ML20055E208

Summary of 900531 Meeting W/Tva in Rockville,Md Re Plant safety-related Cable Inside Containment.List of Attendees, & Handouts Presented at Meeting Encl

ML20055E208
Person / Time
Site:	Sequoyah
Issue date:	07/05/1990
From:	Donohew J Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9007110152
Download: ML20055E208 (14)

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• ' UNITED STATES . .

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[' g1 NUCLEAR REGULATORY COMMISSION -i g 5 j- WASHINGTON, D. C. 20655 ,

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/ July 5. 1990 j

-Docket Nos. 50-327 and 50-328 .

LICENSEE: Tennessee Valley Authority (TVA)

FACILITYi Sequoyah Nuclear Plant, Units 1 and 2

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SUMMARY

OF THE MAY 31, 1990 MEETING ON SEQUOYAH SAFETY-RELATED CABLE INSIDE CONTAINMENT a d

On Thursday, May 31, 1990, a meeting was held at the headquarters of the TVA J Projects-(TVAP) Division,OfficeofNuclearReactorRegulation,NRC,in-l Rockville, Maryland. The meeting was between the TVAP staff and TVA's repre- 1 sentatives. It was beld at the request of NRC to discuss the safety related 1 cables at- Sequoyah in light of cable damage found at Watts Bar in 1989. In ,

a its letter dated March 28, 1990, TVA submitted an evaluation of its Sequoyah cable testing program and the cable pulling damage found at Watts Bar. The purpose of this meeting was to discuss this evaluation of the Sequoyah cable-- -[

L ' testing program.. Attachment 1 is the list of individuals who attended the L meeting, Attachment 2 is the TVA letter dated March 28, 1990, and Attachment 3 is the handout prescnted by TVA in the meeting. There was no handout from the L

TVAP staff. The following is a summary of the significant: items discussed and the actions, if any, taken or proposed.

The Sequoyah cable testing program was first developed in 1987 to address the i staff's concerns about potential (.able damage during cable installation from a three situations:- (1) cable pullbys, (2) cable jamming, and -(3) vertical i cable supported by 90-degree condulets. The staff's review of this cable stesting program was part of-its review of the restart of Sequoyah from its

!. _ extended shutdown from 1985 to 1988 and is discussed in Section 3.12, Cable Installation, of NUREG-1232, Volume 2, on the Sequoyah Nuclear Performance

" ~ Plan. ' This Safety Evaluation Report was issued by the staff's letter dated' LMay 18, 1988 as part of its approval for Sequoyah Unit 2 to restart. In Section 3.12, the staff concluded that the Sequoyah cable testing program was  !

acceptable for the restart of Sequoyah Units 1 and 2.

In 1989,.significant cable pullby damage was' discovered at Watts Bar. By i

= telephone in December 1989, the staff requested that TVA evaluate the condition

'of.the safety-related~ cables at Sequoyah in terms of the cable damage discovered at Watts Bar. This evaluation was submitted in the TVA letter dated March 28, 1990. TVA concluded in its letter that the previous conclusions drawn from the ,

1987 cable testing program regarding the integrity of safety-related cables at Sequoyah are still valid.

The agenda for the meeting is on the first page of Enclosure 3. A comparision of the criteria used to rank the conduits carrying cables at Sequoyah in 1987 and the criteria- developed in 1989 (i.e., (Lxf)/r) and side wall bearing

. pressure (SWBP) developed following the observed cable damage at Watts Bar to rank conduits is presented on Page 3.

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Enclosure:

3liststhe30worstccnduitsrankedby(1)the(Lxf)/r m

selectioncriteriaand(2)theSWBPselectioncriteriaand.the15 conduits-

tested in 1987.- This is the total of 45. conduits listed on the page. The 15. 'i conduits thet were tested in 1987 are marked on this page by an esterict *. .;

~These 1987 tested conduits are throughout the conduits rented by the above

.two criteria.

In its presentation. TVA stated that for 14: conduits at Sequoyah the. (Lxf)/r and SWBP selection criteria could not be calculated because these conduits .

e :were inaccessible because both units were critical and the areas were now  !

high radiation areas. '

TVA ended its presentation with the suiumary given on Page 8 of Enclosure 2.

h 9: TVA concluded that the 1987 Sequoyah criteria, with its cirphasis on material' f' , -susceptibility, was still bounding and provided a high degree of confidence- .

that no cable pullby damage exists at Sequoyah. l After TVA's presentation, the staff requested that TVA (1) identify the circuits involved with the cables in the conduits with the four highest SWBP values on' Page 7 of Enclosure 3 and (2) estimate the SWBP for the 14 conduits for which TVA had stated that calculations could not be made. The staff requested that TV/s provide this information by a telephone conference call

=by June 7, 1990. With this the meeting ended.

