05000388/LER-2015-007, Regarding Primary Containment Isolation Failure Due to Sticking/Sluggish Solenoid Valve

Regarding Primary Containment Isolation Failure Due to Sticking/Sluggish Solenoid Valve

ML15329A018
Person / Time
Site:	Susquehanna
Issue date:	11/25/2015
From:	Franke J Susquehanna, Talen Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7409 LER 15-007-00
Download: ML15329A018 (4)

LER-2015-007, Regarding Primary Containment Isolation Failure Due to Sticking/Sluggish Solenoid Valve

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3882015007R00 - NRC Website

text

NOV 2 5 2015

.Jon A. Franke Site Vice President U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Susquehanna Nuclear, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.2904 Fax 570.542.1504 Jon.Franke@talenenergy.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-388/2015-007-00 UNIT 2 LICENSE NO. NPF -22 PLA-7409 TALEN ~

ENERGY 10 CFR 50.73 Docket No. 50-388 Attached is Licensee Event Report (LER) 50-388/2015-007-00. The LER reports an event involving failure of a primary containment isolation valve to meet Technical Specification requirements. This event was determined to be repmiable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.

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

ory commitments.

Attachment: LER 388/2015-007-00 Copy:

NRC Region I Mr. J. E. Greives, NRC Sr. Resident Inspector Ms. T. E. Hood, NRC Project Manager Mr. M. Shields, P A DEP/BRP

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (02-2014)

Eslimaled, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

6. LER NUMBER

3. PAGE YEAR I

SEQUENTIAL I REVISION NUMBER NUMBER 2 of 3 2015

" 007

" 00 There were no structures, systems, or components that were inoperable at the start of the event that contributed to the event.

EVENT DESCRIPTION

On September 30, 2015, the Unit 2 Reactor Water Sample Outboard (OB) Isolation Valve (HV243F020)

[EllS System Identifier: AD, Component Function Identifier: ISV] failed In-service Testing (1ST) stroke time surveillance testing. The close stroke was timed at 3.85 seconds (the acceptance criteria requires closure in less than or equal to 2 seconds). This required entry into Limiting Condition for Operation (LCO) 3.6.1.3 Condition A.

Following the September 30, 2015 stroke time failure, the associated solenoid valve, SV24320, was replaced. The defective solenoid was returned to engineering for disassembly and inspection. Inspection results confirmed that the previously installed solenoid was sticky/sluggish in changing plunger state.

HV243F020 had failed stroke time testing during the previous quarterly test on July 1, 2015. Investigative valve strokes were performed and timed to be within 1ST stroke time acceptance criteria following the failure. The limit switch was lubricated and a successful surveillance test was performed. A subsequent Failure Modes Analysis was performed and identified solenoid valve sticking as a probable cause, and limit switch sticking as an unlikely cause.

The direct cause of the second failure was sticking/sluggishness of Solenoid Valve SV24320 resulting in excessive closed stroke time. One of the apparent causes for second failure included less than adequate corrective action following the July 1, 2015 failure.

Based on the history and cause, Susquehanna concluded that firm evidence existed that the condition existed prior to discovery on September 30, 2015 for a period longer than allowed by Technical Specifications. As a result, this condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.

CAUSE OF EVENT

The direct cause was sticking/sluggishness of Solenoid SV24320 resulting in excessive closed stroke time.

The apparent causes were as follows:

1. Less than adequate corrective action following HV243F020 stroke time failure on July 1, 2015.

2. Less than adequate Preventive Maintenance (PM) strategy for HV243F020/SV24320

ANALYSIS/SAFETY SIGNIFICANCE

I

6. LER NUMBER

3. PAGE SEQUENTIAL I REVISION NUMBER NUMBER 3 of 3

• 007

• 00 The actual consequence of this event was HV243F020 being declared inoperable, which involved isolating the affected penetration flow path as required by LCO 3.6.1.3 Condition A within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The stroke time failure also resulted in a Maintenance Preventable Functional Failure (MPFF).

Potential consequence of this event would be complete failure of HV243F020 to close, and concurrent failure of the Unit 2 Reactor Water Sample Inboard Isolation Valve, HV243F019. This would also require isolation of the penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (rather than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />) and, if unable to isolate the penetration, entry into MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

CORRECTIVE ACTIONS

1. The faulty solenoid valve was replaced.

2. The HV243F020 actuator overhaul preventive maintenance scope will be revised to include solenoid valve replacement.

COMPONENT FAILURE INFORMATION

Component Identification - HV243F020 Component Name-Unit 2 Reactor Water Sample 08 Isolation Valve Valve Manufacturer-Masoneilan Valve Type-Globe Valve Size-1 inch Actuator Manufacturer-Masoneilan Actuator Model/Size - Model 38, Size 9

PREVIOUS SIMILAR EVENTS

The following are similar Susquehanna events that have occurred within the past five years:

CR-1733145-On August 5, 2013, HV243F019 (Reactor Water Sample Inboard Isolation Valve) failed close stroke time. The cause was identified as solenoid exhaust port blockage combined with potential for solenoid valve internal sticking.

CR-2014-26599-On August 21, 2014, HV143F019 (Reactor Water Sample Inboard Isolation Valve) failed surveillance testing. The caused was determined to be solenoid valve vent blockage and sticking.