ML040580079
| ML040580079 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/05/2004 |
| From: | James Smith Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BL-03-002, EA-03-009, TAC MB2660, TAC MB4579, TAC MC0564 | |
| Download: ML040580079 (27) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 February 5, 2004 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C. 20005-0001 Gentlemen:
In the Matter of Tennessee Valley Authority
)
Docket No. 50-328 SEQUOYAH NUCLEAR PLANT (SQN) UNIT 2, NRC BULLETIN 2003-02,
"LEAKAGE FROM REACTOR'PRESSURE VESSEL LOWER HEAD PENETRATIONS AND REACTOR COOLANT PRESSURE BOUNDARY INTEGRITY," (TAC No. MC0564) AND NRC ORDER EA-03-009 -
INTERIM INSPECTION REQUIREMENTS FOR REACTOR PRESSURE VESSEL HEADS AT PRESSURIZED WATER REACTORS
References:
- 1. TVA Letter to NRC dated September 22, 2003, "Sequoyah Nuclear Plant (SQN) Units 1 and 2 and Watts Bar Nuclear Plant (WBN) Unit 1 -
Thirty-Day Response to NRC Bulletin 2003-02,
'Leakage from Reactor Pressure Vessel Lower Head Penetrations and Reactor Coolant Pressure Boundary Integrity,' dated August 21, 2003"
Unit 2 Item 5 Response to NRC Bulletin 2001-01,
'Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles,' dated August 3, 2001 (TAC No. MB2660) -
Unit 2, Item 2 Response to NRC Bulletin 2002-01,
'Reactor Pressure Vessel Head Degradation and Reactor Coolant Pressure Boundary Integrity,'
dated March 18, 2002 (TAC No. MB4579)"
- AMo P-nted on recyced papW
U.S. Nuclear Regulatory Commission Page 2 February 5, 2004 The purpose of this letter is to update NRC regarding the status of SQN Unit 2 reactor pressure vessel (RPV) upper head inspections and the inspection results for the lower head.
The subject NRC Order, Item IV.C.(3) states:
"For those plants in the Low category, RPV head and head penetration nozzle inspections shall be performed as follows.
An inspection meeting the requirements of 3(a) must be completed at least every third refueling outage or every five (5) years, whichever occurs first.
If an inspection meeting the requirements of 3(a) was not performed during the refueling outage immediately preceding the issuance of this Order, the Licensee must complete an inspection meeting the requirements of 3(a) within the first two (2) refueling outages following issuance of the order."
In accordance with item 3(a) of the NRC Order, SQN Unit 2 falls in the low susceptibility category and requires a bare metal visual inspection of 100 percent of the RPV head surface (including 360 degrees around each RPV penetration nozzle).
The inspection of SQN Unit 2 that complies with 3(a) of the NRC Order was performed during the Unit 2 Cycle 11 refueling outage that immediately preceded the issuance of the NRC Order.
The results of the Unit 2 RPV head inspections were provided by Reference 2 in accordance with Section IV, Paragraph E of the NRC Order EA 03-009.
Item 2 of NRC Bulletin 2003-02 requires Licensees to submit a report detailing the inspection results of the lower head within sixty days after returning the plant to operation.
The RPV lower head inspections for SQN Unit 2 were performed during the SQN Unit 2 Cycle 12 refueling outage that ended December 11, 2003.
Bare metal visual inspections were performed on the lower head penetrations and lower head surface by Level III visual testing (VT) certified personnel using video equipment mounted on remote magnetic crawlers.
The examinations were recorded on videocassettes for archival and off-line review.
U.S. Nuclear Regulatory Commission Page 3 February 5, 2004 A total of 58 RPV lower head penetrations and the lower head surface were examined.
The VT results indicate no detectable boron leakage.
A slight discoloration was noted in some areas of the lower head coating; however, no minimal surface corrosion was noted.
Enclosure l provides excerpts from the Examination Report Number BOP-2449 that documents the complete inspection of the lower head.
The video, photographs, and resolution verification are filed as life-of-plant documentation. provides TVA' s engineering analysis associated with the observed discoloration (i.e., exterior residue).