.On June 6, 1990,.in a-telephone conference call, TVA stated the following:  !

(1)thecircuitsinvolvedwiththecablesintheconduitswiththefour-highest SWBP values were safety related circuits including reactor protection-and engineered safety features circuits, and (2) of the 14 conduits for which SWBP values were not calculated, two have no pullbys and the SWBP  ;

does not have to be calculated, ten have been. walked down during the recent 1 Unit I shutdown and the SWBP values will be calculated, and-two still'are inaccessible with Unit 2 at power o > ation.

I ac, i. Donohew, enior Project Manager

?roject.Directora e 11-4 IivisionofReactorProjects-I/11 J Office of Nuclear Reactor Regulation

Enclosures:

1. . Attendance List .

2. Letter dated March 28, 1990 3.. TVA Handout cc w/ enclosures:

See next page 3

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Document-Name: MEETING

SUMMARY

- 5/31

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< cc:

L Mr. Marvin Runyon, Chairman Mr. Joseph Bynum, Acting Site Director  :

Tennessee Valley Authority Sequoyah Nuclear Plant '

ET 12A 7A Tennessee Valley Authority 400 West Sumit Hill Drive P. O. Box 2000 Knoxville, Tennessee 37902 Soddy Daisy, Tennessee 37379

Director Mr. Mark J. Burrynski Tennessee Valley Authority Site Licensing Manager ET 12A 11A Sequoyah Nuclear Plant -

400 West Sumit !!ill Drive P. O. Box 2000 )

Knoxville, Tennessee 37902 Soddy Daisy, Tennessee 37379 Mr. John B. Waters, Director County Judge Tennessee Valley Authority Hamilton County Courthouse ET 12A 9A Chattanooga, Tennessee 37402 400 West Sumit Hill Drive Knoxville, Tennessee 37902 Regional Administrator, Region 11 U.S. Nuclear Regulatory Comission  :

Mr. W. F. Willis 101 Marietta Street, N.W. i

= Chief Operating Officer Atlanta, Georgia 30323 ET 12B 16B 400 West Sumit Hill Drive Mr. Paul E. Harmon Knoxville, Tennessee 37902 Senior Resident inspector Sequoyah Nuclear Plant General Counsel U.S. Nuclear Regulatory Comission Tennessee Valley Authority 2600 Igou Ferry Road 400 West Sumit Hill Drive Soddy Daisy, Tennessee 37379 .

ET 118 33H Knoxville, Tennessee 37902 Mr. Michael H. Mobley, Director Division of Radiological Health tir. Dwight Nunn T.E.R.R.A. Building, 6th Floor Vice President, Nuclear Engineering 150 9th Avenue North Tennessee Valley Authority Nashville, Tennessee 37219-5404 6N 38A Lookout Place 1101 Market Street Tennessee Valley Authority Chattanooga, Tennessee 37402-2801 Rockville Office 11921 Rockville Pike Dr. Mark 0. Medford Suite 402 Vice President and Nuclear Ro.ckville, Maryland 20852 Technical Director Tennessee Valley Authority Mr. Oliver D. Kingsley, Jr.

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

Manager, Nuclear Licensing Chattanooga, Tennessee 37402-2801 and Regulatory Affairs Tennessee Valley Authority SN 157B Lookout Flace Chattanooga, Tonnossee 37402-2801 l

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ENCLOSURE 1 t' \

ATTENDEES AT MEETING OF MAY 31, 1990 i F

Name Affiliation J. Donohew NRC '

I S. Newberry HRC E. Marinos NRC

!. H. Garg NRC M. Burrynski TVA  !

K. Weller TVA ,

i M. Sedlacik TVA B. Kimsey TVA i- R. Collins TVA i

l Affiliation TVA - Tennessee Valley Authority NRC - Nuclear Regulatory Comission h

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. TENNESSEE VALLEY AUTHORITY CH ATTANOOG A. TENNES$EE 3740)

$N 1$78 Lookout Place WAR 281990 U.S. Nuclear Regulatory Commission' '

ATTN: Document Control Desk Washington, D.C. 20$55 Gentlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authorttv ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - REEVALUATION OF CABLE TESTING PROGRAM - WATTS BAR NUCLEAR PLANT (WBN) PULLBY DAMAGE

'A reevaluation of the.SQN restart cable testing program was performed as a result of the cable pullby damage found at WBN. Comparisons were made with the specific sister conduits and with r,onduit installations in jeneral at SQN for certain key considerations that have direct impact on the success of the pullby operation. These parameters included raceway configur.ition, conduit fill, frequency of pull points, and the utilization during pullbys of an abrasive, previously installed parachute cord. Each such comparison identified the presence of practices at SQN that have mlntmized the potential for pullby damage in the cable system.

