule having an open end facing toward the one zone and a gas-permeable member closing off the open end of the capsule, the capsule containing adsorber material that has been dried and degassed in high vacuum at temperatures of from 500.degree. to 1000.degree. C, the capsule having an interior space between the adsorber material contained therein and the gas-permeable element, and including a metallic foil destructible by a given internal pressure of the fuel rod gas-tightly closing the interior space; and method of production.

Nuclear reactor fuel rod

For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel, can result in the pressurized coolant in the vessel, discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner.

Growing community of inventors

Erlangen, Germany

Josef Steven