ML20096B333
| ML20096B333 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/05/1996 |
| From: | Terry C, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-96006, NUDOCS 9601160202 | |
| Download: ML20096B333 (4) | |
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M Log # TXX 96006
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File # 10010.1 L
905,4 Ref. # 10CFR50.55a(a)(3)(ii)
TilELECTRIC January 5, 1996 C. Lance Terry Group Mce PresiJent
.i U. S, Nuclear Regulatory Commission Attn:
Document Control Desk J
Washington, DC 20555 i
1
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
J DOCKET NOS. 50 445 AND 50-446
. REQUEST APPROVAL AND USE OF ASME CODE CASE N 524 i
i REF:
- 1) Unit 1: 1986 Edition of ASME Code,Section XI, No Addenda, Interval Start Date August 13, 1990 First Interval:
Unit 2: 1986 Edition of ASME Code,Section XI, No Addenda, l
Interval Start Date August 3, 1993, First Interval
- 2) ASME Code Case N 524. " Alternative Examination Requirements for Longitudinal Welds in Class 1 and Class 2 Piping Section XI Division 1." dated August 9, 1993 Gentlemen:
TU Electric requests approval to use ASME Code Case N 524 (Enclosed) for the examination of longitudinal welds in Class 1 and Class 2 piping.
Pursuant to 10CFR50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, " Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the liuitations of design, geometry, and materials of' construction of the components.
The applicable ASME Code Editions for CPSES are noted in Reference 1.
0 Regulation 10CFR50.55a(a)(3)(ii) allows alternate requirements if compliance with the specified requirements of this section
[10CFR50.55a(g)(4)] would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. TV Electric is requesting approval for the implementation of the alternative rules of ASME Section XI Code Case N 524 (Reference 2) for CPSES Unit 1 and 2.
9601160202 960105 DR ADOCK 05000445 PDR 1101c8 Energy Pir.za 1601 Bryan Street Dallas. Texas 75201 3411
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TXX 96006 Page 2 of 3 TU Electric's Inservice Inspection (ISI) program requires one pipe diameter in length, but no more than 12 inches, be examined for Class I longitudinal piping welds. Class 2 longitudinal piping welds are required to be examined Qr a length of 2.5t, where
't' is the thickness of the weld. These lengti,; of the weld are measured from the intersection of the circumferential and longitudinal weld. TU Electric's proposed alternative Code Case N 524, limits the volumetric and surface examination requirements of the longitudinal weld to the volume / area contained within the examination requirements of the intersecting.
j circumferential weld.
1 Longitudinal welds are produced during the manufacturing process of the piping, not in the field as is the case for circumferential welds. The ASME Code contains requirements on characteristics and performance of 4
materials and products, and specifies the examination requirements during the manufacturing of the subject longitudinal piping welds.
In addition, there are material, chemical, and tensile strength requirements in the ASME Code. The manufacturing process that is specified by the ASME Code provides assurance of the structural integrity of the longitudinal welds at the time the piping is manufactured.
The preservice examination and initial inservice examinations have provided assurance of the structural integrity of the longitudinal welds during the service life of the plant to date. The experience in the United States has been that ASME Code longitudinal welds have not experienced degradation that would warrant continued examination beyond the boundaries required to meet the circumferential weld examination requirements. No significant loading conditions or known materia degradation mechanisms have become evident to date which specifically relate to longitudinal seam welds in nuclear plant piping.
If any degradation associated with a longitudinal weld were to occur, it is expected that it would be located at the intersection with a circumferential weld. This intersection is inspected in accordance with the provisions of Code Case N 524.
In addition, there is a significant accumulation of man rem associated with the examination of longitudinal welds, especially in Class 1 piping.
It is requested that approval of this Code Case be granted by the January 31. 1996, so that it may be implemented during the second refueling outage for Unit 2 which is scheduled to start on February 22, 1996, and during all subsequent refueling outages for Unit 1 and Unit 2.
Timely approval is requested in order to obtain, through implementation of the Code Case, the maximum achievable cost savings and reduction in radiation exposure.
Based on the aforementioned, the use of Code Case N 524 would not influence the acceptable level of quality and safety at CPSES.
TXX 96006 Page 3 of 3 If you have any question please call Obaid Bhatty at (817) 897 5839.
Sincerely, C. L. Terry By:
D. R. Woodlan Docket Licensing Manager OB/ob Enclosure cc:
Mr. L. J. Callan, Region IV Mr. W. D. Johnson, Region IV Hr. Tim Polich, NRR Mr. G. Bynog, TDLR Resident Inspectors CPSES
Enclosure to TXX-%006
., tyrW.1* o f 1 CASE N.524 CAlta OF A5MC SoltER AND PaK$sUma VEssat. CODE Approvai cate: Aueust 9.19e3 See Numericalindex for exsNeenon and any reeNirmehon detes.
Case N 524 Alternative Examnimation Requirements for Imagitudinal Welds in Class 1 and 2 Piping Section XI, Division 1 Inguiry: What alternative requirements may be ap-p!!ed to the surface and volumetric caanunation of longitudinal piping welds specified in Table IWB-j 25001, Examination Category BJ, Table IWC-2500 4
1, Examination Categorios C F 1 and C F 2 (Exam-i ination Category C F pnor to Winter 1983 Adden-da), and Table TWC-2520, Examination Category C-0 (1974 Edition, Summer 1975 Addenda)?
Reply: It is the opinion of the Committee that the fo!!owing shall apply:
(a) When only a surface examination is required, examination of longitudinal piping welds is not re-quired beyond those portions of the welds within the examination boundaries of intersecting circumfer-ential welds.
(b) When both surface and volumetric examina-tions are required, esamination of longitudinal piping welds is not required beyond those portions of the welds within the examination boundaries of inter-secting circumferential weids provided the following requirements are met.
(1) Where longitudinal welds are specified and locations are knoem, ev==mation requirements shall be met for both transverse and parallel flaws at the intersection of the welds and for that length of lon-gitudinal weld within the circumferential weld ex.
amination volume; (2) Where longitudinal welds are specified but locations are unknown, or the existence of longitu-dinal wolds is uncertain, the eremination require-ments shall be met for both transverse and parallel flaws within the entire examination volume of inter-sect:.ng circumferential welds.
0 903 sure. e - NC
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