Event Notification Report for July 28, 2015

DISCOVERED ONE INCH DIAMETER HOLE BETWEEN REACTOR BUILDING AND AUXILIARY BUILDING

"At 1358 [EDT] on July 28, 2015, a 1 inch diameter hole was discovered in the secondary containment wall, between the Reactor Building and the Auxiliary Building, causing the Secondary Containment to become inoperable under Technical Specification 3.6.5.1. Reactor Building pressure was maintained at a negative pressure as required by Technical Specification 3.6.5.1 with the Reactor Building ventilation system in service before and after discovery of the hole. In addition, the Filtration, Recirculation and Ventilation system remained fully operable and remained in standby. The hole was sealed at 1600 and technical specification 3.6.5.1 was exited. Plant operation was not impacted by the event and was operating at 100% power. No personnel injuries resulted from this event."

The hole was discovered by plant personnel that were walking past the wall. Due to the discovery of the hole, the plant is performing an extent of condition inspection.

The licensee notified the NRC Resident Inspector and the Lower Alloways Creek Dispatch.

* * * * RETRACTION FROM MARIAZ DAVIS TO STEVEN VITTO AT 1232 EDT ON 08/ 12/15 * * * *

"This event is being retracted.

"Hope Creek Generating Station Unit 1, is retracting the 8-hour non-emergency notification (EN# 51274) made on July 28, 2015, at 1855 EDT. The notification on July 28, 2015, reported that secondary containment was declared inoperable when a 1 inch hole was discovered in the secondary containment wall, between the Reactor Building and the Auxiliary Building. Secondary containment was declared inoperable based on the initial interpretation of the definition of secondary containment. The hole did not impact the ability to maintain the Tech Spec required negative pressure. Subsequent evaluation determined that secondary containment was always operable. Based on the engineering evaluation, the condition reported in EN# 51274 did not result in an inoperability of the secondary containment. Therefore, there is no reportable condition and this event report is being retracted.

"The NRC Resident Inspector has been briefed on the evaluation results and informed of this retraction."

The licensee also notified the Lower Alloways Creek Dispatch.

Notified R1DO (Powell).

PART-21 NOTIFICATION - MICRO SWITCH INTERMITTENT VARIATION IN RESISTANCE

The following report was received via fax:

"On June 4, 2015, Rotork Controls Inc. opened a formal Part 21 [10 CFR 21.21] investigation into a self-identified anomaly relating to a basic micro switch - Pt No N69-921, description 'V12'. The anomaly is intermittent variation in electrical contact resistance and was first observed during the factory acceptance test of a Rotork safety related NA Range Electric Actuator; also referred to as an electric Valve Operator.

"Rotork and the switch manufacturer are currently characterizing switch population contact resistance to establish whether an unsafe condition could exist as defined under 10 CFR 21."

* * * UPDATE AT 0958 EDT ON 9/10/2015 FROM PATRICK SHAW TO MARK ABRAMOVITZ * * *

The following report was received via e-mail:

"Rotork has concluded the investigation and based on test data determine an unsafe condition can exist as defined under 10CFR21. Testing has established that a small percentage of the switches supplied against Rotork purchase order P0116932 may exhibit an open circuit condition when operated. A slightly larger percentage of the population may exhibit high contact resistance ranging from 0.5 Ohm to open circuit. The anomaly affects the normally open and normally closed contacts equally. Contact resistance anomalies are random, not permanent, and appear to be unaffected by accumulated cycles. Additionally when a switch is operated its electrical state remains constant until the next operation.

"Probabilities have been established by resistance measurements and by dynamic testing using voltages representative of customer applications. The dynamic evaluation predicts an open circuit probability of 0.0008% per operation. To date, no switch failures have been reported from any customer sites. Below are listed all orders provided to customers containing V12 switches from the defect batch. Report ER791 provides full details of Rotork's technical investigation."

Notified the R1DO (Gray), R2DO (Shaeffer), R3DO (Pelke), R4DO (Drake), and Part-21 Group (via e-mail).