An enhanced adaptation method for core monitoring systems

摘要

Current core monitoring systems for PWRs are based on online 3D calculations simulating the main physical phenomena. These calculations are affected by inaccuracies due to several causes: uncertainties in the knowledge of the reactor operating point (e.g. control bank positions, inlet water temperature), deviations between the design specifications and the built reactor, etc. These inaccuracies cause deviations between the predicted and measured neutron flux distribution, which can be reduced with an adaptation of the neutronic model to the measurements. As so, an adaptation method was conceived by Framatome. This paper presents the latest enhancements, which make the predictions of the model more reliable. With this adaptation, the computed flux is in good agreement with the incore detectors' response. The method is based on an equivalence procedure which allows determining an adaptation parameter, called pseudo-buckling, acting on the data of the model. Comparisons with experimental data have been performed and show the good method's efficiency. (C) 2021 Elsevier Ltd. All rights reserved.