| Popis: |
This is the second report on work done on time dependent probabilities initiated in cooperation between the International Atomic Energy Agency (IAEA) and IIASA in 1990. The treatment of the underlying mathematical model is rather theoretical, but the intent is to cover a broad range of applications. The advantage with the problem formulation is that it enables the inclusion also of monetary considerations connected to risks and the actions for decreasing them. The intent in formulating the model is that it will be used for a computerized optimization of selected decision variables. Originally, the formulation was initiated by the problem of optimization of test intervals at nuclear power plants. In this paper the non-destructive testing of major components has been approached. The main result of the paper is the formulation of an optimal rule for decision if continued operation can be considered safe enough. The decision rules integrates the earlier operational history, safety concerns and economic considerations. Also other applications are proposed to be treated within the modeling framework. One specific problem is the selection of the most suitable time instant for a major repair or retrofitting at a plant. The time horizon of the model can be selected either short-term, stretching only over a few weeks, or long-term, to encompass the complete life time of a depository of spent nuclear fuel. |
