ML20236D202

Summary of 890307 Meeting W/Licensee in Rockville,Md to Discuss Licensee Proposed Methodology for Cable Separation. Attendance Roster Listed in Encl 1 & Licensee Viewgraphs in Encl 2

ML20236D202
Person / Time
Site:	Browns Ferry
Issue date:	03/14/1989
From:	Moran D Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8903220520
Download: ML20236D202 (10)

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• g UNITED STATES -

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NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 March 14, 1989 f

w Docket No. 50-260 LICENSEE: Tennessee Valley Authority FACILITY: Browns Ferry Nuclear Plants, Units 1, 2 and 3

SUBJECT:

BROWNS FERRY CABLE SEPARATION - STATISTICAL SAMPLING On Tuesday, March 7,1989, the TVA Projects Division staff met with TVA at One White Flint North, Conference Room 6-B-13 to discuss TVA's proposed methodology for resolving electrical cable' separation issues at Browns Ferry, Unit 2. The attendance roster is Enclosure 1.. The TVA viewgraphs are Enclosure 2. The discussion included methods for satisfactorily determining the acceptability of V /V , and V c Enclosure 2. During tbe $1scussi$n,ablethe methodologyseparation as summarized TVA intends to use on in '

determination of acceptability for V /V separation was reviewed. TVA modified its methodology on V4 /V5 ' 4 5 i 1

Concerning 1V /V cable, refer to Pages 1 and 2 of Enclosure 2. V /V, are very 3

lowamperagefofexample,faultcurrentsare10-50milliamp;upto50V;and typically 14 gage to 18 gage wire. TVA noted that short circuit currents that can be generated in this category are less than the ampacity ratings of these- l cables and hence, TVA proposes to do nothing except Appendix R cables which are estimated to be less than 100 cables. The staff suggested that a worst case analysis be included in the submittal to justify the basis.  !

I For Appendix R cable, TVA will evaluate all cables and either verify that these cables do not leave the fire zone or if they do, TVA will perform ,

field inspection or signal trace the cables to evaluate the cable separation  ;

requirement for Appendix R. j Concerning V cable, refer to Page 3 of Enclosure 2: The total population of V}mesthenumberofVsafety t

ca$les safety cables. Thisismakes 5500.theAssociated cablesofare approxim total V2 population safety and associated3cables about 22,000 cables. TVA has a 5 ample of 155 V3 I (80 ampacity, 75 Appendix R) cables including 23 associated cables. This  !

sample was made for another purpose and focused on design significance. TVA 1 found two failures to meet separation requirements associated with ampacity in i this sample. In addition, discrepancies were' identified for Appendix R cables.  !

Based on this discussion the staff proposed the following methodology for V 3 i cable and TVA agreed to' consider this methodology. l i

Determine the various population divisions which the total number l (22,000)ofV 3cables is amenable to. l Set a sample size for attainment of a 95-95 confidence level for each population.

Establish acceptance criteria. 1 f0, 8903220S20 890314 9 DR ADOCK 0500 {

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Perform the sampling

. If failure in any sampling, increase sample size to 100% of the l population division.

1 a If pass,_the inference is, the sample is indicative of the related -l population. 1 l

l Concerning V 4 g/V cable. The staff proposed the following methodology and TVA l agreed to consicer it.

1 TVA has a sample of 443 cables; l Determine the number of discrepancies allowable for a 95-95 confidence level; and TVA will review the remaining discrepancies found in V /V 4 5. )

If the discrepancies are within the allowable limit for the desired confidence level, the sampling will enable the determination of the acceptability of the V,/Ve cable. Otherwise,TVA will increase the sample size to 100 percent of the .

p5puTation. TVA will complete the draft written to document the methodologies I for acceptance of cable separation at Browns Ferry, and put it on the docket. ,

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/ i Ly}: .,l ., %i j David H. Moran, ojectMana TVA Projects Division ~

Office of Nuclear Reactor Regulation 1 .

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Enclosures:

1. Attendance List l 2. TVA Viewgraphs l

cc w/ enclosures:

See next page l

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3- Browns Ferry Nuclear Plant j i

cc: J Regional Administrator, Region II General Counsel Tennessee Valley Authority U.S. Nuclear Regulatory Commission 400 West Summit Hill Drive 101 Marietta Street, N.W.

E11 833 Atlanta, Georgia 30323 j Knoxville, Tennessee 37902 i Resident Inspector / Browns Ferry NP Mr. R. L. Gridley U.S. Nuclear Regulatory Commission Tennessee Valley Authority Route 12, Box 637 SN 1578 Lookout Place Athens, Alabama 35611 Chattanooga, Tennessee 37402-2801 Mr. C. Mason Dr. Henry Myers, Science Advisor ,

Tennessee Valley Authority Committee on Interior l Browns Ferry Nuclear Plant and Insular Affairs P.O. Box 2000 U. S. House of Representatives i Decatur, Alabama 35602 Washington, D.C. 20515 Tennessee Valley Authority Mr. P. Carier Rockville Office Tennessee Valley Authority 11921 Rockville Pike '

Browns Ferry Nuclear Plant Suite 402 P.O. Box 2000 Rockville, Maryland 20852 Decatur, Alabama 35602 Mr. Oliver D. Kingsley, Jr.

