05000388/LER-2017-003

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LER-2017-003, Secondary Containment Breach Due to Simultaneous Opening of Airlock Doors
Susquehanna Steam Electric Station Unit 2
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material
3882017003R00 - NRC Website

Reported lessons learned are incorporated into the licensing process and fed back to industry.

Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-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.

Susquehanna Steam Electric Station 05000388 NUMBER NO.

CONDITIONS PRIOR TO EVENT

Unit 1 — Mode 1, approximately 100 percent Rated Thermal Power Unit 2 — Mode 1, approximately 89 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 2, 2017, at approximately 0930, two contract employees were transporting a cart of scaffold materials from Reactor Building [EIIS Component Identifier: NG] Elevation 818' to Elevation 779'. While maneuvering the cart through an airlock [EIIS Component Identifier: AL] on Elevation 779', personnel failed to ensure that the Reactor Building-side airlock door [EIIS Component Identifier: DR] was fully closed prior to opening the Turbine Building-side [EIIS Component Identifier: NM] airlock door. This resulted in not meeting Technical Specification 3.6.4.1 Surveillance Requirement 3.6.4.1.3, which requires that one secondary containment access door in each access opening is closed.

CAUSE OF EVENT

The cause of this event was determined to be less than adequate use of Human Performance Tools, specifically Verification Practices.

ANALYSIS/SAFETY SIGNIFICANCE

Technical Specification 3.6.4.1 Surveillance Requirement 3.6.4.1.3 requires that one secondary containment access door in each access opening is closed. This event is being reported pursuant to 10 CFR 50.73(a)(2)(v)(C) as having both Secondary Containment airlock doors momentarily open simultaneously results in a condition that could have prevented fulfillment of a safety function to mitigate the consequences of an accident by controlling the release of radioactive material.

There was no actual safety consequence as a result of this event. Engineering analysis of this event has determined that secondary containment could have performed its safety function of isolating, as assumed in the accident analysis, and also of re-establishing 0.25 in w.g. vacuum (drawdown) within the assumed accident analysis time (10 minutes). Therefore, this event will not be counted as a safety system functional failure (SSFF) for the NRC performance indicator.

CORRECTIVE ACTIONS

Key corrective actions include the following:

1. Review Secondary Containment door verification practices communication with all employees of this contractor (Complete).

Reported lessons teamed are incorporated into the licensing process and fed back to industry.

Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555.0001, or by e-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.

The following recent LERs involved loss of Secondary Containment due to simultaneous door opening:

Airlock Doors," dated January 26, 2017.

Open Due to a Human Performance Error," dated November 21, 2016.

Airlock Doors," dated December 1, 2016.

Open Due to a Human Performance Error," dated, August 17, 2016.

Open Due to Human Performance Error During Security Response," dated December 21, 2016.

Open Due to a Human Performance Error," dated June 15, 2016.

Open Due to a Human Performance Error," dated June 9, 2016.

Opening of Double Airlock Doors," dated June 9, 2016.

Open Due to a Human Performance Error," dated May 16, 2016.

Doors on Elevation 779 of the Unit 2 Reactor Building being Opened at the Same Time," dated May 10, 2016.

Open Due to Random Occurrence," dated April 18, 2016.

Open Due to Random Occurrence," dated April 18, 2016.