ML20212A036

Notice of Violation from Insp on 970712-0827.Violation Noted:As of 970717,10 of 48 Ice Condenser Inlet Doors on Unit 2 Required Initial Opening Torque in Ixcess of 675 inch-pound Operability Limit

ML20212A036
Person / Time
Site:	Mcguire, McGuire
Issue date:	10/08/1997
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20212A022	List: IR 05000369/1997016 ML20212A036
References
50-370-97-16, NUDOCS 9710230141
Download: ML20212A036 (33)

Text

_

NDTICE OF VIOLATION Duke Energy Cor Docket No.: 50-370 McGuire Unit ? poration License No.: NPF-17 EA 97-398 During an NRC inspection conducted on July 12 - August 27. 1997, a violation I of NRC requirements was identified. In accordance with the " General Statement of Policy and Procedures for NRC Enforcement Actions " NUREG-1600 the viola-tion is listed below:

Technical Specification 3/4.6.5.3 requires, in part, that the ice condenser inlet doors be operable when in Modes 1. 2. 3. and 4. and that the torque recuired to initially open each door be less than or equal to

! 675 inch-pouncs.

I Contrary to the above, as of July 17.1997.10 of 48 ice condenser inlet doors on Unit 2 required an initial opening torque in excess of the 675 inch-pound operability limit. This condition resulted in the ice condenser system being in a degraded condition that could have existed for an extended period of time between May 1996 (completion of the end-of-cycle 10 refueling outage) and July 11. 1997 (low reactor coolant system flow trip) with Unit 2 operating in Modes 1. 2, 3. and 4.

This is a Severity tevel IV violation (Supplement I).

Pursuant to the provisions of 10 CFR 2.201, the Duke Energy Corporation (Licensee) is required to submit a written statement or explanation to the U. S. Nuclear Regulator.y Commission. ATTN: Document Control Desk. Washington.

D. C. 20555 with a copy to the Regional Administrator. Region II. and a copy to the NRC Resident Inspector at the McGuire facility, within 30 days of the date of the letter transmitting this Notice of Violation (Notice). This reply should be clearly marked as a "Re)ly to Notice of Violation" and should include for the violation: (1) t1e reason for the violation, or, if contested, the basis for disputing the violation. (2) the corrective steps that have been taken and the results achieved. (3) the corrective steps that will be taken to avoid further violations, and (4) the date when full compliance will be achieved. Your response may reference or include previously docketed correspondence. if the correspondence adequately addresses the required response. If an adequate reply is not received within-the time specified in this Notice, an order or Demand for Information may be issued as to why the license should not be modified, sus) ended, or revoked, or why such other action as may be proper should not be taten. Where good cause is shown, consideration will be given to extending the response time.

Because your res)onse will be placed in the NRC Public Document Room (PDR), to the extent possi ale, it should not include any personal privacy. 3roprietary, or safeguards information so that it can be placed in the PDR wit 1out redaction. If personal privacy or proprietary information is necessary to provide an acceptable response, then please provide a bracketed copy of your response that identifies the information that should be protected and a redacted copy of your response that deletes such information. If you request 971023o141 971008 Enclosure 1 DR ADOCK0500g9

e Notice of Violation 2 withholding of such material. you myS1 specifically identify the portions of your response that you seek to have withlelo and provide in detail the bases for your claim of withholding (e.g. , explain why the disclosure of information will create an unwarranted invasion of personal privacy or provide the information required by 10 CFR 2.790(b) to support a request for withholding confidential commercial or financial information). If safeguards information is necessary to provide an acceptable response, please provide the level of protection described in 10 CFR 73.21.