If you have any questions regarding this response, please contact me at (423) 843-6672 or Pedro Salas at (423) 843-7170.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on this 4g-day of r a,7 d
Sincerely, James D. Smith Licensing Supervisor Enclosures cc (Enclosures):
Mr. Michael L. Marshall, Jr., Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop O-8G9A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 Reactor Pressure Vessel (RPV)
Lower Head Examination Results (Excerpts from Report No. BOP-2448)
SEQU1 OYA K2, UNTZ C YCLE fI l REACTOR PRESSURE VESS LWER, HEAD REMOTE VISUAL. (VT---2,)
SE!PENVE TRA TIC!EX-A7NTO FINf14.ALL REPOR~TS-N-iO.VEMPS'BERP, 20,03 Prepared for:
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SEQUOYAH UNIT 2 CYCLE 12 RPV LOWER HEAD VT-2 EXAM TABLE OF CONTENTS Section Description 1.0 Examination Report 2.0 Scan Plan 3.0 Photographs 4.0 Resolution Verification NRC Bulletin 2003-02
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Sequoyah Unit 2, Cycle 12 - RPV Lower Head Remote Visual Penetration Examination Final Report Visual Examination Report Summary INTRODUCTION During the Sequoyah Unit 2 (SQN-2), Cycle 12 Refueling Outage, remote visual (VT) examinations were performed on the outside surface of the Reactor Pressure Vessel (RPV)
Lower Head bottom mounted instrument (BMI) penetrations. TVA Inspection Services Organization (ISO) established a procedure to define the actions required to perform enhanced VT-2 examinations to detect reactor coolant pressure boundary (RCPB) leakage from the reactor vessel lower head penetrations. The examinations were performed on November 11-12, 2003 by Tennessee Valley Authority's ISO and Vistas Corporation.
The examination was implemented through SQN Work Order# 03-001060-000. This Work Order also established the requirements for access into the keyway (i.e. confined space status and heat stress requirements) and included tag-out requirements (2-94-609-RFO) to prevent retraction of the incore instrument thimble tubes. The examination was performed in accordance with NDE procedure N-VT-17, revision 3. The purpose of the VT examination was to identify any leakage from the instrument penetration annulus area and any degradation of the lower head from RCPB leakage. The annulus area is defined as the intersection between the RPV head and penetration, inclusive of 1/2 inch of adjacent RPV head base material. The examination included 100% of the RPV head surface and 360 degrees of the annulus. A total of 58 BMI penetrations and the lower head surface were examined. Personnel performing the examinations were certified as VTI LiII. System resolutions checks were performed at the initiation and completion of the examination, as a minimum (Ref. Section 4.0 for resolution documentation). Any suspected boron leakage areas were to be identified to Materials Engineering for resolution.
TECHNICAL DISCUSSION Remote VT Equipment TVA contracted with Vistas Corporation to provide and operate remote VT equipment to examine the RPV head penetrations. The remote examinations were performed with a Vistas tracked crawler, outfitted with a high resolution, 40:1 color zoom camera having an adjustable LED lighting array, tilt and zoom capabilities. Additionally, the crawler was equipped with both forward and rear viewing cameras used to aid in positional verification and progression.
The data acquisition and crawler control station were located on a platform in the keyway with the associated cabling routed to the RPV lower head. The camera mounted crawler was placed under the head on the insulation surface. Access to the examination area was provided by removing the peripheral insulation panels located below the vessel head. A ladder was placed at one of these openings.
1
Sequoyah Unit 2, Cycle 12 - RPV Lower Head Remote Visual Penetration Examination Final Report The examinations were recorded on Digital 8 video cassette's for archival and off-line review. All penetration annulus areas and the head surface in the area on the penetrations were examined and digitally recorded.
ProcedurelDocumentation The exam was performed in accordance with TVA/ISO NDE procedure N-VT-17, revision 3.
ISO provided two Level IlIl examiners certified in Visual examination to review and evaluate all data on-line.
The visual examination process utilized enhanced VT-2 methodology with camera resolution established on characters less than or equal to.105' high, representative of VT-3 sensitivity.
