ML042750326
| ML042750326 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, Catawba  |
| Issue date: | 09/16/2004 |
| From: | Mccollum W Duke Energy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MC3804, TAC MC3805, TAC MC3807, TAC MC3810 | |
| Download: ML042750326 (6) | |
Text
- MDuke
- rcPower, A Duke Energy Company WILLIAM R MCCOLLUM, JR.
VP, Nuclear Support Duke Energy Corporation Duke Power EC07H / 526 South Church Street Charlotte, NC 28202-1802 Mailing Address:
P. 0. Box 1006 - EC07H Charlotte, NC 28201-1006 704 382 8983 704 382 6056 fax wrmccoll@duke-energy. corn September 16, 2004 U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 ATTENTION: Document Control Desk
SUBJECT:
Duke Energy Corporation Oconee Nuclear Station, Unit 3, Docket Nos. 50-287 McGuire Nuclear Station, Unit 2, Docket No. 50-370 Catawba Nuclear Station, Units I & 2, Docket Nos. 50-413, 50-414 Response to Request for Additional Information Relief Request 04-GO-002 (TAC NOS. MC3804, MC3805, MC3807, MC3810)
Pursuant to 10 CFR 50.55a (a) (3) (i), Duke Energy Corporation (Duke) submitted Relief Request 04-GO-002 for Oconee Unit 3, McGuire Unit 2 and Catawba Units I and 2 on July 14, 2004 and supplemented the request on September 1, 2004. By letter dated September 9, 2004 the NRC Staff requested additional information with respect to several issues within the relief request. Attachment 1 provides the requested information and Attachment 2 provides a sketch illustrating the volumetric coverage for Oconee Unit 3.
Questions regarding this submittal may be directed to Mary Hazeltine at 704-382-5880.
Very truly yours, William R. McCollum, Jr.
Attachments 1)qe
www.dukepower.com
U. S. Nuclear Regulatory Commission September 16, 2004 Page 2 xc w/att:
W. D. Travers, Regional Administrator U. S. Nuclear Regulatory Commission, Region II Sam Nunn Atlanta Federal Center 23T85 61 Forsyth St., SW Atlanta, GA 30303 L. N. Olshan (Addressee only)
NRC Senior Project Manager (ONS)
U. S. Nuclear Regulatory Commission Mail Stop 0-8 H12 Washington, DC 20555-0001 J. J. Shea (Addressee only)
NRC Senior Project Manager (MNS)
U. S. Nuclear Regulatory Commission Mail Stop 0-8 H12 Washington, DC 20555-0001 S. E. Peters (Addressee only)
NRC Project Manager (CNS)
U. S. Nuclear Regulatory Commission Mail Stop 0-8 H12 Washington, DC 20555-0001 M. E. Shannon, NRC Senior Resident Inspector (ONS)
J. B. Brady, NRC Senior Resident Inspector (MNS)
E. F. Guthrie, NRC Senior Resident Inspector (CNS)
U. S. Nuclear Regulatory Commission September 16, 2004 Page 3 bxc w/ att:
R. L. Gill (ECO5O)
C. J. Thomas (MGOIRC)
K. L. Crane (MGOIRC)
N. T. Simms (MGOIRC)
L. A. Keller (CNOIRC)
K. E. Nicholson (CNOIRC)
L. J. Rudy (CNOIRC)
B. G. Davenport (ON03RC)
J. E. Smith (ON03RC)
R. P. Todd (ON03RC)
J. M. Ferguson - Date File (CNO ISA)
R. K. Rhyne (ECOSA)
J. J. McArdle (ECO5A)
North Carolina Municipal Power Agency Number 1 Saluda River Electric Cooperative, Inc.
