Research efforts for the resolution of hydrogen risk

Abstract

a b s t r a c tDuring the past 10 years, the Korea Atomic Energy Research Institute (KAERI) has performed a study to control hydrogen gas in the containment of the nuclear power plants.Before the Fukushima accident, analytical activities for gas distribution analysis in experiments and plants were primarily conducted using a multidimensional code: the GASFLOW. After the Fukushima accident, the COM3D code, which can simulate a multidimensional hydrogen explosion, was introduced in 2013 to complete the multidimensional hydrogen analysis system. The code validation efforts of the multidimensional codes of the GASFLOW and the COM3D have continued to increase confidence in the use of codes using several international experimental data. The OpenFOAM has been preliminarily evaluated for APR1400 containment, based on experience from coded validation and the analysis of hydrogen distribution and explosion using the multidimensional codes, the GASFLOW and the COM3D. Hydrogen safety in nuclear power has become a much more important issue after the Fukushima event in which hydrogen explosions occurred. The KAERI is preparing a large-scale test that can be used to validate the performance of domestic passive autocatalytic recombiners (PARs) and can provide data for the validation of the severe accident code being developed in Korea.

Numerical Analysis for Hydrogen Flame Acceleration during a Severe Accident Initiated by SBLOCA in the APR1400 Containment

“…Before the occurrence of the hydrogen explosion accident of the NPP in Fukushima, most evaluations for a hydrogen combustion risk during severe accidents in the NPP containment were conducted to simply check the possibility of hydrogen flame acceleration or the deflagration to detonation transition (DDT) on the basis of some criteria, such as the sigma and d/7λ indexes or the Shapiro diagram, using a hydrogen distribution result in the containment by a 1-dimensional lumped parameter code or a 3-dimensional computational Hydrogen 2022, 3 29 fluid dynamic code [7][8][9][10][11][12][13]. After the hydrogen explosion accident, for an evaluation of the hydrogen combustion risk in the NPP containment, a numerical analysis to calculate the overpressure buildup owing to the hydrogen combustion has been conducted on the basis of the validation results for the hydrogen combustion models to accurately simulate the flame acceleration [14][15][16][17][18].…”

Analysis of a gas stratification break-up by a vertical jet using the GOTHIC code

“…There was a APR1400 containment hydrogen distribution simulation with GOTHIC and GASFLOW, using the integral severe accident code MAAP as the source term code, performed by KAERI andpresented in 2004 (Kim et al, 2004). Recently they have published an update about their work with GASFLOW for APR1400 (Hong et al, 2015). In the case of the licensing process of EPR in the UK (HSE, 2011a;Dimmelmeier et al, 2012;HSE, 2013), MAAP4 was used as a basis for simulating severe accidents, using COCOSYS for cases that need more detail, and for the most penalizing cases GASFLOW was used.…”