ML20213D411
| ML20213D411 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Sequoyah |
| Issue date: | 10/28/1986 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML082401853 | List: |
| References | |
| 224.5-(B), 224.5-(B)-R, 224.5-(B)-R00, NUDOCS 8611120071 | |
| Download: ML20213D411 (9) | |
Text
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SCptember 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUMBER:
224.5 (B)
SPECIAL PROGRAM REPORT TYPE:
SEQUOYAH ELEMENT REVISION NUMBER: 0 v
TITLE:
RACEWAY SUPPORT DESIGN Support of Cables PAGE 1 0F 9 REASON FOR REVISION:
PREPARATION PREPARED BY:
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SIGNATURE DATE SIGNATURE DATE OCKh5hO259 PDR ECSP MANAGER DATE MANAGER OF NUCLEAR POWER DATE CONCURRENCE (FINAL REPORT ONLY)
September 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUM8ER: 224.5 (8)
SPECIAL PROGRAM REVISION NUM8ER: O PAGE 2 0F 9 v
1.
CHARACTERIZATION OF ISSUE (S):
Concern :
Issue:
MAS-86-005 "Are the non-supported The non-supported Flamastic-Flamastic covered cables covered cable in the spreading in the spreading room that room that penetrates walls and penetrate the walls and ceiling may not be seismically ceiling seismically safe."
safe.
2.
HAS ISSLE BEEN IDENTIFIED IN ANOTHER SYSTEMATIC ANALYSIS? YES NO X Identified by Date Documentation Identifiers:
3.
DOCUNENT NOS., TAG NOS.. LOCATIONS. OR OTHER SPECIFIC DESCRIPTIVE
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IDENTIFICATIONS STATED IN ELEMENT:
Cables in the cable spreading room.
4.
INTERVIEW FILES REVIEWED-The interview files for concern MAS-86-005 were reviewed by the etaluation team on 06/19/86 and 06/26/86. The file contained the concern itself and several memos written to DNE between 01/86 and 03/86 requesting an investigation and within DNE to establish the responsible group for responding to this issue. The memos indicate that the concern relates to the vertical cable runs that penetrate the ceiling. No other significant information was available in the file.
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September 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUM8ER:
224.5 (B)
SPECIAL PROGRAM REVISION NUM8ER: O PAGE 3 0F 9 v
5.
DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
See Appendix A.
6.
WHAT REGULATIONS. LICENSING COMMITMENTS. DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?
See Appendix A.
7.
LIST REQUESTS FOR INFORMATION. MEETINGS. TELEPHONE CALLS. AND OTHER DISCUSSIONS RELATED TO ELEMENT.
See Appendix A.
J 8.
EVALUATION PROCESS:
a.
Obtain and review design documents that support the existing configuration.
s-J b.
Perform a walkdown of the cable spreading room and main control room to review existing conditions.
Identify vertical and horizontal support at the cable spreading room ceiling and determine if there are other supports.
c.
Perform analysis as required.
9.
DISCUSSION. FINDINGS. AND CONCLUSIONS Discussion:
The issue relates to a concern that certain free hanging cab.'es #1 the cable spreading room may not be adequately s'tpported to withstand a seismic event.
NRC General Design Criterion 2 requires Category I structures, systems and components to be designed to withstand the effects of natural phenomena such as earthquakes. Sequoyah compliance with this criterion is stated in SNP FSAR Section 3.1.
The seismic design bases of Category I items are described in FSAR Section 2.5 and 3.7.
Specific application of these bases for Category I i
raceway is contained in FSAR Section 3.10.
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e September 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUMBER: 224.5 (B)
SPECIAL PROGRAM REVISION NUMBER: O PAGE 4 0F 9 v
To respond to this employee concern, TVA personnel initiated a full-scale shake table test program to realistically assess the seismic capability of selected representative cables enveloping the as-built configuration. The test program was based on an enveloping length of approximately 20 feet. The test program is contained in CEB-BN-1010. The objectives and methods of the test program have been reviewed by the evaluation team and have been determined to be adequate.
