05000348/LER-2016-004

LER-2016-004, Unapproved Environmental Qualification Material Caused Inoperability of One Containment Cooling Train

Joseph M. Farley Nuclear Plant
Event date:	10-20-2016
Report date:	12-19-2016
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3482016004R00 - NRC Website

LER 16-004-00 for Joseph M. Farley Nuclear Plant, Unit 1, Regarding Unapproved Environmental Qualification Material Caused lnoperability of One Containment Cooling Train

ML16354B551
Person / Time
Site:	Farley
Issue date:	12/19/2016
From:	Gayheart C A Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-16-2595 LER 16-004-00
Download: ML16354B551 (6)

A. PLANT AND SYSTEM IDENTIFICATION

Westinghouse - Pressurized Water Reactor

B. DESCRIPTION OF EVENT

On 10/20/2016 with Unit 1 in Mode 6 during a refueling outage, motor field cables on the 1C Containment Cooler were found to contain splice material that was not approved for use in containment. During the previous refueling outage the 10 Containment Cooler was being replaced with a refurbished motor. An emergent design change was needed when it was discovered that the field cable was located farther away from connection box on the refurbished motor than for the previous motor. As part of this design change an incorrect splice kit was chosen. The design called for a bolted in-line splice instead of a bolted "V" splice. An environmental qualification subject matter expert did not review the design change. The result was the installation of an unapproved splice kit. This unapproved material could have exposed the associated connectors to accident environments in the event of a Design Basis Accident (DBA) and was an untested configuration for Environmentally Qualified (EQ) purposes. This could have led to one train of containment cooling not being capable of performing its specified safety function under some postulated accident scenarios.

This error resulted in the operability of the 10 Containment Cooler not being supported for Cycle 27.

During Cycle 27 there were four periods during applicable modes when the 1C Containment Cooler was the selected cooler for B train for a period greater than seven days. This exceeded the required action completion time for Technical Specification (TS) 3.6.6 Condition C for one containment cooling train being inoperable, and is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.

C. UNIT STATUS AT TIME OF EVENT

Mode 6, 0 percent power

D. CAUSE OF EVENT

The cause was a Human Performance error that resulted in selection of an incorrect splice kit for a design change.

E. REPORTABILITY ANALYSIS AND SAFETY ASSESSMENT

Because the period of B train containment cooling inoperability exceeded the required action completion time of TS 3.6.6 this condition is considered reportable per 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.

During Cycle 27 there were four periods during applicable modes when the 1C Containment Cooler was the selected cooler for B train for a period greater than seven days:

14:19 on 5/4/2015 to 17:17 on 5/26/2015 22 days 9:38 on 5/29/15 to 10:18 on 6/22/2015 24 days 1:28 on 2/24/2016 to 3:37 on 7/13/2016 140 days 0:52 on 8/10/2016 to 23:30 on 10/1/2016 53 days There were no periods of concurrent inoperability for both the A and B trains of Containment Cooling, therefore this condition does not meet the reporting criterion for a condition that could have prevented fulfillment of a safety function required to mitigate the consequences of an accident, and is not reportable for 10 CFR 50.73 (a)(2)(v)(D).

The containment cooler system consists of two separate trains, of equal capacity, each capable of meeting the design bases. Each train is of sufficient capacity to supply 100 percent of the post accident heat removal design cooling requirements. Because there were no periods of concurrent inoperability for both the A and B trains of Containment Cooling, this condition did not significantly degrade plant safety, and the safety significance of this event is considered very low.

F. CORRECTIVE ACTION

The immediate corrective actions was the installation of an appropriately EQ qualified splice suitable for use inside containment. Also there was additional training conducted subsequent to the installation of the splice for design engineering to strengthen understanding of design inputs. A new expectation to have a corporate environmental qualification specialist review design packages when working with EQ component replacements was also implemented.

G. ADDITIONAL INFORMATION

1) Failed Components: The component did not fail. Its operability could not be supported for cycle 27 due to the untested configuration for EQ purposes.

2) Previous Similar Events: None 3) Other system affected: No systems other than those mentioned in this report were affected by this event.

4) Commitment Information: This report does not create any licensing commitments 5) Energy Industry Identification System Code: [BK]