Authors & Affiliations

Golovko Yu.E., Manturov G.N.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia

Golovko Yu.E. – Senior Researcher, Cand. Sci. (Tech.), A.I. Leypunsky Institute for Physics and Power Engineering. Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7(484) 399-43-67; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Manturov G.N. – Head of Laboratory, Dr. Sci. (Phys. and Math.), A.I. Leypunsky Institute for Physics and Power Engineering.

Abstract

At the beginning of 2000th a number of experiments with high enriched uranium performed at ORNL, Rocky Flats, LANL, VNIITF, VNIIEF have been used in 235U neutron cross sections validation and in estimation of criticality calculation accuracy for systems with high enriched uranium. These experiments includes those performed at IPPE. During statistical analysis so called “reference” experiments without poisons or with poisons which concentration is neglible small have been eliminated as contradictive. Such experiments have been excluded from further considerations.

In the proposed work the undetermined lagrangian coefficients method have been applied. It have been allowed to estimate biases to dimensions and concentrations measured in experiments with high enriched uranium performed at IPPE. Taking into account of these biases we can make agree calculation data with experimental ones. These in turn will allow to leave such experiment’s data for further considerations and thus to increase reliability of criticality uncertainty estimation results for systems with high enriched uranium.

In current work it has been shown than a large discrepancies of experimental and calculation results are mainly caused by gadolinium concentration measurements in solutions. The values of experimentally measured solutions heights, free nitric acid concentrations and tank radiuses affects on calculation results in smaller extent. If we’ll take into account biases to mainly these parameters we remove all contradictions and compensate all discrepancies between calculation and experimental results which have been confirmed by direct calculations via different neutron cross sections.

Keywords
Undetermined Lagrangian Coefficients Method, multiplication factor, neutron cross-sections, criticality, criticality benchmark experiment, covariance matrix, adjustment, maximum likelihood method

Article Text (PDF, in Russian)

References

UDC 621.039.51.17

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants", 2017, issue 2, 2:5