(Ref: Section 3, Figure No's: 1 & 2)
Examination Process An examination Scan Plan (Section 2.0) was developed in order to ensure that examinations were performed in a logical sequence, while minimizing radiation exposure and validating positional accuracy.
A total of 15 scan sequences were performed to examine all penetrations. During the examination of each penetration, the head area adjacent to the penetration was also visually examined for boron deposits as well as the overall head surface. Each BMI penetration was viewed in two separate 180-degree segments to ensure 100% coverage. In orderto ensure positional verification, the outer peripheral penetration numbers were physically marked on the head surface adjacent to the tube. All of the numbers were video taped during the examination.
Radiation work permit (RWP) No. 27081 was used for the inspection work.
The examination team received 378 mr. in 71 RWP hours.
RESULTS Bare Head Surface Condition The overall condition of the bare head surface was very clean, with minimal coating degradation. The surface of the head and the instrumentation tubing exhibited markings consistent with construction activities. Ref: Section 3: Figure No's: 3 through 12 Observations A dark stain was observed on 25 instrument tubes that originated approximately 1V-2' below the penetration (reference Section 3, Figure No's: 13-16). This condition was reported to site Engineering for evaluation and PER No. 03-016523-000 was generated to document the condition.
2
Sequoyah Unit 2, Cycle 12 - RPV Lower Head Remote Visual Penetration Examination Final Report CONCLUSION All 58 penetrations were accessible and the Vr examination results indicated no detectable boron leakage. A slight discoloration was noted in some areas of the lower head coating; however, no minimal surface corrosion was noted. Examination results for each penetration are contained in Section 2.0.
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SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 1
52 1
F 1
43 6
C 3
10 Af 1
0 X M 0
5 18 C
1 0
2 55 1
0F0 1
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52 180 Fore 1
0:01.20 X MCW 1
43 180 Fore 1
0:01:54 X MCW 1
43 180 Aft 1
0:02:32 _
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52 180 Aft 1
0:03:29 X MCW 2
55 180 Fore 1
0:04:25 X MCW 2
36 180 Fore 1
0:05:24 _
X MCW 2
40 180 Fore 1
0:05:51 X
X MCW BlackStain 2
49 180 Fore 1
0:06:15 X MCW LPMClamp_&Stain 2
49 180 Aft 1
0:07:59 X MCW f
2 40 180 Aft 1
0:08:38 X MCW 2
36 180 Aft 1
0:09:12 X MCW 2
55 180 Aft 1
0:09:45 X MCW 3
45 180 Fore 1
0:10:35 X MCW 3
32 180 Fore 1
0:10:52 X
X MCW Black Stain 3
24 180 Fore 1
0:12:30 X MCW LPM Clamp & Stain 3
58 180 Fore 1
0:13:29 X MCW 3
58 180 Aft 1
0:15:03 X MCW 3
24 180 Aft 1
0:15:28 X MCW 3
32 180 Aft 1
0:16:51 __
X MCW 3
45 180 Aft 1
0:17:12 __
_X MCW 4
22 180 Fore I1 0:18:10 1
____X MCW IStain 4
17 180 Fore 1
0:19:10 __
____x MCW 4
31 180 Fore 1
0:19:46
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31 180 Aft 1
0:20:09
__X MCW 4
17 180 Aft 1
0:20:24 x
IMCW Page 1 SQN U2 RPV Lower Head VT Scan Plan field.xls
Sort (Scan No.)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 4
2:
050 53 18 0
.0 X
Z 9
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0 5
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9 180 Fore 1
0:23:00 X MCW Stain 5
21 180 Fore 1
0:23:42 X MCW 5
54 180 Fore 1
0:24:24 X MCW
_Stain 5
54 180 Aft 1
0:25:00 X MCW 5
21 180 Aft 1
0:25:31 X
MCW 5
9 180 Aft 1
0:25:51 X MCWSti 5
18 180 Aft 1
0:26:06 X MCW 5
53 180 Aft 1
0:21:46 X MCW 6
13 180 Fore 1
0:26:34 X MCW Stain 6
6 180 Fore 1
0:27:20 X MCW Stain 6
23 180 Fore 1
0:28:16 X MCW 6
23 180 Aft 1