Mr. D. L. Williams Senior Vice President, Nuclear Group Tennessee Valley Authority Tennessee Valley ~ Author,ity 400 West Summit Hill Drive 6N 38A Lookout Place W10 885 1101 Market Street Knoxville, Tennessee 37902 Chattanooga, Tennessee 37402-2801 l Chairman, Limestone County Commission ,

i P.O. Box 188

Athens Alabama 35611 Claude Earl Fox, M.D.

State Health Officer State Department of Public Health State Office Building Montgomery, Alabama 36130 t

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ENCLOSURE 1 4

MEETING ATTENDANCE LIST MARCH 7. 1989 NRC/TVA MEETING ON CABLE SEPARATION ISSUES AT BROWNS FERRY ROOM 6-B-18 l i

NAME AFFILIATION David H. Moran NRC/TVA David T. Langley TVA 3 J. D. Collins TVA l P. J. Schaffer Sargent and Lundy M. Amin Sargent and Lundy D. Lurie NRC/ ARM Angelo Marinos NRC/TVA Gerry Gears NRC/TVA Fred Paulitz NRC/TVA

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David Skridulis TVA Jim D. Hutson TVA  ;

Philip Polk TVA/Rockville }

Rex G. Wescott NRC/TVA l

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l ENCLOSURE 2 ELECTRICAL CABLE SEPARATIONS l

V3 AND V1/V2 CABLES

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BROWNS FERRY NUCLEAR PIAV" l

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l MARCH 7, 1989

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l V1/V2 CABLES o CABLES CONSIST OF:

COMPtRER INPtTT/OtKPtTT CIRCUITS INSTRUMENT ' TRANSMITTER CIRCUITS RECORDER AND INDICATOR CIRCUITS RTD AND STRAIN GAGE CIRCUITS DETECTOR CIRCUITS ANNUNCIATOR CIRCUITS THERMOCOUPLE CIRCUITS o POTENTIAL SHORT CIRCUIT CURRENTS LESS THAN CABLE AMPACITY - NO EFFECT ON REDUNDANT CIRCUIT o NO REVIEW REQUIRED (EXCEPT APPENDIX R REQUIRED CABLES) o e

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REVIEW OF APPENDIX R V1/V2 CABLES o VERIFY TOTAL POPULATION o EVALUATION DETERMINE INSPECTION NEED'  ;

i FIELD INSPECTION (CONDUIT)  !

- FIELD INSPECTION AND/OR SIGNAL TRACE (CABLE TRAY) 1 1

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l I V3 CABLES

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o '155 CABLES FIELD VERIFIED (AMPACITY, APPENDIX R)

A A o 94 DRAWING DISCREPANCIES (80 - AMPACITY; 14 APPENDIX R) o EVALUATION COMPLIANCE WIDI DESIGN BASIS DEFICIENCIES FOR DESIGN SIGNIFICANT (NO IMPACT ON REDUNDANT FUNCTION) o ACCEPTANCE. CRITERIA - ZERO DESIGN SIGNIFICANCE o FURTHER ACTION (IF REQUIRED)

ROOT CAUSE ANALYSIS 100% REVIEW OF R00r CAUSE POPULATION 4

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,p; Perform the sampling If failure inlany sampling, increase sample size to 100% of the population division.

If pass, the inference.is, the sample is indicative of the related population.

Concerning V 4 /Ve cable. The staff proposed the following methodology and TVA agreed to consider it.

TVA has a sample of 443 cables;

, Determine the number of discrepancies allowable for a 95-95 l confidence level; and TVA will review the remaining discrepancies found in V /V 4 5.

If the discrepancies are within the allowable limit for the desired confidence-l level, the sampling will enable the determination of'the acceptability of the V /V cable. Otherwise TVA will increase the sample size to 100 percent of the i phpuIation. TVA will complete the draft written to document the methodologies for acceptance of cable separation at Browns Ferry, and put it on the docket.

I Original signed by David H. Moran, Project Manager TVA Projects Division Office of Nuclear Reactor Regulation

Enclosures:

1. Attendance List

2. TVA Viewgraphs cc w/ enclosures:

See next page Distribution Docket File NRC PDR Local PDR Those on Attached List (OFC :NRR:TVA/LA :NRR:IVA/PM ,:hiUP" BC :TVA:AD  :  :  :

l NAME :MSims i :AM os :SBlac  :  :  :

DATE:03/I0/89 :03/ /89 :03//f/89 :03// d /89  :  :-  :

nmman wrxwa cae '

DISTRIBUTION FOR MEETING

SUMMARY

DATED: March 14, 1989 Facility: Browns Ferry Nuclear Plant, Unit 2*

,wDocketsFile?'?

NRC PDR Local PDR l

Projects Reading ADSP Reading D. Crutchfield B. D. Liaw S. Black R. Pierson D. H. Moran '

G. Gears M. Simms F. McCoy J. Rutberg D. Lurie A. Marinos H. Garg F. Paulitz ACRS(10) ,

GPA/PA l GPA/CA (M. Callahan) (5) l S. Varga  !

E. Jordan I B. Gr'.ir; P. Gi 11,  !

J. Scarvorough G. Marcus l

T. Elsasser L. Norrholm C. Ader BFN Rdg. File

• cc: Licensee / Applicant & Service List

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