ML20205M873
| ML20205M873 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 04/11/1986 |
| From: | Gieseker J, Thorsell T COMMONWEALTH EDISON CO., SARGENT & LUNDY, INC. |
| To: | |
| Shared Package | |
| ML20205M802 | List: |
| References | |
| OL, NUDOCS 8604150416 | |
| Download: ML20205M873 (42) | |
Text
- _ _ . _
.y April 11, . 1986, '
- 'tLATED CONREseoNoen,,3 N O UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION I.
j BEFORE THE ATOMIC SAFETY AND LICENSING BOARD 4 ? I4 pp ,,,,
V%
In the Matter of ) OC'fC2kf e UC5 ' C I.
)
COMMONWEALTH EDISON COMPANY ) Docket Nos. 50-456
-) 50-457 (Braidwood Station Units 1 and 2) )
TESTIMONY OF JAMES W. GIESEKER AND THOMAS B. THORSELL (ON ROREM Q.A. SUBCONTENTION 10.D.)
(Electrical Separation) 0.1. Please state your full _ names for the record.
l A.l. James W. Gieseker.
1 Thomas B. Thorsell.
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! Q.2. Mr. Gieseker, who is your employer and what is your occupation?
! A.2. I am employed by Commonwealth Edison Company (CECO) . I
- have been working at Braidwood Station as an electrical
! engineer since August 6, 1984. My title is Supervising Engineer in the Project Construction Department (PCD).
4 Q.3. Mr. Thorsell, who is your employer and what is your occupation?
A.3. I am employed by Sargent & Lundy (S&L) as a Senior Electrical Project Engineer. My business address is 55 East Monroe Street, Chicago, Illinois 60603. I am l I
8604150416 860411
9 currently assigned to Commonwealth Edison Company's Braidwood Project.
Q.4. Mr. Gieseker, please state your educational background and professional experience.
A.4. I graduated in 1971 from Valparaiso University with a Bachelor of Science Degree in Electrical Engineering. I have been employed by CECO since July 19, 1971.
Prior to my transfer to Braidwood Station, I was assigned to the LaSalle Nuclear Generating Station. While at LaSalle, I worked in the Quality Assurance Department, the Station / Production Construction Department and the Station Operating Department. I worked in the Quality Assurance Department from May 1976 to August 1979, where I conducted surveillances and audits to assure that various site contractors, including the electrical contractor, adhered to their QA programs. I also reviewed and approved site work instructions and procedures for these contractors in conjunction with the Station Engineering and the Station Construction Departments. In general, I was familiar with l
the daily operation of the contractors' quality assurance i departments.
l In August of 1979, I transferred into the Station Construction Department where I worked in the Electrical
9 Group. I was responsible for overseeing the electrical contractor's Quality Department and was the main contact for Nuclear Regulatory Commission (NRC) inspectors in the electrical area. I transferred to the Station Operating Department Technical Staff in July 1982, about the time construction of LaSalle was nearing completion. As a member of the Technical Staff, I was first in charge of the Licensing Group and then the Engineering Group. The Engineering Group was responsible for the development and coordination of construction modifications to the plant.
Q.5. Mr. Thorsell, please state your educational background and professional experience.
A.S. I have a Bachelor of Electrical Engineering Degree and Master of Science Degree in Electrical-Engineering from d
the University of Minnesota. I am a Registered Professional Engineer in the State of Illinois. I have been employed by S&L since June 1973. l i
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In addition to my specific work on the Braidwood Project described in A.7. below, I have experience at S&L in the electrical design, engineering and analysis of steam-electric generating stations. This experience includes design and economic evaluation of auxiliary power systems, review of electrical designs to assure compliance with various IEEE standards, including IEEE-384, and 1
4 performance of a. variety of studies covering grounding system design, power system reliability and power system expansion and distribution system protection. I have developed computer programs for calculating power system reliability and for economic evaluation of power pool contracts between utility and industrial generation.
Q.6. Mr. Gieseker, what are your responsibilities with respect to the Braidwood Project?
A.6. I am presently an Electrical Group Leader in PCD. My Group has responsibility for working.with L. K. Comstock's j (LKC's) Quality Control Department. LKC is the site contractor performing the electrical work at Braidwood. I also assist in the development and review of CECO positions and responses to various questions and matters raised in the electrical area by the NRC as a result of their inspection activitiec. During the course of my work, I have acquired knowledge of the design requirements for separation of electrical systems and LKC's procedures which incorporate those requirements at Braidwood. I have the responsibility in PCD for addressing the NRC's questions concerning electrical separation at Braidwood which are the subject of 0.A. subcontention 10.D.
Q.7. Mr. Thorsell, what are your responsibilities wi.h respect to the Braidwood Project?
e A.7. As S&L- Senior Electrical Project Engineer for Braidwood, I am responsible for directing electrical engineers and designers in the development of conceptual design, design of individual electrical systems and preparation of procurement spccifications. I evaluate the proposals of manufacturers, make purchase recommendations and monitor the activities of manufacturers to ensure;Ehat manufac-turers' drawings and finished components are received on schedule. I work with CECO and with manufacturer and contractor representatives to assure that the electrical design, engineering and construction of Braidwood incorporate the latest applicable techniques. I also coordinate the work of S&L electrical engineering personnel with that of other S&L departments and review specifications, design requirements.(including those relating to separation of electrical systems) and drawings to ensure that electrical work is performed correctly.
