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[en] Methods of calculation of thermal processes of the isolating materials are considered, in problems of nondestructive diagnostics of the main and distributive power stations. Theoretical justification of calculation of thermal processes of the multilayered isolating structure was given. On the basis of the analysis of results of operation, service life, physical processes of “ageing” and use of diagnostic parameters of the isolating structure characteristics of resistance of the equipment to refusal are offered. Time of refusal and a residual service life allow to predict using of dependences of refusal resistance. (paper)
[en] Microchannel-plate photomultipliers (MCP-PMTs) are the favored sensors for the DIRC detectors (Detection of Internally Reflected Cherenkov Light) of the PANDA experiment. They are usable in high magnetic fields of up to 2T and reach a time resolution of better than 50 ps (σ). The anticipated average luminosity of 2.10"3"2 cm"-"2 s"-"1 in the detector requires a rate capability high enough to withstand a detected photon rate of about 200 kHz cm"-"2 at the MCP-PMT surfaces. The major drawback until recently was the limited lifetime of MCP-PMTs, which appears to be solved for the latest generation of MCP-PMT prototype devices. The aging parameter is the quantum efficiency as a function of the integrated anode charge, which will be in the region of 5 C/cm"2 for the Barrel- and the Disc-DIRC. We simultaneously measured the aging of several MCP-PMTs, which were treated with different methods to enhance the lifetime. Results of these measurements are presented.
[en] The High Flux Australian Reactor (HIFAR) is operated by the Australian Nuclear Science and Technology Organisation (ANSTO) with objectives associated with the non-energy uses of nuclear technology. HIFAR is one of six DIDO-class reactors designed in Britain in the 1950s. The design was chosen for its versatility, utility and longevity and has brought wide benefits to health care, to environmental protection and to the development of high technology. HIFAR is expected to be operating to the early years of the next century. After the government decided not to develop a nuclear power programme, materials testing work tapered off while the use of the reactor for producing radioisotopes increased. This growth continued to the point where radioisotope production became the major application of the reactor's in-core facilities. With the growth in the world semiconductor industry, ANSTO built facilities at HIFAR in the early 1980s to convert silicon to neutron transmutation doped (NTD) silicon for semiconductor manufacture. (Author)
[en] The extension of service life of Nuclear Power Plants (NPPs) in the United States from 60 to 80 years requires an assessment of the durability of all components under long-term operation conditions, including the concrete structure itself. This, in turns, requires building predictive numerical models able to represent the long-term material behavior.
[en] In some environments, components might not always fail fully, but can degrade, and there can be multiple stages of degradation. In such cases, the efficiency of the system may decrease. After a certain stage of degradation the efficiency of the system may decrease to an unacceptable limit and can be considered as a total failure. However, the system can fail randomly from any stage. and can be repaired. Further, the repair action cannot bring the system to the good stage, but can make it operational and the failure rate of the system will, therefore, remain the same as before the failure. In this study, we present a model for predicting the reliability, availability, mean life time, and mean time to first failure of multistage degraded systems with partial repairs. In the analysis, state dependent transition rates for the degradation process, as well as repair processes, are considered. A numerical example is provided to illustrate the results
[en] We give an overview of the scenario aiming to gathering 2000 fb"−"1 at the end of the LHC lifetime. The compatibility of the hardware foreseen in the so-called performance improvement consolidation (aiming at 1000 fb"−"1) is verified, and the requirements on the new hardware are outlined