05000483/LER-1917-003, Regarding Violation of Technical Specification 3.6.3, Containment Isolation Check Valve Found in Open Position

Regarding Violation of Technical Specification 3.6.3, Containment Isolation Check Valve Found in Open Position

ML17355A560
Person / Time
Site:	Callaway
Issue date:	12/21/2017
From:	Cox B Ameren Missouri, Union Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ULNRC-06404 LER 17-003-00
Download: ML17355A560 (9)

LER-1917-003, Regarding Violation of Technical Specification 3.6.3, Containment Isolation Check Valve Found in Open Position

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)() 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii)
4831917003R00 - NRC Website

text

Ameren MiSSOURI Callaa Plant December 21, 2017 ULNRC-06404 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 10 CfR 50.73(a)(2)(i)(B)

Ladies and Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

RENEWED FACILITY OPERATING LICENSE NPF-30 LICENSEE EVENT REPORT 2017-003-00 VIOLATION Of TECHNICAL SPECIFICATION 3.6.3 CONTAINMENT ISOLATION CHECK VALVE FOUND IN OPEN POSITION The enclosed Licensee Event Report (LER) is submitted in accordance with 10 CfR 50.73(a)(2)(i)(B) to report a violation of Technical Specification 3.6.3. Containment Isolation Valves due to the inoperability of the inside containment isolation valve for containment penetration P-67.

This letter does not contain new commitments.

If you have any questions concerning this LER, please contact Torn Elwood, Supervising Engineer, Regulatory Affairs arid Licensing at (314) 225-1905.

Sincerely.

Barry L. Cox Senior Director, Nuclear Operations

Enclosure:

LER 2017-003-00 P.O. Box 620 Fulton, MO 65251 AmerenMissouri.com

ULNRC-06404 December XX. 2017 Page 2 of3 cc:

Mr. Scoff A. Morris Acting Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington. TX 7601 1-4511 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission

$201 NRC Road Steedman, MO 65077 Mr. L. John Kios Project Manager. Callaway Plant Office of Nticlear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop O$H4 Washington, DC 20555-0001

ULNRC-06404 December XX. 2017 Page 3 of3 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 6100 Western Place. Suite 1050 Fort Worth, TX 76107 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via LER ULNRC Distribution:

F. M. Diya B. L. Cox T. F. Herrmann S. P. Banker R. C. Wink T. B. Etwood K. A. Mitts M. G. Hoehn Corporate Oversight Corporate Communications NSRB Secretary Performance Improvement CoordInator Resident Inspectors (1JRC)

STARS Regulatory Affairs Mr. Jay Sitberg (Pillsbury Winthrop Shaw Piflman LLP)

Missouri Public Service Commission

NRC FORM 366 US. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPtRES: 0313112020 (04-201/)

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 regarding burden estimate to the Information Services Branch (T-2 F43), US.

kt (See Page 2 for required number of dighs/characturs for each blk)

Nuclear Regulatory Commisson, Washington, DC i0555-0001.

or by e-mail to lntocoflects gov.

and to the Desk

Officer, Office of Information and Regulatory

Affairs, NEOB-10202, 3150.0104), Office of Managnmen) and Budget. Washington, DC 20503. If a means (See NUREG-1 022, R.3 for instruction and guidance for completing this form used to impose an information collection does not display a currently valid 0MB contra) number, http:llwww.nrc.ciov/reading-rm/doc-collections/nuregs/staff/sr1022/r31) the NRC may not conduct or sponsor and a person is not required to respond to, the information collection

3. PAGE Callaway Plant Unit 1 05000483 1 OF 6

4. TITLE Violation of Technical Specification 36.3, Containment Isolation Check Valve Found in Open Position

5. EVENT DATE

6. LER NUMBER

- i

7. REPORT DATE1

8. OTHER FACILITIES INVOLVED SE UENTlAL

FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER REV MONTH DAY YEAR 05000 10 31 2017 2017 003 000 12 29 2017 FACILITYNAME DOCKETNUMBER

9. OPERA11NG MODE

11. THIS REPORT IS SUBMflTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)

Defueled LI 20.2201(b) 0 20.2203(a)(3)C)

LI 50.73(a)(2)()i)(A)

L] 50.73fa)(2)(viii)(A) 0 20.2201(d)

LI 20.2203(a)(3)(ii)

LI 50.73(a)(2)(ii)(B)

LI 50.73(a)(2)(viii)(B)

LI 20.2203(a)(1)

LI 20.2203(a)(4)

LI 50.73(a)(2)(iii)

LI 50.73(a)(2)(ix)(A)

LI 20.2203(a)(2)O)