Q.8. Mr. Gieseker, what is the purpose of your testimony?
A.B. My testimony addresses Inte$venor's' quality assurance subcontention 10.D which concerns compliance-with the separation requirements applicable to installed electrical systems, such as raceway and cable, at Braidwood. A statement of the subcontention is attached to this testimony as Attachment 10.D (Gieseker/Thorsell-1).
Specifically, my testimony explains the basic i -
4 requirements contained in the Braidwood FSAR for separation of installed raceway and cable systems and the questions concerning these requirements that resulted from inspections conducted by the NRC Construction Assessment Team (CAT) upon which subcontention 10.D is based. My testimony also describes the corrective actions taken by CECO, where necessary, in response to the NRC's questions.
Q.9. Mr. Thorsell, what is the purpose of your testimony?
A.9. My testimony explains how the electrical separation requirements contained in the Braidwood FSAR are incor-porated into the design of raceway and cable systems at l Braidwood. My testimony also addresses several of the questions concerning electrical separation raised in the CAT report. I will also explain how the Braidwood electrical separation requirements comply with applicable regulatory requirements.
Q.10. Mr. Gieseker, please describe the general nature of the questions concerning electrical separation raised by the CAT report.
A.10. During inspections of raceway and cable systems at' Braidwood, the CAT inspectors observed that safety-related raceway and cable installations were generally in )
accordance with applicable design criteria. However, the CAT inspectors questioned (1) CECO's implementation of a
some of the electrical separation requirements in the Braidwood FSAR for certain installed raceway and cable l systems; (2) LKC's installation and inspection procedures for certain of these systems; and (3) whether certain l electrical separation requirements contained in the l
l Braidwood FSAR complied with regulatory requirements.
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Q.11. Mr. Gieseker, please describe electrical raceway and cable systems.
A.ll. An electrical raceway system is comprised primarily of cable tray or conduit. Cable tray is a solid bottomed, 1
galvanized steel trough, typically 24 inches wide with 4 inch or 6 inch sides, that is used to convey large numbers of cables. Conduit is rigid steel pipe, ranging from 3/4 of an inch to 6 inches in diameter, that is used to route smaller numbers of cables.
Cables are insulated and jacketed copper conductors which interconnect electrical equipment. Cables convey electri-cal energy to power equipment and provide instrumentation and control functions.
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Cable tray and conduit form a network of pathways for routing cables throughout the plant. Typically, cable tray will be used to route cables to the general location of a piece of equipment and conduit will then be used to l
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complete the routing of the cable from the cable tray and to the equipment.
L Q.12. Mr. Thorsell, what is meant by the term electrical separation?
A.12. A fundamental design philosophy for nuclear power plants is to provide for the independence of redundant safety systems so that a single failure will not disable both safety systems. In order to maintain this independence, it is necessary to separate the redundant electrical circuits that service these systems. To facilitate this l separation, electrical raceway and cable systems are 1
l designed to be spatially segregated in accordance with 1
established separation distances. This physical separation of electrical raceway and cable systems minimizes the potential for a fault condition on one circuit affecting the proper functioning of a nearby circuit which may ultimately affect the performance of a safety function.
Q.13. Mr. Gieseker, what are the principal electrical separation requirements at Braidwood?
A.13. The principal electrical separation requirements at Braidwood are contained in the Braidwood FSAR and are based on the requirements of IEEE-384-1974 and NRC Regulatory Guide 1.75. The requirements include:
m (a) The basic separation required between redundant safety-related raceway systems, including cable tray and conduit, located in general plant areas is 5 feet in the vertical direction and 3 feet in the horizontal direction.
(b) The basic separation required between redundant -
safety-related raceways in cable spreading areas or other plant areas where power cables are installed in enclosed raceways is 3 feet vertical, and 1 foot horizontal.
(c) The basic separation required between safety-related and non-safety-related raceway is 12 inches vertical and 3 inches horizontal.
(d) Where termination arrangements or space limitations preclude maintaining the foregoing basic separation distances, (a) through (c), the minimum separation distance required is one inch, provided barriers or raceway which serve as barriers, for example, metal ,
i conduit, are installed between redundant safety-t related raceway systems or between safety-related and i
non-safety-related raceway systems.
9 (e) The basic separation required between redundant safety-related cables routed in free-air and between safety-related and non-safety related cables routed in free-air is 12 inches.
Mr. Thorsell will explain how these requirements comply with NRC regulatory requirements.
Q.14. Mr. Gieseker, how is compliance with the separation requirements contained in the FSAR implemented at Braidwood?
A.14. CECO has overall responsibility for assuring that the FSAR's electrical separation requirements are implemented at Braidwood. That responsibility is divided between the CECO Project Engineering Department (PED) and PCD. PED is responsible, through S&L, for incorporating the established separation requirements into the design of raceway and cable systems. PCD is responsible for assuring that LKC installs raceway and cable in accordance with design.
Q.15. Mr. Thorsell, please describe the process used by S&L to incorporate electrical separation requirements into the design of raceway and cable systems.
