Swiss federal authorities

Guidelines in force

A05 Probabilistic Safety Analysis (PSA): Quality and Scope – ENSI-A05/e

The guideline ENSI-A05 defines the quality and scope requirements regarding the plantspecific level 1 and level 2 Probabilistic Safety Analysis (PSA) for both internal and external events and covering all operating modes of the nuclear power plants.

In  addition, this guideline establishes the PSA requirements for other nuclear installations.

The quality and scope requirements in this guideline shall ensure that in particular the following PSA applications are possible:

  1. Assessment of overall plant safety
  2. Assessment of the balance of the risk contributions
  3. Assessment of the safety impact of plant modifications
  4. Evaluation and rating of reportable events
  5. Assessment of the safety importance of components
  6. Probabilistic evaluation of operational experience

In accordance with international PSA practice, no requirements regarding the consideration of risks due to war, terror and sabotage are provided in this guideline.

Guideline ENSI-A05 English (PDF, 1.2 MB)