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On 8/27/2015 at 1347 (EDT), a cart and personnel were being traversed through an airlock in the Unit 2 reactor building and both airlock doors were inadvertently opened at the same time for a brief period of time (approximately one minute). Secondary Containment differential pressure was maintained throughout the time period that the doors were opened. The doors serve as a Secondary Containment boundary and at least one in series is required to be closed at all times for Secondary Containment Operability. This event is being reported under 10 CFR 50.72(b)(3)(v) and per the guidance of NUREG 1022 Rev 3 section 3.2.7 as a loss of a Safety Function. There is no redundant Susquehanna Secondary Containment System. The licensee notified the NRC Resident Inspector.

• * * RETRACTED ON 10/22/15 AT 1645 EDT FROM ALEX MCLELLAN TO DONG PARK * * *

NUREG-1022, Revision 3, Section 3.2.7, 'Event or Condition that Could Have Prevented Fulfillment of a Safety Function,' states, in part, that 'events covered in paragraph (b)(3)(v) of this section may include one or more procedural errors, equipment failures, and/or discovery of design, analysis, fabrication, construction, and/or procedural inadequacies.' The level of judgment for reporting an event or condition under this criterion is a reasonable expectation of preventing fulfillment of a safety function. A SSC (System, Structure, and/or Component) that has been declared inoperable is one in which the SSC capability has been degraded to the point where it cannot perform with reasonable expectation or reliability. For SSCs within the scope of this criterion, a report is required when: - There is a determination that the SSC is inoperable in a required mode or other specified condition in the TS (Technical Specification) applicability, -The inoperability is due to one of more personnel errors, including procedure violations; equipment failures; inadequate maintenance; or design, analysis, fabrication, equipment qualification, construction, or procedural deficiencies, and -No redundant equipment in the same system was operable. Subsequent to the reporting of this condition, Susquehanna Nuclear, LLC performed an investigation of the event. Below are the results. When the airlock doors were opened at the same time, they were being operated as designed. Each individual had a 'green' light, which allowed them to open each door. Based on the investigation, the doors were open at the same time for approximately one second. In summary, the inoperability of Secondary Containment was not due to personnel error or a procedure violation. At the time of the event, both airlock doors were operable. No equipment failures, inadequate maintenance, or design, analysis, fabrication, equipment qualification, construction, or procedural deficiencies were identified. In summary, based on the above, the identified condition is not reportable in accordance with 10 CFR 50.72(b)(3)(v), for an event or condition, that at the time of discovery, could have prevented the fulfillment of a safety function. As such, this 8-hour event notification is being retracted. The licensee has notified the NRC Resident Inspector. Notified R1DO (Gray).

At 1040 hrs during setup for Unit 1 Division 1 LOCA/LOOP Surveillance testing, the controlling procedure required making the Loss of Power instrumentation for the 1A and 1C ESS buses inoperable. The specification has a 1 hour time limit for restoration, or the associated Diesel Generators must be declared inoperable. Due to delays during the setup of equipment the time requirements were not met, and the 'E' (Substituting for 'A') and 'C' Diesel Generators were declared inoperable at 1140 hrs. The Loss of Power instruments were restored, and the Diesel Generators declared operable at 1206 hrs. Unit 1 is in Mode 5 requiring only 2 diesel generators operable, therefore not impacted by the Loss of Power instrumentation inoperability. Also during the surveillance, two pump start timers failed to meet the required acceptance criteria. The 'A' ESW Pump timer actuated at 47.86 seconds (criteria; 36 sec. to 44 sec) and the 'C' ESW Pump timer actuated at 50.38 seconds (criteria: 39.6 sec. to 48.4 sec). With failure of the timers, proper loading on the Diesel Generators is not assured, and they were declared inoperable until the associated pump control breakers were opened. The 'E' Diesel Generator was declared inoperable at 1448 hrs, when the data analysis identified that the 'A' ESW pump timer did not meet acceptance criteria. The 'E' Diesel Generator was returned to operable at 1453 hrs when the DC Knife switches for the 'A' ESW pump were open. The 'C' Diesel Generator was declared inoperable at 1524 hrs, when the data analysis identified that the 'C' ESW pump timer did not meet acceptance criteria. The 'C' Diesel Generator was restored to operable at 1706 hrs after supported systems were realigned to prevent further loss of safety function and the DC Knife switches for the 'C' ESW pump were open. The Susquehanna safety analysis requires three operable Diesel Generators to safely shutdown the plant. Therefore with only two operable Diesel Generators, the condition requires an 8 hr ENS notification in accordance with 10CFR50.72(b)(3)(v)and (vi). All times referenced above are EDT. The licensee informed the NRC Resident Inspector.

* * * RETRACTION FROM R. FRY TO M. RIPLEY 1419 ET ON 05/27/04 * * * *

The following is a retraction of ENS Notification #40642 AND #40646: On April 5, 2004, PPL Susquehanna, LLC reported three events to the NRC associated with Unit 1 Division 1 LOCA/LOOP surveillance testing. In each case, the safety function of two (out of 4) emergency diesel generators was brought into question during the testing. In two of these events, the E (substituting for A) and C diesel generators were administratively declared inoperable per Technical Specifications. This was necessary because Loss of Power instrumentation for the 1A and 1C buses, rendered inoperable in support of the test procedure, was not restored within 1 hour. In the third event, the E (for A) and C emergency diesel generators were, again, declared inoperable when two ESW pump start timers failed to meet acceptance criteria thus bringing the proper start sequencing of emergency loads into question. Because the Susquehanna Safety Analysis requires three diesel generators to safely shutdown an operating unit, the potential compromise of the diesel generator safety function was a concern for Unit 2 in each instance. (NOTE: Unit 1 was in Refueling Mode 5 and was, therefore, not impacted by these events.) Accordingly, Control Room personnel conservatively initiated ENS reporting under 10CFR50.72(b)(3)(v) in response to the apparent loss of safety function for Unit 2. Subsequent engineering analysis has concluded that, although the declaration of diesel generator inoperability was correct and in accordance with Technical Specifications, fulfillment of these administrative actions did not result in an actual loss of safety function during any of the above described events. Details of the analysis show that the diesel generators were available to supply emergency power to the ESS buses and/or that sufficient redundant equipment was available to fulfill the safety function needs of Unit 2. These analysis conclusions provide the basis for retraction of the ENS reports made on April 5, 2004." The licensee notified the NRC Resident Inspector. Notified R1DO (R. Conte)