NPP POWER UPRATING IN BELGIUM THE DOEL3 AND TIHANGE 1 EXPERIENCE

摘要

The three steam generators at Doel 3 nuclear powerplant were affected by primary side stress corrosion crackingas early as 1983, after a single year of operation. Electrabel,the owner of Doel 3, decided in 1989 to replace the steamgenerators and in parallel an uprating feasibility study waslaunched by Belgatom. During the summer of 1993, thesteam generators were installed and in the beginning ofSeptember 1993 the plant was operated at a powercorresponding to 110% of the initial design power.In 1991, SEMO the owner of the Tihange 1 power plantasked EdF and Belgatom to evaluate the achievable upratingin case of steam generator replacement. The steam generatormanufacturing contract was awarded in March 92 and anuprated power level of 105% of initial design level wasreached in September 95. Final core uprated power level of108% will be reached during the second transition cycle aftera complete unload of the old limiting fuel.Belgatom, acting on behalf of the Utilities, tookresponsibility for the overall project management and wasalso in charge of the uprating study programme. Part of thestudies was performed by Belgatom, part has beensubcontracted to NSSS suppliers who were not in all casesthe steam generators suppliers. This paper gives an overviewof the two projects and presents the main milestones ofthem. Both projects have been divided in three phases : aconceptual phase, a detailed design phase and animplementation phase. The paper presents shortly twoBelgatom methodologies that were developed and appliedduring these two projects.