0:28:59 X MCW Stain 6
6 180 Aft 1
0:29:37 X MCW 6
13 180 Aft 1
0:30:11 X
MCW 7
37 180IFore 1
0:30:44 x MOW 7
3 180 Fore 1
0:31:04 X MCW 7
12 180 Fore 1
0:31:33 X MCW 7
47 180 Fore 1
0:31:51 X
MOW IStain 7
47 180 Aft 1
0:32:56 X
MOW 7
12 180 Aft 10:33:21
_X M O 7
3 180 Aft 10:34:34
_X M O 7
37 180 A t 0:35:02 1_
_X M O Page 2 SQN U2 RPV Lower Head VT Scan Plan field.xis
Sort (Scan No.)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 44 180 Foe103:5>
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1 180 Fore 1
0:38:14 X MCW Stai 8
5 180 Fore 1
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15 180 Fore I
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27 180 Fore I
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35 180 Fore 1
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35 180 Aft 1
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27 180 Aft 1
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15 180 Aft 1
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0:52:37 X MCW Stain 8
1 180 Aft 1
0:54:20 X MCW 8
10 180 Aft 1
0:56:05 X MCW 8
25 180 Aft 1
0:57:10 X MCW Minute (1/16") white particle at crevice.
Verified with direct VT as non-relevant EnI 8
44 180 Aft 1
0:57:40 X
X MCW Tape No. 1 9
16 180 Fore 1
0:43:47 X MCW Stain 9
2 180 Fore 1
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7 180 Fore 1
0:45:27 X MCW 9
28 180 Fore 1
0:45:51 X
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28 180 Aft 1
0:50:21 X MCW Stain 9
7 180 Aft 1
0:53:39 X MOW Stain 9
2 180 Aft 1
0:55:05 X MOW Stain 9
16 180 Aft 1
0:56:27 X MCW Q
Page 3 SQN U2 RPV Lower Head VT Scan Plan field.xfs
Sort (Scan No.)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 0C 10 50 180 Foe?00:2 C
10 0
21.
10 8
L.
23 10 0
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10 39 1
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0:03:34 X MCW 10 3
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3 180 f 2
0:05:
X MCW Tape No.2 4:22 cts.
Also examined by FCL on Tape 2;- 14:14 10 4
180 Aft 2
0:06:30 _
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11 20 180AtAlso examined by FCL on Tape 2, 13:29 10 10 ft 00806
_____X MCW Cts.
10 29 180 Aft 2
0:09:01 X MCW 10 50 180 Aft 2
0:09:45 X FCL CoatingX MCW 11 19 180 Fore 2
0:01:41 X FCL Tape rezeroed after power loss.
11 11 180 Fore 2
0:03:44 X
FCL 11 20 180 Fore 2
0:04:23 X FCL 11 33 180 Fore 2
0:05:42 I
____X FCL Stains 11 33 180 Aft 2
0:07:15 __
X FCL(
11 20 180 Aft 2
0:08:22 __
X FCL lCoating on tube 11 11 180 Aft 2
0:10:55 X FCL Coating on tube 11 19 180 Aft 2
0:11:45 X FCL Coating on tube 12 48 1 80 Fore 2
0:15:05 XFL San 12 41 180 Fore 2
0:15:27 X
FCL Stains 12 14 180 Fore 2
0:16:04 __
X FCL 12 14 180 Aft 2
0:17:31 X
FCL Coating on tube 12 41 180 Aft 2
0:18:381_
X FCL _
I Page 4 SQN U2 RPV Lower Head VT Scan Plan field.xls
Sort (Scan No.)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 0 8 1
A 0
C C
Fore E
0=
1
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FrU 2
03 13 57 10 For 2
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0.0:20:48
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0:21:32 X FCL 13 30 180 Fore 2
0:22:16 X FCL C
13 42 180 Fore 2
0:23:33
=
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0:24:30 X FCL 13 57 180 Aft 2
0:25:56 X FCL 13 42 180 Aft 2
0:26:43
=
X FCL Taperesidue 13 30 180 Aft 2
0:29:07 X FCL Coatin on tube 13 26 180 Aft 2
0:29:44 X FCL Coating on tube 14 56 180 Fore 2
0:31:28 X
FCL 14 38 1 80I Fore 2
0:32:07 X FCL Coating on tube 14 34 180 Fore 2
0:33:55 X FCL 14 34 180 Aft 2
0:34:53 X
FCL Tape residue 14 38 180 Aft 2
0:35:11 X
FCL 14 56 180 Aft 2
0:36:03 X FCL 15 46 180 Fore 2
0:40:21.