An additional review was undertaken of the validity of the SQN screening process in light of the WBN findings. This review determined that the damaging mechanism identified at WBN (abraston) was precisely the thrust of the SQN criteria, wherein emphasis was placed on material susceptibilities.

TVA finds that its original ranking criteria were well designed for finding the worst case.

In addition, the results of the SQN high potential withstand tests on a group of cables that had been identified as worst case with respect to the pullby

' concern were reviewed. The.trits were found to be in accordance with typical industry methodology for the .erformance of dielectric testing in general, yet far more conservative than sbndard in situ tests utilized to identify defective installed cables. The test results provide positive, concrete evidence 6f the integrity of cables subject to pullbys at SQN.

TVA finds that the previous conclusions drawn regarding the integrity of the SQN Class'1E cable systems continue to be valid. ,The details of the reevaluation of the SQN cable test progrom are includsd as an enclosure to this!)etter, a,crtr4o5osos ,voom h

An Equal opportunity Employer

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U.S. Nuclear Regulatory Commission MAR 281990 l Please direct questions concerning this issue to Bruce S. Schofield at (615) 843-6172.

Very truly yours, TENNESSEE VALLEY AUTHORITY I1 E. G. Wallace, Manager L Nuclear Licensing and Regulatory Affairs Enclosure cc (Enclosure):

Ms..S. C. Black, Assistant Director forProjects TVA Projects Division U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr.-B. A. Wilson, Assistant Director for Inspection Programs TVA Projects Division --

U.S. Nuclear Regulatory Comml slon

' Region _II  !

101 Marietta-Street, NW, Suite 2900 l Atlanta, Georgia 30323 l: NRC Resident Inspector-Sequoyah Nuc1 car Plant 2600_Igou Ferry Road Soddy Daisy, Tennessee 37379 L

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., ENCLOSURE REEVALUATION OF THE CABLE PULLBY ISSUE AT SEQUOYAH NUCLEAR PLANT (SON) IN LIGHT OF RLCENTLY DISCOVERED PULLBY DAMAGE AT WATTS BAR NUCLEAR PLANT (WBN) 1.0 PURPOSE This report summarizes the results and conclusions of TVA's evaluations of the SQN cable installation in response.to the discovery of pullby damage in Class 1E cable systems at WBN.

2.0 BACKGROUND

During the summer of 1986 NRC began a review of concerns relating to the, adequacy of construction practices at TVA's WBN. The review identified that meny of the concerns centered on potential damage to electrical cables because of alleged improper or inadequate installation practices.

A comprehensive review was performed by TVA to determine if significant

, damage had occurred to cables during their installation at WBN. The review was extended to the cable installation at SQN since the SQN and WBN plants are of the same overall design.

TVA performed a comprehensive evaluation of the issues identified in the NRC's Technical Evaluation Report (TER) for SQN. One issue involved a concern for potential damage to cables as a result of the practice of pullbys (the pulling of cables into occupied conduits).

In order to evaluate the concern. TVA developed screening criter16 to

. . . identify a population of conduits that have sorre credible chance of having sustained conductor insulation damage becaut.1 of pullbys." .

Within that population a worst-case (i.e., highest darnage potential) family was identified. Fifteen of those worst-case condults were then subjected to high potential, in situ testing at 4,800- to 7,200-volt direct current. All 873 conductors in the 298 cables passed the subject -

test. .

TVA concluded that the testing results provided reasonable assurance that past pullby practices at SQN, though now outdated, had resulted in satisfactory cable installation (i.e., no systematic pullby damage).

Following a review of these test results, NRC issued a Safety Evaluation Report (NUREG-1232, Volu.i:e 2) that found the SQN installation to be adequate. ,

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In June 1989, damage was discovered at WBN to five cables in three l conduit segments comprising a single run of condult< The damage was discovered while performing work intended to resolve an employee concern related to potential heat damage to cables as the result of alleged improper welding activities near condults at WBN. Subsequent visual and i laboratory evaluations confirmed that the damage occurred during a pullby. An additional 33,500 feet of cable was removed to assess the scope of that damage and one further instance of pullby damage was noted.

These findings were considered to.be of significant magnitude to warrant l reevaluating the pullby analysis previously performed for the SQN cable installation. This work is described below. j

-3.0 SUPPLEMENTAL CABLE PULLBY ANALYSIS FOR SON l 3.1 The following items were evaluated as part of.a supplemental cable

