PERIODIC SAFETY REASSESSMENT OF BELGIAN NUCLEAR POWER PLANTS

摘要

The seven Belgian nuclear units (which are all of the PWR type) have accumulated up to 100 reactor-years of operating experience. The three oldest ones (Tihange 1 and Doel 1-2) were designed in the late 1960s and started commercial operation in 1975; the four others (Doel 3-4, Tihange 2-3) produced their first kilowatt-hours between 1983 and 1985. To maintain and, if possible, to upgrade the safety of Belgium's nuclear units during their operating life, the Belgian regulators decided to incorporate, in their authorization to operate, a request to conduct a comprehensive safety reassessment of every unit after each ten-year period of operation. Such a re-evaluation consists of a comparison of the design, construction and operating rules of the existing plants with the regulations applicable at that time in the United States of America and other European Union countries. In order to conduct such programmes, Tractebel Energy Engineering (TEE) has developed a methodology which can be best characterized as being pragmatic, global, integrated and cost effective. It has been used extensively in Belgium (ten reassessment programmes up to now) and abroad (in the Netherlands, Hungary, the Czech Republic and the Russian Federation). As illustration, typical examples of backfitting activities for the oldest Belgian NPPs are presented, demonstrating the ability to upgrade the safety level of the plants built to earlier standards as closely as possible to that of the most recent units.