X FCL 15 51 180 Fore 2
0:41:17
___XFLK 15 51 1 0 A t 2
0:42:25
_X FC__
1 5 4 6 1 8 A t 0:4 3:4 -1
_X F C_
Tape No. 2, 36:50 counts to 40:20 counts (General under head visual)
Original Signed 11/14/2003 Original Signed 11/12/2003 Frank Leonard, TVA Level III Date IMatt Welch, TVA Level III Date I
___T_____I__IT__T_____I__II__I__I c-K.
Page 5 SQN U2 RPV Lower Head VT Scan Plan field.xIs
Sort (Penetration ID)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 2
8 0
- 1.
X 0 1 1
Af 9
0 Fore 1-04 X
z
.10 0 1 0:X C
7 3 1
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0:63 Comments 8
1 180 Fore 1
0:38:14 X MCW 8
1 180 Aft 1
0:54:20 X MCW 9
2 180 Fore 1
0:44:57 X
MCW Stain 9
2 180 Aft 1
0:55:05 X MCW Stain 7
3 180 Fore 1
0:31:04 X MCW 7
3 180 Aft 1
0:34:34 X MCW Stai 10 4
180 Fore 2
0:02:55 X MCW 10 4
180 Aft 2
0:06:30 X MCW cts.
8 5
180 Fore 1
0:38:44 X MCW 8
5 180 Aft 1
0:52:37 X MCW Stain 6
6 180 Fore 1
0:27:20 X MCW Stain 6
6 180 Aft 1
0:29:37 X MCW 9
7 180 Fore 1
0:45:27 ___
X MCW 9
7 180 Aft 1
0:53:39 x
MCW Stain 101 8
18011Fore 2
0:02:32 _____
X MCW 10 8
180 Aft 2
0:08:06 X
FMCW Cts.
5 9
180 Fore 1
0:23:00 X MCW Stain 5
9 180 Aft 1
0:25:51 X
MCW 8
10 180 Fore 1
0:37:47 x
MCW 8
10 180 Aft 1
0:56:05 X
MCW 11 11 180 Fore 2
0:03:44 _
X jFCL 11 11 180 Aft 2
0:10:55 _
X FCL Coating on tube 7
12 180 Fore 1
0:31:33 X MCW Stai 7
12 180 Aft 1
0 3 : 1 X
M CW 6
13 180 For 1
0:63I
_X MCW IStain K-Page 1 SQN U2 RPV Lower Head VT Scan Plan field.xis
Sort (Penetration ID)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan o60 1
M CC 1
4 8
2 2
0 0o 1
9 1
0 TapeFCount 0
Lo.
C o mm ent U
IM 0
0 a
00 hr_ mn ec w
CLO MO 0
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13 180 Aft 1
0:30:11 __X MCW 12 14 180 Fore 2
0:16:04 X MCW 12 14 180 Aft 2
0:17:31 X FCL Coatin on tube 8
15 180 Fore 1
0:39:06 X
MCW Stain 8
15 180 Aft 1
0:51:11 1X MCW ta 9
16 180 Fore 1 0:43:47.
X FCL STain r oearwrs 9
16 180 Aft 1
0:56:27 _
X MCW Coatingontube 4
17 180 Fore 1 0:19:10 X MCW 4
17 180 Aft 1
0:20:24 X MCW 5
18 180 Fore 1
0:22:00 1X MCW Stain 5
18 180 Aft 1
0:26:06 X
MCW 11 19 180 Fore 2 0:01:41 X FCL Tape rezeroed after power loss.
