ML17354A429

Ampacity Derating Response to NRC GL 92-08 for Cables Routed in Conduit & Tray w/Thermo-Lag 330-1 Barrier Sys Coating.

ML17354A429
Person / Time
Site:	Turkey Point
Issue date:	03/07/1997
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17354A428	List: ML17354A427 ML17354A429 ML17354A430 ML17354A431 ML17354A432
References
GL-92-08, GL-92-8, PTN-BFJE-93-001, PTN-BFJE-93-001-R00, PTN-BFJE-93-1, PTN-BFJE-93-1-R, NUDOCS 9703130422
Download: ML17354A429 (40)

Text

Page i CALCULATION COVER SHEET Calculation No: PTN - BFJE 001

Title:

AMP%CITY OERATING RESPONSE to NRC GL 92-08 for CABLES ROUTED in CONDUIT and TRAY with THERMO-LAG 330-1 FIRE BARRIER SYSTEM COATING

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~pS 'e ISITIAL ISSUE No Description REVISIONS 9703i30422 970307 05000250 PDR ADOCK PDR 7/9

~P" Fornl 82A Rev

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Page ii LIST OF EFFECTIVE PAGES Calculation No. PTN - BFJE - 93 - OOI Rev. 0 Title AMPACITY DERATING RESPONSE to NRC GL 92-08 for CABLES ROUTED in CONDUIT and TRAY with THERMO-LAG 330-1 FIRE BARRIER SYSTEM COATING Page Section Rev. Page Section Rev.,

i Cover Sheet 0 ii iii' List of Effective Pages 0 Table of Contents 0 1.0 Purpose 0 4 2.0 References 0 5 2.0 References '0 5 3.0 Xethodology 0 5 4.0 Assumptions/Bases 0 6 4+0 Asslsllptiotls/Bases 0 7 4e0 Assllllptiolls/Bases 0 7 5.0 Calculation 0 8 5.0 Calculation 0 9 5.0 Calculation 0 10 5.0 Calculation 0 11 5.0 Calculation 0 12 5.0 Calculation 0 13 5.0 Calculation 0 14'5

'.0 Calculation 0 5.0 Calculation 0 15 6.0 Results 0

'16 6.0 Results 0 17 6.0 Results 0 18 6.0 Results 0 19 6.0 Results 0 20 6.0 Results 0

,JPN Form 8828, Rev 7/9<

0 Page iii TABLE OF CONTENTS CALCULATION NUMBER PTN - BFJE 001 REV.

SECTION TITLE PAGES Cover Sheet List of Effective Pages Table of Contents 1 ~ 0 Purpose/Scope 2 ' References 4 - 5 3 ' Methodology 4' A'ssumptions/Bases 5-7.

5' Calculation 7-15 6.0 Results 15 - 20 ATTACHMENT NO ~ TITLE NUMBER OF PAGES JPN Form ¹82C, Rev. 7/90

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CALCULATION NO ~ PTN - BFJE 001 SHEET NO.

REF.

AMPACITY DERATING RESPONSE to NRC GL 92-08 f'r CABLES ROUTED in CONDUIT and TRAY with THERMO-LAG 330-1 FIRE BARRIER SYSTEM COATING 1.0. PURPOSE The purpose of this calculation is to provide a tabulation of power cable ampacity calculations performed for derating, of power cables used in Turkey Point Nuclear (PTN) 3 and 4. Power cables that are not evaluated in previous calculations will be addressed within this calculation. The results of this calculation will be referenced in the engineering response to NRC "Thermo-Lag 330-1 Fire Barriers (Generic Letter 92-08)".

2.0. REFERENCES FPL Document 5610-M-722, Turkey Point Plant-Units 3 & 4, Appendix R Safe Shutdown Analysis, Revision 1, Dated July 17, 1992.

2. FPL Document 5610-M-723, Turkey Point Plant-Units 3 & 4, Appendix R Essential Equipment L'ist, Revision 1, Dated July 17, 1992.

3. FPL Document 5610-E-2000, Turkey Point Plant - Units 3 & 4, Appendix R Essential Cable List, Revision 1, Dated July 17, 1992.

4. Bechtel Power Corporation Calculation 5177-304-E-04, Revision 1, Dated January 23, 1984:.

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5. Bechtel'Calculation 5177-EF-Ol, Revision 2, Dated November 10, 1989.

6. Bechtel Calculation 51T7-EF-09, Revision 1, Dated November 10, 1989.

7. Bechtel Calculation 5177-EF-10, Revision 1, Dated November 10, 1989.

8. Bechtel Calculation'5177-EF-12, Revision 1, Dated November 10, 1989.

9. Bechtel Calculation.5177-EF-13, Revision 0, Dated November 7, 1985.

10. Bechtel Calculation 5177-EF-15, Revisi'on 1, Dated November 10, 1989.

,11. Bechtel Calculation 5177-265-EF-25, Rev. 1, Dated November 10, 1989.

12. EBASCO Calculation EC-50, Revision 1, Dated March 9, 1990.

13. EBASCO Calculation EC-127, Revision 6, Dated June 25, 1991.

14. EBASCO Calculation EC-128, Revision 6, Dated June 25, 1991.

15. EBASCO Calculation EC-129, Revision 7, Dated June 28. 1991.

16. EBASCO Calculation EC-130,, Revision 5,* Dated June 17, 1991.

17. EBASCO Calculation EC-132, Revision 6, Dated July 9, 1991.

1$ . EBASCO Calcul'ation EC-164, Revision 3,, Dated. May 19, 1991.

