ASSESSMENT OF THE SAFETY PERFORMANCE OF THE PAKS NUCLEAR POWER PLANT UNITS USING ADVANCED ANALYSIS AND COMPREHENSIVE PERIODIC SAFETY REVIEWS

摘要

Because of international interest in the safety of Soviet designed reactors, comprehensive safety reviews have been carried out in recent years for the Paks nuclear power plant (NPP) units. In addition to routine inspection and review work by the regulatory body, a reassessment of the safety of the Paks NPP was launched in 1991 by the Hungarian Atomic Energy Commission (HAEC). Furthermore, according to the legal regulations of Hungary, a periodic safety review (PSR) of the first two units of the Paks NPP is under way and will be finished by the end of 1996. The advanced, general and new evaluation of safety (AGNES) project was successfully completed by mid-1994, producing results on system analysis, analysis of design basis accidents and severe accidents, and level 1 probabilistic safety assessment. The results of the reassessment have verified the expectations concerning the large safety margins of the WWER-440/V-213 systems; however, several weaknesses have also been highlighted. The main risk contributors have been identified and included in the already existing safety enhancement programme of the Paks NPP. The main conclusion of the AGNES project is that the safety level of the Paks NPP has reached that of other NPPs constructed at the same time and that it is high enough for the plant to be operated. However, safety upgrading measures have to be implemented in the near future for further enhancement of safety. The