ML20094C001
| ML20094C001 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 07/12/1984 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| SBN-680, NUDOCS 8408070332 | |
| Download: ML20094C001 (10) | |
Text
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seAnaOM STATION IPUEBLIC SERVICE Engineedng Office:
Companyof New Hampshire 1671 Worcester Road 7
Frominoham, Massachusetts 01701 (61' 1 - 872 - 8100 7
t July 12, 1984 SBN-680 T.F. J10.1.6 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) Telephone Conversation of April 26, 1984 between V. Nerses and J. Knox of NRC, G. Tsouderos and A. Legendre of Yankee Atomic Electric Company, and G. Aggarwal of United Engineers and Constructors, Inc.
Subject:
Spaced Conductors
Dear Sir:
During the telephone conversation in Reference (b), we discussed an apparent deviation of FSAR Section 8.3.1.4 1(1) which deals with the cable tray loading criteria for heavy power cables and specifies that the cables in the trays be in one layer with a nominal one quarter diameter air spacing between the cables.
In the field, there is an occasional crossing or touching of cables. This typically occurs when cables exit the trays to terminate at a awitchgear or other point of termination. This has been considered as a deviation from the FSAR commitment.
It was explained ta Messrs. Knox and Nerses of NRR that we have investigated the subject of spaced conductors, and it is our engineering judgement that even though the conductors may touch (point contact) here and there or cross each other, the effect on ampacity is not significant. There is no calculation to our knowledge that can prove this theoretically; therefore, in trying to resolve this issue generically, we have decided to have our engineering judgement in this matter verified by a third party, such as a cable authority (recognized cable manufacturer).
We have, therefore, written to two recognized cable manufacturers and requested that they determine the effects on conductor ampacity of not adhering to strict spacing requirements, such as occasional crossing or touching of condo.ctors. Our letters to them and their responses are enclosed. As it can be seen from their responses, they have concurred with our engineering judgement.
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United States Nuclear Regulatory Commission July 12, 1984 Attention:
Mr. George W. Knighton,-Chief Page 2 Based on'the above, we plan to add a note to FSAR Section 8.3.1.4 1(1) to clarify the spacing requirement of heavy power cables. Our proposed change is shown on the attached marked up page of the FSAR and will be included in a future OL Application Amendment. We believe that this resolves the issue of the spaced conductors and the apparent deviation from the FSAR.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY John DeVincentis Engineering Manager Enclosures cc: Atomic Safety and Licensing Board Service List Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 l
I' william S. Jordan, III, Esquire Brentwood Board of Selectmen
- Harmon & Weiss-RED Dalton Road 1725 I Street, N.W. Suite 506 Brentwood, New Hampshire 03833 Washington, DC 20006 Roy P. Lessy, Jr., Esquire Office of the Executive Legal Director Edward F. Meany U.S. Nuclear Regulatory Commission Designated Representative of Washington, DC 20555 the Town of Rye 155 Washington Road Robert A. Backus, Esquire Rye, NH 03870 116 Lowell Street P.O. Box 516 Calvin A. Canney Mancehster, NH 03105 City Manager City Hall Philip Ahrens, Esquire 126 Daniel Street Assistant Attorney General Portsmouth, NH 03601 Department of the Attorney General Augusta, ME 04333-Dana Bisbee, Esquire Assistant Attorney General Mr. John B. Tanzer Office of the Attorney General
, Designated Representative of 208 State House Annex the Town of Hampton Concord, NH 03301 5 Morningside Drive Hampton, NH 03842 Anne Verge, Chairperson Board of Selectmen Roberta C. Pevear Town Hall Designated Representative of South Hampton, NH 03642 the Town of Hampton Falls Drinkwater Road Patrick J. McKeon Hampton Falls, NH 03844 Selectmen's Office 10 Central Road Mrs. Sandra Cavutis Rye, NH 03670
~ Designated Representative of the Town of Kensington Carole F. Kagan, Esq.
RFD 1~
Atomic Safety and Licensing Board Panel
- East Kingston, NH 03827 U.s. Nuclear Regulatory Commission Jo' Ann Shotwell, Esquire Assistant' Attorney General Mr. Angie Machiros Environmental Protection Bureau Chairman of the Board of Selectmen Department of the Attorney General Town of Newbury One Ashburton Place, 19th Floor Newbury, MA 01950 Boston, MA 02108 Town Manager's Office Senator Gordon J. Humphrey Town Hall - Friend Street U.S. Senate Amesbury, Ma.
