Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
SEVERE ACCIDENT ANALYSIS FOR TLOF OF STEAM GENERATOR COMBINED WITH AN ATWS
Submission Author:
Marcos Coelho Maturana , SP
Co-Authors:
Marcos Coelho Maturana, Nathália Araújo, Maritza Gual, Marcelo Ramos Martins
Presenter: Maritza Gual
doi://10.26678/ABCM.COBEM2019.COB2019-2229
Abstract
An Anticipated Transient Without SCRAM (ATWS) is a trip failure for severe accident initiated from the transients like a control bank withdrawal, and a loss of feedwater. The main concern is whether a power excursion and pressure oscillation can occur in such an event: an ATWS event could produce system over pressurization and increases the core power, producing rapid uncovered and reactor fuel cladding damage and resulting in a release of radioactive fission products to the containment if the fuel in the reactor core was melting. Furthermore, since thermal-hydraulic feedback plays an important role in these accidents, the uncertainty of the reactivity feedback coefficients used can impact the outcome of the analysis for such a power excursion. Since transients accompanied by scram failure would result in serious consequences (and it could be expected to occur in the future population of nuclear plants), the objective of this work was to perform analysis for severe accident scenarios of a generic Pressurized Water Reactor (PWR) using MELCOR v2.2 code, considering a Total Loss of Feedwater (TLOF) scenario combined with a reactivity transient and an ATWS event. The results obtained with the MELCOR core model were compared with those references reported in the NUREG-0800.
Keywords
severe accident, MELCOR, Anticipated Transients Without SCRAM (ATWS), Pressurized Water Reactor (PWR), Loss of Feed Water (LOFW)
