LWR availability trends and programmes in the United States of America

This paper charts United States LWR performance over the last fourteen years and describes current availability programmes. The overall cumulative statistics for 68 operating reactors representing 550 years of operation are: reactor availability 74.7%; plant availability 70.9% and capacity factor 61.8%. A noticeable decrease in LWR availability occurred in the 1979-1980 period. This was due to backfitting and modifications resulting from the Three Mile Island accident. However, performance has strongly rebounded in 1981. Industry-wide availability programmes such as those sponsored by the Electric Power Research Institute (EPRI) have emphasized power plant data gathering and reporting systems. In addition, all United States reactor vendors have extensive availability programmes. To this end, Westinghouse has established on-site service managers at plants, and offers managed maintenance and turbine availability programmes. Specific design improvements have also been carried out on steam generators and reactor coolant pumps. In summary, it is felt that part of the improvement in 1981 United States LWR performance was due to these aggressive availability programmes. The potential for future improvements is even greater. (author)