A.15. The specific Braidwood separation requirements for raceway !
l have been incorporated into an S&L Design Criterion which 1
is used as the basis for the preparation and review of
l e
S&L's electrical installation drawings for raceway sys-l tems. The electrical installation drawings specifically l dimension the location of electrical raceways. These raceway systems are designed to maintain proper separation and are reviewed to assure that the design is in accor-dance with the FSAR's electrical separation requirements.
Installation of the raceway in accordance with the design shown on the electrical installation drawings will result in installations that meet the FSAR separation requirements.
LKC is required to install raceway systems in accordance with the design shown on the S&L drawings. In some instances, the use of acceptable installation tolerances can result in the installation of raceway with less than the basic separation distance. Notes are provided on the installation drawings that instruct the installer to identify the lesser separation and either add cable tray covers which justify the lesser separation or report the lesser separation to S&L for analysis or redesign.
S&L does not specify on the installation drawings the location of cables that exit raceway and run in-free air before entering equipment. For cables in free air, PCD has instructed LKC to include the 12 inch separation
installation requirement in its cable installation and inspection procedures.
Q.16. Mr. Gieseker, please describe the process used by LKC to insure that the installation of raceway and cable complies with the designed electrical separation.
A.16. LKC is issued a controlled set of S&L installation drawings along with other design documents. From these drawings, LKC has responsibility for preparing installa-tion procedures for raceway and cable systems which translate the drawing requirements into work procedures.
LKC also has responsibility for preparing Quality Control inspection procedures to verify that safety-related raceway and cable systems are installed in accordance with the installation drawings and other design documents.
These procedures are reviewed and approved by CECO and S&L. Once approved, LKC craft personnel install raceway and cable systems in accordance with the installation drawings using their installation procedures. Following installation of safety-related raceway and cable systems, LKC Q.C. inspectors inspect the installations to verify that the installed systems conform to the installation drawings.
Q.17. Mr. Gieseker, what were the specific questions raised by the NRC CAT report regarding electrical separation?
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l A.17. The CAT report made the following observations and raised the following questions regarding electrical separation: ;
l (a) Installations were observed where the separation between safety-related cable tray and non-safety-related cable tray appeared to be in violation of the FSAR's 12 inch vertical and 3 inch horizontal basic separation requirement for safety-related to non-safety-related raceway. This apparent violation was attributed to LKC's failure to include sufficient electrical separation acceptance criteria in its cable tray installation and QC inspection procedures.
(b) A question was raised as to whether the 12 inch vertical and 3 inch horizontal basic separation requirement between safety-related and non-safety-related cable tray and conduit contained in the FSAR was in compliance with the requirements of IEEE-384-1974 and Regulatory Guide 1.75.
(c) While no specific question was raised in the CAT
- report, table II-3 of the report listed installations f where the separation between conduit and cable tray appeared to violate the FSAR's 12 inch vertical and 3 i inch horizontal basic separation requirements.
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(d) Cables exiting raceways and run in free air were observed to be in violation of the FSAR's 12 inch basic separation requirement.
(e) Cables run in free air were observed to be in physical contact with raceway. The report questioned whether this complied with the requirements of d
IEEE-384-1974 and Regulatory Guide 1.75.
(f) Raceway was observed to be installed with less than the 1 inch minimum separation re'quirement stated in the FSAR.
(g) Cables identified as non-safety-related were observed to be routed with safety-related cables in safety-related raceway.
(h) A question was raised concerning the use of cable jacket insulation as an approved fire barrier for ,
I safety-related cable.
Q.18. Mr. Gieseker, you testified in A.17 (a) . that the CAT report questioned installations where separation between safety-related cable tray and non-safety-related cable tray appeared to be in violation of the FSAR's 12 inch vertical and 3-inch horizontal basic separation requirement. Why was this a concern?
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A.18. The CAT report identified installations where the separation between safety-related and non-safety-related cable tray was found to be less than the 12 inch vertical and 3 inch horizontal basic separation required by the FSAR. The FSAR permits a separation of less than 12 inch vertical and 3-inch. horizontal, provided cable tray covers are installed or an engineering analysis to justify the lesser separation is performed. Seven of the identified installations were examined by CAT inspectors to determine if the lesser separation was acceptable based either on the existence of an installation drawing j requiring cable tray covers or a previously performed l
i analysis justifying the lesser separation distance. Based 4
on this examination, three installations were determined to be in violation of the FSAR's basic separation require-ment. The CAT report attributed these deficiencies to inadequate LKC cable tray installation and inspection procedures.
Q.19. Mr. Gieseker, what deficiencies in LKC's cable tray installation and inspection procedures were identified in j the CAT report?
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A.19. The CAT report identified two deficiencies. The first deficiency was the fact that LKC Procedures No. 4.3.5,
" Cable Pan Installation," and No. 4.8.5, " Inspection of Class 1E Safety-Related Cable Pan Installations," required only that one inch' separation be maintained between 3
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safety-related and non-safety-related cable tray. This was believed to be in conflict with the 12 inch vertical and 3 inch horizontal basic separation distance required by the FSAR. The second deficiency was that the procedures did not require QC inspection of installed non-safety-related cable tray to determine whether separation from safety-related cable tray was adequate.
