The All in One Surveillance Unit, or ALIS, provides a comprehensive view of the reactor hall. (Source: Dean Calma/IAEA) 

At a facility, C/S measures are commonly applied:

• to ensure (during material verification) that each item is inventoried without duplication and that the integrity of each item is preserved
• to ensure that safeguards instruments, devices, working papers and supplies are not tampered with
• to reduce the need of repeating verification measurements of previously-verified items or of containers whose integrity  have not been changed
• to cover specific safeguards situations - i.e., on-load refueled reactors where fuel in the core is not easily or routinely accessible for an inventory taking