Publications / CCC 2025 - Zadar, Croatia

INTEGRATED FRAGILITY OF UNDERGROUND CRITICAL INFRASTRUCTURES EXPOSED TO BLAST EVENTS

Gal Shany, David Ornai, Robert Levy and Igal M. Shohet
Pages 164-174 (CCC 2025 - Zadar, Croatia, ISBN 978-1-7643710-0-1, ISSN 2413-5844)
Abstract:

Civil society is frequently threatened by terror and war activities. The scenarios caused by these events are highly relevant to the continuous performance and safety of underground Critical Infrastructures (CIs) such as Nuclear Power Plants (NPPs), data centers and hazardous materials storage facilities. The present research is focused on the development of a risk informed decision support methodology, demonstrated on a case study of a tunneled CI in chalk rock, exposed to two war threat scenarios composed by direct hits of Earth Penetrator Weapons (EPWs). The investigated CI is NuScale® Small Modular Reactor (SMR) NPP, built in a tunneled cavern. If this NPP and its nuclear power modules (NPMs) are damaged, it might lead to Core Damage and Large Release of radioactive materials, with significant negative impact on public health and the environment. Integrated risk analysis and assessment methodology was developed while addressing three levels for consideration: (1) Geotechnical level; (2) Structural level; and (3) Systems and Components level. An Integrated Fragility Model (IFM) was developed for blast induced in-structure motions caused by the EPWs, based on seismic fragilities of this SMR and the Nuclear Engineering Institute (NEI) median tolerance values of NPPs systems and components exposed to aircraft crash. The in-structure motions (displacements, velocities and accelerations) were calculated according to analytical-empirical expressions of the blast induced ground shock that fit numerical simulations. The research delivers a novel risk-informed methodology for assessing the resilience of underground Critical Infrastructures (CIs) against Earth-Penetrating Weapons (EPWs) combining Integrated Fragility Modelling for resilience assessment of the NPP and RF modeling for the durability of the Protective cavern.

Keywords: Blast, Critical Infrastructures, Earth Penetrator Weapons (EPW), Fragility, Nuclear Power Plant (NPP)