[en] If nuclear power is to contribute its share to ensuring in the long run low-cost and environmentally sound power supplies, and to managing the climate problem, any new nuclear power plant to be built has to be designed so as to be accepted by the public as a justifiable safety risk, and by the utilities as an imputed investment risk. The Konvoi-type nuclear power plants that started operation in 1988/89 have demonstrated already after this short period a very high safety standard, measured by international standards, which is based on and ensured by valuable construction and operation experience, as well as by the reliable and established licensing procedure. Starting from the current status and achievements, dynamic, evolutionary developments will bring about purposeful design improvements and a still enhancing safety standard by introduction of in-plant emergency management measures, so that even in the case of design-exceeding accidents, there will be no undue radiological hazard to the environment conceivable by the standards of practical reason. (orig.)

[en] Nuclear energy in industrialized countries has contributed considerably for many years to energy supply. Assessment of the state of the art, in particular of safety concepts, requires a differentiated approach. Analysis shows that advanced Western plants have both a satisfactory safety standard and a positive operating experience. That is a good starting point for further technological developments. For the next generation of nuclear power plants, worldwide plenty of reactor concepts are under discussion, the recognizable tendencies being both the evolutionary further developments of proved lines and the development of completely new (revolutionary) concepts. Most of the essential developments are achieved by international cooperation. A necessary prerequisite for the implementation of safety-related and economically improved nuclear installations is the acceptance of nuclear energy by politicians and the public. (orig.)

[en] Anaerobic processes are getting increasing attention in the disposal of liquid waste of the food industry and chemical industry and solid organic residues of the municipal sector. The main advantages of anaerobic processes are the favourable energy balance and the comparatively small volume of new biomass produced. There are new satisfactory technical solutions for nearly all problems encountered in practice. A conference on ''Anaerobic treatment of solid and liquid residues'' was held on 2-4 November 1994. The state of the art and new developments were presented in lectures by experts from research and practice. (orig.)

[en] The invention described concerns nuclear reactors with replaceable fuel elements. According to the invention, parts of the reactor core burned up in a first nuclear reactor are used for the first core of a second nuclear reactor. This permits considerable savings, particularly in pressurized-water reactors

[en] Lack of public acceptance in most of the industrialized countries presently impedes expansion of nuclear energy. Regain and reestablishment of public acceptance demand safety performance improvements appropriate to convince the public that the risk of occurrence of a severe accident will be further decreased and, in addition, that even an accident sequence exceeding the design basis will not expose the environment to an unacceptable radiological impact. Probabilistic risk analysis has proven to be an excellent guiding instrument for identifying safety improvement needs. The recently commissioned 1300 MW Konvoi PWR plants have already achieved a highly acceptable level of safety, the frequency of an accident event not coped with by the safety systems amounting to approximately 1.4x10^-6 per year. Following a predominantly evolutionary way of safety improvements the proven safety features are to be maintained also for the next generation of NPPs since one of the most important criteria of design advance is reflection of operating experience and incorporation of proven technology. In addition, however, some potential safety performance improvements merit consideration, especially in the following areas: A novel I and C system using exclusively digital microprocessor-based technology as, e.g., presently under advanced development at Siemens will contribute markedly to further improve man-machine interface performance. Implementation of preventive accident management or equivalent design measures to maintain core coolability and pressure vessel integrity after incipience of an event exceeding the design basis. Exploration and elaboration of mitigative accident management measures and/or provision of precautionary design measures to maintain containment integrity even in case of a core melt accident. Implementation of such safety improvements will practically exclude occurrence of a severe accident with unacceptable radiological consequences to the environment. (author). 13 refs, 8 figs, 2 tabs

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[en] Till now 175 Pu-bearing fuel assemblies with altogether 7896 mixed oxide fuel rods designed and specified by KWU and fabricated by ALKEM have been or are in operation in German power reactors. In the Obrigheim (PWR) and in the Gundremmingen (BWR) plant up to 20% of the core are made up of Pu fuel. Fuel and core performance has been very satisfactory. This extensive operating and performance experience supplemented by results of post irradiation evaluations, irradiation tests, and nuclear experiments furnished sufficient evidence that large scale use of recycle Pu fuels in commercial LWR cores, at least up to SGR level, is technically feasible with the same degree of reliability and safety as in U-fueled LWRs

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[en] After a general review of the present world-wide energy situation (with particular reference to those of the Federal Republic of Germany and of Argentina) the possible contribution of nuclear energy in general, and of proven light water and heavy water reactor types in particular, to meeting the energy demand is discussed. The technical and economic development potential of those reactors is evaluated, both regarding plant components technology as well as fuel and fuel cycle improvement, with special emphasis on the Pressure Vessel Heavy Water Reactor type. The last section presents some results of nuclear reactor strategy calculations made for a scenario similar to that of Argentina over the period from 1970 through 2040 and involving the use of: A) heavy water reactors (HWR's) only, with and without plutonium recycling, and B) the use of HWR's plus fast breeder reactors. (M.E.L.)