.pullby analysis for the SQN cable systems performed as a result of the HBN. findings. A detailed evaluation was performed of the SQN conduits and cables that have the same functions as their WBN l

l. counterparts where the pullby damage was identified. This i

( evaluation is described in paragraph 3.2. Further evaluations were performed of other differences in each plant's overall cable installation practices. These evaluations are described in paragraphs 3.3 and 3.4. The SQN pullby screening criteria were reviewed to assets their validity. In addition, an assessment of the conduits that were screened out using the original criteria was performed to ensure that the " lessons learned" from WBN would not i significantly alter the previous SQN ranking. This review is described in Section 3.5. A review of the SQN high-voltage ,

withstand testing is provided in paragraph 3.6. l 3.2 Following discovery of the damaged cables at WBN and the inttlal determination that the damage had been infileted during a pullby, the decision was made to investigate the " sister" conduits and cables at SQN. This review was undertaken to establish the degree c 1: of similarity to the HBN installation with respect to configuration, l' conduit fill, and cable pull sequencing. Walkdowns were performed l to obtain dimensioned 1sometric sketches of the SQN routes. The pulling sequence was determined from the pull cards. Pull tension i and sidewall bearing pressures were calculated using industry  ;

standard methods.

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The calculations established that each of the pullbys in the SQN condults was within acceptable limits, as defined by TVA General Construction Specification G-38 entitled, " Installing Insulated Cables Rated for Up to 15,000 Vnits."

i A comparison of the sketches of the sister conduits at the two plants established that the SQN condults were shorter, had more frequent pull points, and had a lower fill than the WBN condultb. ,

SQN more closely adhered to the. practice of bulk pulling, resulting in fewer and smaller pullbys.

3.3 SQN controlled conduit fill in an effective manner. A review of the 770 condults evaluated at SQN for the issue of pullbys revealed only one conduit that was overfilled (40 percent allowable, 42 percent calculated).. In contrast, conduit overfill has been identified as an issue to be resolved at WBN. As a result, the WBN pullby corrective action plan included direct consideration for overfill in the screening process.

Trie industry has only recently recognized the significance of corduit fill as a risk factor when performing pullbys. Lower fills increase the potential for obtaining a clear path during the pullby operation. The raceway fill at SQN, coupled with bulk pulling, l further ensures that fewer pullbys occurred and that those which did would be small and with less potential for pullby damage.

L 3.4 The final assessment of the WBN cable damege was that it had been L inflictpd during a pullby from a combination of pulling forces and l the rather abrasive parachute cord. In contrast, no evidence exists 1 to indicate that parachute cords were used for making pullbys at Instet.d Insulated pull wires were utlll:ed, resulting in a SQN.

lower coefficient of friction and reduced abrasiveness as conpared L with the parachute cord.

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'( 3.5 The first three condults at WBN in which pullby damage was discovered were determined not to be in the worst-case group as defined by a project specific calculation. Since the criteria for the ranking process applied were a close derivative of that

developed for use at SQN, a reanalysis of the SQN criterla was

! warranted. One criterion in both programs was that at least three polyvinyl-chloride (PVC) jacketed cables must be present in the conduit prior to the final pullby. It was this criterton that was found to be responsible for the elimination of the first three l conduits containing damaged cable at WBN and for the exclusion of the sister condults at SON.

That criterton was developed to select particular conduits. .

containing specific jacket materials based on the knowledge of their I abrasion resistance. Such an approach correctly assumes that if l

pulling practices are uniform (good or bad), the cables most likely to have experienced significant damage are those with thermoplast'.c jackets. Among the thermoplastic jackets PCV war acknowledged as b the most readily violated under abrasive loadino. Furthermore, t>

screening method assigned even higher susceptibilities to such conduits when rubber-like jackets (e.g., Hypalon) were pulled over t

resident therm ylastic jacketed cables.

! -Subsequent to the WBN findings, two additional evaluat'lons at SQN were performed betwetn the 15 condults that were determined to be worst case and those conduits that were eliminated. (This latter group of 366 included the sister conduits identified above.) ,

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The first of these evaluations involv'ed a calculation of forces l anticipated during the pullby process on the original 15 worst-case J L condults- and the top 30 from the family of 366. A uniform L coefficient of friction was'used. Based on sidewall bearing l

pressure, the highest rated conduit (i.e., greatest potential for damage) is still from the original worst-case group. Otherwise, the two groups seem to have experienced similar forces, l' The second evaluation was based on application of coefficients of friction that a e specific to the materials involved in eac'i i pullby. In the absence of standard data for the various jacket-to-jacket combinations, TVA . conducted tests using conventional incline plane methodology. Based on this data, expected Installation. forces during pullbys were recalculated for L .the top 15 conduits of the combined family described in the L preceding paragrapt, The forces for A.lj,15 conduits were well below their allowables. l

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In summary, laboratory analysis confirmed that the damaging mechanism at WBN had been abraston of the outer jackets and primary insulation caused by a combination of the pullihg forces and the

'- parachute cord.. TVA's screening criteria gave special emphtsis to material susceptibilities. Those conduits and cable's deleted from the review have a higher resistance to this mechanism. Evaluation of the forces encountered during pullbys in those eliminated condults reveals that they are in th! same range as the " tested" condults and thus, when coupled with their superior abrasion resistance, have a lower damage potential. Cable removal activities at WBN, undertaken to assest the scope of the pullby issue, further confirmed the screening process when pullby damage was found to two cables in a worst-case conduit. Therefore, TVA finds that,its ,

original screening criteria used to select a group of worst-case conduits at SQN are still valid in light of the WBN findings.

