ML20206G374
| ML20206G374 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah |
| Issue date: | 11/04/1988 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20206G037 | List:
|
| References | |
| NUDOCS 8811220253 | |
| Download: ML20206G374 (2) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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SAFET) EVALUATION REPORT BY THE OFFICE OF SPECIAL PROJECTS EMPLOYEE C0' CERN ELEMENT REPORT 22110 (B)
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USE OF SNUBBERS i
TENSESSEE VALLEY AUTHORITY SECUOVAH NUCLEAR POWER PLAET. UNIT 1 DOCKET NO.: 50-327 1.
STATEMENT Or EP:LOYEE C0' ctRN The basis for Element Repert 22110 (B), Rev.1. Dated December.'s0,1956 is enleyee cencern SQN.F.6-001-02 which states that the Upper 'ead d
injection Systen vertical riser requires a rigid support where a snubber a
was usec.
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!!. SUw?M Y OF ISSUE
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A rigid type sup; ort is specified in the piping analysis for a specific location on the vertical riser of the Upper Head Injectica (VHI) system, but the detail drawings and as-built condition show use of a snubber at this location.
UH! has a plant safety-related function.
!!!. EVALLATION l
In Merch 1986, this discrepancy was identified by TVA in a significant ccrdition report SCR SQN CEB 8615. Elernent report 22110 (B), Rev.1.
recognizec the empic In a subsequent letter J.A. McEenald (TVA) yee concern as valid.to B.J. Youngblood (NRC), Dated l
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responding to an NRC request for additional inforr.ation, the root cause of this disparity between thk pipe support analysih and the al built 2
1 concition was given as a lack of attention to detail, specifically, that Jn engineering judgeFent w3s made regarding support orientation and design I
without proper documentation and comunication to in erfacing groups.
t The letter also identified a 100t (nginee-ing revies of all snubbers in the plant against the piping analyses, and confirme this instance to be a single, isolatec case. The T'.A re-analysis (060v104 15 01) of the UH!
3 pipe restraint at this location utilizirig a snubber demonstrated the use of the snubber to be an adequate design, able to sustain required seismic j
and therr.al stress levels. TVA has identified this as an acceptable
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resciution to the issue. Tre st:ff believes the depth and extent of the review tc be adecuate and concurs that installation of the snubber is j
acceptatie, and the rt;iace ant of the snutbet' is not necessary.
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8011220253 88;104 PDR AfOCK 05000327 P
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L The corrective action has been tracked under terrective Action Track.ng (CATD) 2211~ SON 01, and was reported as completed and verified Docurer:
for Secucyah Unit 1 on July 11, 1988.
The proble-described in the CATD has also been tracxed by SCR SON CEB FE15.
The piping analysis 0600104-15-01 was r',norted as completed and verified in the Tracking and Reporting of Open Items (TROI) document dated September 12, 1958.
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CONCL US10'.
i The issue conc 3rning ER 22110 (B), Use of Snubbers, has been substantiated.
The staff finds the licensee's corrective action to be adequate and acceptable for SON, Unit I restart.
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