Estimativa de fontes internas de nêutrons para a condução estacionária de distribuições prescritas de potência em sistemas subcríticos segundo o modelo bidimensional de ordenadas discretas e multigrupo de energia

• Autor(a) principal: Moraes, Leonardo Rodrigues da Costa
• Data de Publicação: 2020
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13633
• topic: Adjoint transport problems; Energy multigroup; Discrete ordinates; Response matriz spectral nodal methods; Problema adjunto de transporte; Multigrupo de energia; Ordenadas discretas; Métodos espectronodais de matriz resposta; CNPQ::ENGENHARIAS::ENGENHARIA NUCLEAR

In this thesis a methodology is presented to determine the distribution of interior neutron particles which must be inserted into a subcritical system to drive it to a steady state, generating a prescribed power distribution. This work has been motivated by the principle of operation of the ADS (Accelerator Driven Systems), which have subcritical cores stabilized by the action of external sources. To achieve this goal, we use the timeindependent and two-dimensional neutron transport equation and the equation which is adjoint to it, whose solution is interpreted, in this thesis work, as a distribution which measures the importance of the angular ux of neutrons to a linear functional. These equations are correlated through a reciprocity relation, leading to a relationship between the interior sources of neutrons and the power produced by the system by unit length of height of the domain. Due to the complexity of obtaining the analytical solutions of these integrodifferential equations that compose the mathematical model, we used the discrete ordinates (SN) method and the energy multigroup formulation. A coarse-mesh numerical method of the spectral nodal class, referred to as adjoint response matrix constant-nodal (RMy-CN) method, was developed to solve numerically the importance equations in the SN and multigroup formulations. Numerical experiments are performed in two model problems to analyze the accuracy and the characteristics of the present methodology, and to illustrate its potential practical applications.