[en] A new formulation of multigroup cross section collapsing based on the conservation of point or zone value of hamiltonian is presented. This attempt is proper to optimization problems solved by means of maximum principle of Pontryagin. (author)

[en] An attempt to formulate the multigroup burn-up equations of the fuel in nuclear reactors is presented. The introduction of the pseudoproducts and the collapsing of multigroup cross sections are considered too. Finally, a comparison of the derived formulae with those of the one-group case is given. (author)

[en] Multigroup constant calculation system for TRIGA-type reactor analysis was provided. Calculations for initial criticality, temperature coefficient, flux and power distributions of TRIGA-Mark III reactor were carried out by using diffusion code CITATION. And some of results were compared with the values of start-up experiments and design values. It could be confirmed that the prepared computation system is very useful for TRIGA-type reactor analysis. (author)

[en] An explicit formula for the discrete Case normalization coefficient is presented in terms of functions related to the dispersion function. These functions are easily determined and provide the normalization coefficient without need of prior evaluation of the eigenvectors

No abstract available

[en] The collapsing formulae for the optimization problems solved by means of the Pontryagin maximum principle in nuclear reactor dynamics are presented. A comparison with the corresponding formulae of the static case is given too. (author)

[en] The ORNL FORSS Sensitivity and Uncertainty Analysis System was demonstrated in the 1978 Radiation Shielding Information Center (RSIC) Workshop. The first versions of this code system for both IBM and CDC computers are now packaged and are available from RSIC. Features of the FORSS system are described and guidelines for its use are given. An assessment of the status of the system and plans for future updates are provided. Examples of applications of the system to fast reactor and fusion integral experiments, to reactor dosimetry problems, and to the adjustement of a cross-section library are discussed

[en] The energy-dependent equation for the slowing-down of energetic ions in fully ionized plasma is cast into a multigroup form. The resulting multigroup equation is a linear equation for the flux of the energetic ions and is easy to solve. It can take into account large-energy-transfer reactions preserving their discrete nature. The sensitivity of the multigroup approximation to the group width and weighting function used for generating group constants is investigated. It is found that few groups with simple, problem-independent weighting functions can yield results of reasonable accuracy. The relation between the multigroup and other methods for the solution of the slowing-down equation is discussed. (author)

[en] Multigroup cross-section libraries for shielding applications in formats for direct use in discrete odinates codes have long been a part of the Radiation Shielding Information Center's (RSIC) Data Library Collection (DLC). In recent years libraries in more flexible and comprehensive formats which allow the user to derive his own problem-dependent sets have been added to the collection. The current status of both types is described as well as projections for adding data libraries based on ENDF/B-V

[en] Continuous slowing down theory calculations have been found to yield significant discrepancies in the presence of strong absorption. An algorithm has been formulated for evaluating continuous slowing down theory parameters that should be applicable for cases with strong absorption. Excellent agreement with more precise calculations is obtained when the new parameters are used