ML20207E184

Rev 1 to Comanche Peak Response Team Results Rept Isap: I.b.1, Flexible Conduit to Flexible Conduit Separation

ML20207E184
Person / Time
Site:	Comanche Peak
Issue date:	12/10/1986
From:	Beck J, Bizzak R, Mallanda J TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:
Shared Package
ML20207E095	List: ML20207E141 ML20207E163 ML20207E184 ML20207E195 TXX-6184, Forwards Revs 1 to Isap:V.A, Insp for Certain Types of Skewed Welds in Nf Supports, ISAP:I.b.2, Flexible Conduit to Cable Separation, ISAP:I.B.1, ... Flexible Conduit Separation & ISAP:VII.a.7, Housekeeping & Sys..
References
NUDOCS 8701020082
Download: ML20207E184 (37)

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COMANCHE PEAK RESPONSE TEAM RESULTS REPORT ISAP: I.b.1

Title:

Flexible Conduit to Flexible Conduit Separation REVISION 1

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John W. Beck, Chairman CPRT-SRT Date O .

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Page 1 of 37 ,

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3 RESULTS REPORT s j .

ISAP I.b.1 Flexible Conduit to Flexible. Conduit Separation

.1.0. DESCRIPTION OF_ ISSUE IDENTIFIED BY NRC'(NUREG-0797, Supplement

No. 7, page J-42)

"The TRT could find no evidence that an analysis was performed to support the practice that allowed certain separate safety- and nonsafety-related flexible conduits inside control room panels to be lin direct contact with each other or to be separated by less +

than 1. inch, as required by Section 5.6.2 of IEEE Standard 384..."

2.0 ACTION IDENTIFIED BY'NRC (NUREG-0797, Supplement No. 7. Item 6.'a), (

page J-43)

"TUEC shall accomplish the following actions prior to fuel load:

Reinspect all panels at Comanche Peak Steam Electric Station, in addition to those in the main control room for Units 1 and 2, that contain (1) redundant safety-related conduits, or (2) safety- and nonsafety-related conduits. TUEC shall either b correct each violation of the separation criteria or demonstrate by analysis the acceptability of the conduit as a barrier for each case where the minimum separation is not met.

This analysis shall be accomplished in accordance with the requirements specified in Section 5.6.2 of IEEE Standard 384-1974. Furthermore, in the event that the acceptability of the conduit as a barrier cannot be demonstrated, TUEC shall correct the engineering drawings and related documents to indicate the revised minimum separation of conduits inside the panel for each case."

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3.0 BACKGROUND

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, The main concern expressed by the NRC-TRT team is that the SERVICAIR flexible metallic conduit

• used in the control room panels has not been shown by analysis to qualify as a barrier **.

Both IEEE 384-1974, "IEEE Trial-Use Standard Criteria for  ;

Separation of Class 1E Equipment and Circuits," and IEEE 420-1973,

• The flexible conduit used for separation inside the control room l panels is SERVICAIR flexible metallic conduit (referred to in this j report as SERVICAIR flex or flex).

• • As defined in IEEE 384-1974, a barrier is "a device or structure

'O interposed between Class 1E equipment or circuits and a potential source of damage to limit damage to Class IE systems to an l

acceptable level."

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l RESULTS REPORT

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ISAP 1.b.1 1 (Cont'd). l l

3.0 BACKGROUND

(Coat'd) l

-" IEEE Trial-Use Guide for Class 1E Control Switchboards for Nuclear Power Generating Stations," reccanize metallic conduit as an acceptable barrier in lieu of a minimum six-inch separation between redundant *. cables. Since SERVICAIR flex is a metallic conduit, it

.was judged by the Project to be an acceptable barrier in accordance with the Standards, and no specific testing and/or analyses was considered necessary.

,u In the construction of nuclear power plants, it is necessary to.

ensure that isolated failures of individual safety systems do not cause consequential damage to and possible failure of redundant safety systems., In the area of electrical cabling, this assurance i historically has been provided by specifying and enforcing requirements on the minimum allowable physical separation of ,

redundant,' safety-class cables or by requiring the use of physical '

barriers to protect redundant cable trains. The specified i separation aust be maintained throughout the lensch of each cable.

h IEEE 384-1974, "IEEE Trial-Use Standard Criteria for Separation of Class 1E Equipment and Circuits," IEEE 420-1973, "IEEE Trial-Use  :

Guide for Class 1E Control Switchboards for Nuclear Power '

Generating Stations," and Regulatory Guide 1.75, Revision 1 ,

" Physical Independence of Electric Systems", which are generally i accepted as the documents governing electrical separation requirements and which are applicable to the CPSES (Comanche Peak .

Stesa Electric Station) Project, indicate that within electrical panels and cabinets, " metallic conduit" is an acceptable separation barrier in lieu of physical separation. As a result, rigid  ;

metallic conduit has been recunised by the nuclear industry as an

, acceptable barrier inside electrical panels. t

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However, there are situations where maintaining sufficient physical  !

separation is difficult or impossible and for which rigid conduit is an unsuitable alternative. Hand switch modules in the CPSES l j control boards are an example. By design, these modules have l redundant cables in close proximity to each other. Additionally,

- it is required to have slack in the cables attached to these 1' devices to accommodate routine maintenance and adjustment of the '

controls. As a result, rigid metallic conduit cannot be used to solve the separation problems associated with these devices.

i O' All separation requirements in this report are for redundant cables. The word " redundant" as used herein means that the cables p requiring separation belong to diffarent trains, i.e., Class 1E train A, Class 1E train B, or non-Class IE train C.

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Revision: 1 4

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,h , RESULTS REPORT k) '

ISAP'I.b.1 (Cont'd) 3.0 BACEGROUND (Cont'd)

This.same situation has arisen elsewhere in the nuclear industry and has been successfully resolved by the installation of SERVICAIR flexible metallic conduit as a barrier. After obtaining IEEE 323-1974,and IEEE 344-1975 environmental and seismic qualification

data for the SERVICAIR flex and after discussions with the supplier of the control boards (Reliance Electric Company). TUGC0 issued design change documents at Comanche Peak specifying the use of SERVICAIR flex.as a barrier.

When the Project criteria were modified in November 1979 to specify the use of SERVICAIR flex, its use was limited to the main control

,, boards. The use of SERVICAIR flex was expanded in October 1980 to include all panels supplied by Reliance Electric Company (procured under Purchase Order CP-0605 to Specification 2323-MS-605, " Nuclear ,

Safety Reisted Control Boards"), which include the control room i control boards and vertical ventilation . panels. In November 1980, >

a Design Change Authorisation (DCA) was issued to the' Electrical Erection Specification 2323-ES-100 that listed SERVICAIR flex as metallic conduit, thereby allowing its use as a separation barrier in all electrical panels. For the reasons stated previously, TUCCO l' undertook no specific effort to qualify this material as a barrier.

The above facts notwithstanding, the NRC-TRT expressed a concern that SERVICAIR flex used in the CPSES control boards had not been qualified as a barrier through appropriate analysis and/or testing.

'Ahis action plan was designed to address the TRT's concern by demonstrating the adequacy of SERVICAIR flex as a barrier.

4.0 CPRT ACTION PLAN 4.1 Scope and Methodology The objectives of this action plan were 1) to determine, by testing and analyses, the minimum acceptable separation distance between cables of redundant trains, each enclosed within'SERVICAIR flex and 2) to reinspect all panels which contain redundant cables that could violate the final separation criteria

• for SERVICAIR flex to SERVICAIR flex.

• The final separation criteria (see Tabis 1) are the separation

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criteria developed as a result of this action plan. See DCA 21,446 Revision 1, to Draving 2323-El-1702-02, " Cable and Raceway Separation Typical Details" and Section 5.4.

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i' 4, RESULTS REPORT

i. ISAP I b.1 (Cont'd)

'4 0' CPRT ACTION PLAN (Cont'd)

.The following tasks were implemented to achieve these objectives:

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Circuit evaluation and thermal-analyses to demonstrate the adequacy of SERVICAIR flex as a barrier Testing to demonstrate the adequacy of SERVICAIR flex as a barrier

- Inspections of cabits in the control room control boards and vertical ventilation panels for adequate separation Procedure / Drawing revisicas to incorporate the final separation criteria

- Examination of panels other than the control boards and

-vertical ventilation panels for the use of SERVICAIR I flex.