LI 50.36(c)(1)(i)(A)

LI 50.73(a)(2)(iv)(A)

LI 50.73(a)(2)(x)

10. POWER LEVEL LI 20.2203(a)(2)(ii)

LI 50.36(c)(1)(ii)(A)

LI 50.73(a)(2)(v)(A)

LI 73.7lfa)(4)

LI 20.2203(a)(2)(fli) 0 50.36(c)f2)

LI 50.73(a)(2)(v)(B) 0 73.71(a)(5) 0%

LI 20.2203fa)(2)Øv)

LI 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(C)

LI 73.77(a)(1) 0 20.2203(a)(2)(v)

LI 50.73(a)(2)(i)(A)

LI 50.73(a)(2)(v)(D)

LI 73.77(a)(2)(i)

LI 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B)

LI 50.73fa)(2)(vii)

LI 73.77(a)(2)(ii)

LI 50.73(a)(2)(i)tC)

LI OTHER Specify in Abstraci below or in NRC Form 366A

12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT TELEPHONE NUMBER t(nclude 4rea code)

T.B. Elwood, Supersinngineer Regulatory Affairs and Licensing J314-225-1905______

13. COMPLETE ONE UNE FOR EACH COMPONENT FJLURE DESCRIBED IN THIS REPORT

CAUSE

SYSTEM COMPONENT FACTURER REPORTABLE

CAUSE

l SYSTEM COMPONENT FACTURER TOEPiX B

JM ISV Velan I

14. SUPPLEMENTAL REPORT EXPECTED

15. EXPECTED MONTH DAY YEAR YES (Ifyes, complete 75. EXPECTED SUBMISSION DATE)

NO SUBMISSION L

BSTRACT (Limit to 7400 spaces, i.e.. approximately 15 single-spaced typewntten lines)

Between 4/21/2016 and 11/2/2017, containment isolation valve KCV0478 was inoperable due to an improperly functioning check valve internal assembly (i.e. hanger / disc). This check valve serves as the inside containment isolation valve (CIV) or penetration P-67. The containment isolation integrity function was maintained by KCHVO253, the outer CIV for penetration P-67, during the time KCV0478 was inoperable.

the valve was found in the fully open position on 10/31/2017 (during Refuel 22) after the penetration failed to pressurize for he Local Leak Rate Test (LLRT). The valve appears to have been stuck in the open position from a fire protection system low test conducted on 4/21/2016 during Refuel 21. Technical Specification (TS) 3.6.3 requires each CIV to be OPERABLE n Modes 1 through 4.

In this case, it was not known that the valve was in full open position when the plant entered Mode 4 on 5/5/2016. Therefore, a condition prohibited by TS 3.6.3 subsequently occurred due to failure to comply with the Required Actions specified in the TS for an inoperable CIV.

the root cause of the valve inoperability was dimensional interferences due to inadequate design clearances in the vendor supplied internal assembly (i.e. hanger / disc) on KCV0478. For corrective action, the check valve will be replaced with a new design utilizing corrosion resistant materials.

NRC FORM 366 (04.2017)

1.

DESCRIPTION OF STRUCTURE(S), SYSTEM(S) AND COMPONENT(S):

The issue addressed in this LER concerns the failure of a normally closed check valve that serves as a containment isolation valve (CIV) [EIIS System: JM, Component: ISV]. The affected valve is situated in a fire protection line [EIIS System: KPJ that penetrates containment at penetration P-67 and runs to hose racks / sprinkler inside containment. The containment isolation provisions for this line consist of CIVs inside and outside containment, consistent with the requirements of General Design Criterion (GDC) 56.

In general, the containment isolation valves form part of the containment pressure boundary and provide a means for fluid penetration flow paths not serving accident consequence limiting systems to be provided with two isolation barriers that are closed on a containment isolation signal. These isolation devices are either passive or active (automatic). Manual valves, de-activated automatic valves secured in their closed position (including check valves with flow through the valve secured), blind flanges, and closed systems are considered passive devices. Check valves, or other automatic valves designed to close without operator action following an accident, ate considered active devices.

Two barriers in series are provided for each penetration flow path so that no single credible failure or malfunction of an active component can result in a loss of isolation or inleakage that exceeds limits assumed in the safety analyses. The Limiting Condition for Operation (LCD) of TS 3.6.3, Containment Isolation Valves, applies to ClVs and was derived from the assumptions related to minimizing the loss of reactor coolant inventory and establishing the containment boundary during a design basis accident (DBA).

TS operability requirements for the CIVs support assumptions in the safety analysis of any event requiring isolation of containment. The DBAs that result in a release of radioactive material within containment are a loss of coolant accident (LOCA) and a rod ejection accident.

