Unavailability evaluation and allocation at the design stage for electric power plants: methods and tools

Electricite de France is currently carrying out a project called CIDEM with the objective of integrating availability, operational feedback, and maintenance in the design of future power plants (especially nuclear power plants) in order to improve their profitability. The work reported in this paper was performed in the framework of the research part of the CIDEM project, managed by the R&D division of EDF. The paper shows that the availability assessment of an electric power plant raises a number of specific modeling problems. The paper gives the modeling schemes that EDF had to devise in order to take into account various dynamic features, along with an estimation of the corresponding errors. It also gives a quick description of the tools they used to carry out real studies: the FIGARO workbench, which enables the building of knowledge bases to automate the fault-tree construction; and the ARPO tool, used to perform allocation with two different methods.