3.6 The evidence provided by the 873 successful, high-pottntial withstand tests of conductors in worst-case pilby conduits provides the greatest degree of confidence in the integrity of the SQN cable systems.

In'those tests, a stress of 240-volt direct current per mil of cable insulation thickness was applied based on the SQN specific, minimum environmentally qualified insulation thickness for-the voltage rating, insulation type, and manufacturer. This voltage level is in accordance with guidance for establishing environmental qualifications for Class IE cables as given in Institute of Electrical and Electronics Engineers Standard 383-1974. In each condult, all conductors, with the exception of the one under test, were tied together (along with any shicids and drain wires) and tied to ground. This technique ensures an effective ground plane. This method is consistent with industry standard methociology (i.e..

Insulated Power Cable Engineers Association Standard S-61-402) for the final acceptance testing of multiconductor cables prior to shipment from the factory. Of the 298 cables tested for pullby

• concern, 297 are of multiconductor construction. The sole remaining a cable (2-1/C 14 AWG) has a bralded fiber jacket, which is regarded as being one of the most durable, abrasion-resistant jackets available.

While these test voltages were intended for factory or laboratory use, their adaptation to installed cables provides a very conservative assessment of a plant's installation process. This test program represents th6 most comprehensive in situ, high-potential evaluation of low-voltage cables in the industry.

In every conduit where pullby damage was identified at WBN, multiple conductors were exposed on at least one cable. Given the close

. proximity of a grounded conductor, separated only by a low resistance path, it is clear that if such damage existed in the 15 worst-case conduits at SQN, it would have bee,n detected.

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4.0 CONCLUSION

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i- In'the preceding analysis, a review has been performed of the HBN pullby findings. Comparisons were made with the specific sister condults and with condult installations ~ln general at SQN for certain key considerations that have direct impact on the success of the pullby l l operation. These parameters included raceway configuration, conduit fill, frequency of pull points, and the uttilzation during pullbys of an I. abrasive, previously installed parachute cord. Each such comparison identified the presence of pract,1ces at SQN that have minimized the potential for pullby damage in the cable system.

4 An additional review was undertaken of the validity of t'he SQN screening process in light of the WBN findings. This revleu determined that the i damaging mechanism identified at WBN (abraston) was precisely the thrust of the SQN criteria, wherein emphasis was placed on material susceptibilities. Alternate evaluations were performed based on pulling forces encountered in tested and " screened out" conduits and determined I that both groups would have experienced approximately the same tensions I and sidewall pressures. Since the durability of the two groups to those I forces is distinguished by their respective abrasion resistances, TVA l finds that its original ranking criteria were well designed for finding the worst case. l In addition, the results of the SQN high-potential withstand tests on a group of cables that had been identified as worst case with respect to '

the pullby concern were reviewed. The tests were found to be in I accordance with typical industry methodology for the performance of I general dielectric testing, yet far more conservative than standard in  !

l situ tests utilized to identify defective installed cables. The test l

results-provide positive, concrete evidence of the integrity of cables

i. subject to pullbys at SQN.

The findings herein are consistent with previous evaluations at SQN regarding cable system integrity and consistent with the plant's cable maintenance nistory. In summary, TVA finds that the previous conclusions drawn-regarding the integrity of SON Class IE cable system; continue to be valid.

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,. ENCLOSURE 3 NRC AND TVA MEETING OBJECTIVES SEQUOYAH NUCLEAR PLANT - CABLE TEST PROGRAM RE-EVALUATIC'N RESULTS

• PROVIDE THE bETAlLS TO SUPPORT THE CONCLUSIONS PROVIDED TO NRC IN THE MARCH 26,1990 SUBMITTAL

• PROVIDE DISCUSSION OF RANKING METHOD AT BROWN'S FERRY VERSUS THE ORIGINAL SEQUOYAH SELECTION CRITERIA

• PROVIDE RESPONSE TO THE FOLLOWING NRC QUESTIONS HOW DOES THE RANKING PROCESS USED ON THE RE-EVALUATION OF THE CONDUlTS THAT WERE " SCREENED OUT" 0F THE SEQUOYAH CABLE TEST PROGRAM (CTP) COMPARE WITH THE CONDUIT SELECTION PROCESS USED FOR THE BROWNS FERRY CTP?

HOW DOES THE (L x f)/r RANKING VALUES GENERATED IN THE .

SEQUOYAH CTP RE-EVALUATION COMPARE TO THE SWBP VALUES OF THE " SCREENED OUT" CONDUITS?