.V The majority'(over ninety percent) of the SERVICAIR flex is located in the control room control boards and vertical ventilation panels. Therefore, the analyses, testing, and inspections described above were based on the circuits and configurations present in these penale. The remaining Unit 1 and common area panels with two or more trains were examined by the Electrical Review Team to identify the location of all SERVICAIR flex.

4.1.1 Analyses 4.1.1.1 Circuit Evaluation An evaluation of circuits in the control boards and vertical ventilation panels was performed to determine the maximum current available for the control circuits. This information was used to help establish the test conditions for the testing described

, below. In addition, this circuit evaluation was used to determine those circuits which contain multiple series protective devices and those circuits for which the maxfium

, faulted current is insufficient to result in heat damage to the subject circuits

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Page 5 of 37 .

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RESULTS REPORT ISAP I.b.1 (Cont'd)

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4.0 CPRT ACTION PLAN (Cont'd) y . themselves or adjacent cables. For these circuits, less stringent criteria for separation from other redundant circuits may be used. This is allowed per Paragraph 5.6.2 of IEEE 384-1974. The circuit evaluation specifically addressed the modular wiring to hand switches where the required cable slack creates difficulties in maintaining fixed spatial separation. Other circuits that are in close proximity to the hand switch module wiring were also included in the evaluation.

No specific circuit evaluation was planned for circuits contained in panels other than the control boards and vertical ventilation panels. For those cases where SERVICAIR flex ,

is used in panals outside of those evaluated, '

the acceptability of SERVICAIR flex as a (o) barrier requires further evaluation on a case-by-case basis.

4.1.1.2 Thermal Analyses Thermal analyses, supported by the results of tests described in Section 4.1.2, were performed to determine the adequacy of l SERVICAIR flex as a barrier. These analyses were based on the heat transfer characteristics of the cable and SERVICAIR i flex and apply to this actica plan, " Flexible 1 Conduit to Flexible Conduit Separation," as  !

t -ti as Action Plan I.b.2, " Flexible Conduit to Cable Separation." l 4.1.2 Test Program A two-part test program was conducted to determine the adequacy of the SERVICAIR flex as a barrier.

The first part of the test program was designed to determine the ability of SERVICAIR flex to carry a short circuit current without inflicting damage to cables contained in adjacent or touching SERVICAIR flex. In this test, two flex conduits were placed

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Page 6 of 37 .

RESULTS REPORT J

• ISAP I.b.1 (Cont'd) 4.0. CPRT ACTION PLAN (Cont'd)

<, perpendicular to one another, touching at one point.

One lead from the current source was attached to one SERVICAIR flex; the other lead to the other SERVICAIR flex. Test currents representative of the maximum possible fault currents from the control boards' and vertical ventilation panels' power supplies were applied during the tests. The test current flowed along one flex, across the point of contact, and then along the second flex (both flex conduits were isolated from ground). A cable was inserted in one of the flex conduits to serve as a " target" cable to enable monitoring of any damage incurred by cables contained in SERVICAIR flex due to the current in the flex.

The second part of the test program was designed to determine the ability of the SERVICAIR flex to act as an effective . thermal barrier between a cable (within 7- SERVICAIR flex) experiencing an overload condition and

(_3) a redundant cable either exposed and one inch away or contained within an adjacent SERVICAIR flex. For this test a source cable was placed inside a one-inch SERVICAIR flex and subjected to several different currents. A target cable was placed inside n 5/8-inch SERVICAIR flex which was in contact with the one-inch SERVICAIR flex; a second exposed target cable was l placed one inch above the one-inch flex. Surface temperatures of the two pieces of flex and the exposed target cable were monitored throughout the test, as well as the temperatures of the faulted conductors.

l The test procedures were written and tests conducted ,

such that the test results are applicable to the l control room control boards and vertical ventilation l panels. The procedures for the test program were prepared by the Third-Party Adviser, in conjunction with Gibbs & Hill, and approved by the Electrical Review Team Leader prior to implementation of the test program.

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Revision: 1

. Pcg3 7 of 37 ,

'RESULTS REPORT i :

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'L 'ISAP I.b.1

~(Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4.1.3 Investigations / Inspections f

4.1.3.1 Preliminary Investigations Concurrent with the above testing and ,

analysis program, an inspection of the Unit 1 control boards and vertical ventilation panels was performed to determine the extent  !

to which SERVICAIR flex was used as a barrier.

Separation guidelines based on preliminary, conservative separation distances were provided by Gibbs & Hill for review and approval by the Electrical Review Team >

Leader. Third-party inspectors inspected the control boards and vertical ventilation panels using these guidelines to determine

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the extent of potential acdifications required for compliance with the final  :

I separation criteria. In addition, this investigation provided input as to the types of cable insulation used in the control boards and vertical ventilation panels. This information, in turn, was used to determine <

the scope of the testing and to identify  ;

additional circuits that should be included in the circuit evaluation described above.

These inspections involved all aspects of cable separation, including the issues addressed in Action Plan I.b.2, " Flexible Conduit to Cable Separation," and Action Plan I.b.4, " Missing Barriers."

The intent was to compare the CPRT third-party inspection findings against the finsi separation criteria. Those third-party findings that did not meet the finsi ,

separation criteria were to be reported on l Nonconformance Reports (NCRs). l O

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RESULTS REPORT ISAP I.b.1 (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4.1.3.2 TUCCO Inspections Prior to issuing NCRs for the findings identified by the CPRT third-party, TUGC0 validated the findings, using the final separation criteria. For those findings which clearly violated the final separation criteria, NCRs were issued. Another group of findings were acceptable when compared to the final separation criteria, since some of the attributes of the final separation criteria were less stringent than those used by the CPRT third-party. For other findings where the minimum separation distance was reduced by the final criteria, it was difficult to determine from the third-party reports if the less stringent, final criteria were met, 7~ since the actual separation distances had not

3_

, been recorded.

To resolve this issue, the Electrical Review Team Leader initiated, through the TUCCO Coordinator, an inspection of all third-party findir.gs that did not clearly violate the final separation criteria.

Since the final separation criteria had changed to be more restrictive than the previous Project criteria, it was decided that a reinspection of the panels for those separation attributes that were revised to be more restrictive be performed concurrently with the above validation of the CPRT third-party findings. This inspection would provide the inspection of record for the control boards and vertical ventilation panels.

4.1.3.3 Third-party Overview In addition to the above TUGC0 inspection, there will be a post-construction inspection performed by TUCCO after all rework resulting

(~' from cutstanding Nouconformance Reports for

\ Action Plans I.b.2 and I.b.4 has been completed. CPRT third-party personnel will overview this final inspection.

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RESULTS REPORT l i

ISAP I.b.1  !

(Cont'd) l 3:  : 4.0 CPRT ACTION PLAN (Cont'd) l 4.1.4- Procedure / Drawing Revisions I Based on the results of the above analyses and testing, f TUGC0 revised Drawing 2323-El-1702-02, " Cable and Raceway Separation Typical Details" to reflect the '

final separation criteria. This drawing provides the i separation criteria used by the Project.

l The applicable QC inspectfon procedures were also {

revised to reflect the proper documents that specify j the final separation criteria.

l These document changes were reviewed by the Electrical l Review Team Leader, as discussed in Section 5.6.  !

4.1.5 Examination of Other Panels for SERVICAIR Flex

'A 100% examination of all panels in Unit 1 and cosmon j areas containing two or more trains was performed by -

the CFRT Electrical Review Team to determine where SERVICAIR flex was used outside the control roon l control boards and vertical ventilation panels. Since this action plan addresses the use of SERVICAIR flex in j the control boards and vertical ventilation panels t only, the acceptability of SERVICAIR flex as a barrier j in other panels requires further evaluation on a '

case-by-case basis by TUGCO. The CPRT third-party 7 overviewed this evaluation for those cases where flex  ;

was found in panels other than the control boards and vertical ventilation panels. i 4.1.6 Use of Results  ;

For Unit 1 and common areas, if any deviations from the final separation criteria were noted during the third-party and TUGC0 inspections, they would have been  !

identified and dispositioned on Nonconformance Reports,  !

and rework performed as required. In addition, NCRs were issued for all cases where SERVICAIR flex was used I outside the control boards and vertical ventilation panels. For Unit 2, installation procedures and QC  !

inspection procedures have been or are being revised to l ensure that personnel are aware of the required i

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=i i= i - '*i i iii i= i-panel configurations that meet the specified t requirements. l

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RESUI.TS REPORT ISAP I.b.1 (Cont'd) 4 .