19; EBASCO Calculation EC-182, Revision 0 Dated April 20, 1990 29 Thermal Science, Incorporated (TSI) Technical Note 11781, Rev. 5

21. Industrial Testing Laboratories (ITL) Report No 84-10-5, Dated October, 1984.

22. FPL Drawing 5613-E-10, Revision 4, Dated September 12, 1992.

23. FPL Document 5613-E-320, Revision 4, Dated November 12, 1992.

24. FPL Document 5614-E-320, Revision 3, Dated June 23, 1992.

25. FPL Document 5613-E-321, Revision 6, Dated November 12, 1992.

26. FPL Document 5614-E-321, Revision 4, Dated June 23, 1992.

27. FPL Document 5610'-E-305, Revision 38, Cable and Raceway Schedule

28. FPL Drawing 5610-T-E-1592, Revision 36, Dated July 29, 1991.

29. FPL Drawing'.5610 E-25, Sheet 99A, Revision 1, Dated August 28, 1989.

30. FPL Drawing 5614-E-10, Revision 0, Dated December 14, 1991 MAS-4 JPN

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CALCULATION NO ~ PTN - BFJE 001 SHEET NO.

31. FPL Drawing 5610-T-E-1591, Revision 46, Dated December 30, 1992.

32. FPL Drawing 5613-'E-ll, Revision 1, Dated October 28, 1992.

33. FPL Drawing 5613-E-12, Revision 0, Dated December 12, 1991.

34. FPL Drawing 5614-E-11, Revision 2, Dated November 12, 1992.

35. EBASCO Calculation EC-138, Revision 4, dated March 31, 1992.

36. FPL Drawing 5614-E-1713, Revision 1, Dated. June 18, 1992.

3.0. METHODOLOGY This calculation is prepared in two parts; a tabulation which was compiled from a review of calculations referenced in Section 2.0 which evaluated cable sizing and derating of PTN power cables and a section which evaluates power cables that are 'not specifically identified within previous calculations. The population of power cables to be evaluated was determined from a review of power cables at PTN which had been Q, o.l. specifically evaluated for the PTN Safe Shutdown Analysis (SSA) and those

@,0.X power:cables affected by the Thermo-Lag 330-1 Fire Barrier System. Power

.0.3 cables from the following distribution sources were evaluated:

4160 Volt AC Switchgear: 3A(3AA), 3B(3AB), 3D(3AD), 4A(4AA),

4B (4AB), 4D(4AD), and.

480 Volt AC Load Centers 3A(3B01) 3B(3B02), 3C(3B03), 3D(3B04),

3H(3B50) 4A(4B01), 4B(4B02), 4C(4B03),

4D(4B04) 4H(4B50), and 480 Volt AC Motor Control Center: 3A(3B05) 3B(3B06), 3C(3B07), 3D(3B08),

3K(3B52) 3L(3B53), 3M(3B54), 4A(4B05),

4B(4B06) 4C(4B07), 4D(4B08), 4J(4B51),

4K(4B52) 4L(4B53), 4M(4B54), and 125 Volt DC Bus: 3A(3D01) 3B(3D23), 4A(4D23) and 4B(4DOl) 4.0. ASSUMPTIONS BASES

.O. W Fire protective coatings used at PTN are the Thermal Science, Inc.

(TSI) Thermo-Lag 330-1 Fire Berrier System (fire wrap). Based on testing conducted by TSI, a power cable; i.e., two single ¹00 American Mire Gage (2-1/c ¹2/0. AWG), in a two inch (2") magnetic conduit coated with one hour TSI protection will be derated by 7.47%. The same type cable within a two inch (2") conduit coated with three hour TSI protection will be derated by 9.72%.

2. The scope of this calculation applies to conduit and tray sections inside and outside containment. For cables inside containment, the ambient air temperature is assumed~ to be 50 'C. Outside containment, the ambient temperature is assumed to be 40 'C.

3. Basic data from the calculations referenced in Section 2.0 applies to this .calculation where required because this calculation is.

essentially a tabulation of data from previous calculations.

Control and Instrumentation cables are not included in this evaluation because ampacity derating is not of concern for these types of cable service.

MAS -4. JPN JPH FORM 83 Rw. 3/90

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CALCULATION NO. PTN - BFJE 001 REV'. 0 SHEET NO.

5. This calculation does not size any new cables. Evaluations per formed within this calculation use data and tables from referenced calculations as noted.

6. The following assumptions were used in the original calculations for sizing cables at PTN.

~ Calculation 5177-EF-01

1) for 600, 5000 and 8000 volt insulation rated cables, the conductor temperature is assumed to be,90'C and the cable load factor is 100%,

2) Thermo-Lag der'ating factors from TSI based on testing of 2-1/c ¹2/0 cable in a 2" conduit are:

I'c AWG 1-hour 7.47%; i.e., I' Ic x (1 - 7.47%) - 0.9353Ic 3-hour 9.72%; i.e., x (1 - 9.72%) - 0.9028Ic that is, the allowable ampacity (I') of a cable is the rated ampacity of the cable (Ic) reduced by the derating factor

3) for -600 volt AC cables connected to Motor Control Centers (MCC), the capacity, is equal to 125%

~ Calculation 5177-EF-09 g.o. < 1) .. used TSI derating factors (1-hour 7.47$ , 3-hour 9.72%)

2) calculation for cables outside containment ambient temperature is 40'C

3) evaluated all cable ampacity based on 3-hour coating for conservatism

4) based on conclusions in calculation 5177'-304-E-04, derating factor was 0.5 assuming a worst case cable tray power cables 'in tray) fill (> 43

5) an,.additional derating factor of 0.9132 was used to account for Flammastic coatings

6) cable in tray was assumed to have conductor temperature of 85'C

7) for cables sizes ¹10'AWG and.¹12 'AWG, an added.derating factor of 0.9 was required per ICEA; therefore, the overall derating factors. to be used in cable si'zing based on ampacity in a full tray with Flammastic coating of the cables were:

( ¹10 and ¹12 AWG) 0.9 x 0.5 x 0.9132 0.411

( ¹8 and larger AWG) 0.5 x 0.9132 0.457

7. For circuits which are evaluated within, this calculation, the source of design bases and background information is referenced within each section for the affected circuit.

