ML20211A420

Submits Modified Request for Relief RR-25 for Second 10-Yr ISI Program

ML20211A420
Person / Time
Site:	Vogtle
Issue date:	09/17/1997
From:	Mccoy C SOUTHERN NUCLEAR OPERATING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LCV-1016-C, TAC-M98977, TAC-M98978, NUDOCS 9709240255
Download: ML20211A420 (6)

Text

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C. K. McCry S:uticen Nuciser Vee President . Operating Company,Inc.

' VogtJe Project 40irwerness Center Pwkway P.O Box 1295 .

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• B'rmingham, Alabama 35201 Tel 205992.7122 Iax 20;.992.0403 SOUTHERNAta COMPANY Energ to Serve Your World" E

Se:atember 17, 1997 LCV-1016-C 2

Docke', Nos.: 50-424, 50-425 U. S. Nuclear Regulatory Comiaission ATTN. Dcoment Control Desk Washington, D. C. 20555 Ladies and Gentlemen:

VOGTLE ELECTRIC GEhERATING PLANT INSERVICE INSPECTION PROGRAM REOUEST FOR RELIEF RR-25 3 By letter LCV-1016-A dated September '0,1997, information was provided in response to the NRC ietter dated Augast 8,1997, which requested additional information concerning the Vogtle Electric Generating Plant (VEGP), Units I and 2, Second Ten-Year Inservice Inspection Program. Specifically, information was provi6ed in response to the NRC questions concerning our requested use of ASME Section XI Code Cases N-533, N-544, and N-566, as discussed in Requests for Relief RR-26, RR-22, and RR-25, respectively. Included in our September 10,1997 letter were revisions to Requests fct Relief RR-25 and RR-26. The NRC TM' numbers associated with the request for additionalinformation were M98977 and M98978.

On September 12,1997, Southern Nuclear Operating Company personnel contacted the NRC and its contractor, INEEL Research Cer.:er, to discuss our submittal of September 10,1997. Based on comments from the NRC staff and the INEEL representative, it was noted that Request for Relief RR-25 would not be accep;ed in its current form. As a I

- result, we hve modified RR-25 which is enclosed herein. The enclosed version of J

- Request for Relief RR-25 supersedes the one submitted in our letter of September 10, 1997J The remaining infonaation provided by that letter remains unchanged.  !

9709240255 970917 PDR ADOCK 05000424--

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'U. S. Nuclear Regulatory Commission LCV-1016-C Page Two 3

Your pompt review and approval of the enclosed version of Request for Relief RR-25 is respectfully requested so that it may used during the VEGP-1 maintenance / refueling

} outage currently in progress.

A copy of this submittalis being provided directly to Mr. M. T. Anderson of the INEEL Research Center based on your canier request of August 8,1997. .

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Should there be any questions in this regard, please contact this ofTice at your earliest J convenience.

Sincerely, 7;.

C.K.McC >

'! ' CKM/JAE/jae

Enclosure:

Revision 1 to Request for Relief RR-25 xc: INEEL Research Center Mr. M. T. Anderson (w/ enclosure)

Southern Nuclear Ocerating Company Mr. J. B. Beasley, Jr. (w/o enclosure)

Mr. W. L. Burmeister (w/o enclosure)

Mr. M. Sheibani(w/ enclosure)

NORMS ( denclosure)

U. S. Nuclear Regulatory Con mission Mr. L A. Reyes, Regional Administrator (w/ enclosure)

NRC Serdor Resident Inspector, Vogtle (w/ enclosure)

Mr. L. L. Wheeler, Senicr Project Manager, NRR (w/ enclosure)

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ENCLOSURE:

. .' TO SOUTHERN NUCLEAR OPERATING COMPANY LETTER LCV-1016-C

' VOGTLE ELECTRIC GENERATING PLANT I_ NSERVICE INSPECTION PROGRAM REOUEST FOR RELIEF RR-25 l Revision 1 of Request for Relief RR-25 supersedes the similar request for relief which had been submitted to the NRC in SNC letters LCV-1016 and LCV-1016-A dated May 29, 1997 and September 10,'1997, respectively. Revised Request for Relief RR immediately follows this introduction.- To the extent practical, the page numbers which are found in the enclosed request for relief corresponds with the page numbers in the VEGP-1 and 2 Inservice Inspection Program - Secorid Ten-Year Interval which accompanied the SNC letter of May 29,1997.

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SOUTilERN NUCLEAR OPERATING COMPANY VOGTLE ELECTRIC GENERATING PLANT. UNITS 1 AND 2 SECOND TEN-YEAR INTERVAL,

. . REOUEST FOR RELIEF NO. RR-25

1. Eufem/ Component for Which Relleris Reauested:

Class 1,2, and 3 pressure retaining bolted connections.

II. Code Reanirement:

ASME Section XI, IWA-5250(a)(2) requires that ifleakage occurs at a bolted connection, the bolting shall be removed, VT-3 visually examined for corrosion, and evaluated in accordance with IWA-3100.

