[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 fluid dynamic behavior of pulsed plate columns is influenced by the inner parameters of the extraction system while the outer parameters are kept constant. There are two reasons for the change in operating characteristics with time: change in coalescence behavior of the system, change in wetting behavior of the cartridge. There is a strong influence on the dispersed phase holdup in both cases, causing the regime of operation to be discontinued (relinguished) and leading in a situation which requires the through put to be diminished and finally to be stopped. The effect of coalescence is characterized by measurement of coalescence time, the effect of wetting by contact angle measurement. Steps (expedients) in design are proposed to act against retardation in drop-drop coalescence. The required good wettability of column cartridge by the continuous phase is achieved by direct application of a supersonic cleaning method which guaranties the fluid dynamic stable mode of operation in practice. (orig.)

[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] A pulsed floor column for washing with dilute nitric acid was tested for removing the tritium from the organic product flow of the PUREX process, into which it has penetrated due to the carried over aquaeous phase. Phases loaded with uranium were used for the test, and the tritium was simulated by deuterium. The required decontamination factor of 40 is far exceeded with a column length of 6 m at a column diameter of 210.5 mm, where the flow ratio can be increased from the initially required 20 to 40. This means halving the tritiated quantity of wash water. (RB)

[en] The first wall of a fusion device receives from the plasma thermal loads in addition to neutron radiation, chemical and mechanical loads. To qualify a first-wall design, it needs to be tested under these loads, which is done out of the device in separate tests. The test facility described in this paper is designed for testing medium sized first-wall specimens under cyclic thermal loads. A technical description of the facility and its design limits are given. (orig.)

[en] The influence of drop breakage and coalescence on the operation behaviour and the separation efficiency of pulsed perforated plate extraction columns, widely used in spent fuel reprocessing is shown. The results of coalescence studies carried out in the nitric acid-tributyl phosphate system using an experimental setup in the aqueous phase continuous mode of operation are presented. Two different types of drop-drop coalescence, i.e. the collision- and the settling coalescence have been revealed and discussed. 8 refs.; 8 figs

[en] The results of an experimental investigation on the mechanical and thermal behavior of a compliant layer between a first wall mockup and its protection tiles are reported. The heat transfer was reliable and did not depend on the contact pressure within the limits investigated. (orig.)

[en] Published in summary form only

[en] The construction of the test loop, the test section, the power supply, the instrumentation and the data acquisition system have been completed. The shake down period was started in December 1975. The instrumentation of 5 fuel rod simulators was also completed. One heater rod has been tested under realistic conditions. Starting at a heater temperature up to 950⁰C a series of 40 flood cycles was carried out without remarkable damage of the rod and the thermocouples. Difficulties occurred in milling grooves into the cladding for the embedding of the thermocouples. Therefore, a new manufacturing process was developed in cooperation with an industrial company. The success is a more precise method for the instrumentation at lower costs. During the swaging of an intermediate sleeve to the outer surface of the rod for the attachment of the artificial blockage the embedded thermocouples were partially damaged. Therefore, the development of an other method was started to attach the blockage at the rod. The software necessary for the data acquisition system has been specified and ordered. Tests to avoid a too early wetting of the observation windows at the test section were not successful using a metal coating for heating. Due to the high temperatures the lifetime of the coating was too short. On the other hand, it was found that the wetting problem can be reduced by heating up to test section to a high starting temperature. Films taken through these windows with a frequency of 4,000 pictures/sec show that the exposure time was still too long to obtain sharp pictures of the water droplets in the mist flow. To reach shorter exposure times the used lamp for steady light has to be exchanged for a flash light equipment. Such an equipment with a flash time of some Nano-seconds was defined and ordered. (orig.)

[en] The shake down of the loop and the test section including 5 rods without blockages has been successfully completed. Several improvements were made concerning the power control, the safety system for the protection of the heater rods, and the data acquisition. Prestressing of the rods using weights of about 10 kg each has given satisfactory results. After 11 flooding tests the rods have been still straight. Nevertheless in the region of the highest rod power the spacers were permanently deformed. The reason for that is, that the thermal expansion of the rods was restrained by the high friction force between the rod and the spacer in the colder zone. Therefore during the assembling process of the instrumented rods the contact pressure was reduced. The actual experimental work was started. After 3 reflood tests the distance between the heater rods are still uniform. During all preliminary tests, the shake down period, and the experimental work no heater rod has been damaged. During the shake down a short circuit occured due to a leakage of water in the region of the current connectors. Hereby 3 thermocouples were damaged. To avoid that problem the insulation as well as the safety system were refined. (orig.)