01913 Washington, DC 20510 (Atta Tom Burack)
Senator Gordon J. Humphrey 1 Pillsbury Street Diana P. Randall Concord, NH 03301 70 Collins Street (Attn: Herb Boynton)
Stabrook, NH 03874 Richard E. Sullivan, Mayor Donald E. Chick City Hall Town Manager Newburyport, MA 01950 Town of Exeter 10 Tront Street Exeter, NH 03833 L
SB 1 & 2 Am:ndnnt 52 FSAR December 1983 1
The factors which are considered when selecting a raceway for an application include mechanical strength to support and pr otect the cables, resistance to chemicals, resistance to moisture, resistance to high temperature, length of life, flexibility, internally generated heating, vulnerability to fire, and general environmental considerations.
The criteria for thermal and physical loading of raceways are based on IEEE/ICEA recommendations or test results for cables installed in different raceways.
In cable trays, the percentage fill requirements are as follows:
d 1.
For all 15 kV and 5 kV power cables and 480 volt heavy power cables (4/0 and larger in size) - one layer w th a nominal l
one quarter diameter air spacingd$se %& ole. 3.()
2.
For 480 volt medium and small size power cables (2/0 AWG and smaller in size) - 40% (see Note 1) of usable tray volume g
fill, and I
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3.
For control and instrumentation cables and control rod drive power cables - 40% (see Note 1) of usable tray volume fill.
In the Nuclear Island, raceways that carry nuclear safety-related f,
circuit cables are embedded in Category I walls, floors, and duct banks or supported by steel numbers which are qualified by means 51 of seismic analysis.
The bases for selecting, laying out, and loading raceways are to minimize the loss of function of cables in the raceway due to adverse conditions external or internal to the ra :eway.
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Electrical Penetrations The electrical penetration assemblies provide the means to allot.
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passage of power, control and instrument circuits through the con-tainment pressure barrier while maintaining the integrity of the pressure barrier.
The criteria for physical separation of electrical penetrations is the same as for raceways as described a bo ve.
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40*. fill is based on nominal cabic diameters. Actual fill percentage might vary because of manufacturing tolerances in cable l
construction. Cable ampacity reduction factors remain unaffected I
by decreased or increased fill percentages.
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1671 Worcester Road. Framingnam. Massachu:>etts 0 70 1 AN KEE
.x May 10, 1984 Dr. T. 11. Ling Senior Technical Consultant Anaconda-Ericsson, Inc.
Wire and Cable Division 901 Cast 86 Street Indianapolis, IN 46240
Dear Dr. Ling:
Spaced Cables e
As we discussed on April 27, 1984, we have some questions on the potential effects on conductor ampacity of not adhering to strict spacing i
requirements, such as occasional crossing or touching, of cables that are installed in ladder-type ca ble t rays.
At the Seabrook Nuclear Power Station, the sizing of 15 kv, 5 kv, and 600 volt heavy power cables (4/o and larger size) is based on ICEA Publication No. P-46-426, utilizing one horizontal layer of cables, spaced 1/4 diameter a pa r t.
Maximum ambient tempera tu re is assumeu to be 500C.
Anaconda cables used at Seabrook are 5 kV and 15 kV interlocked armor 3 conductor 2/o and 4/o and 5 kV triplexed 350 McM.
In the actual installation at Seabrook, the cables are tied down to the cable tray rungs at intervals in order to maintain the nominal 1/4 diameter spacing assumed in the sizing calculations.
It is possible that the cables might touch here and there in between the tiedown in t e rva l s.
Also, we may have cases where the cables cross each other when they exit the tray on the way to be terminated at a switchgear or other termination point.
The question raised is whether the point touch or crossover constitutes a violation of the assumed 1/4 diameter spacing and whe ther this will have an appreciable affect on cable ampacity, it is our engineering judgement that it will not have an appreciable affeet and that this in an acceptable const ruct f on practice. We are asking for your opinion on this subject, l_
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'.Dr. T.'N.
Ling Page 2
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iWe'will appreciate your early response.
Very truly yours, cuw% khimw R. C. Jamison Elect.ical Engineer Seabrook Projects RCJ/psb bec:
J. DeVincentis R. DeLoach R. Guillette/F, Bean G. Tsouderos e
9
t ANACONDA WlRE & CABLE COMPANY June 25, 1984 R. C. Jamison Electrical Engineer YANKEE ATOMIC ELECTRIC COMPANY 1671 Worcester Road Framingham, MA 01701
Subject:
Spaced Cables R:ference: Your Letter dated May 10, 1984
Dear Sir:
Your referenced letter has been reviewed. We offer the following comments for your purusal.
