ML16146A018

Special Report 296/2016-001 for Inoperable Post Accident Monitoring (PAM) Instrumentation

ML16146A018
Person / Time
Site:	Browns Ferry
Issue date:	05/25/2016
From:	Bono S Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SR 296/2016-001
Download: ML16146A018 (2)

Text

Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 May 25, 2016 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington , D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 3 Renewed Facility Operating License No. DPR-68 NRC Docket No. 50-296

Subject:

Browns Ferry Nuclear Plant (BFN) - Special Report 296/2016-001 for Inoperable Post Accident Monitoring (PAM) Instrumentation In accordance with Technical Specification (TS) 5.6.6, PAM Report, this letter provides notification of a PAM instrument that was not restored to Operable status within 30 days as required by TS Limiting Condition for Operation (LCO) 3.3.3.1, Post Accident Monitoring (PAM) Instrumentation.

BACKGROUND INFORMATION:

On April 11 , 2016, it was determined that the Suppression Pool Water Temperature Element (TE), 3-TE-064-01628, was not functioning properly. This TE causes PAM instruments 3-Tl-064-0162 and 3-TR-064-0162 to read erratically. The instrument was declared inoperable. The Actions of TS LCO 3.3.3.1 were entered.

BFN Unit 3 TS LCO 3.3.3.1 requires two channels of suppression pool temperature monitoring to be Operable in Modes 1 and 2. With one required channel inoperable, TS 3.3.3.1 Required Action A.1 directs the required channel to be returned to Operable status in 30 days. If the required channel cannot be restored to Operable status in the required time period, TS 3.3.3.1 Required Action B.1 requires actions to be initiated in accordance with TS 5.6.6, PAM Report.

The 30 day action completion time for TS LCO 3.3.3.1 was exceeded on May 11 , 2016.

This issue was compounded by the unavailability of replacement TE, as it is obsolete.

CAUSE OF THE INOPERABILITY:

The instrument, 3-TE-064-01628, was declared inoperable due to erratic or false high temperature inputs to the suppression pool bulk temperature recorder and indicator.

Troubleshooting determined that the temperature modifier from the temperature element was the source of the erratic behavior. The root cause of the erratic temperature modifier behavior has yet to be determined. Repeated attempts to correct the readings were

U.S . Nuclear Regulatory Commission Page 2 May 25, 2016 unsuccessful within 30 days, as required by TS LCO 3.3.3.1 , Condition A , restore required channel to OPERABLE status.

PREPLANNED ALTERNATE MONITORING METHOD:

There are two separate channels available to provide suppression pool water temperature ,

3-T-064-0161and3-T-064-0162. Suppression Pool Water Temperature Recorder, 3-TR-064-0161 , remained Operable and was used for monitoring until 3-TE-064-0162B is replaced . A preplanned alternate monitoring method is not required at this time.

PLANS AND SCHEDULE FOR RESTORING THE INSTRUMENT CHANNEL:

The subject PAM instrument was returned to operable status on May 24, 2016 .

There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal , please contact J. L. Paul , Nuclear Site Licensing Manager, at (256) 729-2636.

S. M. Bono Site Vice President cc:

NRC Regional Administrator - Region II Senior Resident Inspector - Browns Ferry Nuclear Plant

Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 May 25, 2016 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington , D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 3 Renewed Facility Operating License No. DPR-68 NRC Docket No. 50-296

Subject:

Browns Ferry Nuclear Plant (BFN) - Special Report 296/2016-001 for Inoperable Post Accident Monitoring (PAM) Instrumentation In accordance with Technical Specification (TS) 5.6.6, PAM Report, this letter provides notification of a PAM instrument that was not restored to Operable status within 30 days as required by TS Limiting Condition for Operation (LCO) 3.3.3.1, Post Accident Monitoring (PAM) Instrumentation.

BACKGROUND INFORMATION:

On April 11 , 2016, it was determined that the Suppression Pool Water Temperature Element (TE), 3-TE-064-01628, was not functioning properly. This TE causes PAM instruments 3-Tl-064-0162 and 3-TR-064-0162 to read erratically. The instrument was declared inoperable. The Actions of TS LCO 3.3.3.1 were entered.

BFN Unit 3 TS LCO 3.3.3.1 requires two channels of suppression pool temperature monitoring to be Operable in Modes 1 and 2. With one required channel inoperable, TS 3.3.3.1 Required Action A.1 directs the required channel to be returned to Operable status in 30 days. If the required channel cannot be restored to Operable status in the required time period, TS 3.3.3.1 Required Action B.1 requires actions to be initiated in accordance with TS 5.6.6, PAM Report.

The 30 day action completion time for TS LCO 3.3.3.1 was exceeded on May 11 , 2016.

This issue was compounded by the unavailability of replacement TE, as it is obsolete.

CAUSE OF THE INOPERABILITY:

The instrument, 3-TE-064-01628, was declared inoperable due to erratic or false high temperature inputs to the suppression pool bulk temperature recorder and indicator.

Troubleshooting determined that the temperature modifier from the temperature element was the source of the erratic behavior. The root cause of the erratic temperature modifier behavior has yet to be determined. Repeated attempts to correct the readings were

U.S . Nuclear Regulatory Commission Page 2 May 25, 2016 unsuccessful within 30 days, as required by TS LCO 3.3.3.1 , Condition A , restore required channel to OPERABLE status.

PREPLANNED ALTERNATE MONITORING METHOD:

There are two separate channels available to provide suppression pool water temperature ,

3-T-064-0161and3-T-064-0162. Suppression Pool Water Temperature Recorder, 3-TR-064-0161 , remained Operable and was used for monitoring until 3-TE-064-0162B is replaced . A preplanned alternate monitoring method is not required at this time.

PLANS AND SCHEDULE FOR RESTORING THE INSTRUMENT CHANNEL:

The subject PAM instrument was returned to operable status on May 24, 2016 .

There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal , please contact J. L. Paul , Nuclear Site Licensing Manager, at (256) 729-2636.

S. M. Bono Site Vice President cc:

NRC Regional Administrator - Region II Senior Resident Inspector - Browns Ferry Nuclear Plant