[en] By taking neutron importance function as a new base of evaluating the coupling magnitude, and by identifying the boundary of a constituent core by zeroes of the first spatial mode, a generalized relation between coupling coefficients and eigenvalue separation is derived. By this equality one can obtain a unified, consistent view in the treatment of a large single core whose two partial zones are loosely coupled, and that of a two-core system with the two physically separated. (Author)

[en] A new theory of leakage in heterogeneous systems has recently been introduced in which the derivation of cell-averaged diffusion coefficients for use in whole reactor calculations is reduced to the calculation of a flux, ξ, arising from a tilted source in one lattice cell only. This report describes the manner which an existing transport theory computer programme was modified to calculate this new flux. It is concluded that the tilted flux is sensitive to boundary conditions. In particular, no generally satisfactory choice of boundary conditions in a cylindricalised cell has been found. (author)

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[en] An advanced method for heterogeneous reactor theory is presented including general formulation of 3 dimensional few-group heterogeneous reactor equation in dipolar approximation, its approximate difference form and method of calculation of heterogeneous reactor cell parameters. On the basis of this new approaches computer codes capable of solving 3 dimensional space and space-time problems for heterogeneous reactors with large number of channels were developed. Some numerical results were developed. Some numerical results of validations are presented. (author). 16 refs., 4 tabs

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[en] A method called area ratio method is derived for a symmetrical coupled-core system. The usefulness of this method is verified experimentally by comparison with the neutron source multiplication method and Farinelli and Pacilio's method. The proposed method is superior to the conventional methods in the respect that it does not need any reference point, and it is suitable for reactivity determination in the filed of nuclear criticality safety. (orig./HP)

[en] This paper describes an application of an approximate decoupling control to the noninteractive power regulation of each core in a coupled-core nuclear reactor model. A method for designing an approximate decoupling controller is presented here. This controller consists of an output feedback compensator and a precompensator which is introduced to diagonalize an open-loop frequency response matrix approximately in the frequency range important to reactor dynamics. A ''multipoint diagonalization method'' is adopted for the design of the precompensator. This method possesses some superiorities compared with the pseudo-diagonalization method. Digital simulations and graphical studies by the Gershgorin band demonstrate the usefulness of the multipoint diagonalization method as well as the effectiveness of the controller for power regulation

[en] The simultaneous decoupling and control problem of multiple-core reactors is solved by using a state-variable feedback technique based on the Luenberger canonical state-space model. Two examples illustrate the theory