The safety and security of a radiological facility
shares a common objective which is to ensure the protection of the population
and the environment from an undue radiological hazard. Adapting and extending
risk assessment to security applications has been limited because of the adaptive
nature of the sub-state actors and the lack of historical data of terrorist
attacks on radiological facilities. Currently, no broad risk index exists for
radiological facilities, such as healthcare centers and universities. This
study develops a quantitative risk-based methodology that radiological
facilities can employ to conduct self-assessments and gain better understanding
of the threat they face. The computation of the Potential Facility Risk Index
(PFRI) is based on the triplet definition (threat, vulnerability, and
consequences) of risk. The threat component of the PFRI is devised as a utility
function weighing the threat group attributes and asset preference. The
principles of probabilistic risk assessment and pathway analysis are
implemented to account for radioactive material theft probabilities in
different attack scenarios. Locational
hazards and nuclear security culture are measured as a function of radiological
facility vulnerability. The consequences
of loss of life and economic loss are computed, as a result of an attack from
the radiological dispersal device (RDD). The methodology is applied to a
hypothetical healthcare facility a single radioactive with three material assets
(60Co, 137Cs, 192Ir). The representation of
the PFRI value on a qualitative scale-ranging from “very low risk” (1) to “very
high risk” (10) presents a holistic view of the state of the facility risk to
RDD. The PFRI may be used by decision makers to evaluate any security upgrades
and justify security investments. The RDD game, developed as an extension to
PFRI, provides the healthcare facility (defender) with strategic options to
budget scarce security resources and make optimal choices under severe
uncertainty about the terrorist adversary (attacker) theat.