The test program is very conservative due to the use of both Watts Bar and Sequoyah SSE vertical and horizontal response spectra based on 2% (SQN) and 5% (WBN) damping.
Experience with similar systems indicates that the actual damping is 20%
or more. The Watts Bar Required Response Spectra (RRS) envelopes the RRS for Sequoyah.
In addition, as indicated in the TVA memo Cruise to Johnson, the actual Test Response Spectra (TRS) enveloped the WBN RRS by an approximate factor of two or greater over the entire frequency range.
The test report TR CEB N-1010 was prepared by TVA based on the results of the full-scale shake table test program conducted by Wyle Laboratory under the technical direction of
\\m_s TVA personnel and is attached to the Cruise to Johnson memo.
This report is titled preliminary, but only because TVA had not received the formal data submittal from Wyle Laboratory when the report was prepared.
The evaluation team performed a walkdown of the cable spreading room and the main control room on 06/24-27/86 to identify existing conditions. Specific attention was given to the vertical and horizontal support provided for the cables at the cable spreading room ceiling.
The following physical conditions were noted:
a.
Cable trays penetrate the cable spreading room ceiling to provide raceway for wiring into the main control room.
In addition, the cable trays enter the cable spreading room high on the walls to provide raceway for wiring to the cable spreading room.
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S:ptemb:r 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUM8ER: 224.5 (B)
SPECIAL PROGRAM REVISION NUMBER: C)
PAGE 5 0F 9 v
b.
The evaluation team found that many vertical bundles of cables are laterally unsupported. These cables penetrate the ceiling at a steel plate box structure that extends approximately 3 feet below the ceiling.
This plate structure is approximately 3 feet wide and follows the main control room panel configuration. The cables penetrate both the bottom and sides of the plate structure. However, no unsupported cables penetrating the walls were found.
Each cable is approximately 3/8 inch in diameter; the vertical cables range from single cables to bundles of many cables up to approximately 10 to 12 inches in diameter. Most such single cables or bundles have Flamastic coating and range f rom very flexible for the small bundles, to very stiff for the large bundles, as determined by hand pushing.
c.
Vertical bundles range in length from approximately 3 to 15 feet. Specification G-38, Section 3.2.1.8 requires cable supoort to be spaced in accordance with NEC Article 300.19, which requires vertical support for cables at least every 100 feet. Although this code does not address seismic effects, it does indicate 4.3/
compliance of these cables to other specified requirements. The Category I cable generally feeds out to the Category I trays which are above the non-Category I trays.
Category I trays start approximately 10 feet above the cable spreading room floor. The total room height is approximately 26 feet.
Drawing SD-E-15.3.4 was used to distinguish between Category I tray and non-Category I tray.
d.
Tie wraps for-the vertical runs of unsupported bundles were used bat are not required by installation specification G-38.
Field observations indicated that the tie wraps are on approximate 6-inch centers for the vertical runs.
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S;ptemb2r 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUMBER: 224.5 (B)
SPECIAL PROGRAM REVISION NUMBER: C)
PAGE 6 0F 9 v
e.
The cable boundary conditions include some cables that are offset laterally between the penetration of the cable spreading room ceiling and the vertical cable run. Such offset is generally accomplished by use of material cut from a cable tray, (i.e., the classical ladder shape).
These offsets are shown on drawing Nos. 45N816-5, 45N816-6, 48N730, 48N731, and 48N731-1 and are based on design calculations SWP 790622 019.
Associated typical electrical drawings are 45N880-8, 45N880-23, and 45N881-ll. These are considered as risers rather than actual cable tray and as such are not included in the cable routing schedules.
Prevalent industry practice would extend such risers to near where the last cables entered their cable tray runs.
Such practice was noted at Sequoyah for a limited number of installations which visually appeared to have been added after the bulk installations.
f.
Horizontal and vertical anchorage of cables in the control room panels and floor was found to exist based on the following:
s,e o
Anchorage at the electrical terminations was inferred rather than seen since both units are operating plants and transmit electrical current through the terminati.ons.
o The cables are bundled with tie wrap at approximate 6-inch centers to each other and to ' hort runs of s
cable tray within and outside the panels.
o The in-panel routing generally makes one or two bends before exiting through the plate box structure floor penetrations.
o The penetrations are filled with a resilient silicone foam seal covered with cotton batting.
