[en] The fuel body of a fuel element consists of fuel particles coated with pyrolytic carbon arranged between walls constructed as screens. The screens are formed as cones, double cones or as corrugated pipes and move between the pipe walls of the cylindrical fuel element from one side to the other and back. The particles are held in their position by graphite-felt, graphite fabric or felt or fabric made of SiO₂. This stable geometric configuration guarantees that during operation changes of the power distribution in the reactor and reactivity jumps can be avoided. In research reactors even the emergency cooling becomes easier to be carried out. (orig.)

[en] Research and development programs from 1945 to the present on coated-particle fuels are reviewed. 11 references. (U.S.)

No abstract available

[en] Description of method and handling of fluidized beds with variable velocity of gas. Special use for coating fuel particles of reactors. (J.K.)

[en] This invention concerns a new type of fluidised bed reactor enabling the advantages of the two main known type to be combined, i.e. the homogeneous fluidised bed reactor and the central jet fluidised bed reactor. This new type of reactor can be built as large capacity units in which the working conditions can be strictly controlled and reproduced in each elementary particle. It is most particularly suitable in the preparation of a nucleus based on uranium oxide or carbide or thorium coated with one or more concentric coats of pyrolytic carbon and possibly silicon carbide

No abstract available

[en] A fuel element comprises highly enriched uranium bodies coated with a nonfissionable, corrosion resistant material. A plurality of these bodies are disposed in layers, with sodium filling the interstices therebetween. The entire assembly is enclosed in a fluid-tight container of nickel

[en] The device for removing the graphite shell of spherical HTR fuel elements has a pair of two parallel cutting discs. (orig./HP)

[en] We describe new image analysis developments in support of the U.S. Department of Energy's (DOE) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. We previously reported a non-iterative, Bayesian approach for locating the boundaries of different particle layers in cross-sectional imagery. That method, however, had to be initialized by manual preprocessing where a user must select two points in each image, one indicating the particle center and the other indicating the first layer interface. Here, we describe a technique designed to eliminate the manual preprocessing and provide full automation. With a low resolution image, we use 'EdgeFlow' to approximate the layer boundaries with circular templates. Multiple snakes are initialized to these circles and deformed using a greedy Bayesian strategy that incorporates coupling terms as well as a priori information on the layer thicknesses and relative contrast. We show results indicating the effectiveness of the proposed method.

No abstract available