Q.20. Mr. Gieseker, were the CAT report's criticisms of LKC's cable tray installation and inspection procedures valid?
A.20. Only with respect to the first deficiency described in A.19. The LKC procedures did fail to fully 'ncorporate S&L's design instructions for maintaining the 12 inch vertical and 3 inch horizontal basic separation between safety-related and non-safety related cable tray.
Specifically, LKC failed to incorporate into its procedures the requirement, which appeared as a note on S&L's installation drawings, that whenever the use of installation tolerances resulted in less than the 12 inch vertical or 3 inch horizontal separation between safety-related and non-safety-related cable tray, either a cable tray cover should be installed or LKC engineering should be notified to disposition the installation.
Instead, the LKC procedures only required that the FSAR's i l
1 inch minimum separation distance be maintained between safety-related and non-safety-related cable tray. LKC's l
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failure to incorporate the S&L note into its procedures created the possibility that installations which exhibited greater than the one inch minimum separation but less than the 12 inch vertical and 3 inch horizontal basic separation between safety-related to non-safety-related cable tray would go undetected.
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- The second deficiency identified in the CAT report is not valid. The report correctly noted the fact that LKC's j procedures do not require QC inspection of non-safety-related cable tray for separation requirements.
I i However, since O.C. inspection of non-safety-related raceways for electrical separation is not mandated by NRC regulations, the criticism in the CAT report is unjustified.
t It is possible for a non-safety-related cable tray to be
, installed closer than the required basic separation distance to a previously installed safety-related cable tray. This situation would not ultimately result in an undetected separation violation because the non-safety-related cable tray is not QC inspected. CECO plans to conduct a walkdown of the Braidwood cable tray systems after the cable tray has been installed to identify and resolve any separation problems. Plans for this walkdown were in place prior to the CAT inspection.
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Q.21. Mr. Gieseker, has CECO taken any action to correct the acknowledged deficiency in LKC's cable tray installation and Q.C. inspection procedures?
A.21. Yes. CECO instructed LKC to revise both cable tray procedures. They were subsequently reviewed and approved by CECO and S&L.
LKC's cable tray installation procedure, No. 4.3.5, was revised to include a requirement that LKC Engineering be notified whenever the required 12 inch vertical and 3 inch horizontal basic separation between safety-related and non-safety-related cable tray is not maintained.
LKC's Q.C. inspection procedure for safety-related cable tray, No. 4.8.5, was revised to include a requirement that there be O.C. verification of the required 12 inch vertical and 3 inch horizontal basic separation between safety-related and non-safety-related cable tray.
Inspection Correction Reports (ICR's) are required to be issued if the installed safety-related cable tray is less than the required basic separation distance from an installed non-safety-related cable tray. I Identified cases of lesser separation are required to be ;
l assessed by LKC Engineering to determine whether they ;
either have been previously addressed by S&L in design, or
are acceptable based on an engineering analysis performed by S&L, or whether a cable tray cover needs to be j installed.
Q.22. Mr. Gieseker, please describe the cable tray walkdown that CECO intends to perform.
A.22. CECO intends to perform a walkdown to verify that required electrical separation is maintained between all installed safety-related and non-safety-related cable tray. During i the walkdown, all safety-related cable tray will be examined to identify installations exhibiting less than the required 12 inch vertical and/or 3 inch horizontal
! basic separation between a non-safety-related cable tray.
l Installations which are identified to exhibit this lesser separation will be forwarded to S&L for review.
, The walkdown will be performed after safety-related and i
non-safety-related cable tray has been installed. As a l
)
result, it will be adequate to verify that basic l I
electrical separation is maintained, notwithstanding the
{ 1 fact that installed non-safety-related cable tray is not QC inspected for separation requirements.
I The walkdown has also been planned to coincide with the installation of cable tray covers, which normally occurs i near the end of construction, so as not to delay the
construction process. Any additional covers that may be required as a result of the walkdown will be installed at this time.
Q.23. Mr. Thorsell, how will S&L evaluate cases of lesser i
separation between safety-related and non-safety-related cable tray identified during CECO's walkdown?
A.23. S&L will review each identified potential separation discrepancy between safety-related and non-safety-related cable tray to determine whether it has been previously identified and justified during the design process or whether further evaluation is required. If further evaluation is required, S&L either will determine through
, further analysis that the installed separation distance is acceptable or will instruct CECO to install a barrier, such as cable tray cover, to accommodate the lesser l
separation distance. j l
Q.24. Mr. Thorsell, Mr. Gieseker testified in A.17(b). that the CAT report questioned whether the FSAR's basic separation requirement of 12 inch vertical and 3 inch horizontal between safety-related and non-safety-related raceway complied with the Braidwood FSAR's commitment to IEEE-384-1974 and Regulatory Guide 1.75. Can you address this question?
l A.24. Yes. IEEE-384-1974 specifies a 3 foot vertical and 1 foot i
i horizontal separation between safety-related and non-safety-related cable tray. However, a lesser
separation distance is allowed by IEEE-384-1974 if an analysis is performed to justify the lesser separation.
