05000387/LER-2016-004

LER-2016-004, Momentary Loss of Secondary Containment due to Both Airlock Doors on Elevation 779 of the Unit 2 Reactor Building being Opened at the Same Time

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
3872016004R00 - NRC Website

LER 16-004-00 for Susquehanna, Unit 1, Regarding Momentary Loss of Secondary Containment Due to Both Airlock Doors on Elevation 779 of the Unit 2 Reactor Building Being Opened at the Same Time

ML16131A736
Person / Time
Site:	Susquehanna
Issue date:	05/10/2016
From:	Franke J A Susquehanna, Talen Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7467 LER 16-004-00
Download: ML16131A736 (4)

mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

CONDITIONS PRIOR TO THE EVENT

Unit 1 — Mode 5, 0 percent Rated Thermal Power Unit 2 — Mode 1, 99.8 percent Rated Thermal Power There were no systems, structures, or components that were inoperable at the start of the event and contributed to the event.

EVENT DESCRIPTION

On March 14, 2016, an individual was attempting to enter the Unit 2 Reactor Building [EIIS: NG] airlock [EIIS: AL] on Elevation 779 through Door 115R, when the opposite airlock door (Door 602) opened due to air pressure/vacuum created when Door 115R was opened. The airlock alarmed at 0925 hours0.0107 days <br />0.257 hours <br />0.00153 weeks <br />3.519625e-4 months <br /> due to both airlock doors (Door 602 and 115R) [EIIS: DR] being open at the same time. The individual immediately closed Door 115R and Secondary Containment was re-established.

An inspection of Door 602 was performed which identified that the strike plate on the door was not maintaining the door latched. Door 115R was maintained closed while Door 602 was being repaired. Door 602 was repaired by tightening the screws of the cover plate on the door's mortise. Operations declared the door to operable at 0957 hours0.0111 days <br />0.266 hours <br />0.00158 weeks <br />3.641385e-4 months <br /> on March 14, 2016.

In accordance with 10 CFR 50.73(a)(2)(v)(C), this LER is being submitted for an event or condition that could have prevented the fulfillment of the safety function of Secondary Containment to control the release of radioactive material. No entry into Technical Specification 3.6.4.1, Action Statement A, was made because at the time the Control Room was made aware of the event, both airlock doors were closed and Secondary Containment had been re-established.

CAUSE OF THE EVENT

The direct cause of the event was due to a loose cover plate on the door's mortise.

ANALYSIS/SAFETY SIGNIFICANCE

The actual consequence of this event was a momentary loss of Secondary Containment. No entry into the Technical Specification 3.6.4.1, Action Statement A, was made because at the time the Control Room was made aware of the event, both airlock doors were closed.

This event will not be counted as a safety system functional failure (SSFF) for the NRC performance indicator.

An engineering analysis was performed and concluded that Secondary Containment could have performed its mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NE08-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3. LER NUMBER

Susquehanna Steam Electric Station, Unit 1 05000387 ANALYSIS/SAFETY SIGNIFICANCE (CONT.) safety function of isolating as in the accident analysis and also of re-establishing 0.25 inch vacuum within the assumed accident analysis time of 10 minutes. Therefore, there was no loss of the ability of the Secondary Containment system to fulfill its safety function.

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

CORRECTIVE ACTIONS

The latch on Door 602 was repaired and the door was declared operable.

PREVIOUSLY SIMILAR EVENTS

The following are recent LERs involving loss of secondary containment due to door issues:

to Random Occurrence, dated April 18, 2016.

to Random Occurrence, dated April 18, 2016.

Been Properly Latched, dated January 29, 2016.

Boundary Door 104-R Breached, dated September 18, 2015.

Found Ajar, dated June 25, 2015.

Surveillance Requirement 3.6.4.1.1, dated May 11, 2015.

Personnel Error Resulting in Entry into Secondary Containment Technical Specification Limiting Condition for Operation, dated December 31, 2014.