In the analyses for each of these accidents, it is assumed that CIVs are either closed or function to close within the requited isolation time following event initiation. This ensures that potential paths to the environment through CIVs (including containment shutdown purge and mini-purge valves) are minimized.

KCVO4ZB AND ASSOCIATED PIPING GENERAL OVERVIEW The Reactor Building Fire Protection (FP) water supply is provided by a single 4-inch line that passes through containment penetration P-67. The FP system inside the Reactor Building consists of stand pipes, hose racks and two sprinkler systems (one for each of the Reactor Building cable penetration areas on Elevation 2026).

The configuration of Penetration P-67 consists of a motor-operated, automatic isolation valve outside containment, KCHV0253, and a check valve inside containment, KCV0478, which complies with 10 CFR 50 Appendix A GDC-56, Primary Containment Isolation, for lines that penetrate containment and connect directly to the containment atmosphere.

The P-67 piping is ASME Ill Class 2, 150 PSI, carbon steel schedule 40 piping.

The valves are ASME Ill Class 2, 150 PSI.

Both the piping and valves are seismic Category 1.

Valve KCHV0253 is positioned closed during normal and shutdown plant modes, and is designed to fail in the as is position. It is normally operated remotely from a hand switch in the Control Room. The valve can also be manually operated at the valve. The valve is opened only during local leak rate tests (LLRTs), during quarterly stroke testing, and if the FP system is called upon to mitigate a fire inside containment. Valve KCHVO253 also closes automatically on a containment isolation signal to minimize the release of fission products following an accident.Page 2 of 6

SEQUENTIAL REV NUMBER I

NO 003 000 The administrative containment leakage limit for penetration P-67 is 9,000 standard cubic centimeters per minute (sccm) for KCHV0253 and KCV0478. When KCHVO253 is opened for LLRTs or stroke testing, the upstream manual isolation valves are closed to maintain the Reactor Building FP piping in a dry condition.

KCV0478 Valve Design:U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-Of 04 EXPIRES: 3/31/2020 (04-20171

, the http://www.nrc,gov/readino-rmfdoc-collections/nuregs/staff/sM022/r31)

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

3. LER NUMBER Callaway Plant Unit 1 05000-483 YEAR 2017 ttEALIOR Lr t.C43I ALJ1IL 15ttY Figure 1

- Containment Penetration P-67 Diagram KCV0478 is an ASME Ill Class 2, safety related, swing style check valve. The valve was supplied by Velan Engineering Companies.

Figure 2

- KCV0478 Design Drawing Side View (M-223C-00021)Page3of6U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 3/3112020 104-2017)

, the http://www.nrc.govkeading-rm/doc-collections)nuregs/staff/sr10221r3/)

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

3. LERNUMBER YEAR SEQUENTIAL REV Callaway Plant Unit 1 i 05000-483 NUMBER NO 2017 003 000 the major internal components of valve KCV0478 Consist of a disc and hanger which are attached to the valve body. The

,alve is designed to open with fire water flow from the fire header to the associated Containment building hose racks I sprinkler and to close or be closed in the event of increased Containment pressure that may occur in an accident in Dontainment. The valve body is carbon steel, and the hanger and disc assembly are stainless steel. The original valve disc was carbon steel. Due to susceptibility to Corrosion and challenges with seat leakage during LLRT testing, the disc vas replaced with a stainless steel disc in 1999 (Refuel 10).

Per discussion with the vendor representative during the root cause investigation for the identified valve failure, it was identified that the dimensions of the disc were too large for the application and had the potential to cause the valve to stick in the open position.

In addition, operating experience was documented in which it was identified/inferred or suggested that the tolerances of the hanger assembly could result in the hanger assembly sticking in the open position.

2.

INITIAL PLANT CONDITIONS

When the LLRT was performed for KCV0478 on October 28, 2017, Callaway Plant was in its Refuel 22 outage. The reactor fuel had been removed from the reactor vessel and placed in the spent fuel pool in the fuel building where cooling was provided by the spent fuel pool cooling system. The plant had shut down for the refueling outage on 10/7/2017. The LLRT on KCV0478 was performed as part of the normally scheduled surveillance for containment isolation valves.

3.

EVENT DESCRIPTION

On October 28, 2017, during Refuel Outage 22, test pressure could not be obtained during the KCV0478 as-found LLRT for containment penetration P-67. Subsequently, on October 31, 2017, during internal inspection of KCV0478, the internal valve disc / hanger assembly was found to be stuck in the fully open position. Upon removal, the valve hanger /

disc assembly was inspected for damage and any possible sign of cause.