8. Note that for cable sizing purposes, ampacity is only one factoi, along with circuit voltage drop at normal and degraded grid voltage and cable short circuit fault withstand capability. Additionally,

'cable sizing used 'standard'able sizes which were cables that were 0 MAS-4.JPN already available on site that were as large or larger than the designed cable required.

JPH PORE 63 Rev. 3/90

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CALCULATION NO. PTN - BFJE - 93 - 001 SHEET NO.

For worst case analysis of cable ampacity deratingcables that were sized per 2.o,4 calculation 5177-EF-09 used a derating factor created for the calculation by dividing the ampacity of three single conductors (3-1/c) routed in rigid steel (magnetic) conduit by the ampacity of one single (1-1/c) conductor in free air The resultant factors varied from 0.653 to 0.769. The value of 0.653 was used to size cable for conservatism. Then the derating factor for three hour fire 4a,t .> wrap on conduit became: (0.653) x (0.9028) 0.590.

Comparing the derating factor for cable ampacity within conduits to the worst case derating factor for cables in tray sections filled to a maximum hypothetical fill limit and coated with Flammastic fire retardant, the derating factor for the coated tray becomes the most restrictive and conservative for use in calculations. Therefore, because cables were sized based on worst case ampacity derating in filled tray (¹8 AWG or larger 0.457) in conduit with fire wrap (worst case factor - 0.590) it was was concluded that cable acceptable.

5.0. CALCULATION 5.1. Tabulation of Cable Sizin and aci Deratin The results of calculations which were performed to size cables atul provide derating factors for power cables at PTN are listed in the. table in Section 6 '. No changes or enhancements were made to the values obtained from the engineering review of the calculations listed in Section 2.0.

In addition to the cables within conduits at PTN, there are six (6) tray sections which have been coated with Thermo-Lag 330-1 fire wrap. These tray sections are:

3AUT10 located in Switchgear Room 3A; (Circuits 3B0406/1, 2 & 3; 3B0408/1 & 2) 3AXT10 - located in Switchgear Room 3A; (Circuits 3B0204/1 & 2; 3B0206/2 3D2302/1) 4AXTaO - located in Switchgear Room 4A; (Circuits 4B0202/1, 2 & 6; 4B0203/1; 4B0206/1 & 2; 4D0106/1) 4LAT20 located outdoors adjacent to Lube Oil Storage Tank; (Circuits 4AB21/OP, OQ & .OR; 4AD06/OP & OQ) 4LAT30 - continuation of 4LAT20 4LAT40 - continuation of 4LAT30 2.0. 't Tray sections 3AUT10 and 3AXT10 are evaluated in calculation 5177-EF-10 using cable sizing calculation 5177-304-E-005 for voltage drop and a maximum derating factor of 22.6% (i.e., 20.55% from I.T.L. Report No 84-3-275A plus 10% for conservatism). Tray section 4AXT10 was evaluated within calculation 5177-EF-13 with the same maximum derating factor; i.e.,

2.0.1 22.6a, that was used for the Unit 3 tray (5177-EF-10).

Tray sections 4LAT20, 4LAT30 and 4LAT40 are a continuous run of tray outdoors at the lube oil storage area containing .the power cables from the HAS -4. JPN JPR FORM 83 Rw. 3/QO

0 CALCULATION NO. PTN - BFJE 001 SHEET NO.

Unit 4B EDG to Switchgear 4B and the power cables from Switchgear 4B to Load Center 4D. Cable ampacity derating factors for these cables were g.o. (9 evaluated within calculation EC'-182. This calculation determined a derating factor based on analysis and then compared the results to a published value from TSI (compilation of Underwriters Laboratories, Inc.

Pro'j ect No. '86NK23826 results) . Based on a .lower value from TSI, the cable within this tray was derated 28%. The allowable ampacity of the cable after being derated was determined to be more than was required of the load on the circuit.

5.2. Individual Case Stud Calculations The following circuits have not been specifically identified in previous calculations but will affect essential equipment in the PTN Safe Shutdown Analysis.

5.2.1. Power cable to MOV-3-536, Pressurizer Power Operated relief Block Valve (A-3B0713/P) g.o,/A.

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This circuit is powered from MCC 3C.

Motor rating 0.33 hp Service factor 1.0 Full load amps 0.75' Locked rotor amps 5.5 g.o. >>. ,Starter (MCC 3C) - 40'C Breaker rating 3.0 A A

Cables to motors are sized to have ampacity equal to 125% of full load current of the load. In addition, the ampacity of the cable size selected shall be higher than the overcurrent rating or trip setting of the feeder breaker provided for protection of the feeder cable. For the motor, ampacity, is 0.75 x 1.25 - 0.9375,Amps and for .the feeder breaker, ampacity

- 3,0 x 1.25 - 3.75 Amps. For conservatism, the locked rotor current (5.5 Amps) is used for the load current (Iz) in this evaluation.

The existing cable is 1-3/c 510 AUG which is rated at (Ic) 36 amps in exposed conduit in free air. Multiplying by the (existing) derating factor for 3-;hour fire wrap, the allowable ampacity (I') becomes: 36 x 0.9028 - 32.5 amps.

The allowable ampacity (I') is larger than the ampacity of the load by 3366% and larger than the breaker overload rating by 491%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the circuit voltage drop or the short circuit withstand capabil'ities of the circuit.

MAS-4.JPN JFN FORM 83 Rw. 3/99

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CALCULATION NO. PTN - BFJE 93 - 001 SHEET NO.

5.2.2. Power Feeder to Unit 3 Train A Sequencer Panel .- 3C23A (A-3D0104/P)

Panel current loads to the 3A Sequencer Panel are calculated based on the individual device loads as identified in the Bus 3A DC Load List (5613-E-321, Rev: 6).

