On 3/31/13 at 0414 EDT, dye penetrant testing identified a 10mm long relevant linear indication on a 3/4 inch
RCS flow instrument line
weld, between the
RCS loop piping and the instrument isolation valve. This constitutes a
weld defect in the primary coolant system that cannot be found acceptable per
ASME Section XI. This section of piping is unisolable from the
Reactor Coolant System. There is no evidence of active leakage currently or during the previous operating cycle, however, based on the dye penetrant testing this is considered a
through wall leak.
This event notification is being made in accordance with 10CFR50.72(b)(3)(ii)(A), as a condition that results in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded.
Unit 1 is currently in a scheduled refueling outage in Mode 5 making preparations to transition to Mode 6. The plant is evaluating the appropriate repair method for this condition. The condition will be corrected during the current refueling outage. Unit 2 is in Mode 1 at 100% power and is unaffected by this condition.
The NRC Resident Inspector has been notified.