05000387/LER-2016-015

LER-2016-005, Secondary Containment Declared Inoperable Due to Airlock Doors Open Due to a Human Performance Error

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
3872016005R00 - NRC Website

LER 16-015-00 for Susquehanna, Unit 1, Regarding Secondary Containment Declared Inoperable Due to Airlock Doors Open Due to a Human Performance Error

ML16167A301
Person / Time
Site:	Susquehanna
Issue date:	06/15/2016
From:	Franke J A Susquehanna, Talen Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7493 LER 16-015-00
Download: ML16167A301 (4)

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 Internet e-mail to 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

-015 2016

CONDITIONS PRIOR TO EVENT

Unit 1 — Mode 1, approximately 10 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 April 22, 2016 at approximately 11:30, a Nuclear Plant Operator (NPO) was entering a Unit 1 Reactor Building [EMS System Identifier: NG] access door [EIIS Component Identifier: DR] and noticed another worker entering the airlock door behind him with a cart. The NPO stated that he was trying to be helpful and opened the reactor building side (inner) door. The NPO stated that they did not notice that the turbine building side (outer) door was still open. Both doors were open at the same time for approximately one second. This airlock serves as a secondary containment boundary [El IS System Identifier: NG]; as such, having both doors open at the same time results in failure to meet Technical Specification 3.6.4.1 as a result of not satisfying Surveillance Requirement 3.6.4.1.3.

The condition requires a Licensee Event Report (LER) in accordance with 10 CFR 50.73(a)(2)(v)(C).

CAUSE OF EVENT

The direct cause of the event was less than adequate verification practices to ensure compliance with Secondary Containment door requirements.

ANALYSIS/SAFETY SIGNIFICANCE

An engineering evaluation was performed and concluded that secondary containment could have performed its safety function of isolating, as assumed in the accident analysis, and also of re-establishing 0.25 inches vacuum (drawdown) within the assumed accident analysis time (10 minutes). Therefore, the subject event did not cause a loss of safety function. This event will not be counted as a safety system functional failure (SSFF) for the NRC performance indicator based on the engineering analysis that shows there was no loss of ability to fulfill the safety function.

CORRECTIVE ACTIONS

Corrective actions include holding the individual accountable for less than adequate verification practices.

- 00 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 internet e-mail to 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.

2016 -015 -00

PREVIOUS SIMILAR EVENTS

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

Due to Degraded Latch Mechanism," dated May 26, 2016.

Due to Degraded Latch Mechanism," dated May 24, 2016.

Human Performance Error," dated May 16, 2016.

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

to Random Occurrence," dated April 18, 2016.

to Random Occurrence," dated April 18, 2016.

Not 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.