ML17258B126

Forwards Rept on SEP Topic VIII-4, Electrical Penetrations of Reactor Containment. Penetrations Have Been Identified as Typical Circuits

ML17258B126
Person / Time
Site:	Ginna
Issue date:	06/09/1981
From:	Maier J ROCHESTER GAS & ELECTRIC CORP.
To:	Crutchfield D Office of Nuclear Reactor Regulation
References
TASK-08-04, TASK-8-4, TASK-RR NUDOCS 8106220286
Download: ML17258B126 (68)

Text

REGULATORY I RMATION DISTRIBUTION SYS (RIDS)

A ACCESSION NBR:0106220206'OC,DATE:

01/06/00 NOTARIZED:

NO DOCKET 0 FACILic50 244 Robert Emmet Ginna Nuclear PlantE Unit ii Rochestei G

05000244 AUTH'AME'UTHOR AFFILIATION MAIEREJ ~ E' Rochester Gas E,Electric Corp'ECIP

~ RAMEY, RECIPIENT AFFILIATION CRUTCHF IELD E D ~

Operating Reactors Branch 5

SUBJECT:

Forwards rept onSEP Topic YIII'"4g "EIlectr ical Pehetrations of Reactor Containment;"

Penetratians have been identified as typical circuits ~

DISTRIBUTION CODE:

A0350 COPIES RECEIVED:LTR g'NCL>> J'IZEt TITLE't SEP Topics NOTES: 1 copy:SEP Sects Ldr.

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89 EAST AVENUE, ROCHESTER, N.Y. 14649 JOHN E.

MA IER VICE PRESIDENT TKLKPHONK ARKA cOOK 114 546.2700 June 9,

1981 Director of Nuclear Reactor Regulation Attention:

Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch No.

5 U.

S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

SEP Topic VIII-4, Electrical Penetrations R.

E. Ginna Nuclear Power Plant Docket No. 50-244

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Dear Mr. Crutchfield:

In response to your March 30, 1981 letter requesting a

detailed report on the subject SEP topic, RG8E is enclosing a

copy of its report which assesses Ginna Station's ability to withstand and clear, low magnitude fault currents on its electrical penetrations.

Specifically, the penetrations identified in the Draft Technical Evaluation have been evaluated as typical circuits and recommendations for improved backup relay protection have been proposed.

In addition, all similar penetration circuits with the potential to cause a seal failure due to various levels of fault current will be evaluated and modifications to improve the backup breaker relay characteristics will be made as required.

Once all the engineering for the proposed modifications is completed, we will inform your office of our intended corrective actions only if they depart from the generic corrective actions contained in our report.

This report and the resulting modifications completes our response to SEP Topic VIII-4.

~'816622 0 VEto Very truly yours, E. Maier ItIoZS l (

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ROCHESTER GAS S

EZ ECTRIC CORPORATION R ~

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GINNA NUCLEAR POWER PZANT EVAZUATION OF SELECTED PENETRATIONS TO WITHSTAND LOW MAGNITUDE FAULTS SEP TECHNXCAL EVALUATXON TOPIC VXXI-4 ELECTRICAL PENETRATIONS OF REACTOR CONTAINMENT DOCKET NO. 50-244 JUNE 3, 1981

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CONTENTS 1.0

SUMMARY

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2.0 INTRODUCTION

3 3.0 ASSUMPTIONS AND CRITERIA...... ~.

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5 4.0 PENETRATION DATA........................................

7 5.0 PENETRATION EVALUATIONS AND RECOMMENDATIONS............

8 5.1 Review of Satisfactory Penetrations...............

8 5.2 Penetration Number AE-6...........................

9 5.2.1 AE-6 Single Line...........................ll 5.2.2 Protective Device Settings AE-6..........12 5.2.3 AE-6 Time-Current Curves...................13 5.3 Penetration Number CE-21..........................14 5.3.1 CE-21 Single Line..........................16 5.3.2 Protective Device Settings CE-21.........17 5.3.3 CE-21 Time-Current Curves..................18 5.4 Penetration Number CE-25 and CE-27................19 5.4.1 RCPlA and RCPlB Elementary.................21 5.4.2 CE-25 and CE-27 Single Line................22 5.4.3 Protective Device Settings CE-25 and CE-27.23 5.4.4 CE-25 and CE-27 Time-Current Curves........24 5.5 Penetration Number CE-23..........................25 5.5.1 CE-23 Single Line..........................27 5.5.2 Protective Device Settings.................28 5.5.3 CE-23 Time-Current Curve..................-29

6.0 REFERENCES

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SEP TECHNICAL EVALUATION TOPIC VIII-4 ELECTRICAL PENETRATIONS OF REACTOR CONTAINMENT R. E.

