ML20195G001

Submits Record of 990430 Telcon Re Nondestructive Exam ISI Issues,Including Increased Sensitivity of UT Exam Performed After Electrosleeve Installation Versus Eddy Current Test Performed Prior to Sleeve Installation

ML20195G001
Person / Time
Site:	Callaway
Issue date:	06/11/1999
From:	Mel Gray NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
TAC-MA3954, NUDOCS 9906150162
Download: ML20195G001 (4)

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UNITED STATES

'8 g . " NUCLEAR REGULATORY COMMISSION WA41NGTON, D.c.

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. June 11, 999

.G~f MEMORANDUM TO:[DUket Filb nn- - > y FROM: . Mel Gray, Project Manager, Section 2 Project Directorate IV & Decommissioning ~

Division of Licensing Project Management ,- .

z  : Office of Nuclear Reactor Regulation

SUBJECT:

' RECORD OF TELECON WITH UNION ELECTRIC PERSONNEL E

REGARDING ELECTROSLEEVE AMENDMENT APPLICATION FOR Call.AWAY PLANT, UNIT 1'(TAC NO, MA3954) .

During the staff's review of Union Electric Company's kUE) amendment application' dated October 27,- 1998, requesting approval of the steam generator tube Electrosleeve repair for o L Callaway Plant, Unit 1, the staff conducted a telecon with UE personnel on April 30,1999, to' discuss nondestructive examination (NDE) inservice inspection issues. : Personnel that participated in the telecon are listed in the attachment.

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The first issue' discussed concemed the increased sensitivity of the ult /asonic testing (UT) .

examination performed after Electrosleeve installation versus the eddy current test performed prior to sleeve installation. UE personnel stated it was possible the UT inspection would detect indications in the parent tube not detected during the eddy current inspection (e.g., scratches, very shallow flaws, etc).. The NRC staff quest'oned how, during the upcoming October 1999 refueling outage, UE planned to disposition these indications in the taper and bond regions where the parent tube was credited as part of the reactor coolant pressure boundary. UE .

personnel stated that indications detected in the parent tube in these regions would be plugged-on-detection, unless qualification of a depth sizing technique was completed by the

' October 1999 outage. UE personnel further indicated that this was a business risk they were

. aware of and were evaluating. UE personnel stated this was an issue that would be addressed

'within the bounds of the current license amendment proposal. It was determined that this issue did _not require any further dialogue.

The second issue discussed was implementation of a staff proposed one inch axial crack length limitation in the parent tube in the ." sleeve-as-pressure-boundary region." (Previously during an

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. i April 22,1999 meeting with the staff, the staff proposed this limit and UE personnel indicated

- they were concemed with the monitoring requirements associated with the proposed flaw length -

~ limitation). The staff asked whether UE would reconsider discussing implementation concems with the proposed flaw length limitation. UE personnel indicated that they would rather support

~ discussions in progress with the staff on the specific Callaway Plant risk, and additional

' Electrosleeve testing in progress,' as a basis for staff approval of the amendment application

without a flaw length limitationi 3

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3 l The staff acknowledged that these other poten[ial success paths (Callaway specific risk information and additional Electrosleeve testing) were being pursued. However, the staff wished to also discuss the licensee's concems with the crack length limitation in parallel in the event the staff determined there is a need for a flaw length limitation. The staff explained that the proposed one-inch crack length _ limitation, which included an assumption that the flaw was 100 percent through the parent tube, was proposed 'as one method of assuring structural integrity during severe accidents. The staff reiterated a willingness to discuss alternative approaches to assuring structural integrity 'during severe accidents, but that the licensee would have to provide the altemative suggestions. The licensee stated they would have intemal '

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1 discussions' on this} issue and suggested a follow-up telecon.' .

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Subsequently on May'3,1999, during a follow-up telecon between myself and D. Shafer of UE,

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~ UE indicated they would focus on further Electrosleeve testing and risk discussions with the j staff, rather than pursue attemative approaches to the p oposed flaw length limitation.

- Docket No. 50-483

Attachment:

List of Telecon Participants original signed by. M. Gray DISTRIBUTION: J Docket File .

PUBLIC '

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,. g 4 .2-The staff acknowledged that these other potSntial success paths (Callaway specific risk information and additional Electrosleeve testing) were being pursued. However, the staff

. wished to also discuss the licensee's concems with the crack length limitation in paral!al in the event the staff determined there is a need for a flaw length limitation. The staff explained that the proposed one-inch crack length limitation, which included an assumption that the flaw was 100 percent through the parent tube, was proposed as one method of assuring structural i

integrity during severe accidents.' The staff reiterated a willingness to discuss attemative approaches to assuring structural integrity during severe' accidents, but that the licensee would have to provide the attemative suggestions. The licensee stated they would have intemal

. discussions on this issue and suggested a follow-up telecon.

, w Subsequently on May 3,1999, during a follow-up telecon between myself and D. Shafer of UE, UE indicated th'ey would focus on further Electrosleeve testing and risk discussions with the staff, rather than pursue altemative approaches to the proposed flaw length limitation.

1 Dock'et No. 50-483 .

Attachment:

List of Telecon Participants i-i.

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. LIST OF TELECON PARTICIPANTS APRIL 30,1999,10:00 a.m. (eastern time)

NEC M. Gray C. Beardslee P. Rush Union Electric Comoany D. Shafer T. Herrmann T. Pettis Framatome Technoloaies incorporated (FTO (Contractor to Union Electric Company)

Jim Galford C.'Voody' J. Wyatt, et al ATTACHMENT s

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