The foam type material will provide some restraint laterally and vertically due to the restraining forces resulting from the expansive curing nature of the foam.
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S:ptember 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUMBER:
224.5 (B)
SPECIAL PROGRAM REVISION NUMBER: ()
PAGE 7 0F 9 v
Findings:
a.
Based on the evaluation of cable anchorage at the cable spreading room ceiling, vertical and horizontal cable restraint is provided to support the vertical cable runs under any design load.
b.
The shake table test report TR CEB N-1010 has been reviewed by the evaluation teatn with the conclusion that it adequately demonstrates the seismic qualification of the vertical unsupported and Flamastic covered cables in the spreading room. This conclusion is based on the fact that, during testing, the cables stayed within allowable conductor tensile load ratings with no loss of power or significant current fluctuation on the instrumented cables.
c.
The evaluation team also performed a structural calculation R0 (09/09/86) on a representative cable configuration to corroborate the above conclusion.
This calculation confirms the above conclusion of seismic qualification.
C
==
Conclusion:==
Therefore, the evaluation team concludes that while the concern was valid when initiated, it is no longer a technical issue because of the seismic qualification after the date of the concern.
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SIptember 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUMBER: 224.5 (B)
SPECIAL PROGRAM REVISION NUMBER: O PAGE 8 0F 9 v
APPENDIX A 5.
DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
a.
TVA drawings SD-E 15.3.4, R4
" Raceways, CA & W Ident Tags (Sequoyah Nuc Plt & all subsequent Nuc Plants)"
45N816-5, R5
" Conduit & Grounding-Floor El 732.0" 45N816-5, R6
" Conduit & Grounding-Floor El 732.0" 45N816-6, R10
" Conduit & Grounding-Floor El 732.0" 45N880-8, R16
" Conduit & Grounding - Cable Trays - 706.0" 45N880-23, R13
" Conduit & Grounding - Cable Trays - Details" 45h881-11, R9
" Conduit & Grounding - Cable Trays - Single Line" s_'
45N730, R6
" Miscellaneous Steel-Cable Gutter Supports -
s Plan Below El 732.0" 45N731, R5
" Miscellaneous Steel-Cable Gutter Supports -
Sections Below El 732.0" 45N731 -1, R1 "Miscella.neous Steel-Cable Gut'ter Supports -
Sections Below El 732.0" b.
TVA Calculations SWP 790622 019, R0
" Control Building Cable Gutter Supports, El 732.0" c.
TVA Specification G-38, R7
" Installing Insulated Cables Rated up to 15,000 Volts" d.
Test Plan CEB-BN-1010, R0 "Stismic Testing of Representative, Flamastic Coated, Vertically Oriented, Class 1E Electrical Cable Bundles," (06/12/86) e.
TVA memo from D. W. Wilson to H. B. Rankin, [B25 860707 007]
(07/07/86).
b...
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September 29, 1986 TVA EMPLOYEE CONCERNS REPORT NUMBER: 224.5 (B)
SPECIAL PROGRAM REVISION NUMBER: (>
l PAGE 9 0F 9 1
i s_-
f.
TVA informal memo from T. C. Cruise to C. N. Johnson on the subject of this employee concern, with attached Preliminary Summary Test Report TR-CE8-N-1010, (07/18/86) 1 6.
WHAT REGULATIONS. LICENSING COMMITNENTS. DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?
SNP FSAR Update through Amendment 3 Section 3.1, "Conformance with NRC General Design Criteria" Section 3.10 " Seismic Design of Category I Instrumentation and Electrical Equipment" 7.
REQUESTS FOR INFORMATION. MEETINGS. TELEPHONE CALLS. AND OTHER DISCUSSIONS RELATED TO ELEMENT:
a.
Sequoyah Plant Trip Report by J. W. Benkert (06/24-27/86) b.
RFI #SQN-535, (09/09/86) v 1009d
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