TXX-6138, Interim Deficiency Rept CP-85-31 Re Indeterminate Structural Integrity of Electrical Raceway Support Sys.Initially Reported on 850827.Addl Supports Added & Conduit Supports Modified.Next Rept Will Be Submitted by 870310
| ML20211N714 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/05/1986 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| CP-85-31, TXX-6138, NUDOCS 8612180293 | |
| Download: ML20211N714 (2) | |
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Log # TXX-6138 File # 10110 903.9 TEXAS UTILITIES GENERATING COMPANY BEYWAY TOWER. 480 fv0RTlt OtJVE STREET.1.B. Al. DAllAB. TEXAS 75398 December 5, 1986
".'.Y1". if f.UE gg Mr. Eric H. Johnson, Director p
Division of Reactor Safety and Projects DEC - 9 l986 U. S. Nuclear Regulatory Commission
, l 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 1
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET N0. 50-445
)
ELECTRICAL RACEWAY SUPPORT SYSTEM SDAR: CP-85-31 (INTERIM REPORT)
Dear Mr. Johnson:
On August 27, 1985, we verbally notified your Mr. D. Hunnicutt of a deficiency l
involving the Unit 1 Electrical Raceway Support System. Specifically, due to additional weight imposed by the installation of Separation Barrier Material (SBM) and Radiant Energy Shield (RES) Material without a complete interdisciplinary review and design analysis, the structural integrity of the raceway is indeterminate. As noted in our previous report (TXX-6030, dated October 20,1986), the impact of weights imposed by SBM on Unit 1 Cable Tray Hanger (CTH) Systems is being evaluated as part of the overall CTH design verification activities addressed by SDAR CP-85-35, Cable Tray Hanger Design.
We are reporting this issue under the provisions of 10CFR50.55(e) and the required information follows.
l DESCRIPTION SBM and RES Material have been installed on Class 1E Electrical Raceways l
consistent with FSAR and Regulatory Guide 1.75, Revision 1, " Criteria for the l
Separation of Redundant Class 1E Equipment and Circuits." Preliminary engineering evaluations prior to SBM and RES Material installation did not include analysis to verify that the additional weight imposed by these l
materials would not adversely affect the conduit support system.
Subsequent i
engineering evaluations have resulted in the identification of conduit and conduit support installations which would fail under accident conditions due to overload conditions. Specifically, from a total population of seventeen (17) conduit runs and eight (8) junction boxes, three (3) conduit runs and thirty-five (35) conduit supports were overstressed.
This issue is applicable to Unit 1 electrical raceway systems only.
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Page 2 of 2 Although this concern is not a specific CPRT Program Plan Item, the evaluation and disposition of this issue is being formulated by Ebasco in the course of the Civil / Structural Design Verification Program outlined in CPRT Program Plan Item DSAP VIII. This planned design verification activity is being subjected to third-party overview to assure resolution of external source issues and compliance to CPSES licensing commitments.
SAFETY IMPLICATIONS Failure of seismic category conduits and conduit supports to meet the required design criteria could result in an inability of associated safety-related systems to perform as required for safe operation and shutdown.
CORRECTIVE ACTION The three (3) conduit runs identified will have a total of eleven (11) new supports added and the thirty-five (35) conduit supports identified will be modified. The necessary design changes will be initiated and performed in accordance with approved travelers.
Physical rework is expected to begin in January 1987.
The TUGC0 Engineering Design Control Program has been revised to provide for more' positive interface controls. This revised program
. includes the establishing of procedural requirements for interdiscipline engineering analysis to be performed for all proposed changes, tests and experiments. This program will prevent the occurrence of similar deficiencies.
The identification of additional corrective actions, if required, will be included in our next report.
We anticipate submitting our next report no later than March 10, 1987.
Very truly yours,
/X6C W. G. Counsil DAR/amb c - NRC Region IV (0 + 1 copy)
Director, Inspection & Enforcement (15 copies)
U. S. Nuclear Regulatory Commission Washington, D. C.
20555 l
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