Ill, Code Reauirement for Which Reliefis Requested:

Reliefis requested from removing bolting from pressure retaining bolted connections and performing the required visual examination (VT-3) should leakage be detected during performance of ASME Section XI pressure testing activities.

IV. Hasis for Relief:

Removal of pressure retaining bolting at mechanical connections for visual, VT-3 examination and subsequent evaluation in locations where leakage has been identified is not always the most pmdent course of action to determine the accep; ability of the bolting.

The Coie requirement to remove, examine, and evaluate bolting in this situation does not allow the Owner to consider other factors which may indicate the acceptability of mechanicaljoint botting. Southern Nuclear Operating Company (SNC) considers this requirement to be unnecessarily prescriptive and restrictive.

Other factors which should be considered when evaluating bolting acceptability when leakage has been identified at a mechanical joint include, but should not be limited to: joint bolting materials, service age ofioint boltmg materials, location ofleakage, history of leakage at thejoint, evidence of corrosion with joint assembled and corrosiveness of process fluid.

ASME Section XI is written to primarily address examinations and testing during periods of plant or system shutdown. No guidance is given to address components that are examined or tested while the plant or system is in service. However, many Code Class 2 and 3 systems are pressure tested, including VT-2 visually examined, utilizing the

" Inservice Test" requirements ofIWA-5000.

Performance of the test while the system is inservice may identify leakage at a bolted connection that, upon evaluation, may be concluded that the joint's structural integrity and pressure retaining sbility is not challenged. It would not be prudent to negatively impact a safety system's availability by removing the system from service to address a leak that does not challenge the system's ability to perform its safety function. i 1

I 7-102 Rev.I i l

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SOUTiiERN NIICLEAR OPERATING COMPANY VOGTLE El ECTRIC GENERATING PLANT. UNITS 1 AND 2 SECOND TEN-YEAR INTERVAL,

'.- . REOUEST FOR REI IEF NO. RR-25 (continued)

IV. Hasis for Relief (continued):

In addition, a situation frequently encountered at commercial nuclear plants such as VEGP is the complete replacement of bolting mate.ials (studs, bolts, nuts, washers, etc.) at mechanicaljoints during plant outages. When the associated system process piping is pressurized during plant start-up, leakage may be identified at thesejoints. The root cause of this leakage is most often due to thermal expansion of the piping and bolting materials at thejoint and subsequent process fluid seepage at thejoint gasket. Proper retorquing of thejoint bolting, in most cases, stops the leakage. Removal of any of thejoint bolting to evaluate for corrosion would be unwarranted in this situation due to the new condition of the bolting materials.

Southern Nuclear Operating Company proposes the following alternative methodology to the requiremeats ofIWA-5250(a)(2) which will provide an acceptable level of quality and safety when evaluating leakage and bolting material acceptability at Class 1,2, and 3 bo ted connections.

V. Alternate Examination:

When leakage is identified at bolted connections by visual, VT-2 examination during system prc;sure testing, an evaluation will be performed to determine the susceptibility of the bolting to conosion and assess the potential for failure. The following factors, may be considered, as applicable, but not limited to, when evaluating the acceptability of the bolting;

1. Bolting materials

2. Corrosiveness of process fluid leaking

3. Leakagelocation

4. Leakage history at connection or other system components

5. Visual evidence of corrosion at connection (connection assembled)

6. Senice age of bolting materials When the press re test is performed with the system in service or required by the Technical Specifications to be operable, and the bolting is suscentible to corrosion, the evaluation shall address the connection's structural integrity until the next component /

system outage of suflicient duration. If the evaluation concludes that the system can perform its safety related function, removal of the bolt closest to the leakage and VT-1 visual examination of the bolt will be performed when the syrtem or component is taken out of senice for a sufliciem duration for accomplishment of other system maintenance activities.

7-103 Rav.1

SOUTIIERN NUCLEAR OPERATING COMPANY VOGT!,E ELECTRIC GENEE.A. TING Pl ANT, UNITS 1 AND 2

. SECOND TEN-YEAR INTERVAI, REOUEST FOR RELIEF NO. RRJ)

(continued)

V. Alternate Examination (continued):

For bolting that is susceptible to corrosion, and when the initial evaluation indicates that the connection cannot conclusively perform its safety function until the next component /

system outage of suflicient duration, the bolt closest to the source ofleakage will be removed, receive a VT-1 visual examination, and be evaluated in accordance with IWA-3100(a).

VI. Justification for the Grantine of Relief:

Evaluating the leakage and the overall condition of the bolted connection, and removing only selected bolts for VT 1 visual examination, in lieu of arbitrarily removing and examining all bolts provides adequate assurance that the integrity of the connect' n is being mr.intained. The proposed alternatives provide for the adequate level - aality and safety and are thereforejustified per 10CFR50.55a(a)(3)(i).

VII. Implementation Schedule:

This request for reliefis applicable to the Second Ten-Year Interval which commenced May 31,1997.

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7-104 Rev.1