Kraftwerk Union Aktiengesellschaft

Siemens Aktiengesellschaft

Heinz Stehle

Eckard Steinberg

Hans Weidinger

Friedrich Garzarolli

Klaus Gregorius

Karl Janner

Helmut Assmann

Hans-Jurgan Romeiser

Walter Janson

Peter Wahode

A fuel rod for a nuclear reactor fuel assembly includes a cladding tube having an outer surface and a given total wall thickness. Nuclear fuel is disposed in the cladding tube. The cladding tube is formed of a first zirconium alloy which may have alloy components of from 1.2 to 2% by weight of tin, 0.07 to 0.2% by weight of iron, 0.05 to 0.15% by weight of chromium, 0.03 to 0.08% by weight of nickel, 0.07 to 0.15% by weight of oxygen, and a total percent by weight for the alloy components of iron, chromium and nickel in a range of from 0.18 to 0.38% by weight. The first zirconium alloy may also have alloy components of from 1.2 to 2% by weight of tin, 0.18 to 0.24% by weight of iron, 0.07 to 0.13% by weight of chromium, 0.10 to 0.16% by weight of oxygen, and a total percentage by weight for the components of iron and chromium in a range of from 0.28 to 0.37% by weight. A surface layer which is disposed on the outer surface of the cladding tube is formed of a second zirconium alloy having a layer thickness in a range of from 5 to 20% of the given total wall thickness of the cladding tube, the second zirconium alloy being formed of at least one alloy component from the group consisting of iron, chromium, nickel and tin having a total percentage by weight of the alloy components of the group of from 0.4 to 1% by weight and/or having from 0.2 to 3% by weight of niobium as an alloy component.

Fuel rod for a nuclear reactor fuel assembly

Fuel rod cladding tube having an inner tubular layer of a zirconium alloy with alloying components of 1.2 to 1.7% tin, 0.07 to 0.2% iron, 0.05 to 0.15% chromium, 0.03 to 0.08% nickel, 0.07 to 0.15% oxygen, with the sum of percentages of iron, chromium and nickel in the range of 0.18 to 0.38%; or with the alloying components 1.2 to 1.7% tin, 0.18 to 0.24% iron, 0.07 to 0.13% chromium, 0.10 to 0.16% oxygen, with the sum of percentages of iron and chromium in the range of 0.28 to 0.37%; and with the inner tubular layer having an outside surface layer of another zirconium alloy with a layer thickness of 5 to 20% of the cladding tube as well as with 0 to 1% iron as an alloying component and with at least one alloying component from the group of: vanadium with 0.1 to 1% by weight, platinum with 0.1 to 1% by weight, and copper with 1 to 3% by weight.

A desired isotope mixed with one or more other isotopes is selectively excited by laser radiation absorbed by only that isotope, so that that one isotope selectively enters into a chemical reaction with a reaction partner fed to the mixture. The desired selectivity can be degraded here by thermally activated reactions between the other isotopes and the partner. To avoid this effect, the mixture and partner in the necessary reaction vessel are irradiated for one or more short time intervals after each of which the vessel's content is adiabatically emptied into a vacuum vessel. Each time interval may be made short enough to avoid the thermal activation.

Method and apparatus for isotope concentration

Method for isotope separation or enrichment in a vaporous mixture of compounds containing the isotopes to selectively excite the group of molecules containing one isotope by means of coherent, polarized electromagnetic radiation (lasers) in which a frequency shift is prevented or greatly reduced and the excitation state can be driven very high to beyond the dissociation limit. This is accomplished by adjusting the frequency and field strength of the radiation so that the dipole moment of the group of molecules to be excited, oscillates, at least at the final amplitude, mainly in phase opposition to the exciting field, and the other group of molecules mainly in phase with the exciting field. In another procedure the radiation has a frequency closer to the resonance frequency of the group of molecules to be separated and is of the order of magnitude of the isotope-determined frequency difference, and both groups of molecules operate in phase opposition.

Method for isotope separation by means of coherent electromagnetic

A pressurized-coolant reactor fuel rod comprises a cladding tube having ends closed gas-tightly, the tube internally defining a fuel-containing space and in which nuclear fuel pellets are positioned. The tube contains a fission gas plenum chamber formed by a capsule having a flow choke connecting the chamber with the fuel, this capsule being positioned between the fuel and one of the tube ends closed gas-tightly. The capsule is made elastically expandable lengthwise with respect to the cladding tube and it engages and restrains the fuel against displacement lengthwise with respect to the tube, by elastically pressing the fuel away from the tube's closed end adjacent to the capsule.

Pressurized-coolant reactor fuel rod

Nuclear fuel rod ends of water-cooled reactor fuel rods, are heated in the region of the fission gas plenums and/or in the region of the upper or lower ends of the fuel columns. The moisture present in the case of damage to the fuel rods' casings, evaporates and is partly condensed at the end caps. In the case of a fuel rod completely filled with water, steam bubbles are generated. Both indications of casing leakage or damage are ascertained by ultrasonic reflection measurements and/or measurement of a temperature-vs-time curve, obtained at the end cap.

Growing community of inventors

Marloffstein, Germany

Heinz Stehle