Dated at Atlanta. Georgia this 8th day of October 1997

E ,

List of Conference Attendees Duke Enerav Corocration B. Barron. Site Vice President. McGuire Nuclear Station (MNS)

P. Herran. Site Engineering Manager. MNS B. Travis, Mechanical Systems Engineering Manager, MNS A. Smith System Engineer. MNS R. Spada. Equipment / System Engineer MNS M. Cash Regulatory Compliance Manager. MNS R. Zuercher. Duke Energy Public Affairs Nuclear Reaulatory Commission L. Reyes Regional Administrator. Region II (RII)

B. Mallett. Acting Deputy Regional Administrator. RII l L. Plisco. Deputy Director. Division of Reactor Projects (DRP). RII C. Casto. Deputy Director. Division of Reactor Safety. RII C. Ogle. Chief. Branch 1. DRP. RII A. Boland. Director. Enforcement and Investigations Coordination Staff (EICS). RII C. Evans. Regional Counsel . RII V. Nerses. Senior Project Manager. Project Directorate 11-2 Office of Nuclear Reactor Regulation (NRR)

S. Shaeffer. Senior Resident Inspector - McGuire. Branch 1. DRP RII R. Carroll. Senior Project Engineer. Branch 1. DRP. RII L. Watson. Enforcement Specialist. EICS, RII B. Uryc. Senior Enforcement Specialist. EICS, RII R. Bernhard. Senior Reactor Analyst. DRS. RII R. Hannah. Public Affairs Officer. RII Enclosure 2

NRC 03EN 3REDECISI0hA_

ENIORCEV ENT CON ERENCE MCGUIRE NUC_ EAR S A- ION UNI 2 i

Doc (et No. 50-370

_icense No. N3F-17 INO3ERABLE UNIT 2 ICE CONDENSER IN_ET DOORS OC 0BER 1, 1997 Enclosure 3

PREDECISIONAL ENFORCEMENT CONFERENCE AGENDA HCGUIRE NUCLEAR STATION OCTOBER 1, 1997, AT 10:30 A.M.

NRC REGION II 0FFICE - ATLANTA, GEORGIA I. OPENING REMARKS AND INTRODUCTIONS L. Reyes, Regional Administrato,'

l II. NRC ENFORCEMENT POLICY A. Boland, Director Enforcement and Investigation Coordination Staff III. SLM1ARY OF THE ISSUES i_. Reyes, Regional Administrator IV. STATEMENT OF CONCERNS / APPARENT VIOLATIONS L. Plisco, Deputy Director Division of Reactor Projects V. LICENSEE PRESENTATION VI. BREAK / NRC CAUCUS VII. NRC FOLLOWUP QUESTIONS VIII. CLOSING REMARKS L. Reyes, Regional Administrator 3

APPARENT VIOLATION A. Tecnnical Specification 3/4.6.5.3 requires, in part, that the ice condensor inlet doors be operable when in Modes 1,2,3, '

and 4, and that the torque required to initially open each door be less than or equal to 675 inch-pounds.

1 As of July 17,1997,10 of 48 ice condenser inlet doors on Unit 2 required en initial opening torque in excess of the 675 inch-pounr' operability limit. This condition resulted in the ice condenser system being in a degraded condition that could have existed for an extended period of time with Unit 2 operating in Modes 1, 2, 3, and 4.

NOTE: The apparent violations discussed in this predecisional enforcement conference are subject to further review and

' are subject to change prior to any resulting enforcement action- 18

APPARENT VIOLATION B. 10 CFR Part 50, Appendix B, Criterion XVI requires, in part, that measures be established to assure that conditions adverse to quality are promptly identified and corrected.

Prior to July 17,1997, when 10 of 48 Unit 2 ice condenser lower inlet doors were found inoperable, the licensee had failed to take measures to assure that conditions adverse to quality (i.e., possible water intrusion events which could have led to ice condenser floor heave and subsequent door inoperability) were identified and afforded appropriate corrective actions. Specifically, the licensee failed to take adequate corrective actions with respect to industry experience and site-specific operational events to preclude inoperability of the Unit 2 ice condenser lower inlet doors from binding due to floor heave caused by water intrusion and subsequent freezing.

