AGE-RELATED REPAIRS AND MODERNIZATION AT OSKARSHAMN-1

''Fenix'' stands for the backfitting program of extensive engineered s afeguards described in this contribution by the example of the Oskarsh amn-1 nuclear generating unit, the first ABB boiling water reactor pla nt (462 MWe) in Sweden. The unit was shut down in the fall of 1992. Fi rst of all, large areas had to be decontaminated for subsequent upgrad ing measures. For this purpose, fuel elements, control rods, fueling s ystems, the diagrid, instrumentation etc, were removed. Repair work on the reactor pressure vessel began in March 1994. The feedwater pipes and nozzles had to be replaced, as had the penetrations for the core s pray system and a number of other installations in the pressure vessel . A special handling system was installed on the vessel floor for this purpose. Probabilistic safety analyses and the implementation of thei r results will allow the Oskarshamn-1 nuclear generating unit to be re connected to the power grid in 1995. The plant will then represent the current state of the art.