No problems detected with steel quality concerning the reactor pressure vessel at Olkiluoto 3
The Radiation and Nuclear Safety Authority (STUK) has approved the report submitted by TVO on steel quality concerning the reactor pressure vessel of the Olkiluoto 3 nuclear power plant unit. According to the report, the steel used in the reactor pressure vessel and other primary circuit elements of the nuclear power plant under construction in Olkiluoto has no quality deviations that affect safety.
STUK requested a report from TVO after deviations that affect strength were detected in the steel used in the reactor pressure vessel of the Flamanville 3 nuclear power plant unit, which is being built in France. Deviations were due to the carbon content of steel.
TVO submitted the report to STUK at the end of June. According to the report, the reactor pressure vessel at Olkiluoto was manufactured using a different method that produces better quality and that the inspections during its manufacture would have revealed any deviations that affect strength or any similar problems. According to the supplementary report submitted by STUK at the beginning of November, the other primary circuit elements were also inspected appropriately during manufacture.
In October TVO inspected the carbon content of the steel used in the pressuriser, which is part of the reactor primary circuit. The results proved that the carbon content meets the requirements.
In its decision issued on 8 December 2015, STUK states that the reports submitted by TVO were sufficient and the conclusions were justified.