No abstract available

[en] This paper addresses the effects of dynamic events induced by support motion on piping systems with snubbers having variable gap sizes. The investigation consists of 3 parts: (i) Mathematical examination of a linear 1 DOF mass-spring-snubber system with gap size zero or infinity. (ii) Numerical analysis of a piecewise linear 1 DOF mass-spring-snubber system with varying gap sizes, by means of a simple computer code. (iii) Numerical analysis of a realistic three-dimensional piping system with 3 snubbers, each having 4 different gap sizes, with the aid of a non-linear F.E. code. (orig.)

[en] The paper presents the results of an investigation on the development of methodologies for coupled water-hammer analyses. The study was conducted because the present analytical methods for calculation of loads on piping systems and supports resulting from water-hammer phenomena are overly conservative. This is mainly because the methods do not usually include interaction between the fluid and the piping and thus predict high loads on piping systems and supports. The objective of the investigation presented in this paper was to develop methodologies for coupled water-hammer analyses, including fluid-structure interaction effects, to be able to obtain realistic loads on piping systems and supports, resulting in production of more economical designs. (orig./RW)

No abstract available

[en] A storage rack for nuclear fuel assemblies comprising lower and upper bearers to support and hold fuel assemblies in their vertical position is described. The feature of this rack is the lower supporting device which comprises a pivoting base on which rests each fuel assembly, thereby enabling the fuel assembly not be subjected to any fatigue during storage

[en] This patent describes a scanning nuclear camera apparatus. A camera head for converting radiation from a subject into output signals indicative thereof; a subject supporting top having a head end, a foot end, and first and second sides; a gantry means for supporting and selectively moving the camera head longitudinally along upper and lower surfaces of the top, and peripherally around a central portion and the head end of the top; and an undercarriage for supporting the top without interfering with the movement of the camera head and without interfering with reception by the camera head of radiation events emanating from the supported subject during the peripheral movement of the camera head

[en] For refuelling the reactor vessel closure head is opened and the annulus between reactor vessel and biological shield respectively reactor cavity is filled with water containing boric acid. In this way an additional shield against neutron and gamma radiation is formed. For support and sealing of the annulus there is used a ring to be mounted on the site and consisting of equal-sized ring segments being firmly and tightly braced with each other. At its lower side there is fastened one each U-shaped sealing ledge sewing as contact surface on the pressure vessel and the biological shield. Thex meet closely and thus form two circular sealing rings. They consist of plastics on the basis of polymethane and get into close contact with the ring segments of ferritic steel. On the ring segments there may also be put a protective sheet of polyethylene. (DG)

[en] Plate-shaped heat exchanger matrices of high capacity are modified so that they can be used for great mass flows at high differential pressure and temperature, particularly in the gas cooled high temperature nuclear reactor. It is proposed that a large number of heat exchanger matrices connected in parallel should be inserted in a tubular housing, which has a polygonal end plate at one of the outside surfaces, which acts as a support. This carries a number of honeycomb shaped cells, which take the individual heat exchanger matrices. An advantageous configuration of the individual components of the arrangement is described. (UWI)

[en] The proposal concerns the reinforcement of a cooling tower made of reinforced concrete, which has a dish-shaped supporting structure and has ribs running in the vertical direction. In order to reduce the cost for fitting the reinforcement, the dish-shaped supporting structure is made wholly or partly as an anisotropic dish. By this construction of the reinforcement (spatial grating with different thickness of beam reinforcement of vertical ribs and of the circular beams provided in the dish, site reinforcement of the areas between the beams) one achieves the anisotropy of the dish. The fixing of constructional steel mats as site reinforcement is advantageous. (UWI)

[en] Practical interest in performing predictive analysis of vibration and wear risks of industrial tube bundles, e.g. in nuclear reactor heat exchangers, subjected to cross flow is broadly recognized. A predictive analysis of an heat-exchanger design against severe vibration and wear has to cope with experimental data on FIV and fretting wear, together with the use of analytical and numerical methods for predicting linear and nonlinear tube response. This paper describes a general approcah of the problem currently under development at C.E.A. Attention is especially paid to some key aspects of the numerical techniques, namely, the modelisation of flow-induced forcing functions and the modelisation of impact and sliding at tube-support gaps. These topics are exemplified by numerical results related to some typical situations including the case of random vibration induced by flow turbulence and fluid-elastic vibration