S&L has prepared, reviewed, and approved an analysis to justify the establishment of the 12 inch vertical and 3 inch horizontal basic separation requirement between safety-related and non-safety-related raceway committed to in the FSAR. The analysis was performed in conformance with Braidwood's FSAR commitments to Regulatory Guide 1.75 which permits the use of such analysis. The analysis is supported by the results of a raceway separation verification test performed to simulate plant conditions for the locations of safety-related and non-safety-related cable tray and the 12 inch vertical and 3 inch horizontal basic separation requirement. The test was performed at Wyle Laboratories.
Q.25. Mr. Thorsell, please describe the raceway separation verification test performed at Wyle Laboratories upon which S&L's analysis is based.
A.25. The raceway separation verification test, or, as I will refer to it hereafter in my testimony, "the Wyle Raceway Test," was performed to verify the acceptability of raceway separation distances between a faulted cable in a raceway and a target cable in a raceway.
The Wyle Raceway Test configurations simulated various field conditions which may exist at Braidwood to justify the 12 inch vertical and 3 inch horizontal separation requirement. The configurations include:
(a) a horizontal cable tray containing target cables located 12 inches above a horizontal cable tray containing faulted cables; (b) a vertical conduit containing target cables separated by 2 inches from a horizontal cable tray containing faulted cables; (c) a horizontal conduit containing target cables located 2 inches above a horizontal cable tray containing faulted cables.
In order to simulate field conditions, a variety of cable sizes were selected for the faulted cables. The target cables selected were small instrumentation cables. The ,
fault currents selected were those that would have the maximum possible heating effect on the cable. It was assumed that the electrical fault would not be cleared by overcurrent protective devices. In each separation .
l configuration for which the test was performed, it was ,
demonstrated that the target cables would be able to l
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perform their safety-related function during and after the sustained fault condition on the faulted cable.
0.26. Mr. Thorsell, are the results of the Wyle Raceway Test reliable?
A.26. Yes. The Wyle Raceway Test, which forms the basis for the S&L analyses, was designed by an S&L electrical engineer familiar with the design and installation of cable and raceway. The test conditions were selected to simulate conditions similar to those which could be experienced at Braidwood, including a worst case condition in the Braidwood electrical design. The test procedure was reviewed by S&L prior to the performance of the test. S&L witnessed the actual performance of the test. In addition, Wyle Laboratories has been reviewed and found to be an acceptable test facility by CECO's Quality Assurance Department.
Based on the Wyle Raceway Test, S&L's analyses established the separation distances of 12 inch vertical and 3 inch horizontal between safety-related and non-safety-related raceway. The analysis also documented the justification -
for the selection of the various test parameters, including justification as to why the test represented a worse case condition. The analysis took into consideration the potential energies of the circuits
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l contained in the. raceways required to be separated; the physical and electrical isolation provided for the circuits by the surrounding cable insulation and cable jacketing; the environmental qualification and fire retardant characteristics of.the cables carrying the circuits; and the potential for hazards in the specific olant areas where the circuits are run; hence it is a r
comprehensive analysis.
i S&L's analysis, along with the supporting Wyle Raceway Test report, were submitted to the NRC's Division of Nuclear Reactor Regulation (NRR) Power Systems Branch for review. NRR documented their acceptance of the analysis i in the February 25, 1985 Braidwood SER supplement.
- Q.27. Mr. Gieseker, you testified in A.17(c). that Table II-3 of the CAT report listed instances where the separation between conduit and cable tray appeared to violate the FSAR's separation requirements. Can you describe these instances?
A.27. Yes. Table II-3 lists a number of conduit to cable tray installations which exhibit less than the required separation distances. The configurations for these l
installations are: l (a) non-safety-related conduit to safety-related cable l
tray
(b) safety-related conduit to safety-related cable tray (c) safety-related conduit to non-safety-related cable tray 1
i The installations were either cases where the conduit and i
cable tray were routed side by side or where the conduit was routed horizontally above an open-top cable tray.
Q.28. Mr. Thorsell, do the conduit installations discussed in A.27. comply with the Braidwood FSAR separation requirements?
A.28. The installations that were identified where conduit and
! cable tray were routed side by side were in compliance l with the FSAR requirement which allows less than the basic separation distance down to a minimum of 1 inch whenever u
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barriers are installed. The metal side of the cable tray and the enclosed metal wall of the conduit serve as
- acceptable barriers.
For the instances where conduit was routed horizontally above an open-top cable tray, S&L has reviewed each of the i
cable tray to conduit interfaces listed in Table II-3 to determine whether the identified installations were l
actually in violation of the FSAR separation requirements.
The review concluded that some of the conduits listed in i
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0 the table were designed and installed without the required separation between the conduit and cable tray.
I This matter could be resolved by either installing covers on the trays or performing an analysis to justify the lesser separation. Since test reports that support such an analysis were already in place, it was decided to perform an analysis rather than install cable tray covers.
i The analysis determined the acceptable minimum separation distance required between cables in a conduit routed horizontally above cables in an open-top cable tray and justified separation between cables of redundant J
j safety-related divisions as well as separation between
$ safety-related and non-safety-related cables. The. tests i
. which support the analysis were performed at Wyle Laboratories. These tests are the Wyle Raceway Test described in A.25. and the Wyle Cable Test described in j A.33. The conduit installation is in compliance with
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Braidwood's separation commitments since each of the interfaces identified in CAT report Table II-3 where conduit was routed horizontally above an open-top cable i
l tray maintained at least one inch separation.
