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Experimental and Analytical strategies to assess the seismic performance of auxiliary power systems in critical infrastructure

The performance of nonstructural components in critical infrastructure,
such as nuclear power plants (NPPs), has been primarily based on experience and
historical data. This topic has been attracting increased interest from researchers
following the Fukushima Daiichi nuclear disaster in 2011. This disaster
demonstrated the importance of using batteries in NPPs as an auxiliary power
system, where such systems can provide the necessary power to mitigate the risk of
serious accidents. However, little research has been conducted on such
nonstructural components to evaluate their performance following the post-
Fukushima safety requirements, recommended by several nuclear regulators
worldwide [e.g., Nuclear Regulatory Commission (NRC), and Nuclear Safety
Commission (NSC)]. To address this research gap, this dissertation investigates the
lateral performance of an auxiliary battery power system (ABPS) similar to those
currently existing/operational in NPPs in Canada. The ABPS was experimentally
tested under displacement-controlled quasi-static cyclic fully-reversed loading that
simulates lateral seismic demands. Due to the presence of sliding batteries, the
ABPS was then tested dynamically under increased ground motion levels on a
shake table. The experimental results demonstrated that the design guidelines and
fragility curves currently assigned to battery rack systems in the FEMA P58 prestandards do not encompass all possible failure mechanisms.
A 3D numerical model was also developed using OpenSees software. The
model was validated using the experimental results. The model results showed that the lateral performance of ABPS with different configurations (i.e. different
lengths, tiers, and seismic categories) is influenced by the capacity of the L-shaped
connection between the side rails and the end rail. However, the model was not able
to predict all the damage states from the dynamic experimental tests, since the
rocking/sliding/impact behavior of the batteries is a highly complex nonlinear
problem by nature and beyond the scope of this study. The model presented is
limited to the assessment of the lateral performance of different ABPS statically.
This dissertation demonstrated the difference between the observed
behavior of laboratory-controlled lateral performance tests of ABPSs
operational/existing in NPPs and the behavior of ABPSs found in the literature that
relied on limited historical and experience data. Finally, this dissertation laid the
foundations for the need to further investigate the behavior of other safety-related
components in NPPs and assess their compliance with new post-Fukushima design
requirements. / Thesis / Doctor of Philosophy (PhD)

Identiferoai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/25422
Date January 2020
CreatorsGhith, Ahmed
ContributorsEl-Dakhakhni, Wael, Tait, Michael, Civil Engineering
Source SetsMcMaster University
LanguageEnglish
Detected LanguageEnglish
TypeThesis

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