HOW DO THE 15 TESTED AND 30

• SCREENED OUT" CONDUITS COMPARE WITH RESPECT TO (a) SWBP AND (b) (L x f)/r RANKING 7

• SHOW THAT THE RANKING METHODS USED AT SEQUOYAH IN THE ORIGINAL CTP ARE STILL BOUNDING

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. i SEQUOYAH CABLE TEST PROGRAM (CPT) RE-EVALUATION

• JULY 1969, PULLBY CABLE DAMAGE DISCOVERED AT WATTS BAR

• RE-EVALUATION OF SQN CTP INVOLVED REVIEW OF 366 CONDUITS

• SCREENED OUT" BY CRITERIA 2,3, AND 4 OF THE ORIGINAL CTP SELECTION CRITERIA .

• RE-EVALUATED 30 " SCREENED OUT" CONDUITS USING BFNP CONDUIT SCREENING METHOD OF (L x f)/r FOR RANKING CONDUITS OVER 20 FEET LONG ,

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• PERFORMED SWBP CALCULATIONS ON THE 30 " SCREENED OUT" CONDUITS  ;

(CONSIDERED ACCESSIBILITY AND CONDUIT GEOMETRY)

• COMPARED ORIGINAL 15 TESTED CONDUITS AND 30 " SCREENED-0UT" CONDUITS FOR SWBP

• A COM?ARISON OF THE SWBP VALUES FOR THE 15 TESTED AND 30  ;

" SCREENED OUT" CONDUITS REVEAL THAT 15 TESTED CONDUITS ARE AMONG THE MOST SEVERE CONFIGURATIONS USING BOTH SELECTION CRITERIA AND SWBP CALCULATION METHODS L

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. QUESTION 1 HOW DOES THE RANKING PROCESS USED ON THE RE-EVALUATION OF THE CONDUlTS THAT 'WERE

• SCREENED OUT" OF THE SEQUDYAH CABLE TEST

-PROGRAM (CTP) COMPARE WITH THE CONDulT SELECTION PROCESS USED

- FOR THE BROWNS FERRY CABLE TEST PROGRAM 7 (COMPARISON 0F SEl.ECTION CRITERI A)

SEQUOYAH BROWNS FERRY

• SAFETY-RELATED CONDUITS

• SAFETY-RELATED CONDUITS

• SEVEN OR MORE CABLES (1)

• EIGHT OR MORE CABLES

• AT LEAST TWO SEPARATE

• AT LEAST ONE PULLBY

PULLBYS (2) ,

• AT LEAST 3 PVC CABLES *

• CONDUITS GREATER THAN ,

BEFORE LAST PULLBY (3) 20 FEET LONG. (FROM AS- '

DESIGNED DRAWINGS)

• LAST PULLBY BEFORE THE *

• RANKED BY LENGTH X FILL USE OF POLYWATER (4) DIVIDED BY BEND RADIUS l

• CONDUIT CONFIGURATION . *

• PERFORMED SIDEWALL COME NEAR OR EXCEED THE BEARING PRESSURE (SWBP)

G-38 LIMITS FOR BENDS CALCULATIONS AND LENGTHS BETWEEN PULL POINTS (5) .

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• AT LEAST TWO CONDULETS (6) ,

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• TESTED 15 (3 PARTIALLY WET -

• TESTED 10 (ALL PARTI ALLY AT POINTS WHERE EQUIPMENT WET - AT CONDULET WHERE DAMAGE WOULD NOT OCCUR AND HIGHEST SWBP WAS WATER WOULD NOT REMAIN IN CALCULATED)

CONDUIT) e USED IN RE-EVALUATION OF SEQUDYAH CONDUITS 3 . .

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QUESTION 2 HOW DOES THE (L x f)/r RANKING VALUES GENERATED IN THE SEQUDYAH CTP RE-EVALUATION COMPARE TO THE SWBP VALUES OF THE " SCREENED OUT" CONDUITS 7

• ELECTRICAL CALCULATION SQN-CSS-031 WAS PREPARED TO COMPARE THE VALUES FOR BOTH (L x f)/r AND SWBP FOR THE 30 " SCREENED OUT" CONDUITS

• (L x f)/r USED AT BFN AS SCREENING PROCESS FOR PROBABLE PULLBY CANDIDATES SELECTION WITH SUSPECTED HIGH SWBP VALUES

• NO DIRECT RANKING CORRELATION EXISTS BETWEEN THE SCREENING

- VALUES AND SWBP VALUES (SEE SLIDE 30RANX1) t

. 4 ,

l *.

3 ,

t i

30 " SCREENED OUT" CONDUITS  :

SELECTION CRITERIA RANKING VERSUS SWBP RANKING j l

CONDUIT RANKING ,

ID. Highest SWP (L x f)/r  ;

.. ........... .== ===== ..... === ........... == ,

1PM2136I l' 13  ;

1PM2080I 2 11  ;

1PM2094III 3 28 ~;

1PM2087II 4 4 2PM2140I 5 3 2PM2084I 6 14 .

