Assessment of risks and control conditions for some scenarios on unauthorised usage of nuclear materials

Conditions of nuclear materials secure management inside the nuclear sites as well as outside the nuclear fuel cycle are analysed from the point of view of nuclear non‐proliferation. Concepts of tolerable and broadly acceptable risks are considered and conditions of their existence are formulated. On the basis of the concepts, a possibility of creating metrics for uranium control at nuclear sites is demonstrated. A three‐level metric for uranium control is introduced. Using the control metric and a developed pathway model, a case study on risk assessment with application of various control measures has been conducted.