ML073410038
| ML073410038 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/04/2007 |
| From: | Brandi Hamilton Duke Energy Carolinas, Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2EOC21 | |
| Download: ML073410038 (5) | |
Text
BRUCE H HAMILTON P& Duke Vice President Mr Energye Oconee Nuclear Station Duke Energy Corporation ONOIVP / 7800 Rochester Highway Seneca, SC 29672 864 885 3487 864 885 4208 fax December 4, 2007 bhhamilton@duke-energy.corn U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001
Subject:
Duke Power Company LLC d/b/a Duke Energy Carolinas, LLC (Duke)
Oconee Nuclear Station, Unit 2 Docket No. 50-270 Steam Generator Inservice Inspection 2EOC21 3 Month Report Gentlemen:
On May 14, 2007, Oconee Nuclear Station notified NRC Region II staff, by telephone, of a case where information supplied to the NRC was not accurate in all material respects. On May 15, 2007, a letter was provided to Dr. William D.
Travers, Administrator, Region II, pursuant to 10 CFR 50.9 Sections (a) and (b),
to further document the erroneous information.
Specifically, Duke submitted the Unit 2 End of Cycle 21 (2EOC21) Steam Generator Inservice Inspection 3 Month Report by letter dated February 23, 2006 (ML060600449). In Enclosure A of that report, Duke indicated that 15,630 tubes had been inspected on the 2B Steam Generator. Enclosure B indicated that 100% of the Steam Generator tubes (a total of 31,257 tubes between the 2A and 2B Steam Generators) had been inspected. It was discovered that these numbers were in error, as documented in Oconee Problem Identification Process (PIP) 07-2685, initiated May 13, 2007.
During the Steam Generator Inservice Inspection for the 2EOC22 Unit 2 outage, discrepancies were noted between current and past inspection data. Resolution of the discrepancies led to the discovery that an AREVA technician had mis-aligned the inspection equipment during part of the 2EOC21 inspections on the 2B Steam Generator. This error resulted in 53 tubes being inspected under incorrect location designations and 33 tubes not being inspected at all because other tubes were inspected instead. The submitted 2EOC21 Inservice Inspection report credited the inspection results to the tubes intended for inspection since the error was not discovered until the next outage.
AOV7 www.duke-energy.com
U. S. Nuclear Regulatory Commission Date: December 4, 2007 Page 2 In the May 15, 2007 letter, Duke committed to submit additional information to correct or clarify the 2EOC21 3 Month Report. This letter is intended to meet that commitment.
Since 33 tubes were not inspected as a result of this error, the percentage of Steam Generator tubes actually inspected was 99.79% for 2B Steam Generator and 99.89%
total for both steam generators, rather than 100% as indicated in Enclosure B of the report. Attached are two tables listing tubes that were misidentified during the 2B Steam Generator examination during the Oconee Unit 2 EOC21 (October 2005) refueling outage. Table 1 lists the 53 affected tubes by their location coordinates, and indicates which of the affected tubes were actually inspected and which were not.
Table 2 lists the 33 tubes which did not receive an inspection during EOC21 and the depth of any wear that exists based on the EOC22 (May 2007) inspection results; the deepest being 17% through-wall.
Please address any questions to Randall P. Todd at (864) 885-3418.
Very truly yours, Bruce H. Hamil resident Oconee Nuclear Site Attachment cc:
Dr. William D. Travers Administrator, Region II U.S. Nuclear Regulatory Commission Atlanta Federal Center 61 Forsyth St., SWW, Suite 23T85 Atlanta, GA 30303 Mr. L. N. Olshan Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C. 20555 Mr. D. W. Rich NRC Senior Resident Inspector Oconee Nuclear Station
U. S. Nuclear Regulatory Commission Date: December 4, 2007 Page 3 bxc:
B.G. Davenport R.L. Gill E.B. Kulesa Parker Downing, Jr.
J. D. Gilreath G.L. Brouette (ANII)
L.F. Vaughn S.J. Magee (WOE)
Document Control (Master File)
ELL PIP FILE CNS:
H.D. Brewer R.D. Hart MNS:
J.A. Kammer K.L. Ashe
Table 1 2B SG Misidentified Tube Locations and Test Status Count 2005 2005 Tested Count 2005 2005 Tested Encode Actual Encode Actual 1
141-47 140-49 Y
28 142-39 141-41 N
2 141-48 140-50 Y
29 142-40 141-42 N
3 141-49 140-51 Y
30 142-41 141-43 N
4 141-50 140-52 Y
31 142-42 141-44 N
5 141-51 140-53 Y
32 142-43 141-45 N
6 141-52 140-54 Y
33 142-44 141-46 N
7 141-53 140-55 Y
34 142-45 141-47 N
8 141-54 140-56 Y
35 142-46 141-48 N
9 141-55 140-57 Y
36 142-47 141-49 N
10 141-56 140-58 Y
37 142-48 141-50 N
11 141-57 140-59 Y
38 142-49 141-51 N
12 141-58 140-60 N
39 142-50 141-52 N
13 141-59 140-61 Y
40 142-51 141-53 N
14 141-60 140-62 Y
41 142-52 141-54 N
15 141-61 140-63 Y
42 142-53 141-55 N
16 141-62 140-64 Y
43 142-54 141-56 N
17 141-63 140-65 Y
44 142-55 141-57 N
18 141-64 140-66 Y
45 142-57 141-59 N
19 141-65 140-67 Y
46 142-58 141-60 N
20 141-66 140-68 Y
47 142-59 141-61 N
21 141-67 140-69 Y
48 142-60 141-62 N
22 141-68 140-70 N
49 142-61 141-63 N
23 142-34 141-36 N
50 142-62 141-64 N
24 142-35 141-37 N
51 142-63 141-65 N
25 142-36 141-38 N
52 142-64 141-66 N
26 142-37 141-39 N
53 142-65 141-67 N
27 142-38 141-40 N
UEN i
"Count" column assigns an item number to each mis-alignment.
"2005 Encode" column indicates the tube coordinates (Row# and tube# within that row) as indicated in 2005 report. This is the location we intended to inspect.
"Actual" indicates the tube coordinates (row# and tube#) actually inspected.
"Tested" column indicates if the intended tube was tested "unintentionally" by another mis-alignment. For example, note that "count" 34 indicates that the tube actually inspected (141-47) was the tube intended to be inspected by "count" 1.
Table 2 2B SG Tube Wear in 2007 for Tubes NOT Inspected in 2005 Count Tube 2007 Count Tube 2007 Identification
% TW Identification
% TW 1
141-58 13/14 18 142-49 NDD 2
141-68 NDD 19 142-50 6/7 3
142-34 NDD 20 142-51 NDD 4
142-35 NDD 21 142-52 NDD 5
142-36 NDD 22 142-53 10 6
142-37 NDD 23 142-54 8/10 7
142-38 NDD 24 142-55 6/11 8
142-39 NDD 25 142-57 17 9
142-40 NDD 26 142-58 NDD 10 142-41 6
27 142-59 NDD 11 142-42 14 28 142-60 8/14 12 142-43 7/11 29 142-61 NDD 13 142-44 4/5 30 142-62 6
14 142-45 4
31 142-63 NDD 15 142-46 5/15 32 142-64 5
16 142-47 NDD 33 142-65 NDD 17 142-48 NDD
% TW = Percent through-wall NDD = No Detectable Degradation Dual Values (e.g. 4 / 5) indicate that two defects were observed in that tube.