05000387/LER-2017-007

LER-2017-007, Secondary Containment Declared Inoperable Due to the opening of a plenum.

Susquehanna Steam Electric Station Unit 1
Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material
Initial Reporting
ENS 53098	10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material
3872017007R00 - NRC Website

LER 17-007-00 for Susquehanna Steam Electric Station Regarding Secondary Containment Declared Inoperable Due to Supply Air Flow

ML17282A019
Person / Time
Site:	Susquehanna
Issue date:	10/09/2017
From:	Berryman B Susquehanna, Talen Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7641 LER 17-007-00
Download: ML17282A019 (4)

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3. LER NUMBER

2017 - 007 - 00

CONDITIONS PRIOR TO EVENT

Unit 1 — Mode 1, approximately 100 percent Rated Thermal Power Unit 2 — Mode 1, approximately 100 percent Rated Thermal Power There were no structures, systems, or components that were inoperable at the start of the event that contributed to the event.

EVENT DESCRIPTION

On November 30, 2017 at 1026, the Susquehanna Control Room received indication that a loss of Secondary Containment Zone 2 differential pressure had occurred. Control Room operators noted a differential pressure of 0" Water Column (WC) for several seconds, followed by a high differential pressure of 0.5" WC. System differential pressure was restored to normal in 3 minutes. The cause of the pressure swings is under investigation. Zone 2 differential pressures being less than 0.25" WC constitutes a loss of Secondary Containment based on not meeting requirements of Technical Specification (T.S.) 3.6.4.1 Surveillance Requirement 3.6.4.1.

There were no actual consequences to the health and safety of the public as a result of this event.

The condition is being reported in accorance with 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented fulfillment of a safety function. This event was reported in ENS 53098 under 10 CFR 50.72(b)(3)(v)(c). There is no redundant Susquehanna Secondary Containment system.

CAUSE OF EVENT

This event is still under investigation. The cause will be provided in the supplement.

ANALYSIS/SAFETY SIGNIFICANCE

This event is still under investigation. The safety significance will be provided in the supplement

CORRECTIVE ACTIONS

This event is still under investigation. The corrective action will be provided in the supplement.

PREVIOUS SIMILAR EVENTS

This event is still under investigation. Previous similar events will be identified under the supplement.