ML18153B730
| ML18153B730 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/09/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 89-337, NUDOCS 8905250230 | |
| Download: ML18153B730 (9) | |
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VIRGINIA ELECTRIC AND* POWER COMPANY RICHMOND, ViRGINIA 23261 39 ::">15 r I: 02 May 9, 1989 U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Gentlemen:.
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 ELECTRICAL CABLE SEPARATION Serial No.89-337 NO/ETS Docket Nos. 50-280 50-281 License Nos DPR-32 DPR-37 In a telephone conference call on May 3, 1989, with Mr. T. Conlon of your staff and Mr.
- E. Grecheck of my staff, we were requested to provide your office with our program to assure separation of Appendix R cables. The attachment to this letter provides a description. of that program, which includes prior to restart, short term, and long term action items.
Should you have any further questions, please cail.
Very truly yours,
~\\,~~
W. L. Stewart Senior Vice President - Power Attachment cc:
U. S. Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555 Mr. W. E. Holland NRC Senior Resident Inspector Surry Power Station 8905250230 890509 PDR ADOCK 05000280 F
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,e ATIACHMENT 1 ELECTRICAL CABLE SEPARATION ASSURANCE PROGRAM
,-----------------------~-- ~
ENGINEERING JUSTIFICATION/ANALYSIS DOCUMENT ELECTRICAL SEPARATION SURRY UNITS 1 AND 2 Revision 7 5/8/89 I.
Problem I I.
Lack of assurance of acceptable train and channel cable separation Reason For Conclusion Deviation Sl-89-629 described specific potential separation problems and made statements indicating the potential for generic separation problems.
Areas for potential separation problems are as follows:
- 1.
Tray markings (color coding) disagreement between drawings and field conditions.
- 2.
NUS 357 interpretation not consistent.
- 3. Justification for Black (non-safety) cables routed with two trains or channels is undocumented.
- 4.
Lack of routing method clarity.
- 5.
Specific cable schedule items which are currently being reviewed.
- 6.
Purple cables noted in black tray.
- 7.
Opposite train cables in same tray.
- 8.
Lack of tray covers required for Appendix R.
- 9.
Unscheduled cables in scheduled tray.
- 10.
Non-fire retardant cable tray.
Purpose A.
Prior To Restart
- 1.
Develop an acceptable level of assurance (95% confidence) of adequate (95% probability) train and channel separation per design criteria requirements for Unit 1 and 2 Appendix R cables.
Resolve the specific items identified in Deviation Sl-89-629 with respect to Appendix R cables.
72-KSB-6428-1
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B.
Short Term C.
- 1.
Revi~w Unit 1 and 2 cable schedule (SE drawings) to verify train and channel separation.
- 2.
Develop a reasonable assurance of the ability to ensure separation for future installations on Units 1 and 2 by upgrading the appropriate procedures and developing additional programmatic controls.
Long Term
- 1.
Develop an increased assurance that safety related and non-safety related circuits are properly separated and scheduled through the company's configuration management program.
III. Methodology A.
Prior To Restart 72-KSB-6428-2
- 1.
Sampling of Appendix R circuits
- a.
The population of Appendix R cables for Unit 1 is 638 cables and for Unit 2 is 572 cables.
- b.
60 cables (List Attached) have been randomly chosen to be physically traced end to end to verify acceptable separation.
With zero cases of unacceptable routing, this quantity achieves a 95 percent confidence level with a 95 percent probability that the remaining cables are separated acceptably.
- c.
Any routing which cannot be shown to be acceptable by_
walkdown or analysis will result in expanding the number of cables to be traced to achieve the 95 percent confidence level and 95 percent acceptability. The sample size required for this assurance is 95 with one failure, 125 with two failures, etc. The* specific routing errors will be resolved by rerouting, adding barr,ers with appropriate fire rating, etc.
- 2.
Sample non-safety related cabie routed with two trains or channels.
- a.
A partial review of cables (1200) on the cable schedule (Unit 1 SE drawings) identified a significant number of cables (120) potentially routed in this manner.
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- b.
