ML20133H671
| ML20133H671 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/15/1985 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 2NRC-5-104, 85-04, 85-4, NUDOCS 8508090448 | |
| Download: ML20133H671 (4) | |
Text
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'Al5 2NRC-5-104 (412) 787-5141 (412)923-1960 l
Nuclear Construction Division Telecopy (412) 787 2629 Robinson Plata. Building 2 Suite 210 July 15, 1985 Pittsburgh, PA 15205 l
United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Dr. Thomas E. Murley Administrator
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Cable Tray Hold-down Clamps Potential Significant Deficiency Report 85-04 Gentlemen:
This Potentially Reportable Significant Deficiency report relating to the T.
J.
Cope cable tray hold-down clamps is submitted pursuant to the requirements of 10CFR50.55(e).
It is anticipated that no additional reports will be submitted with respect to this issue.
DUQUESNE LIGHT COMPANY By J.V.Qarey V
Vice President SDH/wjs Attachment Mr. J. M. Taylor, Director (3) (w/a) cc:
Mr. B. K. Singh, Project Manager (w/a)
Mr. G. Walton, NRC Resident Inspector (w/a)
INPO Records Center (w/a)
NRC Document Control Desk (w/a)
SUBSpR BED AND $1f0RN TO BEFORE ME THIS
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uALh?]Mrcuav Notary Public SHillA 3. FATTORf. MTARY PUSHC 8508090448 050715
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i United States Nuclear Regulatory Commission Dr. Thomas E. Murley Potential Significant Deficiency Report 85-04 Page 2 COMMONWEALTil 0F PENNSYLVANIA )
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COUNTY OF BEAVER
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/), before me, a On this day of said hmmonhalth and County, personally appeared Notary Public in and fo r J.
J.
Carey, who being duly sworn, deposed and said that (1) he is Vice Pres ident of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge.
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kJ Notary Public
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BEAVER VALLEY POWER STATION - UNIT No. 2 DUQUESNE LIGHT COMPANY Report on Potential Significant Deficiency 85-04 Cable Tray Hold-down Clamps 1.
SUMMARY
During efforts to qualify electrical raceway suppo rt systems fo r loads which exceed the original design basis, the SWEC Seismic Raceway Qualifi-cation Group detenained that cable tray hold-down clamps, located at the level of the system's longitudinal brace connections, we re not capable of t rans fe rring the increased loads nor possibly the original loads to the support frame during a seismic event.
2.
IMMEDIATE ACTION TAKEN Upon diccovery of this concern, the BVPS-2 project initiated ef forts to determine the extent of the problem and pos sible so lut ions.
On June 14, 1985, Mr.
S. D. Hall, Acting Manager, DLC Regulatory Af fairs Department, not ified Mr. Jef f Roberte, NRC Region 1, of this potentially reportable deficiency.
3.
DESCRIPTION OF THE PROBLEM During a review of the seismic cable tray support system, the SWEC Seis-mic Raceway Qualification Group noted the existence of a problem due to additional cable and conduit weight resulting fran the BVPS-2 implementa-tion of Regulatory Guide 1.7 5 and fire protect ion requirements.
Spe ci fi-cally, approximately 700 T.
J.
Cope No. 9017 horizontal cable tray hold-down clamps were determined to be subject to increased longitudinal fo rces during a seismic event wh ich could exceed the fr ict ional res is-tance of the clamps.
These conclusions are suppo rt ed by various tests and SWEC anal yse s.
In addit ion, it was de te rmined that clamp slippage might have occurred even if the loads had not been increased.
4.
ANALYSIS OF SAFETY IMPLICATIONS The review of any seismic suppo rt to determine structural adequacy under revised / increased loads may result in suppo rt modi fic a t ions.
These modifications do not indicate a deficiency with the original support, and represent a part of the normal engineering and design process.
Howeve r,
the issue regarding T. J. Cope cable tray hold-down clamps is cons idered to be a potential significant deficiency reportable under the provisions of 10CFR50.55(e) for the following reasons:
a) Tests and analyses indicate that the subject hold-down clamps would a frictional rigid connect ion unde r current, increased not provide loads. These clamps must either be modified or replaced.
b) Elect rical cable tray sup po rt system calcula t ions fo r the original des ign basis cable tray loads did not adequately cons ider longitudi-nal forces on the clamps and the capability of the clamps to provide a frict ional connect ion under these loads.
Specifically, the testing
r
. perfonned by the clamp manufacturer and referenced by SWEC as demon-strating the adequacy of the clamp connect ion, did not include test under simulated longitudinal fo rce s. This condition is considered to
- be a design deficiency.
c) Based on the tests and analyses referenced in a) above, it is pos si-ble that part icular hold-down clamps may have slipped unde r the original cable tray loads in combination with seismic loads. However, l
clamp slippage would not necessarily have led to raceway failures.
d) A nonlinear analyses could be perfonned to determine if the original loads on the hold-down clamps would have caused clamp slippage resulting in failure of a seismic raceway.
However, due to the extensive nature, and uncertainties associated with such an analysis, SWEC's position is that the design deficiency regarding the original cable tray hold-down clamps, if lef t uncorrected, could have resulted in an adverse impact on the safe operations of the plant.
5.
CORRECTIVE ACTION TO REMEDY DEFICIENCY SWEC has issued ESDCR 2P-4740, dated June 18, 1985, changing applicable engineering drawings and providing the modi fication de tails fo r the a f fect ed cable tray hold-down clamps.
Future raceway support installa-tions will be in accordance with the revised drawings; previously installed cable tray hold-down clamps will be modified prior fuel load in accordance with the requirements of E&DCR 2P-4740.
6.
ADDITIONAL REPORTS This is the final report regarding the pot ential significant de ficiency with overloaded cable tray hold-down clamps.
It is anticipated that no additional reports will be submitted.
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