Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Dynamic analysis of pressurization of containment building of a pressurized water reactor with phase change materials
Submission Author:
Rafaela Vilas Boas Pedrassani , RJ , Brazil
Co-Authors:
Rafaela Vilas Boas Pedrassani, Su Jian
Presenter: Rafaela Vilas Boas Pedrassani
doi://10.26678/ABCM.ENCIT2022.CIT22-0003
Abstract
Pressurization of the containment building of a pressurized water reactor nuclear power plant can occur in a short time if a loss of coolant accident (LOCA) occurs due to a break in the primary circuit piping. Recently, phase change materials (PCM) have been considered as a method of passive cooling in the containment building by storing thermal energy in case of accidents. This paper reports a coupled model for the PWR containment pressurization during a LOCA based on Hermite approximations for integrals. It consists of a conservative single-cell thermodynamic model for the mass and energy balance in the containment, and an improved lumped parameter model for one-dimensional heat conduction with the melting of PCM slabs. The nonlinear system of ordinary differential equations is solved numerically using the symbolic-numerical software Wolfram Mathematica 11.0. The containment model is verified by comparing the final containment pressure and temperature with available literature data. On the other hand, the PCM heat conduction model is validated by comparing its melting interface and liquid phase average temperature with an approximate analytical solution. Temperature and pressure variations in the containment were evaluated for different types and heat transfer areas of the PCM. The analysis results demonstrated that the PCM could successfully cool the containment and attenuate the pressure rise.
Keywords
Reactor containment, Phase Change Material, Thermal Energy, heat conduction, lumped model
