A Literature Survey of Neutronics and Thermal-Hydraulics Codes for Investigating Reactor Core Parameters; Artificial Neural Networks as the VVER-1000 Core Predictor

Abstract

In this chapter, we investigated an appropriate way to predict neutronics and thermalhydraulics parameters in a large scale VVER type nuclear reactors. A computer program is developed to automate this procedure using Artificial Neural Network (ANN) method. The neutronics and thermal-hydraulics codes are connected to each other and then the neural network method use results with different configuration of a suggested core for prediction. The main objective of this research is to develop fast and first estimation tool (a software) based on ANNs which allows large explorations of core safety parameters. This tool is very useful in reactor core design and in-core fuel management or loading pattern optimization. Therefore, herein, an overview study on the multiphysics/multiscale coupling methods for designing current and innovative VVER systems by coupling neutronics parameters (using MCNP 5) and thermal-hydraulics simulator (e.g., COBRA-EN) are carried out. This work is aimed to extend the modeling capabilities of coupled Monte Carlo/Subchannel codes for whole core simulations based on pin-level in order to address many problems e.g. higher burn-up, Mox-fuels, or to improve the performances and accuracy of reactor dynamics. Verification and validation of the above development are the main concern and important procedures and therefore taking into account using experimental data or another code-tocode benchmarking. Finally the extended simulation capabilities should be applied to analyze a selected VVER reactor and we present our input computer codes for interested readers. Also, our future designed user friendly Artificial Neural Network (ANN) software would be given for everyone who wants to get it. Bushehr Nuclear Power Plant (BNNP), a VVER-1000 Russian model, was simulated during the first plant operational period using WIMS and CITATION codes (Faghihi et al., 2007). Modelling of all rods (including fuel rods, control rods, burnable and non-burnable poison rods) and channels (including central guide channel, measuring channel) were carried out