Z.o.25 Total loads 2941.5 Watts g 125 volt DC 23.53 Amps 2,0 e3Z Breaker racing 70 Amps, Cable protection 70x1.25 67,54 RsO.2'7 The existing cable is 2-1/c ¹2 AWG which is rated at (Ic)

C.o.S 130 amps in'xposed conduit in free air (reference 2.0.5).

Multiplying by the (existing) derating factor for 3-hour fire wrap, the allowable ampacity (I') becomes: 130 x 0.9028 117.36 amps.

The allowable ampacity (I') is larger than the ampacity of the load by 399% and larger than the breaker overload rating by 34.1%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the circuit voltage drop or the short circuit withstand capaLilities of the circuit.

5.2.3 ~ 125 volt DC Power to EDG 3A Exciter Cabinet - 3E04A (A-3D0147/P & A-3D0147/Q)

These circuits are parallel power feeders required to supply the exciter cabinet and account for voltage drop from the DC bus to the cabinet. The exciter cabinet rating is based on the tabulation of individual loads within the cabinet as provided in the Bus 3A DC Load List.

2.o.Z5 Total load (Tt)- 1929.6 Watts (d 125 volt DC - 15.44 smps 2sOs32 Breaker rating - 125 amps, Cable protection 125 x 1.25 156.25 amps The existing cables are 2-1/c ¹1/0 AWG each rated at (Ic) 179 amps in exposed conduit in free air. Multiplying by the (existing) derating factor for 3-hour fire wrap, the allowable ampacity (I') becomes: (179 x 0.9028 161.6 amps) x 2 323 . 2 amps'.

The allowable ampacity (I') is larger than the ampacity of the load by 1993% and larger than the breaker overload rating by 106.8%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the circuit voltage drop or the short circuit withstand capabilities of the circuit.

MAS -4. J PN JPH FORM 83 Rov. 3/90

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CALCULATION NO ~ PTN - BFJE - 93 - 001 SHEET NO. 10 REF.

5.2.4. 125 volt DC Power to Miscellaneous AFW and Condensate Valve,

,Distribution Panel 3D06 (B-3D2306/A)

Power to the DC solenoid valves and miscellaneous loads from 3D06 are tabulated from the Bus 3B DC Load List. This list assumes that the circuits are continually energized to. 100%,

load capacity.

p.o, 23 Total load (I<)- 610.3 Watts

- Q 125 volt DC 4.88 amps Q.A. 53 Breaker rating 20 amps, Cable protection '20 x 1.25 25 amps The existing cable is 1-2/c ¹12 AWG which is rated at (Ic) 27 amps in exposed conduit in free air. Multiplying by the (existing) derating factor for 3-hour fire wrap, the (I') becomes: 27 x 0.9028 x 0.9 21.94 amps.

allowable'mpacity The all'owable ampacity (I') is 1'arger than the ampacity of'he load by 349% and larger than the breaker rating by 10%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the circuit voltage. drop or the ~hurt circuit withstand capabilities of the circuit.

5.2.5. 125 volt DC Power to EDG3B Exciter Cabinet 3E04B (B-3D2328/P &'-3D2328/Q)

These circuits are parallel power feeders required to supply the exciter cabinet and account for voltage drop from the DC bus to the cabinet. The exciter cabinet rating is based on the tabulation of individual loads within the cabinet as provided in the Bus 3B DC Load List.

.o. as Total load (Iz) 1768.8 Watts Q 125.volt DC 14.15 amps

.o. 33 'Breaker rating 125 amps, Cable protection - 125 x 1.25 - 156.25 anps The existing cables are 2-1/c ¹1/0 AWG each rated at (Ic) 179 amps in exposed'conduit in free air. Multiplying by the (existing) d'crating factor for 3-hour fire wrap, the allowable ampacity (I') becomes: (179 x 0.9028 161.6 amps) x 2 323e2'mp'he allowable ampacity (I') is larger than the ampacity of the load by 2184% and larger than the breaker overload rating by 107%., The additional margins from the load and breaker rating are due to the fact that the cable size, was evaluated and selected based on either the circuit voltage drop or the short circuit withstand capabilities of the circuit.

MAS-4eJPN JPN FCSM 83 Rev. 3/90

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CALCULATION NO. PTN - BFJE 001 SHEET NO.

5.2.6 ~ Power cable to MOV-4-535, Pressurizer Power Operated Reli'ef Block Valve (B-4B0606/P)

This circuit is powered from MCC 4B.

Motor rating 0.33 hp Service factor - 1.0 Full load amps 1.0 A Locked rotor amps - 5.5 A Starter (MCC 4B) - 22'C Breaker rating 3.0 A Cables to motors are sized to have ampacity equal to 125% of full load current of the load. In addition, the ampacity of the cable size selected shall be higher than the overcurrent rating or trip setting'f the feeder breaker provided for protection of the feeder cable. Therefore, for the motor, ampacity - 0. 75 x 1. 25 0. 9375 amps and for the feeder breaker, ampacity (Iz) 3. 0 x 1. 25 3. 75 Amps. For conservatism, calculation EC-50 assumed the load current (II) to be the locked rotor current ( 5.5 amps).

g.y. k7 The existing cable is 1-3/c ¹12 AWG which is rated at (Ic) 27, amps in exposed. conduit in free air. Multiplying by the g.o. b (existing) derating factor for 3-'hour fire wrap, the allowable ampacity (I') becomes: 27 x 0.9028 24.4 amps.

The allowable ampacity (I') is larger than the ampacity of the load by 1850% and larger than the breaker overload rating by 550%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the circuit voltage drop or the short circuit withstand capabilities of the circuit.

5.2.7. 480 volt AC to Battery Charger 4B1 (4D02) (B-4B0614/A)

The current load of the battery charger is based on the.

maximum'rating of the charger. The battery charger can supply 400 amps at 125 volts DQ 50 kw. In all situations except for Station Blackout (SBO) scenarios, PTN battery chargers work as pairs on each DC bus and supply one-half of the bus load. From the SBO diesel load tabulation, the maximum expected load on this single battery charger 56.46 kw.