Q.29. Mr. Gieseker, you testified in A.17(d). that the CAT
- report questioned instances where there was less than the
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basic 12 inch separation between cables run in free air at j Braidwood. Would you please explain this concern.
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A.29. Yes. The CAT report generally notes instances at Braidwood where cables of one electrical division, were in contact with cables of another electrical division but lists no specific examples. In some areas of the plant, such as in the Cable Spreading Rooms above and below the Main Control Room and in'the Auxiliary Electric Equipment Rooms, safety-related and non-safety-related cables may
- come into close proximity to each other as they exit cable trays and enter electrical panels. This situation is limited to separation between safety-related and non-safety-related cables. Plant layout and equipment location is such that safety-related cables of redundant divisions do not come together in close proximity in free i air.
- As Mr. Thorsell testified in A.15., cables in free air are not located on S&L's electrical installation drawings.
However, as directed by PCD, LKC's cable installation and inspection procedures properly include the requirement to either maintain the basic 12 inch separation between cables in free air or document cases of lesser separation for S&L to review. Because no examples of the CAT l
report's concern are listed in the report, it is unclear I
- whether the expressed concern is based on a mistaken belief that LKC's procedures were inadequate or on
- perceived separation violations between cables in free air I
that had not been previously identified by LKC.
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Q.30. Mr. Thorsell, does the CAT report raise a valid question i concerning less than 12 inch basic separation between cables in free air at Braidwood?
A.30. No. The cables in the areas described in A.29 are i
j generally cables which carry low level instrumentation and 1
j control signals. S&L has an extensive on-going program in 4
j which every non-safety-related cable which terminates within the same enclosure (e.g., electrical control panel) i as a cafety-related cable is analyzed to demonstrate that i
- failure of the non-safety-related cable will not degrade i
l any safety-related cable. These analyses assume that the i safety-related and non-safety-related cables are bundled i A" together within an enclosure. The analyses demonstrate that the failure of a non-safety-related cable which i
i shares an enclosure with safety-related cables will not j degrade the safety-related cables. Because the analysis assumes that cables are touching each cther within an i
enclosed electrical panel, it also can be used to i
demonstrate that separation of less than 12 inches between i these same cables in free air outside of the enclosure 3
i will similarly not degrade the safety-related cable.
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Q.31. Mr. Gieseker, you testified in A.17(e). that the CAT report also questioned safety-related cables run in free air which come in physical contact with non-safety-related raceway. Are there instances where this may occur at Braidwood?
A.31. Yes. In cable spreading areas such as those described in A.29., it is possible for a safety-related cable exiting a cable tray and run in free air, prior to entering a piece of equipment, to come in contact with a non-safety-related cable tray or conduit located in the vicinity. This contact is permitted by LKC's approved cable installation and inspection procedures.
I Q.32. Mr. Thorsell, Mr. Gieseker has indicated that LKC's cable installation and inspection procedures allow safety-related cables to come in contact with non-safety-related raceway at Braidwood. Did S&L establish this as an acceptable separation distance?
A.32. Yes. S&L performed an analysis to determine the acceptable minimum separation distance required between cables in free air and cables enclosed in a raceway. The analysis was performed in conformance with Braidwood's FSAR commitment to Regulatory Guide 1.75, which permits the use of such analysis. The analysis is supported by the results of an electrical cable separation verification l
test performed to simulate field conditions at Braidwood.
The test was also performed at Wyle Laboratories.
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. l Q.33. Mr. Thorsell, please describe the electrical cable j separation verification test performed by Wyle Laboratories.
A.33. The electrical cable separation verification test, or, as I will refer to it hereafter in my testimony, "the Wyle Cable Test," was designed to determine acceptable separation distances between a faulted cable and a target cable. The faulted cable is representative of a non-safety-related cabic and the target cable is representative of a safety-related cable.
Four test configurations were used to simulate the various field conditions tha: might exist at Braidwood. These configurations are:
(a) a faulted cable in free-air in contact with a raceway i
containing the target cables; g (b) target cables in free air in contact with a raceway containing the faulted cable; (c) target cables in a raceway in contact with a raceway containing the faulted cable and; (d) target cables in free air separated from the faulted cable in free air.
In order to simulate a worst case situation, the faulted
' cable selected was a large power cable and the target
! cables were small instrumentation cables. The fault i
l currents selected were those that would produce the l' maximum heating effect on the cable. It was assumed that the electrical' fault would not be cleared by overcurrent
] protective devices. For each testing configuration, it i
j was demonstrated that the target cables would perform j their intended safety-related function both during and i
after the sustained fault condition on the faulted cable. ,.
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- Q.34. Mr. Thorsell, are the results of the Wyle Cable Test j reliable?
t A.34. Yes. The Wyle Cable Test, which forms the basis for S&L's analysis, was designed by an S&L electrical engineer who l was familiar with the design and installation of cable and i
raceway at Braidwood. The test conditions were selected j to simulate Braidwood field conditions, including a worst case condition in the Braidwood design. The test
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j procedure was reviewed by S&L and CECO PED prior to the 1
performance of.the test. An S&L electrical engineer also.
i witnessed the actual performance of the test.