11 19 180 Aft 2
0:11:45.
X FCL Coating on tube 61 20 180 Fore 2
0:04:23 _
X FCL 61 20 180 Aft 2
0:08:22 X FCL Coating on tube 5
21 180 Fore 1
0:23:42 X
MCW Stain 5
21 180 Aft 1
0:25:32 X
MCW 4
22 180 Fore 1
0:18:10.
X MCW Stain 4
22 180 Aft 1
0:20:59 X
MCW 6
23 180 Fore 1
0:28:16 x
MCW 6
23 180 Aft 1
0:28:59 __
X MCW Stain 3
24 180IFore 1
0:12:30 x
MCW LPM Clamp & Stain 3
24 180 Aft 1
0:15:28
_X M W 8
25 18 ore 1
0:36:33
_X M C Sti 8
2 5 1 8Af 0: 7 1 M W Q
Page 2 SQN U2 RPV Lower Head VT Scan Plan field.xis
Sort (Penetration ID)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 13 26 18 Foe202E3 C
1 0 f 2
=
8 2
1 8
27 2
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09
=
=
9 28 Tape Count 1
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10 0
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- X (0
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z w.S Comments 13 26 180 Fore 2
0:21:32 X FCL 13 26 180 Aft 2
0:29:44 X FCL Coating on tube 8
27 180 Fore 1
0:40:15 X MCW Stain 8
27 180 Aft 1
0:49:08
=
X MCW Stain 9
28 180 Fore 1
0:45:51 X
X MCW 9
28 180 Aft 1
0:50:21 X MCW Stain 10 29 180 Fore 2
0:01:35 X MCW 10 29 180 Aft 2
0:09:01
=
=
=
X MCW 13 30 180 Fore 2
0:22:16 X FCL 13 30 180 Aft 2
0:29:07 X FCL Coating on tube 4
31 180 Fore 1
0:19:46 X MCW 4
31 180 Aft 1
0:20:09 X MCW 3
32 180 Fore 1
0:10:52
=
X MCW Black Stain 3
32 180 Aft 1
0:16:51 X MCW 11 33 180 Fore 2
0:05:42 X FCL Stains 11 33 180 Aft 2
0:07:15 1
_X FCL I
14 1 34 180 Fore 2
0:33:55 X FCLQ 14 34 180 Aft 2
.0:34:53
___X FCL Tape residue 8
35 180 Fore 1
0:41:10
_____X MCW Stain 8
35 180 Aft 1
0:48:17 X
MCW 2
36-180 Fore 1
0:05:24
___x MCW 2
36 180 Aft 1
0:09:12 X MCW 74 37 180 Fore 1 0:30:44 _
X MCW Coatingontube 737 1 0 A t 1
0:35:02
_X M C 14 38 10 Forel 2
0:201
________XFL Caing on tube I
Page 3 SQN U2 RPV Lower Head VT Scan Plan field.xis
Sort (Penetration ID)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan 1
3 18 6C6
.c
=
C 1
0 2
2 3
3 Tape ount 5
-a 2
c"o-a 4E 1
2 40 18 Af 1
0:83M X MCW cn
- a.
.. iO i-hrs:min:sec ix 0
- 00) 0&~
0 z
sComments 12 41 180 Fore 2_
0:1527__.
X FCL 14 38 180 Aft 2
0:35:11 X
FCL 10 39 180 Fore 2
0:03:34 X
MCW 10 39 180 Aft 2
0:05:55 X
MCW Tape No. 2 X
4:22 cts.