4.0 CPRT ACTION Pt.AN (Cont'd) 4.2 Participants Roles and Responsibilities The organisations and personnel that participated in this effort are described below with their respective work scope.

4.2.1 TUGC0 Comanche Peak Project

'4.2.1.1 Revised QC inspection procedures and will

. revise craft procedure to include new criteria resulting from tests and analyses.

Will retrain craf t and inspection personnel to the new criteria.

4.2.1.2 Revised Drawing 2323-El-1702-02, " Cable and Raceway Separation Typical Details", and other related documents, to reflect the final separation criteria.

(3) 4.2.1.3 Performed reinspections for the Unit 1 control room control boards and vertical ventilation panels for those final separation attributes which have been revised to be more restrictive as a result of this action plan.

4.2.1.4 Processed NCRa that were generated in connection with this action plan.

4.2.1.5 Personnel Mr. W. I. Vogelsang TUCCO Coordinator 4.2.2 Electrical Review Team 4.2.2.1 Reviewed the analyses, circuit evaluation, test results and revised QC inspection procedures. Will review revised craft procedure.

4.2.2.2 Completed 100% examination of all panels with two or more trains to identify cases where SERVICAIR flex is used outside the control room control boards and vertical ventilation panels.

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RESULTS REPORT ISAP I.b.1 (Cont'd) 4.0 ^ CPRT ACTION PLAN (Cont'd) r 4.2.2.3 Reviewed the inspection reports and NCRs generated as a result of this action plan.

4.2.2.4 Reviewed and approved the test procedures and test report.

4.2.2.5 Reviewed changes to Drawing 2323-El-1702-02,

" Cable and Raceway Separation Typical t'etails", and other related documents, which reflect the final separation criteria.

4.2.2.6 Reviewed documentation of training of TUCCO Project inspectors to final separation criteria 4.2.2.7 Will overview the TUGC0 post-construction inspection of the Unit I control room control

,, boards and vertical ventilation panels.

4.2.2.8 Determined root cause, generic implications and safety significance, as required.

4.2.2.9 Personnel (prior to October 18, 1985)

Mr. M. B. Jones, Jr. Review Team Leader Mr. E. P. Stroupe Issue Coordinator 4.2.2.10 Personnel (starting October 18, 1985)

Mr. J. J. Ma11anda Review Team Leader Mr. R. J. Bizzak Issue Coordinator ,

i Mr. M. B. Jones, Jr. Third-Party Adviser  !

I Mr. E. P. Stroupe Third-Party Adviser 4.2.3 CPRT - QA/QC Review Team 4.2.3.1 Inspected Unit I control room control boards and vertical ventilation panels which have SERVICAIR flex for compliance to separation j guidelines (see Section 4.2.5.4).

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Pcg3 12 of 37 ,

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RESULTS REPORT ISAP I.b.1 f (Cont'd) l

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4.0' CPRT ACTION PLAN (Cont'd)

'4.2.3.2 Will perform overview inspection (see Section 4.2.2.7) as determined by the Electrical '

, Review Team. .

4.2.3.2 Personnel Mr. J. L. Hansel Review Team Leader u

4.2.4 Third-Party Advfser j 4.2.4.1 Prepared test procedures.

4.2.4.2 Supervised the tests. l 4.2.4.3 Issued a report of the test results.

4.2.4.4' Reviewed the circuit evaluation, as required.

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4.2.4.5 Personnel Mr. L. D. Bates Third-Party Adviser 4.2.5 Gibbs & Hill 4.2.5.1 Performed circuit evaluation and thermal analyses.

i 4.2.5.2 Assisted in preparation of the test procedures.

4.2.5.3 Reviewed and approved the test report.

4.2.5.4 Prepared separation guidelines for CPRT third-party inspectors.

4.2.5.5 Prepared final Project separation criteria.

4.2.5.6 Assisted in the QC inspections, as required.

4.2.5.7 Assisted in the processing of NCRs that were generated in connection with this action plan.

4.2.5.8 Personnel Mr. S. P. Martinovich Principal Electrical Engineer

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RESULTS REPORT ISAP I.b.1 '

(Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4.3 Qualification of Personnel Where inspections required the use of certified inspectors, qualification at the appropriate level was to the requirements of ANSI N45.2.6, " Qualification of Inspection, Examination, and Testing Personnel at Nuclear Power Plants." CPRT third-party inspectors were certified to the requirements of the third-party employer's cuality Assurance program, and specifically trained to the CPRT Program Plan.

Where tests required the use of certified test personnel, qualification at the appropriate level to the requirements of ANSI N45.2.6 and Regulatory Guide 1.58 was not met. These - ~

requirements were not part of the CPRT Program Plan at the time of testing. However, the qualifications of the individual supervising the tests were considered by the Review Team Leader to be more than sufficient to render the tests valid. "

O Third-party participants in the implementation of this action plan met the personnel qualification and objectivity requirements of the CPRT Program Plan and its implementing procedures. . .

Other participants were qualified to the requirements of the -!

CPSES Quality Assurance Program or to the specific requirements of the CPRT Program Plan. CPRT activities performed by other than third-party personnel were governed by the applicable principles of Section III.K. " Assurance of CPRT Program Quality", of the CPRT Program Plan.

4.4 Procedures The following CPRT procedures were developed in support of u this Action Plant 4.4.1 Procedure 1.b.1-001 " Cable /SERVICAIR lleat Transfer Test". . , _

4.4.2 Procedure I.b.1-002, "SERVICAIR Short Circuit Test" ~

4.4.3 Instruction QI-004, "CPRT Action Item 1.b.1 - Flexible Conduit to Flexible Conduit Separation: CPRT Action Item I.b.2 Flexfble Conduit to Cable Separation".

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RESULTS REPORT l ISAP 1.b.1 (Cont'd)

. l 4.0 CPRT ACTION PLAN (Cont'd) 4.5 Acceptance Criteria 4.5.1 The acceptance criterion for the tests and analyses was that SERVICAIR flex be shown to be a barrier which provides adequate protection at the minimum (or less) separation allowed by IEEE 384-1974, IEEE 420-1973 and ,

Regulatory Guide 1.75, Revision 1, January 1975. '

I 4.5.2 The acceptance criterion for the as-installed condition is that the SERVICAIR flex meets the final separation criteria (see Section 4.2.5.5).

4.6 Decision Criteria If the tests and analyses results did not qualify SERVICAIR flex as a barrier, qualified barriers were to be installed or  !

6" separation provided and the applicable documents revised to

j. indicate the revised minimum separation for SERVICAIR flex. l Q

5.0 DISCUSSION OF RESULTS A chronology of the major activities discussed in this Results Report is provided in Attachment 1.

5.1 Summary The first objective of this action plan was to determine through testing and analyses the miniana acceptable separation distance between cables of redundant trains, each enclosed within SERVICAIR flex. Since SERVICAIR flex was used mainly in the control room control boards and vertical ventilation panels, the program described below was based on the circuits in those panels.

The first step was a circuit evaluation to determine the maximum credible overload or short circuit current that should be used in the subsequent testing. In addition, various circuits were evaluated to determine if they could be shown not to cause damage to adjacent cables either because they were incapable of carrying high currents or because they contained multiple protective devices in series.

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RESULTC ff[RT ISAP I,b.I (Cont'd) 5.0 DISCUSSION OF RESULTS (Cont' d)

An investigation of the e..b?et in the conte i boards 9nd vertical ventilation parelu wa s then un ie <t . den using preliminary, conservative separatien 5.u delines. This investigation provided an assessmen' of the extent to which SERVICAIR flex was used as a barrier. Fu. the rmore , the investigation provided data or. the tyr* of cable insulation used , i.e . . Te f zel* vercus n' ,-Te f zel .. Internal wiring by Reliance Electric is all Tefasi-insulated; field wiring to the terminal blocks in the back of the panels is mostly non-Tefzel. The field investigation provided preliainary confirmation that the majority of the traas where separatici could be a problem involved only Tafeci cable. Therefore, the testing that was performed during the =9te time frame as these investigations was limited to Tefzel cables. These circuits that most commonly used non-Tefzel cables we:< assessed relative to the circuit avaluation that had al en '/, bea.

performed and additional evaluations irare pettormed to justify less stringent minimum separation dist..nuo lar these

\ additional circuits.