Assuming a ten percent (10%) voltage drop during SBO scenarios, the load current to 4D02 is as follows:

kw load on AC side 56.46 kw, voltage (V)at battery charger - 480 - 480(0,1) - 432 volts assuming P.F. (efficiency) 0.8; full load current (FLC) kw x 1000 94.32 amps J3 x Vx eff.

Breaker rating - 150 amps, P.O. 3O Cable protection - 150 x 1.25 - 157.5 ampa MAS-4.JPN JPN FORM 63 Rsv. 3/90

0 CALCULATION NO. PTN - BFJE 001 SHEET NO. 12 CN,O. ~7 The existing cable is 3-1/c ¹4/0 AWG which is rated at (Ic)

Q.o. s 278 amps in exposed conduit in free air (reference 2.0.5).

Multiplying by the (existing) derating factor for 3-hour'ire wrap, the allowable ampacity (I') becomes: 278 x 0.9028 251 amps'he allowable ampacity (I') is larger than the ampacity of the load by 166% and larger than the breaker overload rating by 34%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected base'd'n either the circuit voltage drop or the short circuit withstand capabilities of the circuit.

5.2.8. 125 volt DC Power to AFW Trip 6 Throttle Valve K3B (B-4D0104/R)

Valve motor rating - 0.33 hp - 246.18 Watts Motor current 246.18W g 125 volt DC - 1.9694 Breaker rating - 30 amps, Cable protection 30 .x 1.25 37.5 amps 4.0.> 1' This cable is 2-1/c ¹6 which is rated at (Ic) 75 amps in 0

AWG o.'5 exposed conduit in free air. Multiplying by the (existing) derating factor, the allowable ampacity (I') becomes:

0.9028 x '75 67.74 amps.

This cable is the same size, type and spliced to circuit B-4D0104/Q which is evaluated in calculation 5177-EF-15 as follows: cable current 75 amps, allowable derated ampacity (I') - 44 amps, and load current (I<) - 24 amps.

Based on the evaluation in calculation 5177-EF-15, the allowable ampacity (I') is larger than the ampacity of the load by 83% and larger than the breaker overload rating by 17%. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the. circuit voltage drop or the short circuit withstand capabilities of the circuit.

=:5.2.9. 125 volt DC Power for Alternate Shutdown Panels 3(4)C264 Emergency Lighting (B-4D0107/P) 4.0. elan This cable feeds parallel emergency lighting circuits to the Unit 3 and Unit 4 Alternate Shutdown Panels 3(4)C264. The circuits are parallel fused for 15 amp service and the DC Bus 4B feeder breaker is rated for 50 amps.

Load rating - 15 amps x 1.25 18 75 empt Breaker rating - 50 amps, Cable'protection 50 x 1.25 - 62.5 MAS-4. JPN JFH ECRU 63 Rev. 3190

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CALCULATION NO. PTN - BFJE - '93 - 001 SHEET NO. 13 REF.

The existing cable is 2-1/c ¹ 2 AWG which is rated't (Ic) 130 amps in exposed conduit in free air. Multiplying by the (existing) derating factor for 3-hour'fire wrap, the allowable ampacity (I') becomes: 130 x 0.9028 - 117.36 amps.

'he allowable ampacity (I') is larger than the ampacity. of the

.load by 526% and larger than the breaker overload rating by 88%. The additional margins from the load and breaker rating are due. to the fact that the cable size was evaluated and,

-selected based on either the circuit voltage drop or the short circuit withstand capabilities of the circuit.

5.2.10. 125 volt DC Power for Sequencer 4B Control Power (B-4D0129/P)

The sequencer load rating is ',based on the tabulation of individual loads within the cabinet as provided in the Bus 4B DC'oad List.

Total load (Tt)- 537.98 Watts Breaker rating 30 amps, I .125 volt DC - 4.304 taps Cable protection 30 x 1.25 37.5 amps Ne.~1 'The existing cables are 1-2/c ¹12 AWG each rated, at (I~)

Q<,5 27 amps in exposed conduit in .free air. Multiplying by the (existing) derating factor for 3-hour fire wrap, the allowable ampacity (I') becomes: 27 x 0.',9028 x 0.9 - 21.93 amps.

The allowable ampacity (I') is larger than the ampacity of the load by 410% and is not larger than the breaker overload rating. The breaker trip setting must be set to provide protection for this cable. The additional margins from the load and breaker rating are due to the fact that the cable size was evaluated and selected based on either the circuit voltage drop or the short circuit withstand capabilities of the circuit.

',5:. 3 Worst Case Circuit Am aci Deratin Evaluation After a review of previously issued ampacity derating calculations and the evaluation of circuits in Section 5.2 above, two circuits were identified which have calculated margins, above the derating factor which engineering concluded were not as conservative as would be expected. These circuits are 3AB09/1 and 3AB14/1. Circuit 3AB09/1'eeds power to the Load Center 3B transformer from Switchgear 3B. Circuit 3'AB14/1 feeds power to Load Center 3D transformer from Switchgear 3B. Existing calculation 5177-EF-09, Section 5.B.2, evaluated these circuits based on the transformer power rating and derated for 3-hour fire wrap (0.9028). Based on the calculation with load current of 214.5 amps, the allowable MAS -4. JPN JPH FOBH 63 Rev. 3190

0

CALCULATION'O. PTN - BFJE 001 SHEET NO. 14 derated ampacity is 17% over the required load ampacity with 9.72'.

derating.

