No abstract available

[en] The axial propagation of a fission burn-up wave in a cylinder, consisting originally only of fertile material like U-238 or Th-232, is described. To solve the corresponding (non-linear) wave equation a new 'partial separation technique' is used. The results show that, indeed, an axial soliton-solution exists and that the burn-up of the autocatalytically-driven wave phenomenon is flat with respect to the cross-section of the cylinder. (orig.)

[en] Using the method of ''affine solutions'' three interesting phenomena in a CANDLE Burn-Up strategy were studied and were cast analytically into mathematical formulae: (a) the problem of two burn-up waves one behind the other (''enslavement principle'') (b) the problem of the frontal collision of two burn-up waves (''Scattering''), and (c) the problem of two identical burn-wave twins moving apart from each other after central ignition (''Breathing Out Phenomenon''). To the knowledge of the author this is the first time where such affine problems of the CANDLE Burn-Up wave physics were solved. (orig.)

[en] The complete analytical integration of the non-linear Neutron Flux Wave Equation (NFWE) for an optically thick absorber plate can be determined by the transformation Φ(ξ, τ)=G/(1+G), where G obeys the linear heat equation G_τ=G_ξξ. The backward transformation of a linear superposition in G delivers the complete integration. Aside from Burger's equation this is another example that Cole-Hopf like transformation procedures can be instrumental to solve nonlinear partial differential equations. (orig.)

[en] In March 1989, Stanley Pons and Martin Fleischmann from the University of Utah/USA reported that they had discovered sporadic heat releases of non-chemical character in electro-chemical cells using palladium electrodes and heavy water. In the meantime, a series of new papers have been published in which similar effects and various explanations were described, although a number of qualified international research instituts could not confirm these findings. The subject matter 'cold fusion' is analysed critically. (orig.)

No abstract available

[en] The article outlines relations between advanced fission reactors and fusion reactors, analogies in the heat transfer processes of the two reactor systems, and differences between fission and fusion reactors. The following issues are dealt with: 1) The cooling systems of the Wisconsin Tokamak Fusion Reactors UWMAK I and II, of the sodium- and helium-cooled breeder reactors, fast breeders and hybrid reactors; 2) the differences between D-T, D-D, ³He-D, and ¹¹B-p fusion reactors; 3) some possible combinations of high-temperature and fusion reactors, and; 4) hybrid reactors in which neutrons released in fusion reactions are used to breed plutonium from ²³⁸U or thorium from ²³³U. (Auth.)

No abstract available

[en] The article outlines a few important aspects of an energy strategy with hydrogen as an environmentally harmless secondary energy carrier. Following a compilation of the particular characteristics and advantages of hydrogen, the H₂ production by electrolysis using electrical energy from nuclear power plants and by thermolysis using nuclear process heat from high-temperature nuclear reactors, a few methods of H₂ storage and use, as well as the role of hydrogen in the future energy and raw materials economy are mentioned. (GG/LH)

[en] Parallel to the energy fluxes the entropy fluxes of decentralized hot-water systems based on solar collectors coupled with an electrical auxiliary heating installation are also deduced. As an important result the fact emerges that this kind of solar energy has to remain very restricted, not only for quantitative-energetic reasons, but also for entropy ones, and that a solar hot-water system will always have to rely on an energy system of low entropy. In contrast to this, the provision of heat for space heating sector with the help of the 'nuclear short-distance concept', which practically does not need any external energy, is not subject to these restrictions. This concept is introduced briefly, as well as the heat prices which presumably can be achieved by it. Concluding comments summarize the reasons once again that speak against the installation of a decentralized solar heat supply system. (orig.)