A two-part test program was conducted to determine he adequacy of SERVICAIR flex as a barrier far Tefzel cables.

The first test was designed to determine tne abili:f of SERVICAIR flex to carry a short circuit current without inflicting damage to cables contained in adjacent or tou..ing SERVICAIR flex, even if the short circuit current panset trom the SERVICt.1R flex contait.ing the 5lulted circuit to the SERVICAIR flex in contact with it. The second cest was designed to determine the ability of SERVICAIR fla to .act as an ef f ective thermal barrier between ar av rloaded circ it contained in the SERVICAIR fle/ cnd wither a redin. dant cable contained in SERVICAIR flex touching the first p,cce of flex or an exposed cable one inch away. The case of an exposed cable one inch from a flex containing a faulted circ'it was performed in support of .\ction Plan I '.2. s Subsequent to the test'na program, ,arametric :smputer analyses were performed to deterst ae the ef fectiveness of SERVICAIR flex as a thermal barrier for a range of configurations. Parameters such as current level, flex size, flex length, and flex orientation were examined to determine the effect that .hese parametern would have on the manfrom flex surface temperature.

Tef zel is DuPont's regir:t ered trademark for fluoropolymers 1 sed for, among other thingn conductor insulation and cable j ac'< t ing.

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Page 16 of 37 .

RESULTS REPORT '

ISAP I.b.1 -

(Cont'd) 5.0 DISCUSSION OF RESULTS (Cont'd)

The second objective of this action plan was to reinspect all electrical panels which contain redundant cables in SERVICAIR flex that could violate the final separation criteria. The CPRT third-party identified nonconforming conditions involving separation of SERVICAIR flex to SERVICAIR flex in the control boards and vertical ventilation panels based on the -

preliminary, conservative separation guidelines developed by Gibbs & Hill. When the final separation criteria were developed. TUGC0 QC inspectors performed a validation of the i CPRT third-party findings and a reinspection of these panels to the final separation criteria.

For panels other than the control boards and vertical 3g ventilation panels, the CPRT Electrical Review Team performed {

an examination of all multi-train electrical panels to determine where else SERVICAIR flex was used. Since the testing and analyses that were performed to show that &

SERVICAIR flex is a barrter were bssed on the circuits present h in the control boards and vertical ventilation panels, the use of SERVICAIR flex in other panels would require further i evaluation on a case-by-case basis to demonstrate the acceptability of SERVICAIR flex as a barrier. 7 g

'n i 5.2 Testing 4

A two-part test program was undertaken to determitie the 5.

adequacy of SERVICAIR flex as a barrier when Tefzel cables fj contained therein are subjected to electrically-initiated i failures. i The first part of the test program was designed to determine the adequacy of the SERVICAIR flex to provide a path for short

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g circuit current without causing damage to cables in an A adjacent or touching flex. The circuit in the test set-up consisted of two pieces ci flex in contact with each other, -

crossing at approximately 90 degrees. A target j Tefzel-insulated cable was inserted in one of the two pieces of flex. One lead from the current source was attached to one

)

SERVICAIR flex; tne other lead was attached to the other i

SERVICAIR flex. The flex conduits were isolated from ground. g which resulted in the current passing from one flex to the 2 other at the point of contact. The circuit breaker test se: $

used to supply current for these tests was preset to deliver a A

N 2000 amperes DC current when applied to a single piece of {

flex. Using this machine eetting, current was applied to the ,

test circuit three times with a 30-smpere fuse in the circuit u

L 9 -!

4

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L Page 17 of 37 -

E

'd 7

r Q RFSULTS REPORT

=

a

ISAP I.b.1 -

(Cont'd) -

i b

E g 5.0 DISCUSSION OF RESULTS (Cont'd) -

and three times without a fure. The most severe cases were 1 E

those run without a fuse. During the first such case without 3 a fuse, the circuit breaker test set was preset to trip i l automatically. For the last two casas without a fuse, the R i current was manually interrupted shi dly after two seconds,  ;

which is much longer than the. time normally required for a '

fuse or circuit breaker to open. The test current for the  ;

case of automatic machine interruption was 1560 amperes; the 7 maximum test current for the cases involving u nual l interruption was 1102 amperes. It should be noted that although the test equipment was set to deliver 2000 amperes (a through a single piece of flex, the current in the test passed -

from one flex to the other (both ungrounded) and the additional resistance due to the contact point between the two y r pieces of flex reduced the current. Nonetheless, the test i I currents were representative of the maximum fault currents j g that can be postulated to occur in the control boards and a vertical ventilation panels. j The only cases that resulted in any damage during these tests -

were those where the test corrents were applied to the two q pieces of flex without a fuse in the test circuit and without j automatic machine interruption. The outer bronza braids =

covering the steel bodies of the C ex conduits became welded "

together at the contact point. Nonetheless, there was no

} damage to the steel body of either SERVICAIR flex. The cable [ji inside the smaller 5/8-inch flex was not damaged. '"his was g i

verified by post-test visual examination of the cable jacket -

i for signs of Tefzel melting. In addition, megger testing of  ;

5 the cable did not indicate any damage tc the esble.

-}

[ As a result of these tests it was concluded that SERVICAIR -2j

[ flex could carry currents representative of the maximum fault j i currents expected at the control boards and vertical

( -

ventilation panels without imposing damage to Tefzel cables in  :

an adjac-tt touching flex aven if the fault current were to

?

t flow through both of the touching flex conduits. "E "W

=

The second part of the test program investigated the heat j transfer characteristics of SERVICAIR flex. The test setup f E

included a source cable inside a one-inch SERVICAIR flex. A k target cable was placed inside a 5/8-inch SERVICAIR flex in T t

contact with the one-inch flex. An exposed target cable was '

l

! placed one inch above the one-inch flex. As current was t.

applied to a circuit enclosed within the one-inch diameter i SERVICAIR fler, the temperatures of the copper conducters and P

, d n I F

-al I

. 3 4

1

Revision: 1 Page 18 of 37 .

RESULTS REPORT ISAP I.b.1 (Cont'd) w i 5.0 DISCUSSION OF RESULTS (Cont'd)

E

, the outside surfaces of the two pieces of flex were monitored,

[ as well as the air temperature one-quarter inch above the flex

, and the temperature of the exposed conductor one inch above the flex. Current levels were varied from fifteen to forty amperes per energized conductor (four conductors were t energized to represent the worst case of concurrent faulting

[ of two circuits within the same flex feeding a single piece of

$ equipment). The upper-bound current of forty amperes was b selected since the circuits involved are protected by circuit protection devices (i.e., fuses or circuit breakers) rated at 30 amperes or less; fuses are used exclusively for protection above 20 amperes. Per UL Standard 198B, a current of 135 percent of the fuse rating will open the circuit within one hour. Therefore, the maximum substained current for these circuits in the control boards is less than 40.5 amperes.

The results of this testing showed that the Tefzel insulation melted only during the forty ampere case, during which the

() energized conductors reached a maximum temperature of 350*C.

Even then, the maximum surface temperature of the flex containing the overloaded circuits was only 149'C. The g maximum measured temperature of the flex in contact with the flex containing the overloaded circuits was 84*C. Even though I

the temperature of the flex containing the target cable was not measured at the contact point, this decrease in temperature demonstrates the rapid attenuation of temperature with distance from the faulted circuits. As discussed in Section 5.3.1, these temperatures were shown to be acceptable.

F 5.3 Analyses 9

I 5.3.1 Thermal (Post-Test) A:.alyses for Tefzel Cables l Subsequent to the completion of the heat transftr tests, computer analyses were performed in which

[ several of the test parameters were varied, such as current level, flex size, flex length, and flex 3

} orientation. This parametric study was performed to determine the maximum flex surface temperature due to a faulted circuit within the flex and also te provide quantitative answers to the following questions:

If the protection device malfunctioned, would pG';

4 a current higher than 40 amperes give a higher transient flex surface temperature

, prior to insulation melting than was experienced in the 40 ampere test case?

F'

'n Revision: 1 Page 19 of 37 .

.s , RESULTS REPORT 4 "

ISAP I.b.1 (Cont'd) 4 -

5.0 DISCUSSION OF RESULTS (Cont'd)

Since the melting of the Tefzel insulation during the test significantly reduced the temperature of the copper conductors, and hence the temperature of the SERVICAIR flex, would the flex temperature be higher at the current level corresponding to the point just

, prior to gross melting of the insulation?

