Risk Analysis and Assessment Methodology of Underground Critical Infrastructures Exposed to Munitions Hits

Abstract

Civil society is increasingly exposed to terror and war threats. The scenarios caused by these threats are highly relevant to the continuous performance and safety of Critical Infrastructures (CIs). Underground CIs might be exposed to guided munition hits with high penetration capabilities. Maintaining the continuous performance and physical state (structural and geotechnical) of underground CIs is crucial in ordinary times and even more so during emergency times. Underground facilities are used to protect sensitive installations such as military infrastructures and also Nuclear Power Plants (NPP's) from high explosive charges. The research objective was focused in the development of a risk informed optimal decision support methodology for advanced CIs resilience, exposed to Earth Penetrator Weapon (EPW) hits. The test cases were defined by threat scenarios of EPW penetration and detonation above an underground cavern that contains the NuScale Small Modular Reactor (SMR) reactor building (RXB). The research methodology was composed by the following phases: 1) Literature review; 2) Risk Analysis and Assessment: Underground critical energy infrastructures vulnerability assessment, focused on SMR; 3) Numerical simulations and Analytical-empirical formulation of the in-structure shock; 4) Damage assessment of the SMR critical components and its RXB structure exposed to munitions’ hits; 5) Development of fragility curves due to blast waves based on NPP components’ tolerance under airplane crash and seismic fragility curves. 6) Building deterioration Model of an NPP tunneled in rock: a) Reliability Analysis: Collection of large relevant data sets for the issue; Determine the parameters which affect the prediction; b) Apply the Random Forest (RF) algorithm for the service life prediction of the underground facility; c) Assess the results and specify data to be collected for future analysis. d) Define an equivalent physical state index (PSI) to assess the vulnerability of the tunneled NPP exposed to in-structure shock caused by blast.