05000272/LER-2015-007

LER-2015-007, Inoperable Control Room Emergency Air Conditioning System Due to Failed Charcoal Filter Surveillance Test

Salem Generating Station - Unit 1
Event date:	0-7-2015
Report date:	01-29-2016
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
Initial Reporting
ENS 51504	10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
2722015007R01 - NRC Website

LER 15-007-01 for Salem, Unit 1, Regarding Inoperable Control Room Emergency Air Conditioning System Due to Failed Charcoal Filter Surveillance Test

ML16029A012
Person / Time
Site:	Salem
Issue date:	01/29/2016
From:	Perry J F Public Service Enterprise Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LR-N16-0013 LER 15-007-01
Download: ML16029A012 (6)

0001, or by Internet e-mail to infocdlects.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,1 he NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

2015 - NUMBER 007 - 001

PLANT AND SYSTEM IDENTIFICATION

Westinghouse - Pressurized Water Reactor {PWR/4} Control Room Air Conditioning System {NA/FLT} Energy Industry Identification System (EllS) codes and component function identifier codes appear as {SS/CCC}.

IDENTIFICATION OF OCCURRENCE

Event Date: October 7, 2015 Discovery Date: October 22, 2015

CONDMONS PRIOR TO OCCURRENCE

Salem Unit 1 was in operational Mode 1, operating at approximately 100 percent power. Salem Unit 2 was in Mode 6 with fuel movement in progress. The Salem Unit 1 Control Room Emergency Air Conditioning System (CREACS) {NA/FLT} train was in single train filtration mode supplying air to the common Control Room due to outage activities on the Unit 2. No additional structures, systems or components were inoperable at the time of discovery that contributed to this event.

DESCRIPTION OF OCCURRENCE

On October 7, 2015, a carbon sample was obtained from the unit 1 CREACS charcoal filtration unit for analysis in accordance with the requirements of TS Surveillance 4.7.6.1.b.3.

On October 28, 2015, at 0628, Salem operations was notified of failure of the Unit 1 charcoal filter TS surveillance test. Test results indicated a methyl iodide penetration of 3.054 percent with a TS acceptance criteria of less than 2.5 percent. The Unit 1 CREACS train was declared inoperable due to failure of its charcoal filter surveillance test, resulting in both units CREACS trains being inoperable. Unit 1 entered TS 3.0.3 because of no TS 3.7.6 Action Statement addressing the loss of both CREACS trains. Fuel movement on Unit 2 was suspended to comply with Unit 2's TS 3.7.6, Action c.

Subsequent review indicated that PSEG had received the results of the methyl iodide penetration analysis from the vendor testing laboratory on October 22, 2015, at 1843. PSEG documented the failure to take timely mitigating actions in the corrective action program.

On October 28, 2015 at 0950, the Unit 2 CREACS train was returned to service and aligned to single train filtration mode supplying air to the common Control Room. With single train filtration operation restored, Unit 1 exited TS 3.0.3, and entered TS 3.7.6.1, Action a., which requires alignment of the system to single train filtration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, and restoration of the inoperable filtration train to operable status within 30 days.

The Unit 1 CREACS charcoal filter carbon was replaced, tested, and the CREACS train was returned to service on October 30, 2015 at 1442.

0001, or by Internet 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.ff 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 nor required to respond to, the information collection.

2. DOCKET 6. LER NUMBER 1. FACILITY NAME Salem Generating Station — Unit 1 05000272 a PAGE

MJMBER

The Event Date for this LER is considered to be October 7, 2015, when the charcoal filter sample was taken.

The Discovery Date is considered to be October 22, 2015, when PSEG was notified by the vendor of the sample results. This event is reported as a condition prohibited by TS since at the time of discovery, the filter had exceeded its TS 3.7.6.1, Action a., Allowed Outage Time (AOT) to align CREACS for single train filtration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This event is also reported as a condition that could have prevented the fulfillment of a safety function because both units CREACS trains were inoperable from the time of discovery until the Unit 2 CREACS train was returned to service and aligned to single train filtration mode supplying air to the common Control Room.

An eight-hour NRC Event Notification (EN) was required on or before 0243 on October 23, 2015, as required by 10 CFR 50.72(b)(3)(v)(D) for an event or condition that at the time of discovery could have prevented the fulfillment of a safety function of structures or systems that are needed to mitigate the consequences of an accident. However, the EN was not made until Operations was notified of the surveillance failure. EN 51504 was completed on October 28, 2015, at 1326. This LER is being submitted pursuant to the requirements of 10 CFR 50.73(a)(2)(i)(B) and 10 CFR 50.73(a)(2)(v)(D).

CAUSE OF EVENT

This event was caused by less than adequate procedure guidance and ownership of the surveillance activity by the maintenance shop responsible for performing the work. The direct cause of the TS entry was the filter failure due to aging.

SAFETY CONSEQUENCES AND IMPLICATIONS

The Salem Unit 1 and 2 CREACS is a shared system between Unit 1 and 2 supplying a common Control Room Environment (CRE). The CREACS consists of two independent, redundant trains, one from each unit, that recirculate and filter air in the CRE and a CRE boundary that limits the in-leakage of unfiltered air. Each CREACS train consists of a pre- filter, a high efficiency particulate air (HEPA) filter, an activated charcoal absorber section for removal of gaseous activity, and fans. Following receipt of a Safety Injection or High Radiation actuation signal, one 100 percent capacity fan in each units CREACS will operate in accident pressurized mode with outside air supplied from the non-accident unit air intake duct for continued CRE pressurization.

A single CREACS filtration train is capable of providing adequate removal of post-accident airborne contaminants to ensure radiation exposures in the CRE are limited to 5 REM Total Effective Dose Equivalent (TEDE) or less. The Salem Updated Final Safety Analysis Report (UFSAR) assumes the charcoal filter has a removal efficiency of 95 percent. Vendor performance of multiple analyses of the filter's charcoal methyl iodide penetration indicated that the worst case sample result indicated a greater than 95 percent efficiency. Therefore, the level of degradation of the charcoal filter would not have prevented the filler unit from performing its design safety function.

SAFETY SYSTEM FUNCTIONAL FAILURE

A review of this event determined that a Safety System Functional Failure (SSFF) as defined in Nudear Energy Institute (NEI) 99-02, Regulatory Assessment Performance Indicator Guideline, did not occur.

0001, or byinternet e-mail to Infocdiects.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 im pose 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.

PREVIOUS OCCURRENCES

A review of Salem Unit 1 and 2 Licensee Event Reports forthe previous three years identified no other similar events.

CORRECTIVE ACTIONS

1) The Unit 1 CREACS charcoal filter was replaced, tested, and the CREACS train was returned to service on October 30, 2015.

2) The surveillance procedure will be revised to include an administrative limit for charcoal filter replacement below the TS requirement of less than 2.5% methyl iodine penetration.

3) Other corrective actions are being tracked in the Licensee's Corrective Action Program.

COMMITMENTS

This LER contains no regulatory commitments.