Due to openings found in degraded roof drain piping, Brunswick Nuclear Power Plant Unit 2
secondary containment was declared inoperable at 0215 [EDT] on 04/20/2014. During operator rounds the Reactor Building Aux Operator noted rainwater coming out of a roof drain line into the Reactor building. Upon further investigation a rusted area 2 foot by 2 inches was found on the pipe. Several through wall holes were found in this rusted area and the remainder of the rusted area was allowing water to weep through. The openings resulting from the through wall holes and rusted area exceeded the allowable openings in
secondary containment, and this would have challenged
secondary containment from performing its safety function. This event did not result in any adverse impact to the health and safety of the public. This is a non-emergency notification.
INITIAL SAFETY SIGNIFICANCE EVALUATION: At the time that is was discovered that Unit 2 Secondary Containment was inoperable. Unit 2 was at 100% steady state conditions. Reactor building ventilation was in service in a normal alignment. The Unit 2 reactor building differential pressure was normal during the entire time secondary containment was inoperable. At no time was there a release of radioactive material from Unit 2 secondary containment.
CORRECTIVE ACTIONS: The Unit 2 reactor building roof drain line has had a temporary repair applied. This repair has been evaluated by the Engineering department with site procedures and meets the requirements to maintain Secondary Containment operable. Unit 2 Secondary Containment operability was restored at 04/20/2014 0600 [EDT].
The licensee notified the NRC Resident Inspector.