Q.m. 35 Calculation EC-138; Switchgear, Load Center and MCC Load Study, evaluated the loading on the 480 volt AC load center transformers and 4160 volt AC switchgear units for Turkey Point .Nuclear Units 3 and 4 under various normal and shutdown'onditions. This calculation determined that the normal Mode 1 power operation loading on Load Center 3B was 384 kVA and the loading on Load Center 3D was 752 KVA. Based on these load values the following ampacity loads will 'be applied to the affected cables feeding the primary side of the load center transformers:

Z+.05' Load Center 3B 384 KVA KVA - (V x I x J3 )/1000; where V Bus voltage (480 or 4160)

Solving for I; I KVA x 1000 / ( V x J5 )

then; ILc 3z - 384000 / (480 x 1.732) - 461 amps

,0 The load'center transformer is 'stepping down'he bus voltage from 4160 to 480 volts or 4160:480.

transformers, the current on the primary (line side) is equal .to the current on the secondary (load side) multiplied by the inverse (step up) ratio of the For transformer or in this case 480:4160. Therefore, the current ampacity on the cables from the switchgear to the load center is:

Ip Is x (480/4160) 461 'A x (480/4160) - 53.29 A, Assuming a transformer efficiency of 0.8, the ampacity for circuit 38809/3 53.29 0.8 / - 66.6 smps; With a derating factor of 9.72% for 3-hour fire wrap, the allowable ampacity for this circuit was 251 amps.

Based on the calculated load of 66.6 amps, the margin between allowable and load ampacity becomes 277%.

2 O.M ~ Load:Center 3D - 752 KVA KVA (V x I x J3 )/1000; where V Bus voltage (480 or 4160)

Solving for I; I - KVA x 1000 / ( V x J3 )

then; I< 30 752000 / (480 x l. 732) 904. 5 amps MAS-4. JPN JHl PORN 63 Rw. 3190

0 0

CALCULATION NO. PTN - BFJE - 93 - 001 REV. 0 SHEET NO. 15 The load center transformer is 'stepping down'he bus voltage from 4160 to 480 volts or 4160:480. For transformers, the current on the primary (line side) is equal to the current on the secondary (load side) multiplied by the inverse (step up) ratio of the transformer or in .this case 480:4l60. Therefore, the current ampacity on the cables from the switchgear to the load center is:

IP Is x (480/4160) 904.5 A x (480/4160) 104.4 A, Assuming a transformer efficiency of 0.8, the ampacity

/

for circuit 3AB14/1 104.4 0.8 >> 130.5 amps;

'With a derating factor of 9.72% for 3-hour fire wrap, the allowable ampacity for this circuit was 251 amps.

Based on the calculated load of 130,56 amps, the margin between allowable and load ampacity for Load Canter 3D becomes 92%.

The margin between the previously evaluated allowable ampacity for Load Centers (LC) 3B and 3D and the load ampacity of 17% was of concern to engineering. By evaluating the load center loading based on the values in calculation EC-138, the margin for these cables feeding the load center transformers;i.e., LC 3B 277% and LC 3D 92%, can be concluded as adequate to provide sufficient margin to handle ampacity loads based on postulated more ri.gorous derating factors.

6.0. RESULTS The following table includes the results of the engineering review of the previously prepared calculations referenced in Section 2.0 and the individual calculations prepared in Section 5 2 above. ~

hFFECTED LOhD DERhTING ChBLE DERhTED MARGIN ChLCULhTION DEVICE'X05 hMPS I FhCTOR hMPS Ic hMPS 2 I'51 3hBOQ/1 3-1/c 214.5 0.9025 '275 17 5177-EF-09 I4/0 65.5 277 Sect 5.3 3hB14/1 3X07 3-1/c 214.5 0.9025 275 251 17 5177-EF-09 f4/0 130. 5 92 Sect 5.3 3hB17/1 3PQB 3-1/c 46. 0 0.9253 257 255 475 5177-255 f4/0 EF-25 3B0105/P 3PZOIh 3-1/c 50 0,457 354 175. 5 251 S177-EF-09

~ I350 EC-130 5

MAS-4. JPN JPN FORM 53 Rw. 3/90

0 0

CALCULATION NO. PTN - BFJE 001 SHEET NO. 16 hFFECTED DEVICE CABLE SIZE LOAD hHP DEBATING IFACTOR CABLE hHP Te DERATED hHPS T'ARGTN 2 CALCDLATTON 3B0112/1 3B05 0 3 1/c 0.457 59$ 273 3S.5 5177-EF-00

~

d I750 200 0.9O2$ 59S 540 170 5177-265-I EF-25 3B0112/2'd 3BOS t 3-1/c 0.457 598 273 35.5 S177-EF 00 ~

I750 200 0.9208 59$ 540 170 5177-255 EF-25 3B0203/H 3P201B 3-1/c I350 1$ 1 0.9253 '84. 355'177-265- EF-25 3B0204/P 3V1B 3-1/c 155 0.897 278 249.4 61 S177-EP-1S I4/0 3B0407/OP 3B52 3-1/e 48.2 0.72 588 423 775 EC-132 I750 3B0610/OP 3P203B 3-1/c 18 none 60 (233) EC-130 I2 3B0713/P HOV-3-535 1-3/c 5.5 0.9028 36 32.5 491 . See. 5.2.1 Ilo 3BO715/A 3D02 3-1/c 104.5 0.897 179 162 55 5177-EF-OQ Il/0 3B5001/OP LC3D-LC3H 3-1/e 208 0.925 598(3) 1559.5 698 EC-130 I750 3B5001/OQ LC3D-LC3H 3-1/c 20$ O.QZS 598(3) 1659.6 698 EC-130 I750 3B5001/OR LC3D-LC3H 3-1/c I7SO 20$ 0.025 598(3) 1650.6 605 'C-130 3B5202/OP 3VSSB 1-3/c 3.38 .7x .S97 , 35 EC-132 Ilo 3D0104/P 3C23A 2-1/c 23.5 0.902$ 130 117. 36 399 Sec. 5.2.2 I2 3D 0106/A 3B01 2-1/c 1.0 .Sx.902$ 170 129 12800 5177-255"

~

8 Il/0 0.457 179 81.8 EP-25 5177-EF OQ 3D0108/A 3B03 2-1/c .Sx.9028 170 129 12800 5177-255

~

8 .

