Operation of Finnish nuclear power plants. Quarterly report, 2nd quarter 1997

Quarterly Reports on the operation of Finnish nuclear power plants describe events and observations relating to nuclear and radiation safety which STUK - Radiation and Nuclear Safety Authority considers safety significant. Safety improvements at the plants are also described. The Report also includes a summary of the radiation safety of plant personnel and of the environment and tabulated data on the plants' production and load factors. The Finnish nuclear power plant units were in power operation in the second quarter of 1997, except for the annual maintenance outages of Olkiluoto plant units and the Midsummer outage at Olkiluoto 2 due to reduced demand for electricity. There were also brief interruptions in power operation at the Olkiluoto plant units due to three reactor scrams. All plant units are undergoing long-term test operation at upgraded reactor power level which has been approved by STUK The load factor average of all plant units was 88.7 %. One event in the second quarter of 1997 was classified level 1 on the INES. The event in question was a scram at Olkiluoto 1 which was caused by erroneous opening of switches. Other events in this quarter were level 0. Occupational doses and radioactive releases off-site were below authorized limits. Radioactive substances were measurable in samples collected around the plants in such quantities only as have no bearing on the radiation exposure of the population. (orig.)