Severe Accident Simulation of the Laguna Verde Nuclear Power Plant

Abstract

The loss-of-coolant accident (LOCA) simulation in the boiling water reactor (BWR) of Laguna Verde Nuclear Power Plant (LVNPP) at 105% of rated power is analyzed in this work. The LVNPP model was developed using RELAP/SCDAPSIM code. The lack of cooling water after the LOCA gets to the LVNPP to melting of the core that exceeds the design basis of the nuclear power plant (NPP) sufficiently to cause failure of structures, materials, and systems that are needed to ensure proper cooling of the reactor core by normal means. Faced with a severe accident, the first response is to maintain the reactor core cooling by any means available, but in order to carry out such an attempt is necessary to understand fully the progression of core damage, since such action has effects that may be decisive in accident progression. The simulation considers a LOCA in the recirculation loop of the reactor with and without cooling water injection. During the progression of core damage, we analyze the cooling water injection at different times and the results show that there are significant differences in the level of core damage and hydrogen production, among other variables analyzed such as maximum surface temperature, fission products released, and debris bed height.

Modelling of Severe Accident and In-Vessel Melt Retention Possibilities in BWR Type Reactor

“…The analysis of IVR strategy for BWR type NPP is performed in the frame of IVMR project. As a basis for the analysis the generic BWR model of General Electric BWR-5 reactor installed in Mark-II containment, developed in the frame of the international SCDAP Development and Training Program (SDTP) [11][12][13], was used. The most important features of this modelled generic BWR-5 reactor are presented in the Table 1.…”

“…The RELAP/SCDAPSIM input deck, which was used for large LOCA simulation in this work, initially was developed by the regulatory body in Mexico (CNSNS) [11,12] for Laguna Verde NPP in Mexico. The detailed nodalization scheme and explanation of the model is presented in [13]. This input deck was modified, and the ex-vessel model was appended in order to simulate heat transfer through the vessel wall by flooding the reactor cavity and submerging the RPV in water.…”

Comparative study of the hydrogen generation during short term station blackout (STSBO) in a BWR

“…The MELCOR Accident Code System (MACCS) package (Jow et al, 1993;Chanin and Young, 1998) is widely used and sufficiently trusted by safety authorities for severe accident analysis and to estimate offsite consequences based on calculated or assumed fission product releases, together with geographic, demographic, and meteorological data and assumptions concerning biological uptake.…”

Probabilistic Dynamics for Integrated Analysis of Accident Sequences considering Uncertain Events

“…A typical example is the occurrence of combustion phenomena only if flammability conditions are met, with delays potentially resulting from stochastic ignition conditions and with potential for multiple combustions if the flammability conditions persist. For instance, this can be actually related to the hydrogen generation and possibility of combustion during the severe accident [15]. The more general conditions (including setpoints for thresholds as particular cases) may be considered as stimuli for the transitions (events).…”