05000311/LER-2017-001

LER-2017-001, Emergency Diesel Generator Start Due to a Loss of Power to the 2C 4160 Volt Vital Bus

Salem Generating Station - Unit 2
Event date:
Report date:
3112017001R00 - NRC Website

LER 17-001-00 for Salem, Unit 2, Regarding Emergency Diesel Generator Start Due to a Loss of Power to the 2C 4160 Volt Vital Bus

ML17164A303
Person / Time
Site:	Salem
Issue date:	06/13/2017
From:	McFeaters C V Public Service Enterprise Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LR-N17-0107 LER 17-001-00
Download: ML17164A303 (5)

Collections Eirancri (T-5 F53). U.S. NI,Iciear Regulatory Commission ,iVashington, DC 20555- occ1 or by internet e-mail to Infocoliects.Resc:ircee'Dnrc.gov. and to Me Desk Cfficer: Office of Information and Regulatory Affairs. fILOB-13202. (3:b0-01CA. Office of Mapagement and Budget, Vliastdrigtor. DO 20503. I' a means .red lc impose an inforr ation collection does not display a currently valid OMB control number, the NRC may not concuct or sponsor. and a person is not rec,dred to respond to, Ile information collection.

Salem Generating Station — Unit 2 05000311

PLANT AND SYSTEM IDENTIFICATION

Westinghouse-Pressurized Water Reactor {PWR/4} Medium-Voltage Power System — Class 1 E / Contactor {EB/CNTR}

IDENTIFICATION OF OCCURRENCE

Event Date: 04/14/2017 Discovery Date: 04/14/2017

CONDITIONS PRIOR TO OCCURRENCE

Salem Unit 2 was in Mode 1 at 99.9 percent rated thermal power (RTP).

DESCRIPTION OF OCCURRRENCE

On 4/14/17 at 1357 while attempting to transfer 2C 4kV vital bus from the 24 SPT to the 23 SPT, the 4kV bus infeed breaker from the 24 SPT opened properly but the 4kV bus infeed breaker from 23 SPT failed to close. Failure of the 23 SPT infeed breaker to close as expected resulted in de-energization of the 2C 4kV vital bus and the subsequent start and loading of the 2C EDG to power the bus.

CAUSE OF EVENT

The failure of the infeed breaker from the 23 SPT to close as required was attributed to a large burr located on the movable contact assembly internal to the 52/IS switch. The 52/IS switch is an interlock switch to prevent the breaker from charging and closing if it is not in the correct racked up position.

SAFETY CONSEQUENCES AND IMPLICATIONS

There were no safety consequences as a result of this event.

The operating crew responded correctly to the event. The applicable abnormal operating procedure was properly entered and documentation met expectations.

The EDG and Safeguards Equipment Controller (SEC) operated as designed. There were no nuclear safety implications associated with this event.

SAFETY SYSTEM FUNCTIONAL FAILURE

This condition did not result a safety system functional failure as defined in NEI 99-02, Regulatory Assessment Performance Indicator Guidelines.

con GT by Internet e-mai :o Infocollects.Rescurce@rro.gov, and tc the Desk Officer, Office :Jr raise and Regiilatory Affairs. NEOB-1C202, CY 50-0104;, Cffice o.f Maragesnent ard Budget, Washington, DC 20503.1f a means used to Thpose ar infcrmadon cc;ection does not disray a currertiy van:: OMB coruol sunber, the, IRC may not comouct or sponsor, and a person is not recuirod to respond to, the 'nformation cc:cotion.

Salem Generating Station — Unit 2 05000311

PREVIOUS EVENTS

A review of Salem Licensee Event Reports for the previous three years identified no other similar events.

CORRECTIVE ACTIONS

• The 23 SPT infeed breaker to the 2C 4kV bus was replaced

• The 52/IS switches from the 22 Containment Spray pump (CS) and the 23 SPT infeed breaker to the 2A 4kV bus have been replaced and the removed switches will have internal inspections performed for extent of condition inspection.

• Any additional corrective actions will be determined after the switch inspection results are received.

COMMITMENTS

There are no regulatory commitments contained in this LER.