Abstract: A base beam for formation of a horizontal and vertical, rod-like framework for use in clamping workpieces to be measured, includes a main body defined by a substantially square cross section and having drawn-in flanks formed centrally with a rib, and a carriage detachably securable on the main body for displacement longitudinally in direction of the main body, with the carriage having at least one side formed with one or more precision bores.

Abstract: An organic extraction phase, containing fission materials uranium and plutonium, as well as a minor amount of fission- and corrosion-products, from an extraction step or from a purification step of a nuclear fuel reprocessing process is treated with an aqueous, basic, carbonate ion containing solution, whereby the fission materials and at least a part of the fission- and corrosion-products are stripped into the aqueous phase and the uranium is present in the form of uranium-carbonato-complex. The organic phase is then separated from the aqueous phase. Plutonium is then removed from the separated aqueous phase. The remaining aqueous solution containing the uranium-carbonato-complex and a small residual amount (C) of fission products is adjusted to a ratio of uranyl ion concentration to carbonate ion- or CO.sub.3.sup.-- /HCO.sub.3.sup.-- concentration of 1(UO.sub.2.sup.++) to 4.5(CO.sub.3.sup.-- or CO.sub.3.sup.-- /HNO.sub.3.sup.-), respectively, or more, at a maximum U-concentration of not more than 6- g/l.

Abstract: A process for separating large amounts of uranium from small amounts of radioactive fission products, which are present in basic, aqueous carbonate containing solutions, by means of a basic, organic anion exchanger. Uranium values present as uranykl-carbonato complex in a basic, aqueous, carbonate containing solution can be separated from fission products of the group ruthenium, zirconium, niobium and lanthanide, and with a relatively high degree of decontamination as well. The aqueous solution is adjusted to a ratio of uranyl ion concentration to carbonate ion- or CO.sub.3.sup.-- /HCO.sub.3.sup.- concentration of 1(UO.sub.2.sup.++) to 4.5(CO.sub.3.sup.--, or CO.sub.3.sup.-- /HCO.sub.3.sup.-), or more, at a maximum U concentration of not more than 60 g/l. The adjusted solution is led over a basic anion exchanger made from a polyalkene matrix provided with a preponderant part tertiary and a minor part quaternary amino groups to adsorb fission products ions or fission products containing ions.