How do the results apply to the other sizes of SERVICAIR flex used at Comanche Peak (i.e., S/8-inch-diameter flex and 2-inch-diameter flex)?

How does the orientation of the flex affect the results? The testing was done for a horizontal piece of flex. A vertical flex would have a lower convective film

'()-

w_f coefficient, and, therefore, could have a higher surface temperature.

What effect does the length of SERVICAIR flex have on the maximum temperature?

Th'e initial step in the computer analyses was to develop a model and analyze it at the same current levels used in the testing program. The time history temperatures from the computer analyses and the tests were compared and refinements were made to the computer model until the computer results were validated by the test results. The computer model for a one-inch flex was then used to analyze six different current levels ranging from thirty-two and one-half amperes to sixty amperes. The steady-state flex temperatures were found for those current levels which result in conductor temperatures lower than that at which gross melting of the Tefzel insulation occurs, i.e. 350*C*, For those current levels which resulted in the temperature of the energized conductors exceeding 350'C, the analyses were

, terminated when the conductors reached 350*C. The tests demonstrated that at this temperature the

. f~

• Although the manufacturer's stated melting point of Tefzel intulation is 270'C, a conductor temperature higher than 270*C is required to raise the outer surface of the cable jacket to 270*C.

4'r m

Ravision: 1 Page 20 of 37 ,

/~h 5.)[k RESULTS REPORT ISAP 1.b.1 (Cont'd) 5.0 DISCUSSION OF RESULTS '(Cont'd) insulation experienced gross melting. The results of these analyses provided answers to the first two questions. The maximum: flex surface temperature occurs between 30 and 40 amperes, at the current level that results in a steady-state conductor temperature of 350*C. This is the temperature at which gross melting of the Tefzel insulstion occurs.

Analyses were then performed for a vertical, 5/8-inch flex, which is the worst case by virtue of the smallest convective surface area and smallest natural convective film coefficient. In addition, no axial heat flow was modelled, which corresponds to an infinite length of flex. The results of this analysis gave a maximum flex surface terparature of 211*C at 29 amperes.

In lieu of data regarding the temperature of a cable in gg an adjacent SERVICAIR flex, the unfaulted cable

(_). protected by flex was assumed to be at the same temperature as the surfcce of the flex containing the faulted circuits. This is a conservative approach.

The flex temperature of 21L*C is less than the melting point of Tefsel insulation (270*C). Nonetheless, further study was performed to ensure that the cable would.not be degraded due to the elevated temperature.

The manufacturer provides data that Tefzel has a l qualified life of 1500-2000 hours at 205'C. This allows approximately two months for the operator to  ;

detect and correct the malfunction resulting in the overloaded circuit before the Tefzel qualified life is expended. The following points also provide assurance ,

that a faulted circuit in SERVICAIR flex will not result in damage to a cable in an adjacent flex:

1) The temperature of 211*C is for the surface of the flex containing the faulted circuits.

The temperature of the flex touching the flex with the faulted circuits would be lower and the unfaulted cable temperature within the f14x would be even lower.

/"\

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, Page 21 of 37 .

. M, s RESULTS REPORT.

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.x.-

ISAP I.b.1 (Cont'd) 5.0' DISCUSSION OF-RESULTS (Cont'd) -

2)- These analyses assume that the overload current will not be interrupted by protective

-devices. .In reality, the majority of the instrumentation end control circuits in the control boards and vertical ventilation panels contain protective devices rated at 20 amperes or less. The 20-ampere protective

-devices would open the circuit at a current of 29 amperes within one hour. Protective devices rated below 20 amperes wculd open the

, circuit at a. current of 29 amperes even faster. The remaining instrumentation and control circuits are protected by fuses rated at 30 amperes. An evaluation of-these circuits has shown either that components in the circuit other than the protective devices, such as the switchgear trip and

, ,_s close coils, would interrupt a 30-ampere f[ '

current within one hour or that the circuit current would be limited to low current levels by che resistore in series with the light circuits.

_ 3) The tests and analyses assumed that four conductors carried the faulted current, i.e.

two complete circuits are assumed to malfunction simultaneously. If a single circuit were to fail, the current level required to raise the flex temperature over 205'c is above 40 amperes. At this current level, fuses, which are the only 30-ampere protective devices used, would open the circuit within one hour.

The conclusion drawn from the testing and analyses is that, for the control and instrumentation circuits in the control boards and vertical ventilation panels, SERVICAIR flex containing a faulted, Tefzel insulated cable will not cause damage to Tefzel cable in another SERVICAIR flex, even if the two pieces of flex are in contact with one another. Therefore, it was concluded that SERVICAIR flex meets the IEEE 384-1974 definition of a barrier when both cables are Tefzel-insulated.

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~

RESULTS REPORT

. :cf;);

ISAP I.b.1 (Cont'd)

! 5.0 LDISCUSSION.0F RESULTS (Cont'd)

I

, 5.3.2 Circuit Evaluation for Non-Tefzel Cables

~

Concurrent with the testing program, an evaluation of '

=

the control board and vertical ventilation panel circuits was performed by Gibbs &. Hill. This evaluation addressed the modular wiring to hand I switches as well as other-circuits in close proximity to the hand. switch wiring. The objective of.this evaluation was to determine the maximum current l available to the circuits. This information was used '

to help establish the test conditions for the testing

discussed above. Also, from this evaluation, it was i determined that six categories of non-Tefsel cables

were adequately protected by multiple protective devices in series or that the maximum faulted current was insufficient to result in heat damage to the subject cables or adjacent cables. These six categories are:

(.a): ,

, 1) Annunciator lampbox cables,

2) Safety System Inoperable Indication (SSII) lampbox and field input logic cables, 3)' Power cords from receptacle strips on control wireways to devices such as instrument recorders,

4) Sound-powered telephone cables,

5) Coaxial video CRT cables, and

6) Fire detection cables. ,

An evaluation of the annunciator (category 1), SSII (category 2), and the power cords from receptacle strips (category 3) demonstrated that a single failure of protective devices in these circuits would not result in sufficient energy to compromise the integrity of adjacent safety-related wiring or devices. The circuit evaluation determined that the sound-powered (category 4) and coaxial CRT (category 5) circuits, which operate at voice and video signal levels,

~ " '

respectively, pose no inherent hazards. Fire detection

. ,  ; (category 6) cables comprise 24V de, ungrounded supervised circuits having a 13.1K-ohm series resistor

h Rsvision: 1 Page 23 of 37 .

ff y RESULTS REPORT Vf

• ISAP I.b.1 (Cont'd)

' 5.0: DISCUSSION OF RESULTS (Cont'd) s in.the loop that limits the maximum fault current to

-very small values. Ground detection is also provided for the control room fire detectors. Therefore, the separation criteria for Tefzel-iusulated cables can be

~

used for.these six categories of cables.

This circuit evaluation did not include the 120-volt AC lighting and convenience recaptacle wiring. This

. wiring is considered to be_" power" wiring. The separation criteria for the lighting and convenience

. receptacle wiring were revised to reflect the fact that it is to be considered more stringently than control and. instrumentation wiring. Thus, the criteria state h that SERVICAIR flex is not to be used as a barrier for

'the 120-volt AC lightinh and convenience receptacle wiring. Additional evaluation on a case-by-case basis would be required to demonstrate the acceptability of fsme SERVICAIR flex cs a barrier for these cables.

-O 5.4 Final Separation Criteria The final separation criteria within electrical panels for redundant control and instrumentation cables, each enclosed in SERVICAIR flex, are given in Detail 61G of DCA 21446 Revision r 1, to Drawing 2323-El-1702-02, " Cable and Raceway Separation Typical Details." The final aeparation criteria allow two pieces of flex to touch when each cable is either Tefzel or is a' circuit in one of the six categories of non-Tefzel cables discussed in Section 5.3.2. Furthermore, two pieces of SERVICAIR flex containing redundant cables may touch when one of the cables is a non-Tefsel Class IE cable, provided that t the other cable is a non-Class IE cable which is either

-Tefzel-insulated or non-Tafzel but power-limited (cables discussed in Section 5.3.2). This is a logical extension of the interpretation of the separation criteria, which is only

, to protect Class 1E circuits. For all other cables, which

. were neither tested nor analyzed due to their limited use, a minimum one-inch separation is required, i.e., the separation given in IEEE 384-1974 (Paragraph 5.1.4) for redundant enclosed raceways in general plant areas. These criteria are summarized in Table 1 of this report.

