05000366/LER-2013-005, Regarding Main Steam Isolation Valve Failed to Close During Surveillance Test

Regarding Main Steam Isolation Valve Failed to Close During Surveillance Test

ML13316C079
Person / Time
Site:	Hatch
Issue date:	11/11/2013
From:	Madison D Southern Co, Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-13-2270 LER 13-005-00
Download: ML13316C079 (7)

LER-2013-005, Regarding Main Steam Isolation Valve Failed to Close During Surveillance Test

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3662013005R00 - NRC Website

text

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COMPANY November 11, 2013 Docket Nos.: 50-366 NL-13-2270 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Licensee Event Report 2013-005 Main Steam Isolation Valve Failed to Close During Surveillance Test Ladies and Gentlemen:

In accordance with the requirements of 10CFR50.73(a)(2)(i)(S), Southern Nuclear Operating Company hereby submits the enclosed Licensee Event

Report, This letter contains no NRC commitments. If you have any questions, please contact Greg Johnson at (912) 537-5874.

Respectfully submitted,

$1~J£n l?~d.~

- 6~_

D. R. Madison Vice President - Hatch DRM/stJ Enclosure: LER 2013-005

U. S. Nuclear Regulatory Commission NL-13-2270 Page 2 cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bost, Executive Vice President & Chief Nuclear Officer Mr. D. R. Madison, Vice President - Hatch Mr. B. l. Ivey, Vice President - Regulatory Affairs Mr. B. J. Adams, Vice President - Fleet Operations Mr. M. A. Dowd, Operating Experience Coordinator RTYPE: CHA02.004 U. S. Nuclear Regulatory Commission Mr. V. M. McCree, Regional Administrator Mr. R. E. Martin, NRR Senior Project Manager - Hatch Mr. E. D. Morris, Senior Resident Inspector - Hatch

Edwin I. Hatch Nuclear Plant Licensee Event Report 2013-005 Main Steam Isolation Valve Failed to Close During Surveillance Test

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150*0104 EXPIRES: 10/31/2013 1 (}201 0)

Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments re~arding burden estimate to the Records and FOIA/PJivacy Service Branch ( -5 F53), U.S.

Nuclear Re~ulatory Commission, Washington, DC 20555-0001, or by internet LICENSEE EVENT REPORT (LER) e-mail to in ocollects.resources@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Mana~ement and Budget, Washington, DC 20503. If a means used to impose an in ormation collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to rescond to. the information collection.

PAGE Edwin I. Hatch Nuclear Plant Unit 2 05000366 e-1 OF 4

/1. TITLE Main Steam Isolation Valve Failed to Close During Surveillance Test

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER SEQUENTIAL REV MONTH DAY YEAR YEAR MONTH DAY YEAR NUMBER NO.

FACILITY NAME DOCKET NUMBER 09 13 2013 2013 - 005 -

00 II 12 2013

~. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) o 20.2201 (b) o 20.2203(a)(3)(i) o 50.73(a)(2)(i)(C) o 50.73(a)(2)(vii)

Mode 1 o 20.2201 (d) o 20.2203(a)(3)(ii) o 50.73(a)(2)(ii)(A) o 50.73(a)(2)(viii)(A) o 20.2203(a)(1) o 20.2203(a)(4) o 50.73(a)(2)(ii)(B) o 50.73(a)(2)(viii)(B) o 20.2203(a)(2)(i) o 50.36(c)(1 )(i)(A) o 50.73(a)(2)(iii) o 50.73(a)(2)(ix)(A)

10. POWER LEVEL o 20.2203(a)(2)(ii) o 50.36(c)(1 )(ii)(A) o 50.73(a)(2)(iv)(A) o 50.73(a)(2)(x) o 20.2203(a)(2)(iii) o 50.36(c)(2) o 50.73(a)(2)(v)(A) o 73.71 (a)(4) o 20.2203(a)(2)(iv) o 50,46(a)(3)(ii) o 50.73(a)(2)(v)(B) o 73.71(a)(5) 100 o 20.2203(a)(2)(v) o 50.73(a)(2)(i)(A) o 50.73(a)(2)(v)(C) o OTHER o 20.2203(a)(2)(vi)

~ 50.73(a)(2)(i)(B) o 50.73(a)(2)(v)(O)

Specify in Abstract below or in NRC Form 366A

12. LICENSEE CONTACT FOR THIS LER FACILITY NAME j TELEPHONE NUMBER (Include Area Code)

Edwin I. Hatch I Steven Tipps - Licensing Supervisor 912-537 -5880 MANU-REPORTABLE MANU-REPORTABLE

