The use of PSA in a License Renewal Process

The operating license of the NPP Borssele (Netherlands) must be renewed every 10 years. As part of the second License Renewal Process, the plant specific PSA is used extensively. For this the scope of the original Level 1 power PSA (1989) was extended in several phases. A Level 3 PSA is now available that covers full-, low- and non-power states, which also includes all important external events. This paper describes how the PSA is used in the License Renewal Process and some insights will be given of PSA modelling as part of a living engineering process.