ML18033B150

Summary of 900118 Meeting W/Util in Rockville,Md to Continue Discussions on Resolution of Cable Installation Issues. Concerns Raised Re Ranking Methodology Which Would Take Credit for Cables Tested at Sequoyah.Handouts Encl

ML18033B150
Person / Time
Site:	Browns Ferry
Issue date:	01/29/1990
From:	Gears G Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9002060283
Download: ML18033B150 (22)

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UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Docket No. 50-260 January 29, 1990 LICENSEE:

Tennessee Valley Authority FACILITY:

Browns Ferry Nuclear Plant, Unit 2

SUMMARY

OF MEETING WITH TENNESSEE VALLEY AUTHORITY HELD ON JANUARY 18, 1990 TO DISCUSS THE BROMNS FERRY NUCLEAR PLANT, UNIT 2 CABLE INSTALLATION PROGRAM (TAC 00421)

On January 18, 1990, the NRC staff met with the Tennessee Valley Authority (TVA or the licensee) at the NRC offices in Rockville, Maryland to continue discussions on resolution of the Browns Fer ry cable installation issues.

A list of attendees is attached as Enclosure l.

Enclosure 2 provides TVA's handouts used in its discussion with the staff.

This meeting was a follow-up of a previous meeting between NRC and TVA held on December 18, 1989 (Meeting Summary dated December 22, 1989).

The following points highlight discussions concerning TVA's proposed actions to resolve the cable installation issues at Browns Ferry, Unit 2:

1.

TVA proposed a cable test program involving high potential testings at voltage levels of 240 volts per mil based on the qualified thickness of cable insulation not to exceed 7200 volts d.c. or 805 of the values set by Industry Standards.

These upper bounds were placed only to assure that low voltage coaxial cables, which are generally more heavily insulated for the purpose of maintaining higher insulation resistance, are not subjected to unnecessarily higher voltage levels than the insulation can safely withstand without undue risk of damage during testing.

The staff indi-cated that it would accept the application of the above upper bounds provided that each case, where the upper bounds are applied, will be specifically evaluated.

2.

TVA reported -that the proposed tests will be conducted in the same manner as tests previously conducted at its Sequoyah facility with test voltage duration and acceptance criteria consistent with those applied during the

'able test program at Sequoyah.

3.

TVA further reported that all tests will be conducted, where possible, in conduits where water can be introduced in order to maintain firm electri-cal ground during the test.

In the event where a conduit cannot be flooded with water (i.e., wet testing),

because of plant safety considera-

tions, an evaluation would be made for alternate conduit selection.

The principal aim would remain the selection of a large number of conduits that could be wet tested by flooding.

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4.

TVA also reported that it was its intent to test up to 15 conduits at Browns Ferry, Unit 2.

However, if the sidewall bearing pressure (SWBP) calculations demonstrate, prior to completion of testing, that the con-duits tested at Sequoyah are conservatively bounded by the SWBP values calculated for the selected Browns Ferry cables, then credit would be taken for those tests.

5.

TVA proposed to select 109 conduits for evaluation from a total popula-tion of about 1300 conduits.

This screening selection is based upon length of conduit, conduit fill, and bend radius.

These conduits will be further ranked based upon presence of pullbys, and the top 30 will be walked down and reranked.

For the top 30 reranked conduits, TVA proposed to select 15 either for testing or comparison to the Sequoyah tested conduits.

The staff expressed concerns about the ranking methodology which would take credit for cables tested at Sequoyah.

The staff indicated that if the reranking of the top 30 conduits following the walkdowns indicates a significant shift in ranking order from that established during the initial effort, other actions may need to be taken.

Additionally, the staff indicated to TVA that full credit for the Sequoyah test results may not be appropriate.

This is because most of the conduits tested at Sequoyah were not wet tested.

Because of the cable damage findings at Watts Bar, the staff believes that a higher level of assurance is required to verify the integrity of cable installation at Browns Ferry.

6.

The staff further stated that the validity of the TVA's SWBP calculations and proposed threshold values used to establish worst case cable runs at Watts Bar is still under staff consideration.

The staff and TVA had two follow-up telephone conference calls on January 19 and January 22, 1990.

These calls re-emphasized the above points and further emphasized that if.correlation among the top 30 cables is not established by the walkdown, additional efforts including walkdown of the 109 conduits may need to be done.

In the January 22, 1990 call, TVA committed to submit its proposed plans for cable testing and final resolution of this issue.

Enclosures:

1.

Attendance List 2.

