ML20215C407
| ML20215C407 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/05/1986 |
| From: | Hutzler C, Owen D, Stewart D TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20215C295 | List: |
| References | |
| MC-40302-SQN, MC-40302-SQN-R04, MC-40302-SQN-R4, NUDOCS 8612150125 | |
| Download: ML20215C407 (5) | |
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e 1.*
TVA EMPLOYEE CONCERNS REPORT NUMBER: MC-40302-SQN SPECIAL PROGRAM
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REPORT TYPE:
Sequoyah Nuclear Plant Element REVISION NUMBER: 4
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(Final Report)
TITLE: Valve (Cracked) as Related to Material PAGE 1 OF 4 Control REASON FOR REVISION:
Revision 1:
Revised to incorporate Senior Review Panel (SRP) and Technical Assistance Staff (TAS) comments.
Revision 2: Revised to include corrective action, make minor editorial changes and add attachment A.
Revision 3:
Revised to incorporate Senior Review Panel and Technical Assistant Staff consnents.
Revision 4: Revised to incorporate Senior Review Panel comments.
PREPARATION PREPARED BY:
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SIGNATURE DATE CONCURRENCES 861215o125 8 27.
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- SRP:
/2*S~8b SIGNATURE DATE SIGNATURE
- DATE APPROVED BY:
YO &lb F2-5-86 N/A ECSP MANAGRIV DATE MANAGER OF NUCLEAR POWER DATE CONCURRENCE (FINAL REPORT ONLY)
- SRP Secretary's signature denotes full SRP concurrences are in files.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: MC-40302-SQN SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 2 0F 4 I.
INTRODUCTION This report addresses the perceived problem stated in employee concern PH-85-035-002.
It should be noted that this concern was site-specific to Watts Bar Nuclear Plant (WBN) and was made generic to Sequoyah Nuclear Plant (SQN) during evaluation at WBN. This was based on the fact that one of the valves in question at WBN is now installed in unit 2 at SQN.
II.
SUMMARY
OF PERCEIVED PROBLEMS The perceived problem that this report addresses is that one of the 3-inch valves in the top of the unit 2 pressurizer at SQN was previously installed in the same area in unit 1 at WBN and one of these valves is alleged to have a crack or lamination in the valve body that runs into the weld area. The subject valve was identified during the evaluation at WBN to be serial number 1983-3, manufactured by Target Rock Corporation.
III.
EVALUATION METHODOLOGY 1.
Reviewed expurgated file for additional information related to this perceived problem.
2.
Reviewed element report MC-40302 and the subject case file to determine what additional action was required in order to adequately address this concern for SQN.
3.
Witnessed the visual inspection, as performed by both Level II and Level III Nondestructive Examination (NDE) inspectors, for indications of cracks or laminations.
IV.
SUMMARY
OF FINDINGS 1.
No pertinent information was found by reviewing the expurgated file for the subject concern.
2.
Based on a review of Watts Bar element report MC-40302 and the subject case file, it was concluded that Target Rock Valve serial number 1983-3 was the only valve at SQN that required examination for cracks or laminations.
3.
Spare valve serial number 1985-10 was visually examined for cracks or laminations and none were found. This valve was then placed in service replacing the subject valve (serial number 1983-3). The subject valve received a visual inspection of the interior and exterior of the valve body by a Level II NDE inspector. No indications of cracks or laminations were found in the weld areas.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: MC-40302-SQN SPECIAL PROGRAM REVISION NUMBER:
4 3, ~ - -
PAGE 3 0F 4 However, there was an elliptical shaped indication on the interior surface of the outlet side of the valve body adjacent to the indicator tube. This was further evaluated by a Level III NDE inspector and determined not to be a crack, but the specific nature of the indication and the valve's suitability for service was not determined by this inspection (note:
this valve is no longer installed). The indication identified was also present in the valves that were examined at WBN. The indications in the valves at WBN were evaluated and determined to be inherent to the manufacturing process and not detrimental to the safe operation of the valves. Work Requests (WR) B-115224 and 115223 authorized this work and documented the inspections performed.
Conclusion Based on the above and the information learned during the inspection of the other three Target Rock valves that were examined at WBN, the i
indication found in the subject valve is not in the weld area as stated in the perceived problem, and this indication is inherent of the j
manufacturing process for these valves and not a crack or lamination.
l Therefore, the concern is not valid. However, there is no criterion r
to determine acceptability of this particular valve for use, and this I
needs to be addressed by line management.
(See Corrective Action Tracking Document (CATD) Number 40302-SQN-01]
V.
ROOT CAUSE None VI.
CORRECTIVE ACTION Cer'tification by memorandum attesting to the acceptability of the subject valve to be obtained from the vendor.
Reference:
CATD Number 40302-SQN-01 VII. GENERIC APPLICABILITY The perceived problem, that there is a crack or lamination in the valve body that runs into the weld area of the subject valves, was not substantiated.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: MC-40302-SQN SPECIAL PROGRAM REVISION NUMBER:
4
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PAGE 4 0F 4 The secondary issue identified by this evaluation involved an elliptically shaped indication created by the interface of the IR4 indicator tube material and valve body material. This is not a material defect and is therefore not detrimental to the safe operation of the valves. The elliptical indications associated with the material interface may occur in similar Target Rock Valves at Browns Ferry and IR4 Bellefonte Nuclear Plants, but, will not be evaluated at those plants I
since it is a normal condition.
I VIII. ATTACHMENTS Attachment A:
Listing of concerns indicating relationship to Nuclear Safety and Generic Applicability.
i TVA EMPLOYEE CONCERNS REPORT NUMBER: MC-40302-SQN j
SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 1 0F 1 Attachment A Generic Appl QTC/NSRS P#
Concern SUB PLT BBSW Investigation S
Number CAT CAT LOC FL0B Report R
PH-85-035-002 NC 403 WBN NNYY NS T50194 Concern Description The 3" SS Valve located on the top of the pressurizer in unit.1/ system 68, has a lamination crack running through the valve body into the weld zone on weld upstream from valve. Construction Department concern. CI has no further information.
- PSR Codes:
MS--Nuclear Safety-Related SS--Nuclear Safety Significant NO--Not Nuclear Safety-Related I
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