Abstract: The steps for recovering uranium and transuranic elements are simplified, and the generation of waste solvent and waste materials is suppressed. Spent nuclear fuel is dissolved in nitric acid (S100) and the resulting solution is subjected to electrolytic oxidation so that U, Np, Pu, Am is oxidized to VI using Ce as oxidation catalyst. The solution is cooled, and nitrates of valence VI thereby deposit as crystals and are separated from the mother liquor (S104). The mother liquor is heated and concentrated (S114). The mixed crystalline deposit is dissolved in nitric acid (S106), uranyl nitrate is deposited alone by cooling (S108), and the crystals are separated from the U, Np, Pu, Am mixed solution (S110). The uranyl nitrate is dissolved in nitric acid (S112), and the heated and concentrated mother liquor is added to it to prepare another mixed solution.

Abstract: A method of separating and recovering Pu and Np from a Pu- and Np-containing nitric acid solution. The method comprises the steps of subjecting a nitric acid solution containing Pu and Np to valence adjustment by adding a reducing agent consisting of hydroxylamine nitrate and hydrazlne to said nitric acid solution so as to reduce Pu and Np in said nitric acid solution to Pu (III) and Np (IV), respectively; adjusting a nitric acid concentration of said nitric acid solution after said valence adjustment to 6 to 8 M; bringing said nitric acid solution after said nitric acid concentration adjustment into contact with a strong basic anion exchange resin so as to cause Np to be selectively adsorbed by said resin and to separate and recover Pu as a plutonium nitrate solution; and eluting said adsorbed Np (IV) by using diluted nitric acid of 1 M or below so as to recover Np as a neptunium nitrate solution.

Abstract: A hermetically sealed connector for a glove box and a method for exchanging such connectors in which leakage of radioactive material from within the glove box is minimized and an auxiliary glove box is not needed to exchange the connectors. The connector is formed as a cylindrical member having a flange portion hermetically sealed to a packing provided in a through hole in the wall of the glove box. To exchange connectors, a nut is removed from the outer end of the old connector and a tube is screwed thereto. The other end of the tube is fitted to the inner end of the new connector. The tube is then shoved through the packing until the flange of the new connector aligns with the packing. The tube is then removed from the inner end of the new connector and a nut is screwed on in replacement for the tube.

Abstract: A hermetically sealed connector for a glove box and a method for exchanging such connectors in which leakage of radioactive material from within the glove box is minimized and an auxiliary glove box is not needed to exchange the connectors. The connector is formed as a cylindrical member having a flange portion hermetically sealed to a packing provided in a through hole in the wall of the glove box. To exchange connectors, a nut is removed from the outer end of the old connector and a tube is screwed thereto. The other end of the tube is fitted to the inner end of the new connector. The tube is then shoved through the packing until the flange of the new connector aligns with the packing. The tube is then removed from the inner end of the new connector and a nut is screwed on in replacement for the tube.

Abstract: An apparatus for continuously concentrating and denitrating a radioactive nitrate solution by microwave includes a rotatably supported concentrating and denitrating vessel disposed within an oven into which microwave is applied through waveguides. The concentrating and denitrating vessel comprises a circular vessel body supported rotatably about its center and a plurality of partition plates positioned radially inside the vessel body so as to divide the interior of the vessel body into a plurality of compartments. The nitrate solution supplied into the vessel is heated, evaporated, concentrated and denitrated in sequence in each of the compartments during one rotation of the vessel to form a denitrated oxide powder. The denitrated powder produced in one of the compartments is transferred into a receiving pan positioned adjacent to the outer periphery of the vessel.

Abstract: An annular tank for storing nuclear reaction material in an annular space formed among seamless upper and lower annular dies disposed elevationally in a predetermined space and inner and outer sheaths extended on the inner and outer peripheral surfaces of the upper and lower dies. The tank avoids thermal strain and deformation by forming the upper and lower dies in a seamless manner to thus enhance the heat dissipating effect together with high working accuracy and strength. The method of fabricating the annular tank is simple by omitting the use of jigs for welding the segments with less loss and high production yield.