ML20206M184

Informs That on 990428,staff Conducted Conference Call with Duke Energy Corp Personnel to Discuss Info Related to SG Tube Insp at McGuire Nuclear Station,Unit 2

ML20206M184
Person / Time
Site:	Mcguire
Issue date:	05/11/1999
From:	Rinaldi F NRC (Affiliation Not Assigned)
To:	NRC
References
TAC-MA4703, NUDOCS 9905140210
Download: ML20206M184 (7)

Text

,

a: May 11, 1999 f

LICENSEE: . Duke Energy Corporation FACILITIES: McGuire Nuclear Station, Unit 2 l

SUBJECT:

CONFERENCE CALL

SUMMARY

OF APRIL 28,1999, REGARDING l STEAM GENERATOR TUBE INSPECTION (TAC NO. MA4703)

REFERENCE:

Memorrndum to Docket Fi!e by F. Rinaldi, dated February 22,1999, with Attachment - Questions: Steam Generator Tube inspection Results On April 28,1999, the staff conducted a conference call with Duke Energy Corporation (DEC/ licensee) personnel to discuss information related to the steam generator tube inspection

~a t the McGuire Nuclear Station, Unit 2; The conference call was requested and scheduled by the NRC staff. This McGuire Unit 2 outage inspection is the first since the replacement of the A, B, C, and D steam generators. The licensee performed 100 percent full-length inspection that was completed with a bobbin probe. All tubing indications were inspected with a Plus Point

- Motorized Rotating Pancake Coil (MRPC) probe, except as noted. DEC indicated that it may perform a 20 parcent MRPC during next outage. Enclosure 1 lists the conference call 1

participants. Enclosure 2 provides DEC's answers to the NRC's questions. This summary '

closes TAC No. MA4703. '

i Original signed by:

Frank Rinaldi, Project Manager, Section 1  ;

Project Directorate 11-2 Division of Licensing and Project Management Office of Nuclear Reactor Regulation Docket No. 50-370

Enclosures:

As stated t t

cc w/encls: See next page 9905140210 990511 PDR I G ADOCK 05000370 I pg \ g DOCUMENT NAME: C:\MCGUIRE\MA4703.WPD To receive a copy of this document, indicate in the box C= Copy w/o attachment / enclosure E= Copy with attachment / enclosure N = No copy - -

OFFICE PDil-1/PM ~ PDil-1/LA PDil/SC i d NAME FRinaldi:en CHawes OM REmcip!

DATE- 'f/1///99 [ /lD /99 - [/ ll /99 OFFICIAL RECORD COPY

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% May 11, 1999 l

LICENSEE: Duke Energy Corporation FACILITIES: McGuire Nuclear Station, Unit 2

SUBJECT:

CONFERENCE CALL

SUMMARY

OF APRIL 28,1999, REGARDING STEAM GENERATOR TUBE INSPECTION (TAC NO. MA4703)

REFERENCE:

Memorandum to Docket Fils by F. Rinaldi, dated February 22,1999, with Attachment - Questionsi: Steam Generator Tube inspection Results On April 28,1999, the staff conducted a conference call with Duke Energy Corporation  ;

(DEC/ licensee) personnel to discuss information related to the steam generator tube inspection I

at the McGuire Nuclear Station, Unit 2. The conference call was requested and scheduled by j

the NRC staff. This McGuire Unit 2 outage inspection is the first since the replacement of the A, B, C, and D steam generators. The licensee performed 100 percent full-length inspection that was completed with a bobbin probe. All tubing indications were inspected with a Plus Point l Motorized Rotating Pancake Coil (MRPC) probe, except as noted. DEC indicated that it may perform a 20 percent MRPC during next outage. Enclosure 1 lista the conference call l participants. Enclosure 2 provides DEC's answers to the NRC's questions. This summary J I

closes TAC No. MA4703. i i

j- +e6

, l Frank Rinaldi, Project Manager, Section 1 l Project Directorate 11-2 I

Division of Licensing and Project Management Office of Nuclear Reactor Regulation Docket No. 50-370

^

Enclosures:

As stated cc w/encls: .See next page I

m 1 1

McGuire NUcinr St: tion i

l CC:

Ms. Lisa F. Vaughn Ms. Karen E. Long Legal Department (PBOSE) - Assistant Attorney General L Duke Energy Corporation North Carolina Department of l 422 South Church Street Justice l Charlotte, North Carolina 28201-1006 P. O. Box 629 l Raleigh, North Carolina 27602

(_

County Manager of Mecklenburg County L. A. Keller 720 East Fourth Street Manager - Nuclear Regulatory Charlotte, North Carolina 28202 Licensing Duke Energy Corporation l Michael T. Cash 526 South Church Street l Regulatory Compliance Manager Charlotte, North Carolina 28201 1006 1 Duke Energy Corporation l McGuire Nuclear Site Elaine Wathen, Lead REP Planner 12700 Hagers Ferry Road Division of Emergency Management Huntersville, North Carolina 28078 116 West Jones Street

! Raleigh, North Carolina 27603-1335 l J. Michael McGarry, Ill, Esquire Winston and Strawn Mr. Richarri M. Fry, Director  ;

1400 L Street, NW. Division of Radiation Protection l Washington, DC 20005 North Carolina Department of Environment, Health and Natural l- Senior Resident inspector Resources l l - c/o U.S. Nuclear Regulatory Commission 3825 Barrett Drive t

12700 Hagers Ferry Road Raleigh, North Carolina 27609-7721 l Huntersville, North Carolina 28078 Mr. T. Richard Puryear Dr. John M. Barry Owners Group (NCEMC) l Mecklenberg County Duke Energy Corporation Department of Environmental 4800 Concord Road Protection York, South Carolina 29745 700 N. Tryon Street Charlotte, North Carolina 28202 Mr. H. B. Barron Vice President, McGuire Site Mr, Steven P. Shaver Duke Energy Corporation Senior Sales Engineer 12700 Hagers Ferry Road Westinshouse Electric Company- Huntersvile, NC 28078-8985 5929 Carnegie Blvd.

Suite 500 Charlotte, North Carolina 28209

y 3 c

LIST OF PARTICIPANTS CONFERENCE CALL WITH DUKE ENERGY CORPORATION APRll 28.1999 '

NAME AFFIL'lATION Frank Rinaldi NRC/NRR/ Project Directorate 11-2, Section 1 John Tsao NRC/NRR/EMCB i Andrea Kime NRC/NRR/EMCB Cheryl Beardslee NRC/NRR/EMCB Mike Cash Duke Energy Corporation, Regulatory Compliance Julius Bryant Duke Energy Corporation, Regulatory Compliance

' Keith Davis Duke Energy Corporation, Technical Group Jerry Crump Duke Energy Corporation, Technical Group Enclosure 1

v i

i I

l McGuire Nuclear Station. Unit 2 1 l

Questions and Responses - Steam Generator (S/G) Tube inspection Results for End-of-Cvele 12 l

1. Primary-to-secondary leakage prior to shutdown? I l

ANS: Zero primary to-secondaryleakage observed.

I

2. Results of secondary side hydro.

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^

ANS: Secondary side hydro not performed due to zero primary-to-secondary leakage.  !

3. For each steam generator, provide a general description of areas examined; include expansion criteria and specify type of probe used.

ANS: First inservice Inspection (ISI) requires 100 percent full-length inspection that was completed with a MULC tuned bobbin probe. All tubing indications were inspected with a Plus Point Motorized Rotating Pancake Coil (MRPC) probe, except as noted below.

r

'4. For analyzed Eddie Current (EC) results, describe bobbin indications (those not examined with MRPC, Plus Point MRPC and Cecco indications, include the following information: location, degradation mode, disposition, and voltages /dopths/ lengths of l most significant indications.

l ANS: Allbobbin indications were examined with MRPC except Over Expansions (OXP) in the cold legs. A total of 48 percent of the 60 - OXP bobbin indications were examined with MRPC, no degradation was identified.

l 48 bobbin indications were confirmed and evaluated with MRPC. One additional bobbin

! wearindication was not confirmed as volumetric with MRPC and was removed from l service at he discretion of the Steam Generator Maintenance Group. The following is a breakdown of these results:

(a) Wear indications identified at fan bar locations: A = 4, B = 3, C = 7, D = 3, Total = 17

- The largest wear indication was 0.88 volts, 0.48 inches circumferential, and 0.37lnches axially in tube 81/62 of A S/G at Fan Bar 5.

