Operate-shutdown decision and test policy of safety systems on a nuclear power plant

It is shown that operate-shutdown decision on a main system and test policy in a safety system have to be considered jointly. Two criteria are taken into account: an economic criterion (loss of production) and a risk criterion (risk of accident). A method is described in order to evaluate these two criteria according to given policies and operate-shutdown rules. This method leads to the optimisation of test policies and of operate-shutdown rules. Minimisation of loss of production and risk of accident is determined. (author)