scope:

This RP focuses on recommendations for updating risk assessments during the operational phase of a facility by assessing the effect of changes in the risk assessment basis, using a combination of qualitative and quantitative methods to deliver the decision basis. A three-phase approach has been defined covering the following: screening, re-assessment and implementation, see Figure 1-2.

The purpose of the screening phase is to identify changes to the operational conditions and design basis in order to establish if the effects of these changes are understood and/or critical. This is then used as input for deciding whether updates are necessary. The purpose of the re-assessment phase is to ensure that a sufficient basis for effective risk management is in place for follow-up in the implementation phase.

There are essentially three types of changes that can occur. Firstly, the operational or technical conditions may change, directly affecting the risk level. Secondly, new knowledge acquired may influence the assessment of the risk level. Thirdly, there could be changes to the context, e.g. new regulatory or stakeholder requirements, new risk treatment options etc., affecting the tolerability of risks. Different actions may be required, depending on the type of changes.