[en] With a list of 322 publications, some of which have only recently been published, with 92 sketches and diagrams and 12 tables, the paper gives a survey on the prsent state of research on turbulent flow in pipes and ducts. Also included is a chapter on the analogy between impulse, heat and material transfer, which provides the basic knowledge for a quick understanding of the most recent research findings in the field of heat and material transfer which are constantly being published. (orig./AK)

[en] A suggestion is made instead of using coloured material carriers - the cones and cylindrical tubes in spinning mills and weaving mills are given as example - to use such ones which change colour with irradiation and keep this colour until a new radiation impulse causes a new colour which differs well from the first one. (No data on material or type of radiation are given.) (UWI)

[en] Most of the spent fuel assemblies are temporarily stored in the flooded fuel ponds AB 1 and AB 2 of the RFR, and some are still in the reactor core. The conditioning task described here is part of the RFR spent fuel management concept and covers the safe emplacement of the spent fuel elements in the CASTOR MTR 2 shipping containers and the sealing of the containers in compliance with the nuclear licence issued for the conditioning task. The transfer of the spent fuel assemblies from the present wet storage conditions to the dry storage conditions in the CASTOR MTR 2 containers is done by a mobile manipulation equipment consisting essentially of the transfer sluice gate and a transfer container. Subsequent to conditioning, the shipping containers are to be transported to a licensed intermediate storage facility to await their transport to a national radwaste repository. The technical handling tools for the transfer and manipulation are briefly described, as well as the process steps involved, putting emphasis on the detailed description of processes and the accompanying time frame, so that the conditioning task can be incorporated into the work plan of the entire project. The report further presents the EDP concept established for the task, including the required data archivation and documentation. (orig.)

No abstract available

[en] The dryout heat flux as the limiting parameter for a steady state removal of the decay heat by boiling was investigated experimentally with inductively heated beds of up to 100 cm depth. The uniform beds studied consisted of stainless steel particles of 1 mm and 3 mm in diameter. The dryout heat flux is reported as a function of bed depth. Observed pool oscillations are discussed. The measured axial pressure distribution in the bed was found to be a good tool for early dryout detection. The pre-dryout transient is discussed in the light of the axial pressure distributions including some comments on local dryout phenomena

[en] A facility for performing thermo-mechanical cycle tests (thermal fatigue tests) was designed and constructed. Such tests are in support of the design of first wall structures for fusion reactors. The requirements necessary to achieve the test goals are outlined. The facility and its components are described; its upgrading capabilities are discussed. The main commissioning tests are reported. It is concluded that the facility is ready to perform thermal fatigue tests; the capability of the facility includes the testing of specimens with high surface temperatures. (orig.)

[en] The gammaspectrometrical determination of fission product concentrations in irradiated nuclear fuel is one of the possibilities in getting information on this fuel for IAEA safeguards purposes. Special data given by the operator of NPS as cooling time, burn-up and the Pu/U-burn-up ratio may be checked experimentally by relative measurements in connection with suited correlations. Results of measurements on WWR-S(M), WWER-70 and WWER-440 fuel are given as examples. (author)

[en] A first wall mock-up of the design for the next European torus (NET) was available for experiments as a water-cooled steel structure. The mock-up has not been thought to become a thermal fatigue specimen because of its pre-damage by a large number of thermocouple holes. It was rather used as a prototypical background structure for thermomechanical tests of carbon-based protection tiles and their attachment schemes. In a first series of tests the bare mock-up was thermally loaded by a heat flux to its surface. In this case, the strains measured on its back side verified a corresponding FE model prediction reasonably. In a second series the mock-up was protected by a radiatively cooled tile that was not in close thermal contact with the mock-up; these tests revealed the great importance of appropriately sized gaps that allow the full differential expansion and bowing also during thermal transients. Finally, the mock-up was protected by conductively cooled tiles which, with an intermediate layer of flexible graphite, were pressed to the surface of the mock-up. The heat transfer characteristics of the compliant layer turned out to be uniform and reliable even after thermal cycles at high temperatures. (orig.)

[en] Procedures have been elaborated to investigate isotopic correlations by calculating concentrations of fissionable nuclides and fission products as well as the burnup for an irradiation history consisting in time intervals with constant neutron flux densities. Effective cross sections suitable for a one group formalism are derived. Results of such calculations are checked by mass spectrometric and γ-spectrometric measurements performed on fuel assemblies and elements irradiated in the PWR of the Rheinsberg power station (WWER-70). As a result of this comparison, simple approximation functions are derived concerning the correlation between the burnup and ratios of fission product concentrations. These functions are suited to determine the burnup of irradiated fuel assemblies by means of relative γ-spectrometric measurements with an accuracy sufficient for safeguards. (author)

[en] A method is presented of approximating the transient dryout behavior in particulate beds by a sequence of quasi-steady-state steps. The model describes the slow evaporation of an internal liquid reservoir by introducing a fictitious bottom inlet flow. The effect of capillary forces is included. Results are shown to be in close agreement with a real time-dependent solution. From a comparison with transient experimental data additional support points for the verification of a steady-state dryout model are obtained