USE OF THE METHOD OF GENERATIONS FOR CONSISTENT SIMULATIONS OF STEADY-STATE CHARACTERISTICS
D. G. Modestov
VANT. Ser.: Mat. Mod. Fiz. Proc 2016. Вып.1. С. 37-47.
The simulation of the steady-state characteristics of a critical system can be represented as the solution of the two problems simultaneously: the conditionally critical problem of identifying neutron-physical parameters and the problem of identifying the rest stationary parameters. With the use of a special technique to solve each of the two problems, there is a need to implement an iterative scheme to provide consistency of the obtained characteristics. Hence, there arise questions concerning the scheme convergence and errors in the results. If the method of generations is used to solve the given conventionally critical problem, inherent errors of the method emerge. It is possible to make them indefinitely small, however, with a significant increase in the labor intensity. And if simulations are carried out on multiprocessors, the contribution to the labor intensity of supporting procedures leveling some of these errors may exceed all the rest computational costs. The paper considers the features of the iterative operator used to solve the resultant equation system. It is shown that the scheme minimizing downtime of the method of generations can be constructed with some general assumptions concerning the properties of the system of interest, which allow achieving convergence of iterations. Simulations of the VVER-1000 reactor in its steady state are described for the demonstration purposes. Keywords: numerical schemes, the simple iteration method, the method of generations, VVER-1000.
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