- A range of three 10 percent thru-wall was determined using a qualified bobbin sizing technique with an average of 5.8 percent.

Enclosure 2

m  :.

2

[

- Seven of the wearindications were removed from service by tube plugging due to pit-like tube indication that correlated with an anomalous signal on the fan bar. All wear indications were volumetric as determined by MRPC except the one noted above.

- Three additional outside diameter (OD) volumetric indications were identified at the lattice grids with one being removed from service, tube 43V100 in B S/G, due to its signalcharacterization;

. (h) Manufacturing Bumistk Marks confirmed with MRPC: A = 7, B = 11, C = 3, D = 1, j Total = 22 o

(c) New Freespan Indications confirmed with MRPC es OD volumetric: A = 4, B = 2, Total = 6

- The largest freespan indication, manufacturing bumish mark, was 0.66 1 volts, 0.42 inches circurrferential, and 0.97 inches axially in tube 72/103 of A S/G.

5. Describe repair / plugging plans.

- ANS: The McGuire Nuclear Station, Unit 2 (MNS2) tube sepair limit is 40 percent thru-wall as definedin the MNS2 Tech Spscs. Allindications sere evaluated with MRPC and any indication where its causing mechanism was in question or appeared to be the result of a deformation on a secondary side structure was further evaluated by the Steam Generator Maintenance Engineers and potentially remcVed from service.

6. Discuss previous history, look backs performed.

i ANS: The EC Analysis software contains the Historical Management System that )

automatically brings up the indication history for the tube being analyzed.

7. Discuss new inspection findings.

J ANS: There were 31 new indications, 30 of which were confirmed with MRPC; 20 were volumetric indications at secondary side structures, 6 were freespan volumetric indications, l and 4 were OXP not called during baseline. It is expected that some new indications will be i seen due to the baseline inspection being performed with the steam generator in the  ;

horizontalposition, improvements in the eddy current process sensitivity, and service ,

induced wear.

8. Describe in-situ pressure test plans.  !

ANS: Pressure test not required to verify structuralintegrity for indications identified.  !

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7;

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9. Describe tube pull plans.

' ANS: Tube pull not required to verify structuralintegrity for indications identified.

10. Assessment of tube integrity for previous operating cycle.

ANS: Wearis the onlypotential degradation mechanism identified for the CFR80

. Replacement Steam Generators. A qualified bobbin sizing technique was used to report thru-wallpercentages for wear indications. The structurallimit calculated as part of the Integrity Assessment performedper Steam Generator Maintenance Engineering Procedure (SGMEP) 106is 60 percent thru-wallfor wear. A repairlimit of 47 percent thru-wallis calculsted after accounting for the Non-Destructive Examination (NDE) uncertainties. Our

^ Tech Spec repairlimit of 40 percent bounds this calculated value. The largest wear call was 10 percent thru-wall, 0.88 volts, 0.48 inches circumferential, and 0.37 inches axially. As a result, the Conditioning Monitoring Assessment has been satisfied.

11; Assessment of tube integrity for next operating cycle.

ANS: An Operational Assessment was completed which demonstrated that the Steam Generators are operational until the McGuire Unit 2 End-of-Cycle 13 (M2EOC13) Refueling Outage.

d

Meetina Summarv dated May 11. 1900 l

HARD COPY (Docket File ~ . O PUBLIC PD ll-1 R/F F. Rinaldi OGC ACRS cc: Licensee & Service List (with all enclosures) i E-MAIL J. Zwolinski/S. Black H. Berkow C. Hawes J.Tsao

' A. Kime C. Beardslee M. Satorius C. Ogle, Rll J. Blake, Rll

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