No issues were reported with the hanger / disc assembly, as it was verified to move freely with no discernable damage.

The internal surface of the valve body was cleaned to remove corrosion products. Upon reinstallation of the hanger I disc assembly into KCV0478, the valve internal assembly was stroked I actuated several times manually (with a hanger connected to the valve hanger). After verification of freedom of movement, and hanger! disc measurements, the valve was reassembled. All post maintenance testing (external leak test and LLRT) was completed successfully with satisfactory results.

Prior to finding KCV0478 stuck open on October 31, 2017, the last time KCV0478 was verified to be in the closed position was in RF21 during performance of a LLRT on April 18, 2016. Soon after this LLRT, records show that a flow test of the fire water header to containment was performed on April 22, 2016 via containment penetration P-67 and KCV0478. This test provided sufficient flow to take the valve to its fully open position. Based upon the identification of no other testing, operational line-ups or system transients associated with P-67 or KCV0478 that could have fully opened the valve, prior to Refuel Outage 22, it is likely that KCV0478 was fully open for the entirety of Cycle 22.

As a result of KCV0478 potentially being in the fully open position since the fire protection system flow test on April 22, 2016, it was identified that KCV0478 should have been declared inoperable (incapable of supporting its containment isolation safety function) and that the applicable Conditions and Required Actions under TS 3.6.3 should have been entered. Without knowledge of the condition of the valve, entry into the applicable Conditions and Required Actions under TS 3.6.3 was missed, resulting in a reportable condition.

NRC FORM 3&EA tO6-201e)

Page 4 of 6U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 31 50.0104 EXPIRES: 313112020 t04-2017)

Estimated bcrdes 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 ticensing process and ted back to industry. Send LICENSEE EVENT REPORT ( L ER) comments regarding burden estimate to the Information Services Branch (T-2 F43). U.S.

Nuclear

\\

Regulatory Commission, Washington, DC 20555-0001, or by e.mail to Intocollects Resource@nrc gos, and Is the Desk Officer, Office of Intormation and Regulatory Affairs, V

NEQB-10202. t3i50-0104), Office ot Management and Budget. Washington, DC 20503 If a means (See NUREG-1 022, R.3 for tnstructton and guidance for completing this form used to impoee as information collection does not display a currently valid 0MB control number, the http://www.nrc.gov/reading-rrn/doc-coHections/nuregs/staff/sr1022/r3 NRC may not conduct or sponsor, and a person is not required Is respond to. the information collection.

1. FACILITY NAME

2. DOCKETNUMBER

3. LERNUMBER YEAR SEQUENTIAL REV Callaway Plant Unit 1 05000-483 NUMBER NO 2017 003 000 4.

ASSESSMENT OF SAFETY CONSEQUENCES

With KCV0478 in a fully open position, the containment isolation function is adversely impacted. As discussed previously, KCV0478 is one of three valves associated with P-67 (i.e.

in addition to KCHV0253 and KCV0431).

In this case, it was not known that KCV0478 was in fully open position when the plant entered Mode 4 on 5/5/2016.

In addition to the mode change with an inoperable CIV, the IS Required Action to isolate the affected penetration flow path by use of at least one closed and de-activated automatic valve (within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />), was not met (as explained further below). Therefore, the event is reportable under 10 CFR 50.73(a)(2)(i)(B), i.e., for an operation or condition prohibited by the plants Technical Specifications. An LER is consequently required.

Despite the inoperability of KCV0478 for an extended period of time1 the event is not considered to be a degraded or unanalyzed condition that significantly affected plant safety pet 10 CFR 50.73(a)(2)(ii) since the containment isolation/integrity function was maintained by KCHVO253, the outer containment isolation valve for penetration P-67. The total containment as-found minimum pathway leak rate remained within the limits of TS 3.6.1 during the timeframe when KCV0478 was inoperable, and for this reason, the event/condition was of low safety significance.

5.

REPORTING REQUIREMENTS

This LER is submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) to report a condition prohibited by Technical Specifications.

Specifically, with KCV0478 inoperable, Condition A of TS 3.6.3 would have been required to be entered. This Condition is applicable to penetration flow paths having two containment isolation valves (which is the case for P-67 and its associated penetration flow paths, particularly the KCV0478-KCHVO253 penetration flow path).

Per Condition A, for one or more penetration flow paths with one containment isolation valve inoperable, Required Actions A.1 and A.2 must be entered.