(1) Fundamentally, the calulation of power cable ampacities involve the determination of the amount of heat generated within the cables and the heat dissipated from them.
(2) Some of the numerical values that are required for such calculations are well known, some are empirical and some are estimates. This situation is true with any of the generally accepted tabulations of power cable ampacities, including ICEA P-46-426.
Obviously cables that are touching each other are a violation of the 1/4 to 1 cable diameter spacing criteria and would limit the c6nvection heat transfer from the cables at and near their point of contact.
However, when cables are lashed to the rungs of a cable tray those rungs may be either a heat source or a heat sink depending upon the amount of heat being dissipated from the other cables in that tray. But, the contact area between the cables and the tray runs is so small compared to the eff ectively cooled area between the rungs that whatever influence the rungs may have on the circuit ampacities is usually disregarded.
(3)
It would be expected that the occasional casual point contact between cables, where there is a considerable longitudial distance between those contact points, would have little effect on the circuits actual ampacity.
We sincerely hope that the above comments are of use to you.
Y:urs truly,
,[,I T. H. Ling Senior Con ultant j
co ERICSSON p Anaconda Wire & Catre Compary is a member et the E ncsson Group Anaconda Wire & Cable Cortpany Power Cab'c Division uai ome Acess reop ene PO. Box 40856 901 East 86th Street Indenapolis, IN 46240-0856 Indianapohs, IN 46240 317-253-3505
THE pose arrice sox e40 IO OKONITE Ramsey, New Jersey 07446 201 825-03OO/ Cable: Okonnte May 10, 1984 Mr. G. Tsouderos, Lead Electrical Engineer Seabrook Project Yankee Stomic Ele:tric Company 1671 Worcester Road Framingham, Massachusetts 01701
Dear Mr. Tsouderos:
. Spaced Cables I have your letter of May 7,1984 asking our opinion on the potential effects on ampacity rating due to occasional crossing and touching of cables installed in ladder type trays.
We are in agreement with you that there will be no appreciabJe effects on cabic ampacity.
The methods for sizing used in ICEA P-46-426 are conservative.
Very truly yours, THE OKONITE COMPANY
/
J.
/ La5ky, Vice Pr/npident JSL/ row R
arch and Engined /ing cc: Mr. W. J. Lenahan
D MVkA.AFQ Telephone (617) 8778100 Twx 110380-76 t9 YANKEE ATOMIC ELECTRIC COMPANY
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h*4;th 1671 Worcester Road. Framingham. Massachusetts 01701 s.YAN K EE/
w May 7, 1984 D r. J. S. La s ky Vice President, Research and Engineering The Okonite Company P.O. Box 340 Ramsey, NJ 07446
Dear Dr. Lasky:
Spaced Cables Mr. W. L,enahan suggested that I address this letter to you.
It pertains to the potential effects on conductor ampacity of not adhering to strict spacing requirements, such as occasional crossing or touching, of cables that are installed in ladder-type cable trays.
At the Seabrook Nuclear Power Station, the sizing of 15 kv, 5 kv, and 600 volt heavy power cables (4/o and larger size) is based on ICEA Publication No. P-46-426, utilizing one horizontal layer of cables, spaced 1/4 diameter apart. Maximum ambient temperature is assumed to be 50 C.
Okonite cables used at Seabrook are 600 volt triplexed, 250 and 500 MCM and 1/c 500 MCM.
In the actual installation at Seabrook, the cables are tied down to the cable tray rungs at intervals in order to maintain the nominal 1/4 diameter spacing assumed in the sizing calculations.
It is possible that the cables might touch here and there in between the tiedown intervals.
Also, we may have cases where the cables cross each other when they exit the tray on the way to be terminated at a switchgear or other termination point The question raised is whether the point touch or crossover constitutes a violation of the assumed 1/4 diameter spacing and whether this will have an appreciable affect on cable ampacity.
It is our engineering judgement that it will not have an appreciable affect and that this is an acceptabic const ruction practice.
We are asking for your opinfon on this subject.
m ',
Dr. J. S. Lasky
(
Page 2 o
We will appreciate your early response.
Very truly yours, r
g G. Tso ud e ros Lead Elect rical Engineert Seabrook Project GTs/pmb cc:
W.
Lenahan 22 Indus trial Pat-k Road flingham, MA 02043 bec:
J. DeVincentis R.
DeLoach R. Guillette/F.'lican R. C. Jamison i
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