The High-Reliability Safeguards Approach for Safeguardability of Remotely Handled Nuclear Facilities: 2. A Risk-Informed Approach for Safeguardability

The safeguardability of an advanced nuclear energy systemcan be achieved by implementing International Atomic EnergyAgency safeguards at the initial facility design stages. In acompanion paper (see page 4), a high-reliability safeguards(HRS) approach was introduced, where an envelope of functionalcomponents was proposed as part of a design strategyfor a remotely handled fuel fabrication facility. Discussion wasthen based on a commercial pyroprocessing facility as an examplesystem. The functional components are intended to beflexible and adaptable for various conceptual designs.Here, the HRS methodology is further developed by consideringhow safeguardability can be integrated into a licensingapproach. Primarily, within this context, then, a risk-informed,performance based-framework is qualitatively discussed. Potentialinitiators of diversion strategies that could arise fromsimilar classes of events as that of safety and physical securityare identified and their frequency of occurrence are formulated.This can then be utilized to assess system components byquantifying a licensing envelope that will encompass a spectrumof initiating events ranging from low-frequency normaloperational occurrences to higher-frequency off-normal and security-related events that also challenge physical protection ofthe facility. The consequence of which, for safeguards, wouldbe the probability of a false alarm or false positive anomaly.This framework is adaptable for incorporating additional engineeringexperience as it becomes available, and should also beapplicable to similar remotely-handled facilities.