Event Notification Report for February 28, 2017

SHORT DURATION LOSS OF SECONDARY CONTAINMENT DUE TO SEVERE WEATHER

"At 1825 [CST] on 02/28/2017, Dresden Station received unexpected alarm 923-5 C-1, RX BLDG DP LO [Reactor Building Differential Pressure Low]. Reactor Building differential pressure was observed to briefly lose vacuum and return to a normal reading of 0.6 inches vacuum water gauge. At the time of the transient, Grundy County was under a Severe Weather Warning and gusts of wind were being monitored from the Main Control Room up to approximately 57 mph. The Reactor Building differential pressure returned to [greater than or equal to] 0.25 inches vacuum water gauge at 18:25 after 18 seconds with no operator action. Operators observed differential pressure reading to lose vacuum, below 0 inches vacuum water gauge, for approximately 3 seconds.

"This condition represents a failure to meet Surveillance Requirement 3.6.4.1.1. As a result, entry into Technical Specifications 3.6.4.1 condition A was made due to Secondary Containment being inoperable. This event is being reported in accordance with 10CFR50.72(b)(3)(v)(C) as a condition that could have prevented the fulfillment of a safety function.

"An issue report has been initiated and a 60-day Licensee Event Report will be submitted in accordance with 10CFR50.73(a)(2)(v)(C).

"The NRC Resident Inspector has been notified."

* * * RETRACTION ON 4/14/17 AT 1429 EDT FROM BOBBY SHORT TO DONG PARK * * *

"The purpose of this notification is to retract ENS notification 52582 made on 2/28/17 for Dresden Nuclear Power Station. The previous notification reported a potential loss of Reactor Building differential pressure due to high wind conditions and associated entry into Technical Specification 3.6.4.1 Condition A for failure to meet Surveillance Requirement 3.6.4.1.1 to maintain differential pressure above 0.25 inches vacuum water gauge.

"After further evaluation, it has been determined that the high winds caused a momentary low pressure pocket on the leeward side of the Reactor Building causing the differential pressure reading seen in the Main Control Room, but it did not challenge Reactor Building differential pressure or Secondary Containment. Reactor Building differential pressure indication utilizes four transmitters, one on each wall of the Reactor Building, and the most conservative reading is transmitted to the indicator in the Main Control Room. Wind conditions impacting a single transmitter would result in indication of low Reactor Building differential pressure in the Main Control Room. Procedures direct action to obtain local readings from all four Reactor Building differential pressure transmitters. After the low indication in the Main Control Room, Equipment Operators were dispatched to obtain local indication and all four transmitters were found to be indicating 0.6 inches vacuum water gauge.

"This was a short duration transient with no indications of an equipment failure that could impact Secondary Containment. The entire transient occurred within an 18 second window where differential pressure indication began at 0.6 inches vacuum water gauge, dropped to below 0 inches vacuum water gauge, and subsequently restored to 0.6 inches vacuum water gauge with no operator intervention. Furthermore, a significant change in Reactor Building differential pressure would impact readings on Drywell pressure because the Reactor Building pressure is used as a reference leg. Trends of Drywell pressure during the event indicated no adverse conditions implying that Reactor Building differential pressure was stable. Thus, it has been concluded that this was an indication issue and at no point during the transient would Secondary Containment have been unable to perform its safety function.

"Therefore, this event does not meet the criteria of 10 CFR 50.72(b)(3)(v)(C) as a condition that could have prevented the fulfillment of a safety function, and the ENS notification is being retracted. There is no longer a requirement for an associated 60-day Licensee Event Report in accordance with 10 CFR 50.73(a)(2)(v)(C).

"The NRC Resident Inspector has been notified."

Notified R3DO (Jeffers).

FITNESS FOR DUTY - PROHIBITED ITEM FOUND INSIDE PROTECTED AREA

"Event Report per 10 CFR 26.719(b)(1).

"On February 28, 2017, a violation of the site Fitness For Duty policy was committed. A prohibited item was found inside the Protected Area.

"The licensee notified the NRC Resident Inspector."

AGREEMENT STATE REPORT - TWO SEALED SOURCES TESTED POSITIVE FOR LEAKAGE

The following information was received via email from the Commonwealth of Massachusetts:

"The licensee reported on February 28, 2017 that licensee learned from its licensed leak test service provider that two 6 milliCurie, Cobalt-57, sealed sources, of 20 sources received in a package from the source manufacturer, Isotope Products Laboratories, tested positive for leakage.

