Knowledge and techniques learned from failure accidents and incidents in fossil power plants

Fossil fuel power generation is now supplying about 60% of the electric power consumed in Japan, while the accumulated operation time of approximately 80% of fossil power plants in service is more than the 100000 hour-life anticipated in their design. Furthermore, the maintenance of these aged plants is forcing simplification in order to reduce electric charges under the present severe competitive conditions in the electric power industry. In the future, therefore, it will be essential to improve the safety and reliability of aged fossil fuel plants with the application of risk-based approaches. Furthermore, to avoid the risk of accidents, it is also very important to build a database of the knowledge and wisdom learned from past accidents. The knowledge and wisdom that has been acquired must then be adequately disseminated from this database. This paper reviews typical accidents in boilers and steam turbines experienced in the U.S. and Japan, and describes the knowledge and techniques learned from these accidents. Finally, future issues for the favorable maintenance of fossil power plants in Japan are proposed.