Abstract: Proposed is a silicon solar cell with a substrate body on one side of which an electrical field is generated by an MIS contact to cause separation of charge carriers generated by radiation energy. The minority charge carriers are drawn off in the metal of the MIS contact, whereas the majority charge carriers are conducted away by ohmic contacts arranged on the opposite side. The ohmic contacts are located on elevated areas relative to the substrate surface. Moreover, the side of the substrate body bearing the ohmic contacts is completely covered with at least one passivation layer.

Abstract: For the production of plate shaped fuel elements for material testing and research reactors with highly enriched uranium recently there has been needed U.sub.3 O.sub.8 fuels which have a high density, high strength and a small open porosity. Such fuels are obtained if U.sub.3 O.sub.8 powder produced in known manner is first compressed mechanically to molded bodies of any shape, then processed to a granulate having a size of fuel grains below 200.mu. and subsequently sintered to high density particles, preferably at 1370.degree..+-.50.degree. C.

Abstract: There is provided a process for the production of spherical fuel and/or fertile oxide or carbide particles for a nuclear reactor, especially a high temperature reactor, by casting an aqueous solution of a uranium and/or a thorium and/or plutonium salt, as well as in the case of the production of carbide particles finely dispersed carbon also, from a vibrating nozzle, passing the drops formed through an ammonia containing gas zone into an ammoniacal precipitation bath with subsequent washing, drying and sintering or melting. To the aqueous solution there is added individually or in admixture a water soluble or water miscible monomeric hydrocarbon having an aldehyde, keto, ether, amino, imino, phenol, carboxylic acid or carboxylic acid amide group, which substituted hydrocarbons form stable adducts with uranium, thorium and plutonium in aqueous alkaline solution, which adducts cannot be washed out with water and which does not impart to the solution a viscosity of over 15 cp at 20.degree. C.

Abstract: Block fuel elements are prepared according to application Ser. No. 218,244 of Jan. 17, 1972, and now abandoned, from isotropic graphite granulates and coated fuel particles solely by pressing and without any mechanical processing. The cooling channels are pressed directly along with the other parts of the fuel elements.

Abstract: There is provided a process for recovering block shaped graphite fuel elements made of a graphite block with a parallel cooling channel and which block contains the fuel arranged in separate zones. The process is especially useful for such fuel elements in which the cooling channels and the fuel zones are distributed in a screenlike manner adjacent to each other and wherein these fuel elements are first comminuted mechanically and then are reconditioned by burning and wet chemical separation into fissile material and waste material. For the mechanical comminution of the graphite block conical pins (or mandrels) are simultaneously pressed into several cooling channels until the block is broken apart along the entire length of these cooling channels.

Abstract: Molded block fuel elements having an isotropic structure useful for gas cooled high temperature power reactors are prepared by first producing an isotropic graphite granulate of high density with a definite porosity from a molding powder and then hot pressing this isotropic granulate together with coated fuel particles at low pressure to isotropic fuel element. The molding powder for making the granulate is made from a mixture of natural graphite and binder resin, synthetic graphite and binder resin or a mixture of both types of graphite powder with binder resin.

Abstract: Molded or pressed block fuel elements of high power for gas cooled high temperatures are produced by molding in steel tools using outer dies or bars and punches arranged to be freely moveable in the axial direction and moving said moveable dies or bars and punches in the molding process.

Abstract: Block fuel elements for high temperature power reactors that can be reprocessed simply are prepared in which the feed and breed zones are connected with the graphite matrix directly and without transition. They are disposed separately from each other in such a manner that the feed zones and the breed zones can be separately removed one after the other from the structural graphite. In the reprocessing operation there are recovered uranium 233 from the breed particles, uranium 235 and fission products from the feed particles.