TVA Handout Original signed by Gerald E. Gears, Project t~ianager TVA Projects Division Office of Nuclear Reactor Regulation cc w/enclosures:

See next page

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4.

TVA also reported that it was its intent to test up to 15 conduits at Browns Ferry, Unit 2.

However, if the sidewall bearing pressure (SWBP) calculations demonstrate, prior to completion of testing, that the con-duits tested at Sequoyah are conservatively bounded by the SWBP values calculated for the selected Browns Ferry cables, then credit would be taken for those tests, 5.

TVA proposed to select 109 conduits for evaluation from a total popula-tion of about 1300 conduits.

This screening selection is based upon length of conduit, conduit fill, and bend radius.

These conduits will be further ranked based upon presence of pullbys, and the top 30 will be walked down and reranked.

For the top 30 reranked conduits, TVA proposed to select 15 either for testing or comparison to the Sequoyah tested conduits.

The staff expressed concerns about the ranking methodology which would take credit for cables tested at Sequoyah.

The staff indicated that if the reranking of the top 30 conduits following the walkdowns indicates a significant shift in ranking order from that estab'lished dur ing the initial effort, other actions may need to be taken.

Additionally, the staff indicated to TVA that full credit for the Sequoyah test results may not be appropriate.

This is because most of the conduits tested at Sequoyah were not wet tested.

Because of the cable damage findings at Watts Bar, the staff believes that a higher level of assurance is required to verify the integrity of cable installation at Browns Ferry.

6.

The staff further stated that the validity of the TVA's SWBP calculations and proposed threshold values used to establish worst cable cable runs at Watts Bar is still under staff consideration, The staff and TYA had two follow-up telephone conference calls on January 19 and January 22, 1990.

These calls re-emphasized the above points and further emphasized that if correlation among the top 30 cables is not established by the walkdown, additional effor ts including walkdown of the 109 conduits may need to be done.

In the January 22, 1990 call, TYA committed to submit its proposed plans for cable testing and final resolution of this issue.

Enclosures:

1.,~'Attendance List

'2.

TYA Handout Gerald E. Gears, Project Manager TYA Projects Division Office of Nuclear Reactor Regulation cc w/enclosures:

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MEETING

SUMMARY

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General Counsel Tennessee Valley Authority 400 West Summit Hill Drive ET llB 33H Knoxville, Tennessee 37902 Mr. F. L. Moreadith Vice President, Nuclear Engineering Tennessee Valley Authority 400 West Summit Hill Drive WT 12A 12A Knoxville, Tennessee 37902 Dr. Mark 0. Medford Vice President and Nuclear Technical Director Tennessee Valley Authority 6N 38A Lookout Place Chattanooga, Tennessee 37402-2801

Manager, Nuclear Licensing and Regulatory Affairs Tennessee Valley Authority 5N 157B Lookout Place Chattanooga, Tennessee 37402-2801 Mr. 0. J. Zeringue Site Director Browns Ferry Nuclear Plant Tennessee Valley Authority P.

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Box 2000

Decatur, Alabama 35602 Mr. P. Carier Site Licensing Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P. 0.

Box 2000

Decatur, Alabama 35602 Mr. G.

Campbell Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.

0.

Box 2000

Decatur, Alabama 35602

Chairman, Limestone County Commission P. 0.

Box 188

Athens, Alabama 35611 Claude Earl Fox, M.D.

State Health Officer State Department of Public Health State Office Building Montgomery, Alabama 36130 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street, N.W.

Atlanta, Georgia 30323 Mr. Danny Carpenter Senior Resident Inspector Browns Ferry Nuclear Plant U.S. Nuclear Regulatory Commission Route 12, Box 637

Athens, Alabama 35611 Dr. Henry Myers, Science Advisor Committee on Interior and Insular Affairs U.S.

House of Representatives Washington, D.C.

20515 Tennessee Valley Authority Rockville Office 11921 Rockville Pike

'uite 402 Rockvi1 le, Maryland 20852 Mr. Oliver D. Kingsley, Jr.

Senior Vice President, Nuclear Power Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

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Meetin

Summar, Memoranda for Tri Re orts or Site Visits++

~Docket:Fi 1'e~

NRC PDR Local PDR BFN Reading AOSP Reading J.

Sniezek D. Crutchfield T.

Quay B.

D. Liaw S. Black R. Pierson LA G.

Gears T. Ross B. Wilson, Region II W. S. Little OGC A. Marinos H. Garg D. Carpenter M. Branch R. Borchardt E.

Goodwin A.'ascinatonio ACRS (10)

GPA/CA (M. Callahan)

(3)

E. Jordan B. Grimes J.

Scarborough G. Marcus L. Norrholm C. Ader J.