60 of these cables (20 power, 20 control, 20 instrumentation) were chosen to be analyzed to verify acceptable separation.
With zero cases of unacceptable routing, this quantity achieves a 95 percent confidence level with a 95 percent probability that the criteria used for specifying routing with multiple trains had been met.
- c.
Any routing which cannot be shown to be acceptable will result in expanding the number of cables to be analyzed to achieve the 95 percent confidence level of 95 percent acceptability.
The sample size required for this assurance is 95 with one failure, 125 with two failures, etc.
The specific routing errors will be resolved by rerouting, adding barriers with appropriate fire rating, etc.
- 3.
Ensure cable tray covers are properly installed on Unit 1 and Unit 2 where required or other mitigating measures taken (e.g. fire watch).
- 4.
Walkdown Unit 1 and Unit 2 trays for potential non-fire rated cables.
- a.
Analyze each potential non-fire rated cable type for fire retardancy.
- b.
Remove unacceptable cables or provide alternative 11coping 11 such as a fire watch.
B.
Short Term 72-KSB-6428-3
- 1.
100 percent review of Unit 1 and 2 Cable Schedules (SE drawing series) for routing errors or discrepancies which could compromise train separation.
- a.
Safety related color routed with another train or channel or in trays with a black designation.
- 1.
Identify population by SE drawing review (Unit 1 complete, 62 apparent discrepancies being analyzed).
- 2.
Analyze acceptability of routing for any anomalies noted.
- 3.
Correct unacceptable conditions found.
- 2.
Provide/revise cable tray schematics for Units 1- & 2.
Schematics will also address cable tray cover requirements.
- 3.
Walkdown safety related trays to assure accuracy of cable tray schematics and correct tray designation in the field by:
C.
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- a.
Verifying correct color code on trays and schematics.
- b.
Identifying change locations between color codes on trays and schematics.
- c.
Marking where covers are not required or special covers are required on trays and schematics.
- d.
Note on the tray schematics apparent separation exceptions which have been evaluated as acceptable.
- 4.
Specification NUS 357 and station procedure EMP-C-EPH-99 will be revised to provide clarification of the Surry design requirements. These design requirements will be the basis for acceptability of both existing cable routings, including evaluation of situations identified with this effort, and future cable routing. Additionally, more specific requirements for tray cover installation will be provided.
- 5.
Items 2 and 3 above will be completed within two months of respective unit startups.
Item 4 will be completed within two months of the Unit 1 startup.
Long Term - Configuration Management Program The following items will be addressed on,a long term basis.
Specific programs and scheduling will be developed under the Configuration Management Program.
- 1.
Continue to sample non-safety related cable routings, and additional safety-related cable routing, to result in increased assurance of correct (i.e. - separated or barriered) routing and scheduling.
- 2.
Improve procedures, standards, and specifications as necessary to assure that future routing is correct.
- 3.
Correct instances found of misrouting and discrepant data in cable routing schedule.
IV.
EVALUATION CRITERIA FOR ASSURANCE OF SEPARATION The evaluation performed to make an accept/reject judgement on specific potential separation problems utilizes a single failure criterion and analysis in accordance with design requirements to ensure train and channel functional redundancy is not lost.
The following conditions are identified as reasons to conclude acceptable separation does not exist for the anomaly identified and to initiate sample size expansion and corrective action:
- 1.
Separation is such that Appendix R compliance is not maintained.
72-KSB-6428-4
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- 2.
Color coded cable routed in opposing train or channel and not analytically acceptable.
- 3.
Color coded cable routed in black tray in which other trains' or channels' cables are routed and are not analytically acceptable.
- 4.
Black cable routed with 2 trains or channels and not analytically acceptable.
V.
SUMMARY
The activities described under methodology as Prior to Restart each increase the assurance that Appendix R cables are properly separated.
The primary component of these activities are the samples of cables to be verified. The 95 percent confidence which will be attained by these samples, or expanded sampling as required, is further enhanced by the other activities listed.
The assurance provided by a 95 percent confidence level that at least 95 percent of Appendix R cables are properly separated is acceptable to allow restart.