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Based on the Wyle Cable Test, S&L's analysis established 1
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the acceptable minimum separation distance between cables j in free air and cables enclosed in raceway. The analysis
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D also documented the justification for the selection of the various test parameters, including justification as to why the test represented a worst case condition. The analysis took into consideration the potential energies of the circuits involved; the physical and electrical isolation provided for the circuits by the surrounding cable insulation and jacketing; the environmental qualification and fire retardant characteristics of the cables carrying the circuits; and the potential for hazards in the specific plant areas where this situation may occur; hence it is a comprehensive analysis.
In addition, S&L's analysis, along with the supporting Wyle Cable Test report, were submitted to the NRC's NRR Division, Power Systems Branch for review. NRR documented their acceptance of this analysis in the February 25, 1986 Braidwood SER supplement.
Q.35. Mr. Gieseker, you testified in A.17 (f) . that the CAT report also identified instances where raceway was installed with less than the FSAR's required one inch minimum separation. What types of installations were identified?
A.35. The installations identified in Table II-3 of the CAT report where the 1 inch minimum separation required by the FSAR had not been maintained included interfaces betwben the following types of raceway:
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- 1) safety-related conduit and non-safety-related conduit
- 2) safety-rela ed cable tray and non-safety-related cable tray
- 3) safety-related cable tray and non-safety-related conduit
- 4) safety-related conduit and non-safety-related cable tray 0.36. Mr. Thorsell, did S&L determine whether the types of raceway interfaces described in A.35. which exhibited less than the FSAR's required 1 inch minimum separation were acceptable?
A.36. Separation of less than one inch between a safety-related conduit and a non-safety-related conduit has been found to be acceptable based on the Wyle Cable Test described in A.33. The results of the Wyle Cable Test demonstrate that conduits may touch each other at Braidwood. Therefore, I separation of less than one inch between conduits is also acceptable.
Analyses are not in place to justify, on a generic basis, I
all cases of less than one inch separation between cable
tray and conduit or between safety-related and non-safety-related cable tray. In these cases, a review of each specific installation is required in order to determine acceptability.
Q.37. Mr. Gieseker, how will CECO identify instances where less than the FSAR's required 1 inch minimum separation distance between safety-related and non-safety-related cable tray or between cable tray and conduit may exist at Braidwood in order to determine their acceptability on a case-by-case basis?
A.37. The walkdown discussed in A.22. will also identify instances where less than the minimum 1 inch separation exists between safety-related and non-safety-related cable tray.
To address the situation where less than the minimum 1 inch separation may exist between safety-related cable tray and non-safety-related conduit, or safety-related conduit and non-safety-related cable tray, Ceco has expanded the scope of the planned walkdown described in A.22. In addition to surveying all safety-related cable trays to identify installations which exhibit less than the 12 inch vertical and/or 3 inch horizontal basic separation between non-safety-related cable trays, safety-related cable trays will also be examined during the walkdown to identify instances where less than the required 1 inch minimum separation exists between the
cable trays and non-safety-related conduit as well as between conduit of redundant safety-related divisions.
The scope of the walkdown will also be expanded to examine all non-safety-related cable trays installed in safety-related structures to identify instances where I l
safety-related conduit has been installed less than the required minimum one inch from these cable trays. All instances of less than one inch separation between cable trays and conduit identified during this part of the walkdown will be forwarded to S&L for review.
Q.38. Mr. Thorsell, how will S&L review instances of less than the required 1 inch separation between cable tray and conduit or between cafety-related an'l non-safety-related cable trays identified during CECO's walkdown?
A.38. S&L's review will be performed on a case-by-case basis to determine whether safety-related circuits involved in the interface are degraded below an acceptable level. As with the other analyses I have described and as stated in Braidwood's commitment to Reg. Guide 1.75, which permits such analyses, the analysis will include consideration of the potential energies of the circuits involved; the physical and electrical isolation provided for the circuits by the cable insulation and jacketing; the degree of environmental qualification and fire retardent characteristics of the cables; and the potential for t
hazards in the specific plant areas in which the installations are located.
If the analysis for a particular case demonstrates that separation less than 1 inch may have an adverse effect on the performance of a safety-related function, a design change will be initiated to rework the installation to obtain an acceptable separation.
Q.39. Mr. Gieseker, you testified in A.17(g). that the CAT report identified instances where a cable they considered to be non-safety-related had been routed with safety-related cables in safety-related raceway. Does this condition exist at Braidwood?
A.39. Yes. There are instances in which cables labeled non-safety-related are routed with safety-related cables in safety-related cable tray. The installation of these cables is in accordance with S&L's design.
Q.40. Mr. Thorsell, why did S&L provide for the routing of non-safety-related cables with safety-related cables in safety-related cable tray in the design of the Braidwood electrical system?
A.40. The cables referred to in A.39. are part of circuits which provide inputs to the reactor protection system and, therefore, perform a safety-related function. These cables are routed from equipment located in the Turbine Building, a non-safety-related structure, to the reactor
r protection cabinets located in-the Auxiliary Building, a safety-related structure. Since these cables are routed in a non-safety-related structure, the decision was made to label them non-safety-related but to refer to them as
" quasi-safety-related cables," and to accord them with all other design features of safety-related cables. Thus, in the Auxiliary Building, the cables, although labeled non-safety-related, may be routed in safety-related cable tray. In the Turbine Building, these cables have been physically segregated from other non-safety-related cables by routing them in dedicated conduits installed with seismically designed supports.
