tailieunhanh - Pin to pin neutron flux reconstruction in a PWR reactor using support vector regression (SVR) technique

Coarse mesh nodal methods are widely used in the analysis of nuclear reactors. However, these methods provide only average values of the neutron fluxes. From a safety point of view, it is important to have an accurate analysis of the pin to pin flux distribution that nodal methods are not able to provide. | Pin to pin neutron flux reconstruction in a PWR reactor using support vector regression SVR technique EPJ Nuclear Sci. Technol. 5 3 2019 Nuclear Sciences . Neto et al. published by EDP Sciences 2019 amp Technologies https epjn 2018051 Available online at https REGULAR ARTICLE Pin to pin neutron flux reconstruction in a PWR reactor using support vector regression SVR technique . Neto1 . Alvim1 . Silva1 and . Alvim2 1 Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia COPPE UFRJ Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil 2 Universidade Federal Rural do Rio de Janeiro Rio de Janeiro Brazil Received 17 May 2018 Received in final form 18 October 2018 Accepted 11 December 2018 Abstract. Coarse mesh nodal methods are widely used in the analysis of nuclear reactors. However these methods provide only average values of the neutron fluxes. From a safety point of view it is important to have an accurate analysis of the pin to pin flux distribution that nodal methods are not able to provide. Many articles have been published that make use of mathematical techniques to determine flux distributions. Most of these techniques use expansion functions to estimate these distributions. The expansion coefficients of these works are determined by conditions that take into account the average values of certain fluxes supplied by the nodal methods. There are also methods that employ analytical solutions of the neutron diffusion equation. This article presents a different approach for calculating the pin to pin neutron flux distribution for a PWR reactor. The developed method uses support vector regression SVR technique to determine this pin to pin neutron flux. The SVR technique uses average data computed with the Nodal Expansion Method NEM for learning purposes. A total of 70 of the computed data were used for training and 30 for validation using multifold- cross-validation. Two fuel elements were .