2 40 180 Fore 1
0:05:51 X MCW 2
40 180 Aft 1
0:08:38 X MCW 12 41 180 Fore 2
0:15:27 X FCL 12 41 180 Aft 2
0:18:38 X
X FCL 13 42 180 Fore 2
0:23:33 X
FCL 13 42 180 Aft 2
0:26:43 X
FCL 1
43 180 Fore 1
0:01:54 X
MCW 1
43 180 Aft 1
0:02:32 X
MCW 8
44 180 Fore 1
0:35:55 X
MCW 8
44 180 Aft 1
0:57:40 X
X MCW Verified with direct 3
45 180 Fore 1
0:10:35 X MCW 3
45 180 Aft 1
0:17:12 X
MCW 15 46 180 Fore 2
0:40:21 X FCL 15 46 180 Aft 2
0:43:41 X
FCL 7
47 180 Fore 1
0:31:51 X
MCW Stain 7
47 180 Aft 1
0:32:56 X
MCW 12 48 180 Fore 2
0:15:05 X
FCL Stains 12 48 180 Aft 2
0:20:48 X FCL 2
49 180 Fore 1
0:06:15 x
MCW 2
49 180 Aft 1
0:07:59 _
X MCW 10 50 180 Fore 2
0:00:25 X
MCW 10 50 180 Aft 2
0:09:45 X
MCW 15 51 180 Fore 2
0:41:17 X
FCL Page 4 SQN U2 RPV Lower Head VT Scan Plan field.xls
Sort (Penetration ID)
SQN Unit 2, Cycle 12 RPV Lower Head, Remote Visual Scan Plan o
03 a
U 1
52 18 Af 1D:3:9XIC 6
50 1
F 5
54 180f
- 50 C
z 5
180 F
1.
2
~.'
5 180 A05_
14 56 18 Foe2
- 128===
C 14 56 Tape18ount 00 0:36:03XF 1
5 0
For 2
0 4 0 a
=
=
X cn Q.
.. j o
hrs:min:sec Ix M a.
aMo 0
Q~ 0 z
W.
Comments 15 51 180 Aft 2
0:42:25 X FCL 1
52 180 Fore 1
0:01:20 X MCW 1
52 180 Aft 1
0:03:29 X MCW 5
53 180 Fore 1
0:21:21 counsX MCW underheadvisual) 5 53 180 Aft 1
0:21:46
__X MCW 5
54 180 Fore 1
0:24:24 1__
x MCW 5
54 180 Aft 1
0:25:00 X
MCW 2
55 180 F7ore 1
0:04:25 X
MCW 2
55 180 Aft 1
0:09:45 X
MCW 14 56 180 Fore 2
0:31:28 X
FCL 14 56 180 Aft 2
0:36:03 X
FCL 13 57 180 Fo~re 2
0:24:30 X
FCL 13 57 180 Aft 2
0:25:56 X
FCL 3
58 180IFore 1
0:13:29 X IMCW 3
583 180 Aft 1
0:15:03 x
IMCW I
Tape No. 2, 36:50 counts to 40:20 counts (General under head visual)
Original Signed 11/14/2003 Orikqnal Signed 11/12/2003
[ Frank Leonard, TVA Level IlIl Date Matt Welch, TVA Level IlIl Date 7
III I I
I I
I1=11
_IITI I I I
I 111 r
Page 5 SQN U2 RPV Lower Head VT Scan Plan field.xis
Sequoyah Unit 2, Cycle 12-RPV Lower Head Remote Visual (VT-2) BMI Penetration Examination Final Report Figure I Figure 2 Resolution check @ 14" Resolution check © 38" Figure 3 - BMI No. 25 Figure 4 - BMI 26 General Condition General Condition Figure 5 - BMI 26 Figure 6 - BMI 33 General Condition General Condition I
,]
I l;.
b
%.,4 Sequoyah Unit 2, Cycle 12 - RPV Lower Head Remote Visual (VT-2) BMI Penetration Examination Final Report IO Figure 7 - BMI 46 Figure 8 General Condition General Lower Head Surface Condition Figure d General Lower Head Surface Condition Figure -u General Lower Head Surface Condition Figure 11 Figure 12 General Lower Head Surface Condition General Lower Head Surface Condition 2
1, u
s at~~~.
.i5._
I, t
-o Sequoyah Unit 2, Cycle 12 - RPV Lower Head Remote Visual (VT-2) BMI Penetration Examination Final Report Figure 13 - BMI 23 Figure 14-BMI 24 General View of Black Coating/Stain General View of Black Coating/Stain Figure 15 - BMI 24 Figure 16 - BMI 25 General View of Black Coating/Stain General View of Black Coabng/Stain 3
SQN Unit 2, Cycle 12, RPV Lower Head VT Resolution Check Verifications Tape Examiner Visual Exam Character Date Time No.