Il/0 0.457 179 81. 8 563 EF-25 507-EF 00 3D0114/E 3C10 2-1/c 30 0.$ 55 41 37 5177-255-IS ~.9392 425S EP-2S 3D0147/P 3E04 2-1/c 15. 4 0.9028 170 161.5 94Q See. 5.2.3 Ii/0 3D0147/Q 3E04 , 2-1/c 15. 4 0.9025 170 161.5 Sec. S.2.3 Il/0 3D2301/A 3B04 2-1/c 417. 78 0 '57 170 81.8 ,350 507-EF-00

~

8

• Ii/0 3D2302/A 3BOZ'-1/c 100 0.9028 17Q 162 62 5177 EF-09 Il/0 MAS-4.JPN JPN FORH S3 Rw. 3/90

0 i

CALCULATION NO. PTN - BFJE 93 - 001 REV, 0 SHEET NO. 17 REF.

AFFECTED CABLE LOAD DERATING CABLE DERATED MARGIN CALCtJLATION DEVICE SIZE FACTOR rWPS lc hHPS I I'1.

3D2303/A 4AB20 2-1/c <<33. 16 0.457 179 8 147 5177-EP-OQ

~

8

• ll/0 3D2304/A 3ABOI 2-1/c <<33.1d 0.457 179 81. 8 147 S177-EP-OQ

'6 tl/0 3D2305/P

~

8 3C23B '-1/c IZ 2.0 2.0 0.9253

.5x.9253 130 130

~

120 67 5900 3250 5177-265-EF-25 5177-EF-OQ 3D2306/A 3DOS 1-2/c 4.88 .9028x.9 27 21.94 349 Sec. S.2.4 SIZ 302315/h 2-1/c 1.0 .Sx.9253 75 39 3800 5177-EF-15 dd 3D2328/P 4E04 Z-l/c 14. 15 0.902$ 179 161. 8 1042 Sec. 5.2.5 PI/0 3D2328/Q 4E04 2-1/c 14. 15 0.9028 179 161. 6 1042 Seo. S.2,5 ll/0 3D2334/OP 4877 2-1/c 13.8 0.925 204 188. 7 1267 tZIO 3D2335/OP 4S75 2-1/c 34.85 0.9253 598 553 1486 EC-128 I750 4AB17/I , 4PQB 3-1/c 46 .8x.9253 287 361 5177-EF 15 I4/0 4B0105/OP 4P201A 3-1/c oooo 384 (81.3)

I350 211.85 4B0112/I 4B05 0 3-1/c 700 .9x.902d 570 473 137 507-EP 12 I750

'00 4B0 112/2 4B05 t 3-1/c ~ 9x.902S 570 473 137 5177 "EP-12 I750 4B0204/P 4VID 3-1/c 120 .Sx.9253 278 206 72 S177-EF-IS f4/0 155 0.897 278 249.4 61 EC 129 4B0407/OP 4B52 , 3-1/c 94.83 0.897 598 535 465 EC 132 I750 0.72 423 EC IS2 346'6S

.4B0407/OQ 4B52 3-1/c 94.83 0. 897 598 535 EC-132 I750 0.72 423 346 EC-182 4B0506/P NV 4-535 1-3/c 1.0 0.9028 27 24 2300 Seo. 5.2.5 IIZ

'B0514/A 4D02 3-1/c 104.5 0.9028 278 251 140 Sec, 5.2.7 I4/0 4B0524/P NV 1-3/c 2.63 0.5 36 1$ 584 EC-164 1418 410 4B0539/P NV 1-3/c 3.0 0.5 35 18 500 EC-164 716B IIO 4D0104/OQ 2-1/c 24 .6x.92S3 75 44 83 5177-EP-IS td

, 4D0104/OR 2-1/c 24 0.9028 75 57 179 Seo. 5.2 '

td MAS -4. JPN JPN PORH S3 R~. 3/90

0 0

CALCULATION NO. PTN - BFJE 001 SHEET NO, REF.

AFFECTED CABLE LOAD DERATING CABLE DERATED HARGIN CALCULATION DEVICE SIZE ANPS IL FACTOR rWPS Ic AHPS I I'06 Z-l/c

'79 4D0106/P 4BOZ 1.0 .6%.9253 10500 5177-EF-15 II/0 4D0107/P 3(4)C254 2-1/c 92 50 0'.9028 130 '17. 36; 135 Sec.5.2.9 4D0108/P 4B04 2-1/c 1.0 .6x.9253 179 105 10500 507-EP-15 ll/0 <<17 79 496 4D0109/A 4AB01 2" 1/c 0.457 260 160. S177-EF-01

'6 fl/0 <<33. 15 <<382 4D0112/P ic23B 2-1/c 2.0 .6x.9253 130 77 3750 5177-EF 15 42 4D 0129/P SV4-479B- 1-2/c 4.3 0.9028 27 21. 93 410 Soo,

'499B 912 5.2. 10 4D0133/P 4D06 1-Z/c 6.25 0.897 36 32,29 417 EC-164 IIO 4D0147/OP EDG4B 2 1/c 43.75 0.897 598 536 1125 EC 132

'750 0.72 423 857 EC-182 4D0158/OP 3675 2 1/c 34.85 0.9253 598 553 1487 EC-127 ITSO I,

The following circuits are routed through cable tray sections and were originally evaluated based on the worst case tray ampacity derating and subsequently, the Thermo-Lag derating factor available at the time of design:

TRAY SECTION CABLE SIZE LOAD D ERAT ING CABLE ALPS 'Ic DERATED ALPS I'hRGIN I CALCULATION 3B0204/1 3AXT10 1-2/C 'ontroL NIA 5177 EP 10 IIZ circuit 3B0204/2 3AXT10 1-2/c control NIA S07-EF-10 4112 cfrcuft 3B0205!1 3AXT10 3"1/c 200 0.774 898 540.2 170 5177-EF-10 f750 I 3BOZOS/X'AXT10 3-1/c 200 0.774 69$ ('40.2 170 5177-EP-10 f750 X 3SO~ 3AUT10 3-1/c ISOO 267 0.774 540 417. 9 57 5177 EP-10 X 3B0405/2 3hllT10 3-1/c 267 0.774 540 417.9 57 507 "EF-10 f500

'B0405/3 3AUT10 3-1/o 267 0.774 540 57 5177-EF-10 f500 417.9'17.

