A STUDY OF THE CORRELATIONS AMONG THE COMPONENTS OF ENERGY RELEASE IN AN IGR REACTOR

The paper presents the results of a study on the relationship between the prompt and delayed components of energy release in the core of the pulsed research reactor IGR at the cold state. Using the MCNP6 code, a series of high-precision prompt and delayed energy release calculations was performed, yielding detailed data on the spatial distribution of energy release over all columns and blocks of the core and reflector. The Spearman rank correlation coefficient, applied to quantify the relationship, exceeded 0.98 for all analyzed columns, indicating a monotonic statistical relationship between the components. Parameters of a power-law approximation were determined by the least-squares method in logarithmic coordinates for eight column types, with a coefficient of determination R² above 0.97 confirming the adequacy of the models. It is emphasized that the established correlation does not prove a cause-and-effect relationship, but reflects the joint influence of a single neutron field on the formation of both energy release components. Unlike the conventional approach requiring direct calculation of the delayed component, the developed reconstructive approach allows the delayed energy release to be estimated from the prompt component using the proposed approximating dependences. The results can be used to speed up neutronic calculations in multi-variant analysis of experimental configurations and in the development of coupled simulation methodologies for reactor studies.

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