Count Initials Card ID No.
Height Distance Results Comments 11/11/03 2210 1
0:00:30 MCW 285
.105" 38" SAT VT Card at Nozzle No. 55 11/12/03 510 2
0:00:15 MCW 285
.105" 38" SAT 11/12/03 900 2
0:11:04 FCL 285
.105" 14" & 38" SAT 11112/03 0:00 2
0:45:28 FCL 285
.105" 14" & 38" SAT Original Signed 11/13/20031 Frank Leonard, TVA Level Il1 Date
_I I
_I__
Original Signed I
11/12/2003l Matt Welch, TVA Level Il1 Date
'U I
4 9
I 4
I 4
4 4
9 4
- 4.
9 4
- 4.
9 I
4 I
I 4
I 4
+
I I
4 I
I 4
I 4
4 I
I 4
I 4
- 4.
I 4
4 I
I 4
I 4
4 I
4 4
I I
I 1
A.
I A.
I Visual Vedficabon Checks.xis
ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 Reactor Pressure Vessel (RPV)
Lower Head Examination Results (Exterior Residue Analysis)
SQN Unit 2 Cycle 12 (U2C12) Refueling Outage (RFO)
Bottom Mounted Instrumentation (BMI)
Thimble Guide Tubes, Exterior Residue Analysis
Background:
During the SQN U2C12 RFO, a remote visual examination was performed to evaluate the integrity of the BMI's by looking for evidence of leakage from the vessel at each penetration. South Texas Plant recently identified leakage in this area prompting SQN to perform this examination. The inspection was performed by VISTA' s and evaluated by TVA Level III inspectors and was determined to be acceptable, i.e., no indication of reactor coolant leakage from the penetrations. During the inspection, however, residual deposits were identified on the exterior surface of the guide tubes that were either white or dark reddish in color. The dark substance was also described as "tar-like".
SQN has initiated PER 03-16523 to document and evaluate these findings.
Discussion:
Several attempts were made to obtain a representative sample of the residual deposits to perform chemical analysis.
Due to the tightly adhering nature of the deposits, pure samples were extremely difficult to obtain. Wet sponge swipe tests as well as residual scrapings were both attempted.
The swipe test performed showed some evidence of boron.
This is most likely associated with the "white" substance and is likely boric acid residue remaining after leakage that occurred during reactor cavity flood-up.
The boric acid deposits are dry and have historically not adversely affected stainless steel and nickel alloy materials.
Discussions with site personnel involved in the construction phase of SQN have led to the determination that the substance described as dark and "tar-like" is most likely residue from flagging tape (non-adhesive) used for identification purposes.
The flagging was not removed prior to startup and has consequently melted and adhered to the surface of the guide tubes.
The chemical analysis performed on this residue does indicate the presence of some fluorides, chlorides, and sulfates.
An accurate measurement of total halogens and sulfates associated with this residue could not be qualified due to the irregular nature of the surfaces (small diameter pipe) and the difficulty in obtaining the samples.
However, the quantities reported do not appear to E2-1
be an alarming level from a consideration of stress corrosion cracking.
In addition, the unit is in the twelfth cycle of operation and has never identified any problems such as reported leakage in this area.
Westinghouse considers the BMI's to be a Class D cleanliness level as defined by Westinghouse Process Specification 292722.
This level of cleanliness specifies that surfaces be free of contaminating materials such as grease, oil, and dirt but does not require testing to ensure halogen levels are below specified levels. The other Westinghouse. cleanliness levels do require surface testing to determine halogen levels.
Stress corrosion cracking of the BMI's is not believed to be an issue due to the residual material from the flagging material based on the above evaluation. In order to further substantiate this determination, a liquid penetrant examination using the fluorescent water washable method (N-PT-7) has been performed on three guide tubes (#26, #30, and #46). No recordable indications were identified during the non-destructive examination.
Final disposition of this issue is documented in PER 03-16523.
E2-2