I NOTE: The apparent violations discussed in this predecisional enforcement conference are subject to further review and are subject to change prior to any resulting enforcement action. 19

k _

PRE-DECISIONAL l

l ENFORCEMKST CONFERENCE l

l October 1,1997 k

i Enclosure 4 l

i M--. . . - . - - - . _ _ - _ - . - . _ . . . _ . - . . . . - _ - - _ - . _ . . . .

ICE CO:NDE:NSER LOWER I:NLET DOOR I:NTERFERE:NCE

~d" w.esti snceotneratstr.TATIObTCPTORGMENT CONTTREPCE1G CONDEr5ER 19971TT l

. I Introduction /McGuire Attendees  ;

• Brew Barron, Vice President, McGuire Nuclear Station Pete Herran, Engineering Manager Bruce Travis, System Engineering Manager Mike Cash, Regulatory Compliance Manager Alex Smith, System Engineering Rich Spada, System Engineering cGul

, *C

%2EF1 SRG'OCTMETRESElsTAT10N*ENFORCEMF1 T COtTEREtrENCE COrRPSER 199717T 3

Agenda

• Introduction

• Brew Barron Apparent Violation of Lower

• Bruce Travis Inlet Door Technical i Specification Apparent Violation use of i

• Bruce Travis Operating Experience Corr ^:ve Action Program Conclusions Brew Barron cGul t

l wsri sac'ccueErnEsu: TAT 10MENTORCIMENT CONTIRUCE1CE COFOD6E".1997.TTT 4

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Water intrusion penetrates wear slab surface Water collects in foam concrete and freezes, causing expansion Return to power operation, heat load melts some ice and water migrates lower into the foam concrete Return to cold shutdown, some water in the foam concrete refreezes, causing further expansion Repeated hdatups and cooldowns result in gradual upward movement of wear slab l7 MG HCTGMMSENTATIOtJENTORCEMENT CONERETCENCE CONDOSER 1mm 9

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i Cause of Unit 2 Floor Movement 1 , - --  :

• Water Intrusion Events

- Steam Generator Drain Valve Steam Leak - August 1993 LOOP with PRT Ruptum Disc , Failure - December 1993

• Floor Cooling Abnormalities

- Temperature Controller Drift

- Control Room Annunciator Malfunction om l7 w.censaccantratsrutancutwoactwa r comatrmes camsta wurrr 11

Discovery of Condition

• On 7/12/97, Unit 2 was in mode 5

- Annunciator alarm " Ice Condenser Lower Inlet Door Open" received in Control Room due to ventilation imbalance

- Visual inspection revealed 2 doors open Doors closed, work requests initiated to 11westigate for indication of ice melt or damage

- Doorsloggedinoperable

- PIPinitiated EGUL 1'r WJEFI T>RC'00PMET'RESENTATIONE?EOREMENT CONFEREPL'E1G CONDE?SER 1917.rrr 12 i

Discovery of Condition (mmuma; On 7/16/97 discovered dragging between some lower inlet doors and flashing Cause of dragging thought to be due to ice buildup Testing on 7/17/97 revealed 10 of 48 doors exceeded Tech Spec limit for initial opening force Flashing i1westigation leads to discovery of wear slab cracks and upward nioVenient .

Uplift of the wear slab caused the flashing to contact lower inlet door Yt,NiFI ERG'UONNIEPRESENTATION EfEORCEMENT COrJ'ERrJCETCE COtw*.T.15ER 19971TT 13

9 Immediate Corrective Actions

• Unit 2

- Removed lower flashing

- Z flashing restored to original fit

- Performed survey to establish elevation baseline for floor

- Measured gap distance behveen flashing and wear slab

- Floor cooling system instrumentation checked and repaired

- All lower inlet doors retested with satisfactory results Unit 1

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- Video inspection ,

- Confirmation unit had not been to cold shutdown since mcent door test cGul

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Subsequent Corrective Actions Ptdl test and visual inspection performed on Unit I with satisfactory test results and no wear slab / flashing interaction Weeldy monitoring of floor cooling, parameters Enhanced preventive maintenance program on floor cooling system instrumentation 8