Q.41. Mr. Thorsell, does S&L's design for the routing of
" quasi-safety-related" and safety-related cables in safety-related cable trays violate the 12 inch separation requirement between safety-related and non-safety-related cable contained in the Braidwood FSAR?
A.41. No. Since these cables are performing a safety-related function and are only labeled non-safety-related because part of their route is in the Turbine Building, the routing of these cables with safety-related cables in the Auxiliary Building is appropriate. However, since the cables are labeled non-safety-related, an analysis justifying the lesser separation between non-safet?f-related cables and safety-related cables was
O performed for each of the cables discussed in A.39. The analysis was performed in accordance with Braidwood's FSAR commitments to IEEE-384-1974 and Regulatory Guide 1.75.
This approach was reviewed with the NRC and their concurrence was obtained at the time of initial design.
4 More recently, the labeling of these cables, their routing and the analysis performed by S&L were again reviewed by the NRC and their acceptance is documented in the February 25, 1986 Braidwood SER supplement.
Q.42. Mr. Gieseker, was the installation of these " quasi-safety-related cables" Q.C. inspected?
I A.42. Since these cables are not labeled as safety-related on l
the installation drawinge, they were treated as non-safety- l related cables and, as such, some were not inspected by O.C. at the time of their initial installation. However, S&L identified that these cables do perform a safety-related function; therefore, O.C. inspection of these l cables will be performed to verify conformance with design requirements.
Q.43. Mr. Thorsell, Mr. Gieseker testified in A.17(h). that the CAT report questioned the use of cable jacket insulation as an approved fire barrier for safety-related cables. Is this correct?
A.43. No. Cable jacket insulation is not used as an approved fire barrier at Braidwood. The extent to which cable
jacket insulation is considered in electrical separation is discussed throughout my testimony.
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4 Attachment 10.D.
(Gieseker/Thorsell - 1)
- 10. Contrary to Criterion X, " Inspection," of 10 C.F.R. Part 50, Appendix B, Commonwealth Edison Company has failed to ensure that a program for inspection of activities affecting quality was established and executed by or for the organization performing the activity to verify conformance with the documented instructions, procedures, and drawings for accomp-lishing the activity.
10.D. Applicant failed to provide an a(Equate inspection program in that electrical separation criteria were not s 2fficient to identify installations of raceway and cables by Comstock violatino design re-quirements for separation. (CAT Inspec-tion Report 84-44/40,~4xh. 10.)
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l 9EtATED CORRESPONDENC4
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i UNITED STATES,OF AMERICA NUCLEAR REGULATORY COMMISSION DOLKETEP 1 BEFORE THE ATOMIC SAFETY AND LICENSING BOARD l l
In the Matter of ) 16 art 14 P2:14
)
COMMONWEALTH EDISON COMPANY )
Ogkyt g ;, 50-456 Nos.,60-457
) 00CMEilNG A Stavg. 1 (Braidwood Station Units ) BRANCH 1 and 2) )
I CERTIFICATE OF SERVICE '
I hereby certify that copies of Applicant's testimony on subcontentions 8.B., 8.D., 8.E., 8.F.,
10.B. and 10.D. were served on the persons listed below by deposit in the United States Mail, first-class postage prepaid, this lith day of April, 1986. Courtesy copies are being sent by Federal Express to Mr. Guild and messenger delivery to Mr. Treby.
Herbert Grossman, Esquire Ms. Bridget Little Rorem Chairman 117 North Linden Street Administrative Law Judge P.O. Box 208 Atomic Safety and Licensing Essex, IL 60935 Board U.S. Nuclear Regulatory Commission Atomic Safety and Licensing ,
Washington, D.C. 20555 _ Board Panel !
U.S. Nuclear Regulatory I Dr. Richard F. Cole Commission Administrative Law Judge Washington, D.C. 20555 l Atomic Safety and Licensing Board U.S. Nuclear Regulatory Atomic Safety and Licensing Commission Appeal Board Panel Washington, D.C. 20555 U.S. Nuclear Regulatory l Commission l Dr. A. Dixon Callihan Washington, D.C. 20555 l Administrative Law Judge 102 Oak Lane Oak Ridge, TN 37830
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i i Stuart Treby, Esquire William L. Clements Elaine I. Chan, Esquire Chief, Docketing and Services Office of the Executive U.S. Nuclear Regulatory l Legal Director Commission i U.S. Nuclear Regulatory Office of the Secretary l Commission Washington, D.C. 20555 l Washington, D.C. 20555 l William Little Robert Guild, Esquire Director, Braidwood Project Douglass W. Cassel, Jr., Esquire Region III Timothy W. Wright III, Esquire U.S. Nuclear Regulatory BPI Commission 109 North Dearborn Street 799 Roosevelt Road !
Suite 1300 Glen Ellyn, Illinois 60137 l Chicago, Illinois 60602
)nuAb Joseph fallo b
Ohd'of the attorneys for Commonwealth Edison Company l
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