As part of the approval process to give the go-ahead to construct and operate a nuclear plant, it must be shown that the necessary safety precautions have been taken, in accordance with the current state of the art of science and technology. The evidence required must be considered deterministically, in the light of a reasonable safety strategy, as laid down by the banded safety strategy in Table 2.2, for example.

While plants are operating, the competent atomic supervisory authority monitors the state of their systems and how they are being operated, to verify that these comply with the conditions of the approval order. In addition to these checks, in the operating phase, regular safety status presentations must be made considering whether new safety findings from operating experience, safety studies and research and development should be incorporated.

In Germany, safety status is monitored by periodical safety reviews, or PSUs in German. These must be held every ten years, and cover:

— Deterministic safety status analysis (DSA) in the shape of a safety target oriented review of a plant’s safety status including how it is managed operationally and analysing its operating experience

— Probabilistic safety analysis (PSA) [8]

— Plant safety strategy review.