ML20070D135

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Application for Amend to Licenses NPF-2 & NPF-8,revising Tech Specs Re Alternate Plugging Criteria.Nonproprietary WCAP-12872 & Proprietary WCAP-12871, Jm Farley Units 1 & 2.... encl.WCAP-12871 Withheld (Ref 10CFR2.790)
ML20070D135
Person / Time
Site: Farley  Southern Nuclear icon.png
Issue date: 02/26/1991
From: Hairston W
ALABAMA POWER CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19310D228 List:
References
NUDOCS 9102280117
Download: ML20070D135 (3)


Text

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10 CFR 50.90 Docket Nos: 50-348 50-364 U. S. Nuclear Regulatory Camission ATTN: Document Control Desk Vashington, D. C. 20555 Gentlemen:

Joseph M. Farley Nuclear Plant - Units 1 and 2 Steam Generator (SG) Tube Support Plate (TSP)

Alternate Plugging Criteria (APC)

In order to preclude unnecessarily removing significant numbers of SG tubes from service, Alabama Pover Company has evaluated the possibility of utilizing a revised plugging criteria for SG tube cracks which are contained within the boundaries of the TSP. This evaluation has resulted in the development of the TSP APC.

The need for an APC became evident during a recent Unit 2 outage. The program of eddy current inspections performed at Farley Unit 2 during the seventh refueling outage included full length bobbin coil probing of the available tubes. Vith no application of a voltage amplitude criterion, numerous tubes found to exhibit degradation suggestive of outer diameter stress corrosion cracking (ODSCC) were plugged. This resulted in plugging 243 tubes, 30 in SG A, 64 in SG B, and 149 in SG C due to TSP degradation, i

The scope of application of the TSP APC vill be limited to those cracks contained within the TSP boundaries which are the result of ODSCC. All other portions of the tube vill be covered by the current Technical Specifications. The APC utilizes the eddy current bobbin voltage and phase angle indicated depth as an indication of crack severity within the TSP. Tubes with an indicated depth greater than or equal to 50% vill be plugged if eddy currant bobbin voltage exceeds 3 volts.

Tubes with an indicated depth less than 50% vill be plugged if eddy current bobbin voltage exceeds 8 volts. The APC vas developed to ensure margins against tube burst per Regulatory Guide 1.121 and to minimize leakage at normal operating conditions. The criteria was also developed to ensure that radiological results of a steam line break accident do not exceed a small fraction of the 10CFR100 limits.

Details of the development of the APC are contained in VCAP-12871, "J. M. Farley Units 1 and 2 SG Tube Plugging Criteria for ODSCC at Tube Support Plates." l l I

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I U. S. Nuclear Regulatory Commission l Attn Document Control Desk Page 2 The proposed changed pages to Unit 1 and 2 Technical Specifications are provided in Attachment 1. Alabama Power Company has determined the proposed changes do not involve a significant hazards consideration. In accordance with 10CFR50.92, a significant hazards consideration evaluation is provided in Attachment 2. The technical justification supporting the proposed changes is provided in Attachment 3 as:

1. VCAP-12871-J. H. Farley Units 1 and 2 SG Tube Plugging Criteria .

for ODSCC at Tube Support Plates (Proprietary).

2. VCAP-12872-J. H. Farley Units 1 and 2 SG Tube Plugging Criteria for ODSCC at Tube Support Plates (Non-Proprietary).

Also enclosed are a Vestinghouse authorization letter, CAV-91-130, accompanying affidavit, Proprietary Information Notice, and Copyright Notice.

As VCAP-12871 contains information proprietary to Vestinghouse Electric Corporation, it is supported by an affidavit signed by Vestinghouse, the ovner of the information. The affidavit sets forth the basis on which the information may be withheld from public '

disclosure by the Commission and addresses with specificity the considerations listed in paragraph (B)(4) of Section 2.790 of the Commission's regulations.

Accordingly, it is respectfully requested that the information which is proprietary to Vestinghouse be withheld from public disclosure in accordance with 10 CFR Section 2.790 of the Commission's regulations.

Correspondence with respect to the copyright or proprietacy aspects of i

the items listed above or the supporting Vestinghouse affidavit should

' reference CAV-91-130 and should be addressed to Mr. R. P. DiPlazza, Manager, Operating Plant Licensing Support, Vestinghouse Electric Corporation, P. O.

Box 355, Pittsburgh, Pennsylvania 15230-0355.

Alabama Power Company requests the NRC review and approve this proposed change by April 25, 1991.

Alabama Power Company's Plant Operations Reviev Committee has reviewed the proposed changes and the Nuclear Operation Review Board vill review the changes at a future meeting. A copy of this proposed change is being sent to Dr. C. E. Fox, the Alabama State Designee, in accordance with 10CFR50.91(B)(1)

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T t 8 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Page 3 If there are any questions, please advise.

Respectfully submitted.

ALABAMA POVER COMPANY tm eMN h h G. !!airston, III VGil,III/REHimaf 2239 Attachments SVORN TO AND SUBSCRIBED BEFORE HE cc: Mr. S. D. Ebreter f Mr. S. T. Iloffman TilISd[#f' DAY OF ' h/[#uan /, l'491

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Mr. G. F. Maxwell v , #

Dr. C. E. Fox ' Y./[. -V .t/.lz,yd 7

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