1PM2111II 7 6 2PM2111II 8 8 ,

1PM2107II 9 26 l 2PM2087II 10 17 1PM2140I 11 30 l

2PM20911I 12 12 1PM2084I 13 10 F 2PM4956I 14 5 1PM2100IV- 15 2 2PM2107II 16 21 1PM2142III 17 7 ,

2PM2080I 18 25 2PM2094III 19 24 .

IPN2128I 20 19  !

1PM4956I 21 22  ;

1PM2145IV 22 20 2PM4741B 23 29 2PM2167J 24 27 1PM4996II 25 16 2PM4771B 26 23 1PM20911I 27 1 ,

2PM4996II 28 9 2PM2103IV 29 18 2PM4464A 30 15

)

?

E r

r 30 RANK 1

, a  !

l l

QUESTION 3 )

i HOW DO THE 15 TESTED AND 30 " SCREENED OUT" CONDUITS COMPARE WITH RESPECT TU (a) SWBP AND (b)(L x f)/r RANKING 7

• ELECTRICAL CALCULATION SQN-CSS-031 WAS PREPARED TO COMPARE j THE CALCULATED VALUES OF SWBP AND (L x f)/r OF THE 15 TESTED l CONDUITS WITH THE CALCULATED VALUES OF THE 30 " SCREENED OUT" .J CONDUITS

• THE HIGHEST SWBP VALUES BELONG TO ONE OF THE 15 TESTED 'I CONDUITS AN 5 OF THE FIRST 9 IN THE RE-EVALUATION

\

i

• 110F THE 15 TESTED CONDUITS ARE IN THE TOP HALF (1-23) OF THE 45 TOTAL CONDUITS EVALUATED AND THE MAGNITUDE OF DIFFERENCE BETWEEN CONDUITS 24 THROUGH 45 IS LESS THAN 100 LBS/FT

• THE TOP RANKED CONDUIT FULFILLED ALL THE ORIGINAL CRITERIA OF THE SEQUOYAH CTP, SUCESSFULLY PASSED THE IN-SITU TEST, AND HAD A CALCULATED SWBP VALUE ALMOST TWICE THAT OF ITS NEXT COUNTERPART p

• USING DIFFERENT SELECTION CRITERIA RESULTS IN RANKING l DIFFERENCES

• THE MAJORITY OF THE (L X F)/R VALUES FOR THE 15 TESTED CONDUITS FALL NEAR THE BOTTOM OF THE TOTAL POPULATION OF 45 EVALUATED CCNDUITS ,

• NO DIRECT RANKING CORRELATION EXISTS BETWEEN (L x f)/r l AND SWBP VALUES I

l l'

5 0_ _.,.

___._______.___..,__..t____...__, , _ _ . _ _ _ _ _ _ . _ _ . __

. l l

. )!

TESTED PULLBY CONDUITS AND " SCREENED OUT" CONDUITS (L x f)/r SELECTION CRITERIA VERSUS SWBP RANKING i 45 RANK RANKING (L x f)/ r (L x f)/ r SWBP SWBP NUMBER RANKING ~ VALUES RANKING VALUES

=== ===== ...................... =======================

1 1PM2091II 469.30 MC1750A

• 4816.27 j

-2 1PM21001V 411.40 1PM21361 2448.81 i 3 2PM2140I 371.66 1PM20801 1348.65 4 1PM2087II 370.30 MC1754A-

• 842.20 l 5 2PM4956I 341.38 1PM2094III 826.47 6 1PM2111II 338.80 MC1730B

• 824.20 i 7 1PM2142III 337.85 MC1751A

• 803.25 I 8 2PM2111II 336.00 1PM2087II 771.89 )

9 2PM4996II 331.46 MC1728B

• 679.95 10 MC1607A

• 303.73 2PM2140I 607.98 11 1PM2084I 297.10 2PM20841 503.11 l 12 1PM2080I 282.90 1PM2111II 482.61 '

13 2PM2091II 282.83 2PM2111II 462.22 i 14 MC1497B

• 276.91 MC1606A

• 331.88 15 1PM2136I 275.40 1PM2107II 317.80 ,

16 2PM2084I 268.23 MC1607A

• 312.61 17 2PM4464A 265.50 MC1732B

• 300.78 18 1PM4996II 248.73 2PM2087II 271.50 19 MC1605A

• 239.56 MC2788A

• 247.89 20 2PM2087II 230.56 1PM2140I 223.27  ;