The programmatic activities described assure that future installations will not create separation violations after restart and increase the confidence of proper separation.
72-KSB-6428-5
e APPENDIX R CIRCUIT SAMPLE CABLE NO.
TO FROM 1H5PH10*
SWGR15H5 SIA RACK 1J2PH3 BENCHBD 1-1 SWGR-15J2 1J6PL118 BENCHBD 1-1 MCC 1Jl-l-4D 1HlOPL503*
SWGR 1H-15Hl DC DIST. PNLlA 1H5PH3*
BENCHBD 1-1 SWGR 1H-15H5 1JlOPL434 MCC 1Jl-2-4A VERT.BO. 1-1 1J4PH1 l-FW-P-3B SWGR 15J4 1H6PL327*
UPS lA-2 MCC lHl-1 1Ll6 LTG SWBD SECT-2 1Sl2 (LP) 1SOV292*
XMTR 196 BENCHBD 1-2 1SOV691*
RCPV 15C/6 PAMC-1 1SOV706 RCPV* lC/6 PAMC-1 1SOV688*
RCPV 15C/6 PAMC-1 1SOV703 RCPV lC/6 PAMC-1 1SOV683*
-JB-RCPC 15C/6 1SOV263 RCPV lOE/4 BENCHBD 1-1 1SOV264
-JB-RCPC lOE/4 1HlOPL406 MCC1Hl-2-6A BENCHBD 1-1 1H10PL404 RCPV 12C MCC lHl-2 1HlOPL405 MOV 1535 RCPC-12C 1JlOPL386 MCC lJl-2 BENCHBD 1-1 1JlOPL384 RCPV 5A/2 MCC lJl-2 1JlOPL385 RCPC SA/2
- MDV 1536 1SOV68 RCPV 7C/4 BENCHBD 1-1 1SOV69 JB RCPC ?C/4 1NI183 RCPV 13E/2 BENCHBD 1-1 1NI184 RCPC 13E/2 E/P 1137 1NI401 AUX SHTUDN PNL BENCHBD 1-1 1HlOPL26 PS-VS-118A VNTX-R 131/EFW/04282 - 1
APPENDIX R CIRCUIT SAflllPLE CABLE NO.
TO FROM 1J6PL70A MCC 1Jl-.1-4B BENCHBD 1-1 1JlOPL185 LCV-11150 MCC-lJl-2 5A 1H10PL374*
RPA-RK-3A BENCHBD 1-2 1J4PH10 SIBRK #VI MAIN BO REAR 1H4PH7*
MCC 1Hl-1-5C MAIN BO 1-1 1M374 MCC lJl 5A RMT PNL 1JlOPL183 LCV-WT -ll 15C MCC-1Jl-26A 1H6PH3 BENCHBD 1-1 15H6 1J5PH11 SIB-RACK COMP VI 15J5 1J5PH2 BENCHBD 1-1 15J5 1H6PL50 MCC lHl-10 1-SW-PlOA 1J6PL46 MCC-1Jl-1-4B 1-SW-PlOB 1NIB126 PR-17 INST.RM PT-1485 1NIW136 PR-18 INST.RM PT-1474 1Jl6PL1 480SWGR lJl-1 MCC-lJl-1 1H6PL327*
MCC lHl-1 UPS lA-2 lSOV-312 INST. RACK BENCHBD 1-2 lSOV-309 SIA-RACK BENCHBD 1-2 1H6PL10 MCC 1Hl-l-5C l-CC-P-2A 1J6PL117 MCC lJl-40 1-CC-P-2B 1NIB214 LT-1461 RCPC-13C 1NIB215 RCPC-13C RK-20 lNI~lOO MB.RACK-3 BENCHBD 1-1 1J6Plll8 BO 1-1 MCC lJl-140 1JlOPL504 MCC lJl-2 UPSlB-2 1J6PL37 JB EMER GEN RM MCC 1Jl-l-4C 1860 SWGR 15J2 DC DIST PNL-lB 1J6PL65 VENT PNL U-2 MCC 1Jl-l-6A 1M911 REPEATER BE EMER PWR EXPER 131/EFW/04282 - 2