No abstract available

[en] This report contains a survey of the Karlsruhe Programme-System KAPROS. It enables the user of the system to set up complex reactor calculations and the programmer to produce new KAPROS modules and procedures. In addition to the rules for the correct use of KAPROS all guidelines which have to be obeyed by writing new modules or procedures are placed together. This report contains also a list of all modules presently integrated in KAPROS, the guidelines for programme abstracts of KAPROS modules and the extensions of the KAPROS concept to special problems. (orig.)

[en] 1 - Nature of physical problem solved: The multigroup neutron diffusion equations are solved for two-dimensional x-y, r-z and r-theta geometries in the homogeneous or inhomogeneous case. 2 - Method of solution: The analytical equations are approximated by five-point difference formulas and the resulting numerical problem is solved by an inner-outer iteration technique, where inner iterations are performed along a cyclically reduced block over-relaxation with pre-calculated relaxation factors. 3 - Restrictions on the complexity of the problem: The maximum number of mesh points and/or groups depends on the available core storage in the following manner: Assume: C = total number of available core storage words; P = program length in words; NGP = number of groups; NM = number of material compositions; MXN = number of mesh points; Q = NM*NGP*(NGP+5)/2 - approximate store for cross sections then: C.GE.(P+Q+S+4.5*MXN) must be true. If this relation holds, the program searches for an optimal way to solve the problem with a minimum number of I/O devices (max. 2) using the adjustable dimension feature

No abstract available

[en] The Godunov method that tracks nonstationary fronts and interfaces as boundaries of subregions moving with time is extended to include radiation transport. In each subregion and at each time step, a new grid is created by use of boundary-fitted coordinates. The radiation transport is performed in a multiangle-multifrequency approach. The numerical method is based on a finite volume method in the space time-domain, and the hydrodynamic fluxes are calculated using the solution of Riemann problems. Numerical results are shown for some selected problems to demonstrate the efficiency of this approach

[en] 1 - Problem solved: Calculation of compressible and high energetic hydrodynamic fields including photon transport and heat conduction in two-dimensional curvilinear geometry. 2 - Methods: The analytical hydrodynamic equations are solved by a combined Lagrangian and Eulerian approximation applying Godunov method and finite volume technique. The space angle dependent photon equation is treated similar to the neutron transport equation using a set of predefined space angles and a multigroup structure of opacity data. The time-step size is adapted by CFL control. 3 - Restrictions on the complexity of the problem: The underlying equation of state data library for the high temperature and pressure regime is restricted to aluminum only. The numerical accuracy is restricted by allocatable fast and disk storage

[en] The nuclear computer code system KAPROS with its codes and data banks is the result of intensive theoretical work in order to make available all auxiliary means for neutron-physical core design especially for fast reactors. (RW)

[en] In most ICF target simulation calculations, alpha and other charged particles are assumed to be reabsorbed in the plasma whereas neutrons are often allowed to escape without interaction. However, in reactor-size targets, neutrons lose about the same amount of energy in the DT fuel as α-particles and can considerably influence the burn characteristics of the target and the reactor blanket performance. Results with a simple adiabatic model and time-dependent neutron transport calculations are presented. The total gain obtained for the HIBALL target is 157 for both the simple adiabatic model and the time-dependent neutron transport calculation. With the free neutron escape approximation the gain was calculated to be 179. Thus, neglecting the neutron fuel interaction overpredicts the pellet gain by about 15%. The strong moderation of the neutron has a marked influence on the blanket/breeding ratio. (author)

[en] The behavior of divertor materials under the high heat load during a plasma disruption, a key problem in tokamak fusion technology, is studied at several laboratories under simulated plasma disruption conditions. Numerical modelling of the complex processes taking place at the divertor during a plasma disruption event was started recently at Kernforschungszentrum Karlsruhe. The aim of these activities is to determine the erosion rate of divertor material under different heat loads, to quantify the vapor shield effect and to give insight in the mechanisms of the beam target interaction. The simulation studies are performed with the Karlsruhe target code KATACO. This is a 1D plasma hydrodynamic code including beam energy deposition and multigroup radiation transport. First results for 10 and 100 keV proton beams with a power density of 5 and 50 MW/cm² respectively at a pulse duration of 100 μs show, that an equilibrium state at a plasma temperature of a few electron volt is reached shortly after the beginning of the disruption. A substantial part of the incoming energy is radiated back into the cavity. (orig.)

No abstract available