AGEING MANAGEMENT OF FOSSIL-FIRED PLANTS OF ELECTRICITE DE FRANCE: PVP MAINTENANCE ASPECTS

摘要

The generation mix of EDF comprises 17,000 MW of fossil-fired units, the ages of which go from 10 to 32 years. As the structure of the grid is essentially based on nuclear power, the fossil-fired network plays a role of "goal keeper": it is a potential reserve of power, its energy output is limited except in exceptional conditions. A major concern today is: which future for these units in the years 2000/2010? Extensive studies have been launched in 1994, inside the Company, to determine: 1) prospects of needs of the grid (domestic/exports), 2) prospects of possible competition in generation field, 3) environmental aspects and possible evolution, 4) adaptation of management of men and organizations, 5) management of condition of equipment through maintenance policy. This paper focuses on the last item, spotted on pressure vessels and piping. The question is: How to conserve the "patrimony" for very long term, with lowest costs to keep it competitive in its very specific role? Several items are examined: 1) the background, the different programs of retrofitting, refurbishment and life extension 2) conservation during outages, and mothballing procedures and experience, 3) design review, actual design life expectancy, 4) analysis of ageing mechanisms through experience feedback, 5) determination of critical components, analysis of their condition, periodical updating, 6) maintenance adaptation, extensive condition-monitored maintenance approach: use of existing probes and data, development of new devices and skills, 7) policy of progressive replacement of worn-out and potentially dangerous components; examples concerning generic problems, 8) management of requirements of pressure vessels regulations, 9) adaptation of spare parts policy, 10) research and development needed by life management