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. oe

. -( _ RESULTS REPORT

'O

• ISAP I.b.1-(Cont'd)_

5.0 DISCUSSION OFlRESULTS (Cont'd)

, I5.5L Investigations / Inspections / Examinations

-The second cbjective of this action plan wassto reinspect all

-panels which contain redundant cables that could violate the final separation criteria for~SERVICAIR flex to SERVICAIR flex. -This program involved three distinct activities:

1); Preliminary third-party investigations of the control boards-and vertical ventilation panels using preliminary, conservative separation guidelines,

-x 2) _ Reinspection of the control boards and vertical ventilation panels by TUGC0 to the final separation criteria, and

3) .A third-party' examination of multi-train panels to identify all other uses of SERVICAIR flex.

( }) 5.5.1 Preliminary Investigations Prior to the completion of the testing and analyses

~ described above, a CPRT third-party-inspection of the Unit'l control boards and vertical ventilation panels was performed. Since the majority of SERVICAIR flex is located in the control room control boards and vertical

$f ventilation panels, the third-party QC inspections were

. limited to these panels. This inspection provided an

, assessment of the extent to which SERVICAIR flex was used as a barrier. In addition, this investigation was used-to determine which additional circuits should be included in the circuit evaluation.

It should be noted that conservative separation

. guidelines, specified by Gibbs & Hill and approved by the Electrical Review Team Leader, were used in this investigation. As such, they were more restrictive than the final separation criteria. Using these more restrictive guidelines ensured that all deviations to the final separation criteria that might exist would be discovered. This was intended to minimize the need for any subsequent inspections.

Based on these more restrictive inspection guidelines, the third-party inspectors identified 34 instances of

_O SERVICAIR flex to SERVICAIR flex separation findings.

7~  ;> - e Revision: 1

_ Paga 25 of 37 ,

RESULTS REPORT

. R.,J .

ISAP I.b.1

'(Cont'd) 5.0--D1SCUSSION OF RESULTS (Cont'd)

.5.5.2 TUCCO Inspections Prior to issuing NCRs for the findings identified by the CPRT third-party, TUGC0 validated the findings, using the final separation criteria. For those findings which clearly violated the final separation criteria, NCRs were issued. Another group of findings were acceptable when compared to the final separation

. criteria, since some of the attributes of the final.

separation criteria were less stringent than those used by the lCPRT third-party. For other findings where the minimum separation distance was reduced by the final criteria, it was difficult to determine from the third-party reports if the lesa stringent, final criteria were met, since the actual separation distances had not been recorded.

-To resolve this issue, the Electrical Review Team kl(c-_): ~

Leader initiated, through the TUGC0 Coordinator, an inspection _of all third-party findings that did not clearly violate the final separation criteria.

, Since the final separation criteria had changed to be )

more restrictive than the original separation criteria *, it was decided that a reinspection of the panels'be performed concurrently with the above validation of the CPRT third-party findings. Only those separation attributes that were revised to be more restrictive were inspected. For example, the final criteria require a one-inch separation between two pieces of flex when one flex contains certain non-analyzed, non-Tefzel cables; the original criteria allowed the two pieces of flex to touch. This inspection provided the inspection of record for the control boards and vertical ventilation panels.

• The original separation criteria are defined as the criteria in l existence prior to this action plan, i. e., Detail 61 of Drawing I

(~' 2323-El-1702-02, " Cable and Raceway Separation Typical Details",

Revision 2, not including any outstanding Design Change Authorizations (DCAs).

S y' Revision: 1 Page 26 of 37 ,

~

RESULTS REPORT

.v _ 1

. ISAP I.b.1 (Cont'd) 5.0 DISCUSSION'OF RESULTS (Cont'd)

.:s The:TUCCO QC inspection did not identify any additional violations of SERVICAIR flex to SERVICAIR flex.

The original 34 findings identified by the CPRT i

third-party inspectors were compared to the final separation criteria. Twenty-three of these findings involved Tefzel-to-Tefzel cables; ten involved Tefzel-to-non-Tefzel cables from the analyzed categories noted in Section 5.3.2, and one finding involved.a non-Class 1E non-Tefsel cable from the analyzed categories and a non-Tefzel Class 1E cable.

All of the above findings have been compared to the final s,eparation criteria developed as a result of this

' Action Plan and have been found acceptable. In addition, all of the above findings are in compliance with'the original separation criteria.

As noted above, there were no violations of the final

(,~) . separation criteria for SERVICAIR flex to SERVICAIR 5 '

flex. However, in control board CPI-ECPRCB-04, TUGC0 QC inspectors noted~that two pieces of flex were in contact'due to a loose bracket (this finding was also noted in the third-party inspection reports). However, the discrepancy was the loose bracket; the flexes in contact with each other did not represent a deviation since they are allowed to touch by the final separation criteria. An NCR has been issued for the nonconforming condition of a loose bracket. The Electrical Review Team has reviewed the findings from both the third-party inspection and the TUGC0 inspection and concurs with these conclusions.

TUGC0 is currently performing rework in the control room control boards and vertical ventilation panels to resolve the outstanding Nonconformance Reports issued as a result of deviations related to Action Plans I.b.2 and I.b.4. When this work is complete, a post-construction inspection will be performed by TUGC0 QC inspectors and overviewed by CPRT third-party personnel.

n

['.

,m

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Ravision: 1 Page 27 of 37 .

k ~

%,((j' '

RESULTS REPORT

, & ISAP I.b.I' I

(Cont'd)

N, ,

~5.01-DISCUSSION l0F RESULTS.(Cont'd) In 5.5.3 Third-Party Examination of Additional Multi-Train Panels The Electrical Review Team requested that TUGC0 identify all other panels outside the control room

control boards and vertical ventilation panels that contain_SERVICAIR flex. TUGC0 examined panels purchased to Specification MS-605, which bounds the panels authorized to contain flex per DCA-8830 to

'ff Electrical Erection Specification 2323-ES-100. TUGC0 provided a list of six additional panels that contain SERVICAIR flex. (It was subsequently determined that DCA-9086 to the same specification defines SERVICAIR c flex as an acceptable metallic barrier and does not limit its use to any particular type of panel.)

J Subsequent to this response, the action plan was revised to require the CPRT Electrical Review Team to

' (,, s). ~

examine all Unit.I and common area electrical panels with two or more trains to identify any additional uses of SERVICAIR flex. Panels other than multi-train panels were not examined since a panel that contains only one train does not require electrical separation; therefore, SERVICAIR flex would not have been used as a barrier.

The first' step of this examination process was to generate a list of electrical panels with two or more trains. To determine this, all Unit I and common electrical panel connection drawings and one-line diagrams were reviewed by the CPRT third-party. This review showed that there are no more than 115 electrical panels with multiple trains, including the thirteen control room centrol boards and vertical ventilation panels. During subsequent investigations it was determined that some of these panels contained cables exempt from separation requirements, some panels had been removed, some panels were not multi-train panels, etc. The number of multiple train panels requiring cable separation was ultimately reduced from 115 to 88. The CPRT Electrical Review Team examined the panels and found three that contained SERVICAIR flex in addition to the six identified by TUGCO.

O

G" :r;

& ~

[.5 '

Ravision: I s> Page 28 of 37 .

+

1

- RESULTS REPORT-

- a.7

.ISAP I.b.1- l

, (Cont'd) 15.0' DISCUSSION OF RESULTS (Cont'd)-

For all instances where SERVICAIR flex 7as used outside

'. the control room control boards and vertical

ventilation panels, Nonconformance Reports were written. Since the analyses and testing performed for

)

SERVICAIR flex are applicable only to the control room '

control boards and vertical ventilation panels, the acceptability of SERVICAIR flex as a barrier elsewhere requires further evaluation by TUGC0 on a case-by-case ,

. basis.  !

\

The CPRT Electrical Review Team reviewed and concurred '

with the disposition of the NCRs issued for SERVICAIR flex in panels other than the control boards and vertical ventilation panels, f

. l 15.6 Procedure / Drawing Revisions )

The primary document detailing separation requirements between

.l -( )' ., '

redundant cables used by the Project is Drawing 2323-El-1702-02, " Cable and Raceway Separation Typical

~

Details." 'In particular, Detail 61 provides the separation criteria for control and instrumentation circuits within electrical panels.