Piedmont Municipal Power Agency North Carolina Electric Membership Corporation MNS MasterFile MC-801.01 (MGOIDM)
CNS MasterFile CN-80 1.01 (CN04DM)
ONS MasterFile ON-801.01 (ON03DM)
ELL RAI Questions and Responses for Relief Request 04-GO-002 NRC Question 1:
Regarding CNS-1, you plan on using the proposed alternative after the second inservice inspection (ISI) interval ends. Please clarify if you plan to extend the second ISI interval for CNS-1, or if CNS-1 will ask for relief from the requirements in a different edition of the Code.
Facility Applicable Code Applicable Interval Proposed Alternative Used During CNS-1 1989 Edition, No Addenda Second Spring 2006 ?
June 29, 1995 to June 29, 2005 CNS-2 1989 Edition, No Addenda Second Fall 2004 Aug._19,_1996 to Aug. 19, 2006 MNS-2 1989 Edition, No Addenda Second Spring 2005 (Extended through a RR)
February 29, 1994 to June 1,2005 ONS-3 1989 Edition, No Addenda Third Fall 2004 Dec. 16, 1994 to Dec. 16, 2004 Duke Response 1:
Duke made a mistake in the original relief request submittal by misidentifying 2006 as the year of the CNS-1 inspection. The inspection is actually scheduled to be performed in the spring of 2005, which is within the second ISI interval.
NRC Question 2a:
Please provide the volumetric coverage that could be obtained under current Code requirements (i.e. third interval for ONS-3 and second interval MNS-2, and CNS-1&2). You did not provide this information in your response to our request for additional information dated August 11, 2004 and your original submittal provided the coverage obtained during the last interval for each plant.
Duke Response 2a:
The coverage for the Flange-to-Shell Weld in each unit is shown in the table below:
Station/Unit Coverage from the Estimated Coverage Coverage from the Flange Vessel ID Using from the Vessel ID Seal Surface Using 1989 1989 Section XI Code Using Alternative Section XI Code CNS-I 90.5%
90.5%
100%
CNS-2 90.5%
90.5%
100%
MNS-2 90.5%
90.5%
100%
ONS-3 68%
72.6%
100%
NRC Question 2b:
The estimated volumetric co6verage for the reactor upper sheli-t6-flange weld at ONS-3 using the proposed alternative is 72.6 percent, which is less than the required 90 percent coverage.
Please confirm whether the most critical areas susceptible to degradation (the weld + heat affected zone) will be covered using the proposed alternative.
Duke Response 2b:
Although this particular exam (UT from vessel wall) results in limited coverage of 72.6 percent, please note that this exam is only considered as 50% of the total examination requirement specified in ASME Section XI, Table IWB-2500-1, Category B-A, Item B 1.30.
Duke uses the deferral allowed by the code table to perform two partial exams, flange face and vessel wall, to be conducted at different times within the 10-year interval. Table notes (3) and (4) provide details to the user on how to implement the deferral. The flange face partial exam was previously performed during the first inspection period while the vessel wall partial exam is scheduled for the third inspection period.
In Duke's Response 2a above, the table data shows coverage of the weld and heat affected zone to be 100% by the flange face partial exam and 72.6 % by the vessel wall partial exam.
The vessel flange partial exam is unaffected by the use of the proposed alternative; however, the following particular limitations were identified for the vessel wall partial exam.
- 1. A limited coverage area begins at a point 1.125 inches from the weld edge on the outside surface of the flange and continues upward for a distance of 5 inches along the base material (flange forging) toward the flange seal surface. This condition exists 360° around the vessel. It is caused by a flange inside surface geometry change that limits the scanning probe from being positioned high enough to cover the entire inspection volume. The limitation is shown as a triangular area on the Attachment 2 cross-section sketch.
- 2. There are four clad patches above each main coolant loop nozzle that limits coverage of the outer surface of the weld and heat affected zone for 14.4 inches of the weld length above each nozzle. This limitation only applies to the axial scan from below the weld. The cumulative length of the limitation is 57.6 inches.
ONS-3 Coverage Limitation Sketch (Reference Duke Response 2b) 12" Oconee Unit 3 Reactor Pressure Vessel Flange-to-Upper Shell Weld