Abstract: In a nuclear fuel reprocessing plant for processing a used nuclear fuel by a nitric acid solution, the present invention provides a nuclear fuel reprocessing plant characterized by including electrolytic reduction means for reducing the valence of oxidizing metal ions consisting of the nuclear fuel and dissolved in the nitric acid solution while they are kept under the ionic state. In a processing method of a nuclear fuel reprocessing plant for processing a used nuclear fuel by a nitric acid solution, the present invention provides also a corrosion-proofing method of a nuclear fuel reprocessing plant characterized in that electrolytic reduction is carried out so that the valence of oxidizing metal ions consisting of the nuclear fuel and dissolved in the nitric acid solution is reduced while the metal ions are kept under the ionic state and NOx gas is also generated.

Abstract: The present invention provides a process for removing a metal surface oxide from a metallic substance by contacting the metal surface oxide layer with a deterging liquid to introduce electrons into the metal surface oxide in contact with the deterging liquid to dissolve the metal surface oxide, which process is characterized in that a metal piece or carbon piece is immersed in the deterging liquid into which gaseous hydrogen has been introduced and the metal piece or carbon piece is electrically connected to the metal surface oxide on the metallic substance. The metal piece is preferably platinum or vanadium. A preferred deterging liquid is one having a pH of about 5 to 7 and containing a complexing agent.

Abstract: Liquid developers for use in developing electrostatic latent image which contain at least one member selected from the following Group A and at least one member selected from the following Group B.Group A: Cumarone indene resin, rosin modified phenol resin, rosin modified maleic acid resin, rosin modified pentaerythritol resin, alkylphenol modified xylene resin, styrene-vinyltoluene copolymer, and resin acid calcium salt.Group B: Low molecular polyethylene, ethylene-ethylacrylate copolymer, ethylene-vinylacetate copolymer, low molecular polypropylene, chlorinated paraffin (degree of chlorination, 40 to 70%), polybutene resin, .beta.-pinene resin, polyterpene resin, and alkylphenol formaldehyde resin.