As a result of the testing and analyses performed during this action plan, a new detail - Detail 61G - was added to the drawing via DCA 21446, which specifies the minimum separation for redundant cables, where each is enclosed in SERVICAIR flex.

The applicable QC inspection procedures (QI-QP-11.3-28 and QI-QP-11.3-40) were revised to reference this drawing for separation requirements.

In addition, DCA-8830, which originally revised the Electrical Erection Specification but now also applies to Drawing 2323-El-1702-02, was revised to allow flex in " Reliance Control Board and Vertical Ventilation Panels (MS 605)."

These document changes involving the use of SERVICAIR flex as a barrier were reviewed by the Electrical Review Team Leader.

In addition to reviewing these documents, the Electrical Review Team reviewed the sections of Electrical Erection Specification ES-100 relating to internal wiring separation, as well as the applicable portions of the Brown & Root Construction Procedure 35-1195-EEI-8, " Class 1E and Non-Class 1E Cable Terminations."

4 l

l

. , ,--,-,,.~o ,_.-,.m.-- _ , _ . , . . _ - - . - - , , - . . . . . - - - - - . _ . _ _ - _ _ - - . - . - , . . _

=

Rsvision: 1 c Page 29 of 37 ,

7 i: 'RESULTS REPORT.

L) _

ISAP I.b.1 (Cont'd)

5.0 - DISCUSSION OF RESULTS (Cont'd)

Suggestions for enhancement of these documents were transmitted to TUGCO. The Project responded to the comments and the Electrical Review Team concurs with the proposed actions to revise these documents to resolve the comments.

5.7' Review of Training The. Electrical Review' Team also reviewed the current program for training of construction and QC personnel. Craft instructors were interviewed to determine the extent and depth

, of the. instruction given craft personnel in the area of electrical separation inside panels. The program is .

comprehensive and includes classroom training on procedures.

examinations. and " hands-on" experience. The Electrical Review Team noted that separation criteria are shown on

-Drawing 2323-El-1702-02, " Cable and Raceway Separation Typical Details." in addition to the Electrical Erection Specification ys. g 2323-ES-100. Since the instructors were not receiving N ,) . controlled copies of changes to the drawing, they were not aware of the changes made to the separation criteria for <

"s '

SERVICAIR flex. This has since been remedied by having the ,

-instructors receive controlled copies of all changes to this I drawing. Therefore, whenever the drawing is revised or a '

design change is made to the drawing, the instructors will 1 s- automatically receive these documents.

The Electrical Review Team reviewed the QC Lesson Plan developed for QC Procedure QI-QP-11.3-28. The Lesson Plan i presents the subject of separation inside panels adequately l and refers the inspector to Drawing 2323-El-1702-02 for l details. I l

Due to the changes that are currently being incorporated into the procedures, drawing, etc., further training will be required.

5.8 Categorization of Findings 5.8.1 Control Boards and Vertical Ventilation Panels The CPRT third-party inspectors and TUGC0 QC inspectors, during their inspections of the control

- boards and vertical ventilation panels, did not identify any violations of the final separation criteria for two redundant cables, each enclosed in

, SERVICAIR flex.

l

- $1 '

x , ,

Revision: 1 m

, Page 30 of 37 ,

c ;u _  ;

y- RESULTS REPORT Q, -

ISAP I.b.1 (Cont'd) s.

5.0 DISCUSSION OF RESULTS (Cont'd)

5.8.2 Panels Other Than The Control Boards and Vertical-Ventilation Panels For panels other than the control boards and vertical ventilation panels, the CPRT Electrical Review Team examined all multi-train panels to determine where

. SERVICAIR flex had been used as a barrier. During this

~

>? examination of multi-train panels, a total of nine

' ~

l panels were found to contain a total of 16 pieces of SERVICAIR flex. _ Since the existence of these pieces of

'fle: is in violation of the final criteria, Nonconformance Reports were issued.

s In addition to these nine panels, SERVICAIR flex was found in a Reliance-supplied panel, CP1-ECPRLV-17, by third-party QC inspectors performing inspections for Action Plans I.a.2 and I.a.3. During the process of resolving a separation violation, this flex was

), removed priorito the Electrical Review Team's examination of multi-train panels. Therefore, the

.examiration of multi-train panels performed for this action plan did not identify any flex in Panel CP1-ECPRLV-17.

These' cases of SERVICAIR flex in panels other than the control boards and vertical ventilation panels do not constitute deviations since the original criteria permitted SERVICAIR ficx to be used as a barrier in all panels. Nonconformance Reports have been iccued cs a '

result of the criterion change that limits the use of SERVICAIR flex to the control boards and vertical ventilation panels. The Electrical Review Team reviewed and concurred with the disposition of the Nonconformance Reports issued for the 16 pieces of flex outside the control boards and vertical ventilation panels.

1 5.8.3 Observations I l

During the implementation of this action plan, it was apparent that the criteria governing the use of

. SERVICAIR flex as a barrier were confusing. The f .

. Electrical Erection Specification 2323-ES-100 contained two active Design Change Authorizctions (DCAs) that

. L addressed the use of SERVICAIR flex. The first authorized the use o? flex in panels supplied by 1

-~- . - . - - . - . . - , _ _ _ _ . . . . _ _ . ,_ _. _ __~ _ .. _,- _ _ _ _ _ ,__ _ _ .._ _ . _ , _ _ _ _ .

Rsvision: I k Pega 31 of 37 ,

, s RESULTS REPORT (E .

ISAP I.b.1 (Cont'd)

- 5.0! DISCUSSION OF RESULTS'(Cont'd)

Reliance Electric Company; the second DCA allowed flex to be used in all panels. Even though the second DCA was issued within a month of the first, the original DCA was not revised to be consistent with the later

'DCA. Since the two DCAs revised different portions of the . electrical specification, the interpretation as to where SERVICAIR flex could be used depended on the '

1 section of the specification to which one referred. As

, discussed in Section 5.6, the Project has committed.co revise the appropriate documents to identify the panels where SERVICAIR flex can be used as a barrier.

The second observation involved the process by which revised criteria are incorporated into Project Jdocuments. From the start of the implementation of this action plan..the intent was to qualify SERVICAIR flex as a barrier only for the control boards and vertical ventilation panels. However, the engineering s

~() criteria in the electrical erection specification were not revised until May 1986. Nonetheless QC Procedure QI-QP-11.3-28 was revised in June 1985 to limit the use of SERVICAIR flex to the control boards and vertical l ventilation panels, based on the then current status of this action plan. QC procedures should always be consistent with engineering documents. In addition, the engineering and QC review of the QC procedure should have identified and resolved the differences in the engineering and QC documents.

The third observation dealt with the parametric computer analyses performed by Gibbs & Hill in determining the eff ectiveness of SERVICAIR flex as a thermal barrier. During the review of the analyses by the Electrical Review Team, an inconsistency was discovered in the results presented for the S/8-inch SERVICAIR flex. Subsequent evaluation by Gibbs & Hill attributed the inconsistency to a problem in the version of the HEATING-5 computer code used in the analyses. Reanalyses using a later version of the same code demanstrated that the error had been corrected in the more recent version of the code. Gibbs & Hill has reviewed all other calculations that utilized the HEATING-5 computer code and has determined that the factors which caused the above inconsistency are not O.i present in these calculations.

t i.- - - --,-i-- . - , . w.~_ ,. +,.------,.y . , ,.,_w em,,--,7-,,-.----y-s-,.------,-------.v,.--.,.,,-,my- . , , - , --m- , . . - . , - - . - - , , - . , ,w

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'Fevision: 1

. Page 32 of 37 .

RESULTS REPORT

,R-l' , .

-ISAP I.b.1 (Cont'd) 5.0 DISCUSSION OF RESULTS (Cont'd)1 .

.The fourth' observation is that the craft training instructors were not on controlled distribution for-

~ Drawing 2323-El-1702-02, " Cable and Raceway Separation Typical Details." Because.of this, the instructors

~

=

were not aware of the latest separation criteria for SERVICAIR flex. . This was corrected by having the

-instructors receive controlled copies of all changes to the-drawing.

.The facts' relating to these observations were

. transmitted to the. Design Adequacy and QA/QC Review M Team Leaders, as appropriate, to be included in their respective collective evaluations.