3B0408/1 3AUT10 3-1/c 209 0;774 540 9 100 5177"EP-10 fSOO 3B040$ /2 3AUT10 3-1/c 209 0.774 540 417. 9 100 5177-EP-10 ISOO MAS -4. JPN JPN FORl4 83 Rw. 3/90

0 CALCUIhTZON NO. PTN - BFJE 001 SHEET NO. 19 TRAY CABLE LOAD DEBATING CABLE 0ERATED MARGIN SECTION SIZE AMPS IL FACTOR AMPS Ic AMPS I' I CALCULATION 3D2302/1 3AXT10 2-1/c 100 0.774 165 127.7 27.7 5177-EP-10 I1/0 ~ 12. 46 e 925 4AB21/OP 4LAT20, 1-1/c 166 0.72 790 56$ 242 EC-13Z, 30 h 40 F1250 r>> EC-182 4AB21/OQ 4LAT20, 1-1/c 166 0.72 790 58$ 242 EC 132, 30 a 40 F1250 EC-182 4AB21/OR 4LAT20, 1-1/c 166 0.72 790 568 242 EC-132, 30 a 40 I1250 EC-182 4AD06/OP 4LAT20, 3-1/c 250 0.689 689 480 92 EC 128, 30 a 40 I750 411 84 EC-1$ 2 4AD06/OO 4LAT20, 3-1/c 250 0. 689 689 480 92 EC 128, 30 h 40 I750 411 64 EC-182 4B0202/1 4AXT10 3-1/c spare 0.774 256.8 198. 74 5177-EP-13 44/0 4B0202/2 4AXT10 3-1/c 'spare 0.774 256.$ 19$ . 74 5177-EF-13 f4/0 4B0202/6 4AXT10 3-1/c spare 0.774 Z56.8 19$ . 74 5177-EF-13 f4/0 4B0203/1 4AXT10 3-1/c spare 0.774 387. 3 299 ~ 73 5177-EP 13 I350 4B 0206/1 4AXT10 3-1/c 200 0.774 629.4 487.09 144 507-EP-13 4750 4B0206/2 4AXT10 3-1/c 200 0.774 629.4 4$ 7.09 144 5177-EF-13 4750 4D0106/1 4AXT10 2-1/c 5.0 0.774 126.7 98.05 1881 5177-EF 13 II/0 NOTES: + Load current tabulated from Reference 2.0.23, 2.0.24, 2.0.25 and 2.0.26.

Load current to SXs shown as tCC feeder breaker ampacity and not specific to any load on the HK.

For multiple feeder circuits, the breaker load rating is divided between the circuits

'g This value taken Eraa Generic portion of calculation Percent Margin (%) is determined by: [( I'/ I~) - 1 ] x 100

Conclusion:

The original design selection of power cables for use at Turkey Point Nuclear (PTN) 3 and 4 used conservatism created by the selection of cables using voltage drop and short circuit withstand capability analysis and then by evaluating worst case. scenarios for cable ampacity derating based on cables in a filled tray section. In addition to the evaluation of cable sizes by design, to reduce the inventory and purchasing of new cable sizes, cables for several circuits were selected and installed as the next larger 'standard'ize if that size met the design and installation requirements and was readily available on site and in the inventory system.

MAS -4. JPN JPN FORM 83 Rev. 3/90

0 0

0

CALCULATION NO. PTN - BFJE 001 SHEET NO ~ 20 Calculations which evaluated cable ampacity concluded that the derating factor

,(0.457) for power cables in a tray section with the maximum hypothetical tray fill and coated with Flammastic fire retardant was more conservative than the derating factor for cables in conduit with Thermo-Lag fire wrap. Calculati.ons that evaluated ampacity loss in covered conduit also used individual derating factors independent of the vendor information. These values, which were lower and more conservative than the vendor values, were uses to verify the applicability of the cable sizing design assumptions.

Based on the results of previously issued calculations for the derating of. cable ampacity, the smallest margins (17% plus derating 'factor of 0.9028) identified for any ci.rcuits at PTN were for those cables supplying power to Load Center 3B and 3D transformers (3X05 and 3X07). These loads are evaluated based on assuming that the circuit load i6 equal to the, feeder breaker'load rating with the breaker load being at 100% of its rating continuously. 'Actual loads on these power sources were evaluated in Section 5,.3 based on a transformer loading study and determined to have a larger margin between the load ampacity (I~) requirement and the allowable derated ampacity (I') for the affected circuits.

The smallest margin between derated cable ampacity (I') and load ampacity (Iz) requirements as determined by this calculation for any cable in a Thermo-Lag covered tray ls 57$ (with a Thermo-Lag derating factor of 0.,774). For any c~b].e in conduit with Thermo-Lag covering, the smallest margin is 55% (with a Thermo-Lag derating factor of 0.897). Therefore, as noted in the table above and comparing cable ampacity'(Ic) values with the derated ampacity (I') values and the circuit ampaci.ty load (Iz), the cables installed at Turkey Point Nuclear Units 3 and 4 were conservatively design with adequate margin to provide allowances for ampacity derating which encompass the vendor issued values of derating and for the more rigorous values that are, currently being proposed.

0 'MAS-4.JPN JPN FORM 83 Rsv. 3/90

0

~O