Required Action A.1 requires isolating the affected penetration flow path by use of at least one de-activated automatic valve, closed manual valve, blind flange, or check valve with flow secured through the valve, within a specified Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Required A.2 requires verifying that the affected penetration flow path is isolated within a specified Completion Time of 31 days (for isolation devices outside containment). With either (or both) of these Completion Times and Required Actions not met, Condition E applies and its Requited Actions E.1 and E.3 become applicable. These Required Actions require the plant to be shutdown such that per Required Action El, the plant must be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and per Required Action E.2, the plant must be in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

Since KCV0478 was not known to be inoperable when the plant entered the Applicability of LCD 3.6.3 upon restart from Refuel 21 (assuming the condition existed at the time), the above-noted Conditions and Required Actions were not entered and thus not met. Compliance with Required Action Al, in particular, would have required CIV KCHVO253 to be closed and deactivated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. With Required Action A.1 not met within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the plant would have been required to be in Mode 3 within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> per Requited Action El, and in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

It may also be noted that a violation of LCO 3.0.4.a occurred in connection with the plant entering the Applicability of LCD 3.6.3, with the assumed valve inoperability. With an LCD not met, LCD 3. 0.4.a only permits entry into the Applicability of that LCD when the associated Actions to be entered permit continued operation in the applicable Mode for an unlimited period of time. This provision would only have been met if Required Actions A.1 and A.2 of LCD 3.6.3 had been met.Page 5 of 6U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 3/31/2020 (04-2017)

Estimated burden per response to compty with this mandatory collechon request 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reporred lessons learned are incorporated into the licensing process ad fed back to industry. Send

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LICENSEE EVENT REPORT ( L ER) comments regarding borden estimate to the leformation Services Branch (1-2 F43). U S.

Nuclear

• I Regulatory Commission, Washington, DC 20555-0001, or by e-mail to

)nfocollecto Pesource@nrc gus, 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 (See NUREG-1 022, R.3 for instruction and guidance for completing this form cued to impose an information collection does not display a currently uaid DM0 control number, the http://www.nrc.govfreading-rm/doc-collections/nuregs/staff/sr1O22/r3 NRC may not conduct or sponsor, and a person in nst required to respond to, the information collection.

3. LER NUMBER YEAR NTiALR Callaway Plant Unit 1 05000-483 NUMBER NO 2017 003 000 6.

CAUSE OF THE EVENT

The reported condition is the result at dimensional interferences due to inadequate design clearances in the vendor supplied internal assembly (i,e. hanger / disc) for KCV0478. The inadequate design clearances resulted in excessive (i.e.

outside of approved design) contact of the KCV0478 internal assembly with the valve body.

7.

CORRECTIVE ACTIONS

The immediate corrective action was to clean the valve, disc, and hanger assembly and successfully re-perform the LLRT. The planned corrective action to prevent recurrence (CAPR) is to replace check valve KCV0478 with a new design utilizing corrosion resistant materials (e.g. stainless steel). Critical dimensions are to be requested and obtained from the vendor for the new valve and they will be incorporated into applicable work instructions to be used for verification of proper design clearances during initial inspection/installation and future maintenance on KCV0478.

The following actions are being taken to ensure the issue does not re-occur until the above CAPR is complete.

a)

Revise FP full-flow preventive maintenance (PM) test to include a task to perform a post-test LLRT.

b)

Generate new PM to clean check valve KCV0478 every outage.

c)

Install or verify the stainless steel disc is still within the vendor provided dimensions in KCV0478 in RF23.

d)

Inspect the KCV0478 hanger in the installed configuration to ensure no dimensional interference exists between the hanger stop and valve body.

If contact is identified that could impact valve closure, adjust / modify hanger or valve body to ensure KCV0478 internal assembly on the hanger stop is not susceptible to binding and/or the valve will freely move in the open/closed direction as designed.

e)

Administrative controls are in place to ensure the actions of TS 3.6.3 are taken for penetration P-67 if water is flowed through KCV0478. This will ensure the penetration is isolated and compliance with TS 3.6.3 actions are met.

8.

PREVIOUS SIMILAR EVENTS

Based upon a review of available internal QE, Callaway had an opportunity to address the condition identified with KCV0478 in Refuel 10 (1999) when the valve internal assembly stuck after replacing the disc assembly. Actions were taken that verified successful operation of the valve in the closed / open direction. However, the cause of the event was not fully understood, and as a result, the issue was not fully addressed, thus leading to recurrence of this issue.

LER 2010-007-00 documents a violation of TS 3.6.3 where the failure to adequately implement administrative controls for opening a normally closed containment isolation valve was identified. While the LER is associated with the same IS, the cause is completely unrelated and the corrective actions taken would not have prevented the KCV0478 event.Page 6 of 6