05000250/LER-2018-001, Inoperable Containment Purge Exhaust Penetration

Inoperable Containment Purge Exhaust Penetration

ML18325A209
Person / Time
Site:	Turkey Point
Issue date:	11/21/2018
From:	Stamp B Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2018-217 LER 2018-001-00
Download: ML18325A209 (4)

LER-2018-001, Inoperable Containment Purge Exhaust Penetration

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
2502018001R00 - NRC Website

text

U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001 Re:

Turkey Point Unit 3 Docket No. 50-250 Reportable Event: 2018-001-00 Date of Event: September 28, 2018 Containment Purge Exhaust Penetration Fails Leak Rate Test November 21, 2018 10 CPR§ 50.73 L-2018-217 The attached Licensee Event Report 05000250/2018-001-00 is being submitted pursuant to the requirements of 10 CPR 50.73(a)(2)(i)(B) to provide notification of the subject event.

If there are any questions, please call Mr. Robert J. Hess at (305) 246-4112.

Sincerely, Brian Stamp Plant General Manager Turkey Point Nuclear Plant Attachment cc:

Regional Administrator, USNRC, Region II Senior Resident Inspector, USNRC, Turkey Point Nuclear Plant Florida Power & Light Company 9760 SW 344 St., Homestead, FL 33035

NRC FORM 366 (04-2018)

NRC FORM 366 (04-2018)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020

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

LICENSEE EVENT REPORT (LER)

(See Page 2 for required number of digits/characters for each block)

(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)

1. Facility Name Turkey Point Unit 3

2. Docket Number 050000250

3. Page 1 OF 3

4. Title Inoperable Containment Purge Exhaust Penetration

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved Month Day Year Year Sequential Number Rev No.

Month Day Year Facility Name N/A Docket Number 05000 09 28 2018 2018 - 001

- 00 11 2018 Facility Name Docket Number N/A 05000

9. Operating Mode 1

)

No Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)

On September 30, 2018, Turkey Point Unit 3 was in Mode 1at 44% power, preparing for the Unit 3 Cycle 30 refueling outage. While performing the Technical Specification surveillance on the containment purge exhaust penetration, PEN 36, failed the as-found local leak rate test (LLRT) with a measurement of 21,000 standard cubic centimeters per minute (sccm), which exceeded the Technical Specification (TS) limit of 13,860 sccm. Review of maintenance history indicates evidence of a similar condition on 9/28/2018, with Unit 3 at 100% power, when a planned LLRT was aborted because of excessive time to achieve a stable test pressure. The containment purge exhaust penetration was inoperable from 9/28/18 at 0920 until 10/01/18 at 1425. Since PEN 36 was not isolated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, TS 3.6.1.7, Action b was not met.

Corrective actions include seat adjustment for POV-3-2602, and seat replacement of POV-3-2603. This event is considered of very minor safety significance since the overall system capability was well within acceptable TS limits.

21

Event Description

On September 30, 2018, Turkey Point Unit 3 was in Mode 1 at 44% power, preparing for the Unit 3 Cycle 30 refueling outage. At approximately 0945, the containment penetration for the purge exhaust failed its as-found local leak rate test (LLRT) Surveillance Requirement was 21,000 standard cubic centimeters per minute (sccm). The Unit 3 purge exhaust penetration TS limit acceptance criterion is 13,860 sccm. Condition Report AR 2282866 was initiated to document this event. Review of maintenance history indicates evidence of a similar condition on 9/28/2018, with Unit 3 at 100% power, when a planned LLRT was aborted because of excessive time to achieve a stable test pressure.

Consequently, it was concluded that the first indication was on 9/28/2018, which exceeds the TS time limit for remedial action. (Condition Report AR 2282628).

The containment purge valves are required to be operable in Modes 1-4. Technical Specifications 3.6.1.7, Action b., requires a valve determined inoperable to be restored to operable status or the penetration is to be isolated such that the system is within allowed limits within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The inoperability of the containment purge exhaust penetration, PEN 36, lasted until October 1, 2018 at 1425, when Unit 3 entered Mode 5, at which time operability of the containment purge exhaust penetration was no longer required. Since the containment purge exhaust penetration was inoperable and not isolated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, TS 3.6.1.7, Action b., was not met, and this event is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B).

Cause of the Event

The most probable cause for rendering PEN 36 inoperable was a challenge with the outside containment isolation purge valve POV-3-2602 at two locations of the disc/seat interface as well as at several additional locations. The valve seat hardening (aging) of the inside containment purge exhaust valve, POV-3-2603, could also have contributed to the inoperability of PEN 36.

Analysis of Safety Significance The containment purge exhaust isolation valves are safety related valves. Containment isolation valves and penetrations are tested to ensure the system performing within allowed limits. Even though the containment purge exhaust penetration failed its LLRT for exceeding TS limit leakage acceptance criteria of 13,860 sccm, the overall containment leakage during the time of inoperability was well within TS limits. The increase in risk during the period of inoperability of penetration 36 is judged to be very small. As such, this event is considered of minor safety significance since the overall containment leakage was well within TS limits. Page 3 of 3 (04-2018)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020

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

LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)

3. LER NUMBER Turkey Point Unit 3 05000-250 YEAR SEQUENTIAL NUMBER REV NO.

2018

- 001

- 00

Corrective Actions

Corrective actions are documented in the condition report for this event, AR 2282866.

These include:

Valve inspection and seat adjustment of the outside containment purge exhaust valve POV-3-2602.

Valve seat replacement for the inside containment purge exhaust valve POV-3-2603.

Failed Components Identified Containment Purge exhaust power operated isolation valves, POV-3-2602 and POV-3-2603.

Similar Events

There were no similar events reported in the past three years for Turkey Point Units 3 and 4.