"The leak test result for one of the sealed sources was reported to be at least 0.4 microCuries which is the maximum activity that the instrument used can measure. The leak test result for the other sealed source was reported to be below the reporting requirement of 0.005 microCuries.

"The sealed sources are each Isotope Products Laboratories Model 3901-2 sources. The serial number attributed to the source having leak test result of at least 0.4 microCuries was reported to be P3-682. The serial number attributed to the source having leak test result of below 0.005 microCuries was reported to be P3-689.

"The licensee reported that each of the sources is contained and secured in a separate plastic bags; that there is no facility contamination based on area surveys performed; that the external surfaces of the package received, that had contained the sources, had been wipe tested and that the package was not contaminated; and that the sources were not used pending leak test results.

"The licensee reports that it will notify the source manufacturer, to inquire about proper return of the sources back to the source manufacturer.

"The Agency [Massachusetts Radiation Control Program] considers this event to be open."

TECHNICAL SPECIFICATION SHUTDOWN DUE TO REACTOR COOLANT SYSTEM PRESSURE BOUNDARY LEAKAGE

"On February 28, 2017 at 0930 [EST], a containment visual inspection was performed to identify the source of elevated RCS [Reactor Coolant System] leakage. A leak was identified between 13RC6 and 13SS661, 13 RCS hot leg sample isolation valves at 1000 [EST]. These valves are manual isolation valves in the reactor coolant hot leg sample line. Leak isolation could not be initially verified and is considered RCS pressure boundary leakage. Salem Unit 1 entered Technical Specification 3.4.6.2a, RCS operational leakage, for the existence of pressure boundary leakage.

"This event is being reported under the requirements of 10 CFR 50.72(b)(2)(i) for 'The initiation of a plant shutdown required by Technical Specifications' and 10 CFR 50.72(b)(3)(ii)(A) or 'Any event of condition that results in the condition of the nuclear power plant, including its principal safety barriers being seriously degraded.'

"The unit was placed in mode 3 at 1554 [EST] on 02/28/2017.

"This condition has no impact on public health and safety."

Per Technical Specifications, the unit is proceeding to mode 5. The leak rate at the time of shutdown was 0.33 gpm. This event has no effect on Unit 2.

The licensee has notified the NRC Resident Inspector. The licensee will be notifying the Lower Alloways Creek Township, the State of New Jersey and the State of Delaware.

* * * RETRACTION FROM MATT MOG TO HOWIE CROUCH AT 1144 EDT ON 4/14/17 * * *

"The purpose of this notification is to retract event report number 52581 made on 2/28/2017 at 1624 (EST). Previously, PSEG notified the NRC that Salem Unit 1 initiated a shutdown required by Technical Specifications (TS) for Reactor Coolant System (RCS) Pressure Boundary Leakage.

"Subsequent to the initial report, PSEG has determined that the leak occurred in tubing downstream of the design specification break between Safety Related, Nuclear Class 1, Seismic Class1 and Non-Safety-Related, Nuclear Class 2, Seismic Class 2. Therefore, the observed leakage is not RCS pressure boundary leakage as defined in the Salem Unit 1 Technical Specifications and in the tubing design classification specification.

"At the time of the event, during initial entry into the containment, the volume of steam present and the height of the break above the floor made it difficult to ascertain the location of the steam source with certainty. The initial judgment of RCS Pressure Boundary Leakage was conservative under these circumstances. The plant was taken offline to minimize radiation exposure when personnel operated the isolation valves. Following the shutdown, the leak was isolated. Based on an observed reduction in RCS leak rate and visual verification of leakage isolation, the TS Limiting Condition for Operation (LCO) was exited and the unit remained in Mode 3, Hot Standby, to affect repairs. The condition did not meet the Technical Specification Pressure Boundary Leakage definition of leakage through a non-isolable fault in a RCS component body, pipe wall or vessel wall.

"The leakage did not impact the ability to shut down the unit and no TS limits were exceeded during this event. Therefore, the plant shutdown to investigate and correct leakage from flawed sample system tubing does not meet the reporting requirements of 10 CFR 50.72 and PSEG is retracting the notifications made under 10 CFR 50.72(b)(2)(i) and 10 CFR 50.72(b)(3)(ii)(A).

"The NRC Resident Inspector was notified of this retraction by the licensee."

Notified R1DO (Jackson).