Gray R. Borchardt

• cc:

Licensee/Applicant 5 Service List

Name J. McCarthy J.

Hutson H. Weber G. Gears R. Pierson A. Marinos H. Garg S. Black D. Carpenter M. Branch R. Borchardt E. Goodwin R. Auluck A. Mascinatonio T. Ippolito M. Medford K. Brown J. Krieg J. Rinne M. Hunt ENCLOSURE 1

ATTENDANCE LIST Affiliation TVA TVA TVA NRC-TVA NRC-TVA NRC-TVA NRC-TVA NRC-TVA NRC-TVA NRC-TVA NRC NRC-TVA NRC-TVA NRC-TVA TVA-Rockvilie TVA TVA-Knoxville TVA TVA NRC-Region II

ENCLOSURE 2

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OPEN ISSUES MEETING

SUMMARY

I

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BOUNDED BY 15 TESTED CONDUITS

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RESOLVES WBN RELATED CONCERNS

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CONSISTENT WITH SQN PULLBY PROGRAM

~ TESTING TO BEGIN ASAP BFN CABLE PULLBYS

OPEN ISSUES NUMBER OF CONDUITS TO BE TESTED

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TEST 3 BFN WHICH EXCEEDED SWBP ALLOWABLES

~ IDENTIFY WORST CASE 30. AT BFN

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COMPARE WITH 15 TESTED AT SQN

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CONTINUE TESTING UNTIL COMBINED (SQNjBFN)

TOP 15 HAVE BEEN TESTED

~ IF FAILURES OCCUR DETERMINE MECHANISMj APPROPRIATE ACTION BFN CABLE PULLBYS

I

OPLI"N ISSUE" S I<ANKING PROCEDUH,g-

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CONDUI'I'S CON'I'AINING 0 OR MORE CABI.LS VJ-V3 OH 4 OR MORL" CAI3LES V4 AND LENG1'll GREATER TIIAN 20 FEE<T

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Pl<OVII)ES LARGL" GI(OUP COMPARED TO POPULATION OF CONCERN

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. 'L<IILL}/RACEWAYI<ADIUS

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CONFIRM PRESENCE OF PULLI3YS

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WALKDOWN TOP 30

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CALCULATE< INS'I'ALLATIONFORCE<S

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RANI( BY SWBP BFN CABLE PULLBYS

OPEN ISSUES POLARIZATION INDEX VS GONO-GO

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MEASURE POLARIZATION INDEX

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ACCEPTANCE CRITERIA 1.0 OR GREATER RETEST IF PI IS LESS THAN 1..0 IF STILL LESS THAN 1.0 DETERMINE FAILURE MECHANISM/ APPROPRIATE ACTION

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CONSISTENCY WITH SQN TEST PROGRAM BFN CABLE PULLBYS

OPEN ISSUES-WEY VS DRY

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WET WIIERE POSSIBLE CONSIDER PLANT SAFETY CONSIDER WATER REMOVAL

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CONSISTENCY WITH SQN TEST PROGRAM HFN CABLE PULLBYS

OPEN ISSUES TEST VOLTAGE SELECTION

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240 VOLTS PER MIL 'I'IMES TElE MINIMUMQUALIFIED'HICI(NESS NOT TO EXCEED 7200 VDC NOT TO EXCEED OOK OF INDUSTRY STANDARD VALUES 5 MINUTE WITHS'I'AND TEST

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PROVIDES CONSISTENCY Wl'I'Il gQN TEST PROGRAM HFN CABLE PULLI3YS

Bl"N CABLE PULLBYS OPEN ISSUES 1,.

TEST VOLTAGE 2.

WE'I'S DRY 3.

POLARIZATION INDEX VS GO-NO GO 4.

RANKING PROCEDURE 5.

NUÃ113ER OI" CONDUI'I'S TO HE TESTED

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Meetin

Summar, Memoranda for Tri Re orts or Site Visits**

Docket File NRC PDR Local PDR BFN Reading ADSP Reading J.

Sniezek D. Crutchfield T. quay B.

D. Liaw S. Black R. Pierson LA G.

Gears T. Ross B. Wilson, Region II W. S. Little OGC-

'.,Marinos H. Garg D. Carpenter M., Branch R. Borchardt E.

Goodwin A. Mascinatonio ACRS (10)

GPA/CA (M. Callahan)

(3)

E.

Jordan'.

Grimes J.

Scarborough G. Marcus L. Norrholm C. Ader J.

Gray R. Borchardt

• cc:

Licensee/Applicant 8 Service List

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