21 2PM2103IV 227.62 MC1605A

• 202.05 22' MC1606A

• 226.21 2PM2091II 153.65 23 1PM2128I 202.70 MC1497B

• 141.22 24 1PM21451V 199.80 1PM20841 101.03 25 2PM2107II 197.16 2PM4956I 96.39 26 1PM4956I 195.19 1PM2100IV 91.12 27 2PM4771B 195.11 2PM2107II 72.25 28 2PM2094III 181.23 MC1493B

• 69.34 29 2PM2080I 174.30 1PM2142III 66.12 ,

30 1PM2107II 171.70 2PM2080I 64.18 31 2PM2167J 157.14 2PM2094III 61.34 32 MC1493B

• 181.92 1PM21281 59.63 l 33 1PM2094III 154.10 1PM4956I 56.14

• l 34 MC1728A * .149.37 . 1PM2145IV 49.97  ;

35 MC1748A

• 148.31 2PM4741B 46.36 [

36 MC1754A

• 147.21 2PM2167J 38.68 37 2PM4741B 146.40 1PM4996II 38.53 38 1PM2140I 144.99 2PM4771B 36.29 39 MC1751A

• 144.25 MC1734B

• 35.85 40 MC1731B

• 127.29 1PM2091II 34.10 7 41 MC1750A

• 123.39 2PM4996II 31.32 42 MC1734B

• 105.80 MC1731B

• 18.72 43 MC1732B

• 104.70 2PM2103IV 10.20 44 MC1730B

• 85.98 2PM4464A 7.84 45 MC2788A

• 75.89 MC1748A

• 2.29

• 15 pullby conduits tested under original Sequoyah selection criteria i

• _.__._..-.L

... . . . . . . ~ ... . . - ~ .- . ~ . - . ~ - - - - . . . . - - . . - - - - . . . - . .

O, '

MEETING

SUMMARY

• -(L x f)/r WAS USED AS A SCREENING DEVICE TO RANK A POPULATION [

'OF CONDUITS WHICH MIGHT BE SUSPECT OF CONTAINING CABLES WITH  :

PULL 5Y DAMAGE

• (L x f)/r AND SWBP CALCULATIONS DO NOT HAVE A DIRECT r CORRELATION WITH REGARD TO RANKING l

• THE ORIGINAL SEQUOYAH STP CONTAINED CONDUITS WITH AT LEAST TWO PULLBYS WHICH OCCURED BEFORE THE USE OF POLYWATER J LUBRICANT o

• SEQUOYAH IIAS SUCCESSFULLY COMPI.ETED THE MOST COMPREHENSIVE IN-SITU CABLE TEST PROGRAM IN THE INDUSTRY, INCLUDING CABLE PULLBYS, BY TESTING 296 CABLES /873 CONDUCTORS AT VOLTAGES RANGING FROM 4600 TO 7200 VOLTS DC ,

• REVIEW OF THE SISTER CONDUITS AT SEQUOYAH TO THOSE WHEh  ;

PULLBY DAMAGE WAS FOUND AT WATTS BAR REVEALED THAT THE CONDUIT RUNS WERE SHORTER IN LENGTH, HAD MORE FREQUENT PULL POINTS, LOWER FILL, AND WERE WITHIN ACCEPTABLE G38 LIMITS  ;

REGARDING SWBP

• RE-EVALUATION (BY REVIEW AND CALCULATION) 0F THE 15 TESTED CONDUITS AT SEQUOYAH SHOWS THAT THE ORIGINAL SELECTION .

CRITERIA (WITH ITS EMPHASIS ON MATERIAL SUSCEPTIBILITY) IS STILL BOUNDING AND PROVIDES A HIGH DEGREE OF CONFIDENCE THAT NO CABLE PULLBY DAMAGE EXISTS

. 4

. 8 ..

ORIGINAL SEQUOYAH CABLE TEST PROGRAM (CTP) SELECTION CRITERIA

1. SEVEN OR MORE CABLES 2..TWO OR MORE PULLBYS

3. THREE OR MORE PVC JACKETED CABLES BEFORE LAST PULLBY

4. TWO PULLBYS BEFORE USE OF POLYWATER AS LUBRICANT (8/84)

5. LENGTH AND DEGREE OF BENDS MEETS OR EXCEEDS G38

6. TWO OR MORE CONDULETF MET SELECTION CRITERION (SC) 1 MET SC 1, 2, 3, &4 MET SC 1, 2, 3, 4, &6 MET SC 1 -

4&5 MET SC 1 - 6 (10) (18) (366)

0 12 22 40 404 770 NUMBER OF CONDUITS l

l l

'O s.

' +

4 l.

h. -

l Distribution

• Dechetsf 44:e NRC PDR Local PDR F. Miraglia G. Lainas J. Partlow F. Hebdon J. Donohew OGC E. Jordan S. Newberry E. Marinos H. Garg R. Borchardt cca Licensee / Applicant and Service List i

I-1

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