Optimizing plant outages

Since their commissioning 15 years ago, Belgian nuclear power plants have shown above average load factors. The improvement of the average annual load factor as a specific objective requires optimizing the outage. Belgian utilities establish a programme of work for the outage taking into account four factors. 1. Duration of outage (direct impact on load factor). The experience gained in Belgium has shown that trying to reduce the outage to less than four weeks is unwise. 2. Required maintenance work (indirect impact on load factor). The list of maintenance activities is dictated on the one hand by technical specifications to assure the safety of the plant and, on the other by a sound maintenance programme to control outage duration. 3. Quality of work (indirect impact on load factor). As most of the work is performed by subcontractors, the choice and qualification of these companies are of prime importance. Close supervision of the work by plant staff and use of control procedures help to achieve better quality results. 4. Constraints to be respected. All these aspects naturally have to be addressed under the constraints of technical specifications, quality control and quality assurance procedures, dose limitation, social laws and budgets. (author)