[en] The first comparisons of AER benchmark for kinetics parameters calculation of VVER-440 fuel is based on MOBY-DICK and NESSEL-4 calculations. (author)

[en] Solution of 'Dukovany load follow benchmark', is presented. Critical rod positions calculated by BIPR7 with KASSETA data are compared with experimental ones. (author)

[en] Two problems of code validation are addressed. Either problem is connected with the point drop technique. The first one is a specific usage of the point drop technique, in the frame of which the code to be validated is compared to all measured values, then, after discarding a measured value, another fit is made and the estimated value for the discarded measurement is compared to the actual measured value. The point drop carries the same amount of information that carries the original fit. This assertion is restated for casual and random quantities. Notwithstanding, when used appropriately the point drop technique is capable of indicating areas where the model to be tested is less accurate. The second problem is that of the detection of an area where the calculational model is poor, i.e. the proper usage of the point drop technique. (author)

[en] Short-term fuel cycle strategy modification is presented connected with the profiled fuel part of the Control Fuel Assembly (CFA) Introduction. The long-term fuel cycle strategy is drawn. Operational experience from start-up and first full power days of two cycles with profiled Russian fuel is summarised. (author)

[en] In some cases control rod worth efficiencies evaluated by inverse point kinetics from our-core detector currents remarkable differ from direct calculations. Explanation of this effects is given and is supported by the analysis of some VVER-440 rod drop experiments. (author)

[en] Results are presented of the first three-dimensional hexagonal dynamic AER benchmark problem. Detailed results calculated with dynamics version of code MOBY-DICK-SK (Short Kinetics) for the first dynamic AER benchmark problem are presented. (author)

[en] In the SCALE 4.3 code the ORIGEN-S module uses library prepared by the SAS2 module from library 27BURNUPLIB or 44GROUPNDF5. Results are compared by using both libraries. (author)

[en] Linear boundary value problems of diffusion theory in a symmetric region are analyzed with the help of group theory. If the symmetries of the region commute with the operator of the equation to be solved, the symmetries generate a classification of the solution space. This technique is applied to study the numerical behavior of numerical methods. It is shown that approximate polynomials on the boundary and inside the region must be compatible to get stable results. Compatibility conditions are given. To avoid convergence problems, linear functions on the six faces of a regular hexagon would demand as high as sixth order approximation inside the hexagon. The predicted convergence problems have been observed in the neutron physics code VARIANT, which is a routinely used diffusion equation solver at ANL. (author)

[en] Regular meeting of Core Design Group was organized by SKODA Nuclear Machinery, Plzen and held in Plzen 28-29 April 1998, together with Working Group A. Lists of participants and papers are in Appendix. Main topics of the meeting were as follows: Dukovany load follow benchmark; KOLA 3 benchmark; Recent improvements of VVER fuel management; NPP Paks; NPP Dukovany; NPP Paks KARATE. (author)

[en] A new formulation of the well-known VVER-1000 benchmark problem is presented together with an extrapolated FEM-3Di solution. The purpose is to present the results of the solution the VVER-1000 benchmark problem, performed by the new version of HEXAB-3D code and to compare them to the reference data. (author)