CAUSE

SYSTEM COMPONENT

CAUSE

SYSTEM COMPONENT FACTURER TO EPIX FACTURER TO EPIX X

SB ISV E095 Yes

14. SUPPLEMENTAL REPORT EXPECTED

15. EXPECTED SUBMISSION 01 15 2014 181 YES (If yes, complete 15. EXPECTED SUBMISSION DATE)

DNa DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)

On September 13, 2013 at 1438 EDT, with the unit in Mode 1 at 100 percent power, the Unit 2 'D' outboard main steam isolation valve (MSIV) failed to move during surveillance testing that involved partial closure testing of the valve. Based on previous operating experience this test result typically indicated a problem with a solenoid used for partial valve closure testing and was not indicative of a problem with the MSIV. A plan was made to cycle the MSIV to the "closed" position and return it to the "open" position during a planned power reduction on September 14,2013. If the failure was indeed due to the test solenoid, the affected MSIV would function as expected after the power reduction.

At 1105 EDT on Septem ber 14, 2013, following power reduction to approximately 65 percent power, the 'D' outboard MSIV failed to close using its control switch. Actions were taken to isolate the MSIV penetration as required by Technical Specifications The cause determination for this condition has not been completed at this time. Maintenance activities were completed and the MSIV underwent rigorous testing with successful results to confirm the operability of the 'D' outboard MSIV. Additional corrective actions will be reported upon completion of the detailed cause determination.

NRC FORM 366 (9-2007)

PRINTED ON RECYCLED PAPER

PLANT AND SYSTEM IDENTIFICATION

General Electric - Boiling Water Reactor Energy Industry Identification System code (ISV) is associated with the MSIV described in this report.

DESCRIPTION OF EVENT

On September 13, 2013 at 1438 EDT, with the unit in Mode 1 at 100 percent power, the Unit 2 '0' outboard MSIV (ISV) failed to move during the partial closure surveillance test. Based on previous operating experience this test result typically indicated a problem with a solenoid used solely for partial valve closure testing and was not considered a problem with the MSIV (ISV). The performance of this surveillance test was scheduled to be performed in conjunction with a planned power reduction to allow the MSIV (ISV) to be fully cycled if necessary to determine if it was functioning properly. At 1105 EDT on September 14, 2013, following the planned power reduction to approximately 65 percent power, a troubleshooting plan was implemented to verify the "partial close" push button was sending the proper Signal to the valve solenoid. A continuity check was completed to ensure the solenoids and wiring were not damaged and that the solenoids were energizing appropriately. Troubleshooting was completed with no anomalies noted in the electrical circuit.

During the initial attempt to fully cycle the '0' outboard MSIV (ISV), it failed to close during testing when using its control switch as part of the fast closure" method for testing the MSIV(ISV). Actions were then taken to isolate the penetration associated with this MSIV (ISV) as required by Technical Specification 3.6.1.3. A decision was made to shut the unit down and cold shutdown was achieved on September 16, 2013. The valve (ISV) remained open until a pressure of approximately 140 psi was applied on top of the air cylinder piston to assist valve closure. The remaining MSIVs (ISV) operated as expected and closed without assistance.

The Unit 2 shutdown allowed the needed access to support continued troubleshooting of the valve.

A visual inspection of the valve revealed some rubbing between the lower spring plate and yoke rod, but no further anomalies with the upper structure were observed. Detailed measurements were taken of the upper structure indicating some misalignment of the actuator and valve stem was I present, but the alignment was determined to be within procedure tolerances. The actuator was subsequently removed and disassembled with no evidence of severe binding or malfunction. No foreign material was observed. The valve (ISV) was unpacked and the stem inspected with no galling, scoring or abnormal wear conditions noted. The valve (ISV) was repacked and the upper structure was replaced with new components. The lower spring plate and several spacer rings were reused after passing inspection. An Air Operated Valve flow scan was performed with no anomalies noted regarding its seating forces or seating characteristics. The valve (ISV) passed a Local Leak Rate Test (LLRT) with a leakage rate of 18 standard cubic feet per hour, well below the acceptance criteria of 52.1 standard cubic feet per hour.