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1 PlannedCorrective Actions Remove Lower Flashing in Unit 1 during next outage

• Establish baseline floor elevation in Unit 1 Establish a program for gap inspec :' ions on each unit prior to return of service out of cold shutdown Evaluate alternative flashing / insulation design Evaluate water removal and floor sealant options ii

%e5F1 ERGVOtMET'RESENTATICNENFORCDAENT CONTREhCE'tCE C&ODEER IWM 17

e Safety Significance Analysis of containment response with 16 doors blocked closed during Large Break LOCA Design basis pressure still met

- Bounds results of smaller LOCAs Bounds actual conditions at McGuire 10 doors dragging Previous analysis of non-uniform door opening during LOCA indicates complete ice melt will occur

- No concern for non-uniform energy deposition in ice

- Insignificant affect on hydrogen ignitem in ice condenser

- Insignificant affect on iodine petitioning in ice condenser r

4tW ERC'CONNIETRESENTATIONEtEORCD fDITCONTIREtCE1CE CONDE?SER 19973TT 38 l

S SequoyahEvent Background l

t

• Wear slab moved 2 3 inches

• Affected 27 of 48 doors in Unit 1,11 of 48 doors on Unit 2 Pervasive floor cracking ,

Turning vane contacted wear slab Floor drain separation from wear slab in some bays i7 MSM ERC'OOtM ET'RESENTAT10NEPJORCEMENT COf41REPJCE'tCE CONDEF5ER 1977.rrr 19

m Sequoya1 Event Root Cause l

1 J oint Sealant Deficiencies 1 Design

- Construction ,

Maintenance Practices which produce large volumes of water Y

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%e5r1 YiRG'UOtMETRESENTATIOPIDEORCEMENT COEEREFCETCE CONDE?SER INJTr 20

'. I McGuire Use ofIndustry Experience l

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• March 1992

- Sequoyah discovered wear slab was contacting lowerinlet doors

- Sequoyah contacted Duke regarding ice condenser problem 1

- Pervasive floor cracking identified by Sequoyah

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l McGuire Use of Industry Experience 4

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• May 1992

- Unit 1 inspected, no cracking I

l J une 1992 i

- Unit 2 inspected, no cracking l - Sequoyah event released via Nuclear Network i

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• September 1992

! - Duke attended Sequoyah presentation regarding ice condenser wear slab rnovernent l - Water intrusion during niaintenance md freeze thaw cycles identified as cause j li

%CSFI FRG nONNIETRESENTATIOffDEGCEMENT CONTTRUEICE CONDD5ER 1997JTT E

McGuire Use of Industry Experience (conuma m

April 1993

- Discovered localized cracking around clevis areas in Unit 1 Duke Power inspected Sequoyah Units 1 and 2 near slab

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Root cause determined to be failure to remove clevis shims 1

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- May1993: Unit 1 shims mmoved

- August 1993: Unit 2 shims removed System Engineering initiated. routine ice condenser walk-downs in 1993 i=

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Summary System Engineering inspects ice condenser following all maintenance or operational events System Engineering maintain,s strong relationship with industry peers Evaluated Sequoyah corrective actions and implemented those deemed effective Ie Mt?6F1 SRCTlONNIEY'RESENTATIOtIETEORCIMENT CONTEREtCE'(CE CONDEPSER 19ETTT b

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Conclusions i

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Apparent Technical Specification Vioh ',n i

- Selfidentified

! - Lowsafetysignificance - ,

. - Effective conective actions to prevent recunence I

• Apparent Operating Experience Violation

- Aggressively pursued industry experience l - Commitment to maintain consistent ice condenser operability l

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cGuir wesrisRc'eOruEs RtsEnrATIONEPEORCratENT C ~XEEREfCE1CE COtOEN;ER IMm 26 i - __ _ _ _ _ _ _ ._ __

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