Authors & Affiliations

Lukyanov D.A., Albutova O.I.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia

Lukyanov D.A. – Leading 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) 399-42-88; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Albutova O.I. – engineer, A.I. Leypunsky Institute for Physics and Power Engineering.

Abstract

The method for failed fuel assemblies locating in LMFBR (BN type) is developed. Localization is carried out on the operating reactor to reduce the defective assemblies search area at shutdown reactor. To determine the location of failed fuel assemblies, the readings of the Delayed Neutron Monitoring System for Fuel Failure Detection (SSKGO) are compared to the results of statistical modeling of the distribution of fission fragments in the coolant flow. The physical foundations of the localization method as well as the diagnostic models for fission fragments transport in the first circuit coolant are given.
Various calculation methods for determining the increase in SSKGO readings (responses) when failed fuel occurs are considered, and its application recommendations are given. The probabilities of defective fuel element presence in fuel assemblies are estimated by comparison of real and model SSKGO responses, using Bayesian strategy for statistical decisions making.
The full-scale localization program prototype for the BN-600 reactor had been realized. Using SSKGO archive data, the efficiency of the presented method has been confirmed. The localization provides reliable detection of defective fuel assemblies in the compact reactor core area including no more than 12 assemblies with the greatest values of the probability of defective fuel element presence.

Keywords
BN-600, fuel cladding failure detection, failed fuel assemblies detection

Article Text (PDF, in Russian)

References

UDC 621.039.526

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2017, issue 3, 3:8