A "partial closure" test was successfully performed for this valve (ISV) after the upper structure was replaced, and operability testing of the valve (ISV) was completed prior to startup which included stroking the valve to confirm it met required valve (ISV) closure time acceptance criteria. When the valve (ISV) returned to near operating temperatures, the "partial closure" test failed; however, a successful fast closure" test confirmed its isolation capability. Based on this subsequent "partial closure" test failure, the root cause team included consideration of thermal growth and vendor LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION (10-2010)

CONTINUATION SHEET

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2. DOCKET

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NUMBER LNUMBER Edwin I. Hatch Nuclear Plant Unit 2 05000-366 3

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2013 005 00 tolerances as possible contributors to the failure of the valve (ISV). All Unit 2 MSIVs (lSV) were tested successfully after the Unit 2 shutdown. A rigorous test plan was established and is in effect to demonstrate continued reliability of the valve (ISV).

CAUSE OF EVENT

A root cause determination is being performed for this event but the report has not been completed.

The most likely direct cause of the most recent and initiating event is thermal binding. Since the valve (ISV) has reached thermal equilibrium no further thermal binding is expected.

REPORTABILITY ANALYSIS And SAFETY ASSESSMENT The '0' MSIV (ISV) failed to pass the "partial closure" surveillance test with the unit at 100 percent power. As previously discussed, Hatch operating experience with previous test failures using the "partial closure" test method were found to be caused by a failure of a test solenoid. After making a planned power reduction shift management performed the surveillance procedure to cycle the valve (ISV) closed in order to demonstrate the isolation capability of the MSIV (ISV) with the expectation that the "fast close" test would be successful. Instead the MSIV (ISV) failed to close via the "fast close" method. If either test had been successful, operability would have been confirmed and Technical Specifications surveillance requirements would have been satisfied. Since the failure of the "fast close" test occurred nearly 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the "partial closure" test, this failure served as firm evidence that the MSIV (ISV) had been inoperable at least since the time of the "partial closure" test. Since there was firm evidence that the valve (ISV) was inoperable for a time frame longer than the completion time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to isolate the penetration as required by the Technical Specifications, this condition is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specification 3.6.1.3, which states "Each PCIV, except reactor building-to-suppression chamber vacuum breakers, shall be OPERABLE.

Since the redundant MSIV (ISV) in that penetration remained operable throughout this event, isolation capability of the penetration and thereby its safety function was maintained. Based on this information this event was determined to have very low safety significance.

CORRECTIVE ACTIONS

Valve (ISV) maintenance was performed as well as a successful LLRT. A slow closure test was successfully performed for this valve (ISV) after the upper structure was replaced. Further, operability testing of valve (ISV), including stroking the valve (ISV) to confirm it met required valve closure acceptance criteria, was completed prior to startup. When the valve (ISV) returned to near operating temperatures, another test failure was experienced while performing the partial closure test. Based on this subsequent event, the root cause team included the consideration of thermal growth and vendor tolerances as possible contributors to the initial failure of the valve (ISV). All Unit 2 MSIVs (ISV) were successfully tested after the Unit 2 shutdown. A rigorous test plan is in effect to demonstrate continued reliability of the valves.

The valve (ISV) was determined to be capable of performing its intended safety function based on (1) the confirmation that the test and control circuits were properly working, (2) the confirmation that the pneumatic and hydraulic control systems were functioning properly, (3) the confirmation that the mechanical alignment was within procedural tolerances, (4) the absence of galling or scoring on the valve stem, (5) the replacement of components in the upper structure and reconditioning of the lower LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION (1 (}-2010)

CONTINUATION SHEET

1. FACILITY NAME

2. DOCKET

6. LER NUMBER

3. PAGE SEQUENTIAL IREVISION YEAR NUMBER l NUMBER Edwin I. Hatch Nuclear Plant Unit 2 05000-366 f

4 OF 4

2013 005 00 stem plate bushings, (6) the performance of a successful flow scan and LLRT, (7) the successful stroking of the valve (ISV) within its Technical Specification acceptance criteria, and (8) the implementation of compensatory measures included in the associated operability determination.

Based on the preceding information as well as the successful completion of two "partial closure" and one "fast closure" tests of the valve (ISV) there is reasonable assurance the valve can continue to perform its safety function.

Final corrective actions have not been finalized, but a design change package to replace the valves (ISV) is under consideration. Additional corrective actions will be provided once the Root Cause report is completed.

ADDITIONAL INFORMATION

Other Systems Affected: None

Failed Components Information

Master Parts List Number:

2B21 F028D EllS System Code: SB Manufacturer: Edward Valves Reportable to Epix: Yes Model Number: Fig 1612 Root Cause Code: X JMMNTY Type: Flite Flow Stop Valve EllS Component Code: ISV Manufacturer Code: E095 Commitment Information: This report does not create any new permanent licensing commitments.

Previous Similar Events

A review of LERs and Corrective Action Program documents did not reveal any events similar to those discussed in this re~ort within the last three :lears.