Safety improvements and PSA of Loviisa NPP

The safety improvements of the plant between 1989 and 1994 are listed. The plant risk estimates are broken down according to internal initiating events. The overall estimated plant risk was reduced by a factor of ten although new initiators and phenomena were identified while updating the PSA. New findings and ongoing design efforts at safety significant modifications have necessitated two updated PSA's, one for the plant as it is today and one for the plant after all modifications. This predictive PSA shows that the plant risk can be further reduced by plant modifications to be implemented by the end of 1996. In addition to keeping up an updated PSA model of the plant, PSA activities have been going on to identify and analyze fire, flood, weather and seismic risks. (J.B.) 1 fig