Abstract: A fuel rod for a nuclear reactor fuel assembly includes a metal cladding tube having two closed ends. A column of nuclear fuel pellets is disposed in the cladding tube. A compression spring has helical coils and is coaxial with the column of pellets within one of the ends of the cladding tube. A shim has two sides and is disposed between the column of pellets and the helical spring. A pair of leaf springs on one of the sides of the shim is locked to and biased against the coils of the helical spring.

Abstract: Method for manipulating and/or storing a nuclear reactor fuel assembly including an elongated skeleton structure with fuel rods and a holding device, which includes placing neutron-absorbing material adjacent the fuel rods, fastening a supplemental body with a handle to the skeleton structure, engaging the neutron-absorbing material with the supplemental body, and fitting a coupling part of the holding device to the handle, and a fuel assembly produced according to the method.

Abstract: Method for manufacturing sintered oxidic nuclear fuel bodies by molding uranium oxide starting powder, a mixture of uranium oxide and plutonium oxide starting powder or of uranium-plutonium oxide mixed-crystal starting powder to form blanks and by a heat treatment of these blanks with a U.sub.4 O.sub.9 or (U, Pu).sub.4 O.sub.9 crystal phase developed in them to a degree which can be crystallographically detected at a sintering temperature in the range of 1000.degree. to 1400.degree. C. in an oxidizing and subsequently in a reducing gas atmosphere. The starting powder and/or the blanks are preroasted at a roasting temperature below the sintering temperature in a roasting gas atmosphere with oxidizing action and with an oxygen potential in which the U.sub.4 O.sub.9 (U, Pu).sub.4 O.sub.9 crystal phase is developed and cooled down subsequently to a starting temperature below the roasting temperature in an inert or oxidizing cooling-down gas atmosphere.

Abstract: A method for assembling a nuclear reactor fuel element including a head part, a base part and grid-shaped spacer parts for accommodating fuel rods containing nuclear fuel and for accommodating control rod guide tubes having holding bodies for at least one of the head, base and spacer parts at given welding spots, includes threading the control rod guide tubes into the spacers, subsequently inserting a rod with support reinforcements into the control guide tube with one of the support reinforcements located at least at each respective given welding spot, and subsequently pressing and resistance spot welding the holding bodies against the outside of the control rod guide tube at the welding spots with welding electrodes of electric welding tongs.

Abstract: A supporting device for a member formed of at least part of an elongated nuclear reactor fuel element, the supporting device having an elongated receiving sleeve mounted vertically on a base surface and having an upper end formed with an opening and a holding device located at the upper end of the sleeve for suspending the member inside the receiving sleeve includes a removable cover closing the opening at the upper end of the receiving sleeve, the holding device being secured to the inside of the cover.

Abstract: Method for the manufacture of oxidic sintered nuclear fuel bodies by compacting UO.sub.2 -starting powder or a mixture of UO.sub.2 -and PuO.sub.2 starting powder which contains up to 10% by weight rare-earth oxide, especially Gd.sub.2 O.sub.3, as an additive into blanks and subsequent densification of these blanks by a heat treatment in a sintering atomsphere with reducing action. The UO.sub.2 -starting powder used for compacting has a specific surface in the range of 2 to 4.5 m.sup.2 /g and/or a mean crystallite diameter in the range of 80 nm to 250 nm, and the heat treatment in the sintering atmosphere with reducing action is carried out at a temperature in the range of 1,500.degree. C. to 1,750.degree. C.

Abstract: Manufacture of oxidic nuclear fuel bodies with oxygen-to-metal ratio of 2.0.+-.0.02 at relatively low sintering temperature in range of 1000.degree.-1400.degree. C. Nuclear fuel powder with an arbitrary oxygen-to-metal ratio is mixed with a grain-growth promoting additive (U.sub.3 O.sub.8) and pressed into blanks. The blanks are subjected to a two-stage operation in a furnace at 1000.degree.-1400.degree. C. - an oxidative-sintering stage in a carbon dioxide atmosphere and a reducing stage in a hydrogen containing atmosphere.

Abstract: Reconditioning ammonium nitrate-containing radioactive filtrates as produced in AUC or AU Pu C process by feeding preheated filtrate into the cathode chamber of an electrolysis cell containing boiling ammonium nitrate solution. The filtrate is brought to the boiling temperature with the assistance of the joulean heat of the electrolysis current. Ammonium carbonate and free NH.sub.3 in the filtrate are given off as gaseous CO.sub.2 and NH.sub.3 and steam and electrolytically formed NH.sub.3. The uranium and/or plutonium originally in solution as carbonate complexes is precipitated and separated by continuous circulation of the cell contents through a filter as well as electrolytically at the cathode.

Abstract: In the production of UO.sub.2, ammonium uranyl carbonate is an intermediate product wet with water and contaminated with ammonium carbonate and is washed with methanol to remove water and ammonium carbonate. The spent methanol containing 50% water and up to 10% ammonium carbonate is subjected to rectification in a column under subatmospheric pressure with cooling the top of the tower to a low temperature to retard decomposition of ammonium carbonate and condense a liquid water fraction. Clogging of the column, vapor lines and condenser by recombination of the decomposition products is prevented. The purified methanol contains less than 5% water and may be returned for further washing of ammonium uranyl carbonate.

Abstract: A boat for carrying a load of stacked layers of interspaced pellets through a high-temperature continuous furnace, has a base for carrying the load through the furnace and having upstanding posts, each of the layers being carried by a sheet having holes through which the posts are inserted to prevent lateral shifting of the sheets.