-5.9 Safety Significance Evaluation / Root Cause/ Generic Implication Since no deviations were found, no safety significance (gs a evaluation, root cause analysis, or evaluation of generic

-(_)- -implications were performed.

The root cause hypothesired by the NRC is that "The lack of analysis to substantiate the adequacy of separation ... may be an indication of weakness in the QA/QC program concerning design control." As noted in Section 3.0, the Project did not consider specific testing and/or analyses to be necessary since SERVICAIR flex is a metallic conduit; metallic conduit is recognized as an acceptable barrier per IEEE 384-1974 and IEEE 420-1973. Nonetheless, the CPRT Design Adequacy Program is addressing, on a comprehensive basis, instances elsewhere that may involve a lack of analysis to substantiate the adequacy of design.

5.10 Corrective Action Although no deviations were noted during the implementation of this action plan, TUGC0 is developing corrective action to resolve separation issues identified through Action Plans I.b.2 and I.b.4. Since this corrective action program is related to the subject of this action plan, the major elements of the program are described below.

TUGC0 has recognized the need to establish and maintain cable

. separation inside electrical panels for all stages of the

(~' plant life -- construction, start-up, and operations. Key elements to achieving these objectives are the establishment

, I Rsvision: I  !

_ Page- 33 of 37

• l

) RESULTS' REPORT J -

W ISAP I.b.1 (Cont'd) l 5.0L DISCUSSION OF.RESULTS (Cont'd).

)

Lof clear criteria, the training of responsible personnel, the timely performance of inspections, and the control'of activities performed after inspections have been performed.

To this end, TUGC0 is currently taking the following actions: i

1) Updating all procedures, drawings, specifications, etc., dealing with internal separation to clarify the criteria,

2) . Instituting a special training program to ensure that personnel involved with multi-train panels, i.e. craft, QC inspectors, engineers, start-up personnel, and

. operations personnel, are sensitized to the need to establish and maintain separation of electrical cables, 3)- Providing job-specific training for craf t, QC inspectors, start-up, and operations personnel to the fN ,

' revised documents,

- V 4)- Performing a baseline inspection to ensure that the

~

required separation criteria have been set, and

, 5)- Controlling personnel who access panels requiring

}, cable separation after the baseline inspection has been

n completed.

5.11 Additional Findings

-All' additional findings including cable-to-cable and cable-i to-wireway separation nonconformances noted during the implementation of this action plan will be addressed in the

, Results Report for Action Plan I.b.4. Separation

-nonconformances involving SERVICAIR flex and cables are addressed in Action Plan I.b.2; the root cause analysis and generic implication evaluation for the I.b.2 deviations will be described in the Results Report for Action Plan I.b.4.

5.12 Unit 2 Multi-Train Panels The inspections and examinations performed under this action plan involved Unit I and common area multi-train panels.

However, the TUGC0 program outlined in Section 5.10 will also apply to Unit 2. This corrective action will ensure that the l.O i use of SERVICAIR flex meets the final separation criteria developed as a result of this action plan.

f 4

~e ----em--+ ,,w,n-- -r-m-- . - - - , , - - , , - , , - . - _,--n,-----,-------,-----------------n--- --

,,---.,--v,nn-,-----,----a,-,- --m--

n ; - -s l

1. 4 Rsvision: 1 Page 34 of 37 .

EI[g' t.

RESULTS REPORT ISAP I.b.1 (Cont'd)

+.

4 6.0L. CONCLUSIONS =

. The. actions identified by the NRC in Section 2.0 of this report can

~

be. separated into the following three items:

1)' Reinspect all panels which contain SERVICAIR flex,

2) Demonstrate by analysis the acceptability of SERVICAIR flex as a barrier or provide the necessary separation, and

3) Revise'the engineering drawings and related documents to reflect the. final-separation criteria.

To satisfy Item 1, the Unit I control boards and vertical ventilation panels were reinspected. In addition, all Unit 1 and common area multi-train panels that-require separation of cables were examined to determine if they contain SERVICAIR flex. Since the criteria have been revised to authorize the use of flex only in

- the control boards and vertical ventilation panels, Nonconformance 1

- Reports were issued whenever SERVICAIR flex was used in panels

• s_)s'

~

other than the control boards and vertical ventilation panels. For Unit 2, the TUGC0 program described in Section 5.10 will ensure that field installations meet the final separation criteria for SERVICAIR flex.

To satisfy Item 2, analyses and testing were performed to

~ demonstrate that SERVICAIR flex is an acceptable barrier for the majority of the circuits in the control room control boards and vertical ventilarion panels. For the remaining circuits, a one-inch separation is specified.

To satisfy Item 3, the final separation criteria are being incorporated into the appropriate project documents.

These actions, in conjunction with the completion of ongoing activities, will ensure that all concerns regarding separation of redundant cableu, each enclosed in SERVICAIR flex, are resolved.

7.0 ONGOING ACTIVITIES The NCRs issued for the control room control boards and vertical ventilation panels as a result of deviations related to Action Plans I.b.2 and I b.4 have not yet been completely resolved. After the NCRs are closed, TUGC0 will perform a post-censtruction

()

inspection of these panels, which will include verification of adequate separation between two pieces of SERVICAIR flex containing

redundant cables. This inspection will be overviewed by the CPRT third-party.

t

, , - -.,y - r y,_ --.e---,--,~.w,-

Ravision: 1 Page 35 of 37 .

_[

RESULTS REPORT ISAP I.b.1 (Cont'd) 7.0 ONGOING ACTIVITIES (Cont'd)

TUGC0 also is.in the process of developing and implementing a.

program to establish and maintain separation within electrical panels, as_ described in Section 5.10. The Electrical Review Team will review this program as it is being developed and implemented. ,

Upon the completion of these ongoing activities, a Supplemental Report will be issued; this supplement will provide the results of the activities described above.

8.0 ACTION TO PRECLUDE OCCURRENCE IN THE FUTURE The program described in Section 5.10 will ensure that separation inside multi-P. rain panels will be established and maintained.

O

,, Ravision: 1 Page 36 of 37 .

/ ' RESULTS REPORT ISAP I.b.1 (Cont'd)

Table 1 Final Separation Criteria for SERVICAIR flex to SERVICAIR flex inside the

~ Control Boards'and Vertical Ventilation Panels Tefzel or Analyzed Non-Analyzed 4

Non-Tefzel Non-Tefzel Class IE Non-Class 1E Class IE Non-Class IE Tefsel or Class 1E 0" 0" 1" 1" Analyzed ,

Non-Tefzel Non-Class 1E 0" X 0" X Class IE 1" 0" 1" 1" 1 p(g - Non-analyzed Non-Tefzel Non-Class 1E 1" X 1" X i

X -- No Separation Required (Circuits are not redundant)

.O

b .

• -  ::i; Revision: 1

[, Page 37 of 37 ,

's ~RESULTS REPORT

(%l

'ISAP I.b.1 (Cont'd) i Attachment 1 I i

< Chronology.of Major Activities Related to Action Plan I.b.1.

July-September 1984~ The NRC-TRT conducted.onsite inspections.

including a review of the-Unit 1 control room control boards.

October 1984 The initial version of Action Plan I.b.1 was issued..

November 1984 - TUCCO performed a post-construction

.-January 1985 inspection of the Unit I control boards and vertical ventilation panels.

"Jandary 1985 A draft of the circuit evaluation was prepared.

February-April 1985 An inspection of the Unit 1 control boards p and vertical ventilation panels was performed Aj by the CPRT third-party inspectors.

' March.1985 Short circuit and heat transfer tests of SERVICAIR flex were performed.

July'1985 DCA 21446 to Drawing 2323-El-1702-02, " Cable 3 and Raceway Separation Typical Details," was issued. This DCA contained new criteria for SERVICAIR flex in the control boards and vertical ventilation panels.

July.1985: Revision 1 of the circuit evaluation was

-a issued.

October 1985 TUCCO performed a reinspection of the Unit 1 control boards and vertical ventilatica panels using the final separation criteria.

March 1986 Revision 0 of the computer analysis of SERVICAIR flex was issued.

January, May, and The CPRT Electrical Review Team examined Unit June'1986 1 and common area multi-train panels to determine where SERVICAIR flex had been used.

')' (Future) TUGC0 will perform a final inspection of the Unit I control boards and vertical ventilation panels using the final separation criteria. This inspection will be overviewed by the CPRT third-party.