GINNA NUCLEAR POWER PLANT 1.0

SUMMARY

This evaluation looked at the protection schemes of five electrical penetrations, AE-6, CE-21, CE-23, CE-25 and CE-27, which do not meet present design criteria under the systematic evaluation program (SEP) Topic VIII-4.

SEP Topic VIII-4 requires the electrical penetration be protected under the following conditions:

l.

A loss of cooling accident (LOCA).

2.

An electrical fault has occurred in containment.

3.

Primary protective device fails to clear the fault.

Under the above conservative assumptions, it was found that the backup protection for the five penetrations might fail to clear low magnitude fault currents before these currents could potentially damage the penetration.

The response curves of the different protective devices were plotted with the I t curve for each penetration.

The curves were analyzed to verify where additional secondary protection was desirable and what improvements were needed.

The primary protective devices were also reviewed to insure adequate coverage.

Recommendations are made for the installation of additional protective devices.

These, in conjunction with devices already in operation, will provide a backup protective system capable of

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clearing any value of available fault current while maintaining the integrity of the electrical penetration.

All the remaining issues for this part of the SEP Topic VIII-4 will be resolved when these improvements are implemented.

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2.0 INTRODUCTION

This report will review and address the coverage by the backup overcurrent protective devices used on some of the sample electrical penetrations previously analyzed for the Systematic Evaluation Program.

'Inadequacies in the coverage might cause the penetration seal to fail due to overheating before the fault current could be cleared.

The penetration seal fails when the solder or brazing used in the penetrations construction melts, resulting in damage to its hermetic seal.

There are presently seven different types of electrical penetrations used at Ginna Station that were manufctured by Crouse-Hinds.

They are classified by conductor size, number and configuration of conductors, voltage class and their use.

A sample of each type of penetration and its descriptions are listed in Table I Penetration Data; Section 4.

The same sample penetrations listed were used in the original evaluation.

For the purpose of the SEP Topic evaluation, the following was postulated; the containment penetrations would be uniformly at LOCA temperatures concurrent with a random failure of the circuits primary protective device.

The effects of both high and low magnitude fault currents were then analyzed to review the performance of the backup protective device(s).

Under these conditions, backup circuit protective devices on low voltage penetrations AE-6, CE-21 and medium voltage penetrations CE-25 and CE-27 were found to have problems clearing low magnitude faults prior to potential failure of the penetration seal.

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h addition, CE-23's backup device failed to protect the penetration for all values of fault current in case the primary device, a fuse, failed to open.

This report determines where additional backup protection is needed.

It also recommends what modifications or equipment additions should be made to provide a backup protection system which adequately protects the penetrations for available fault current levels during the conditions postulated in the SEP Topic VIII-4.

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3.0 ASSUMPTIONS AND CRITERIA I~t curves for each penetration under evaluation were required to accurately analyze the characteristics of the protective devices in the circuit.

These I t curves were established using the following criteria:

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1.

The melting point of soft solder is 356 F or 180 C.

Soft solder was used in construction of penetrations AE-S, AE-6, AE-10, CE-l, CE-8, CE-17, CE-18 and CE-23.

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2.

The melting point of silver brazing is 1100 F or 600 C.

Silver brazing was used in construction of penetrations CE-21, CE-25 and CE-27.

3.

-The initial temperature of the penetration was assumed to be 0

140 C based on the conditions found during a loss of coolant accident (LOCA).

4.

The following formula was used to calculate I~t values based on the penetration conductor size and whether soft solder or silver brazing was used during its manufacturer.

I t = (0.0297) (A) log Tz + 234 TI

+ 234 (Formula 1) where t time allowed for the short circuit in seconds short circuit current in amperes conductor area in circular mils maximum operating temperature (140 C, LOCA condition) maximum short circuit temperature of penetration (180 C temperature for melting solder or 600 C for melting silver brazing).

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This formula is based upon the heating effect of the current in the conductor and assumes that the heating process is adiabatic.

(See Reference 4, Attachment 4.)

This formula was used to determine the I~t values because it provided a more conservative value than the test and calculated data supplied by Crouse-Hinds.

Although operating the protective devices under such a restricted curve may limit what devices may be used, it was considered good engineering practice to do so.

This insures a more consistant standard on which to base decisions for penetration protection improvement.

Guidelines established by IEEE Standard 317-1976 "Standard for Electrical Penetrations Assemblies" and U.S.

NRC Regulatory Guide 1.63were used in evaluating the performance of both the primary and secondary devices pertinent to the penetration under study.

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SECTION 4

PENETRATION DATA

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PENETEQ,TION Number Maximum Current Withstand RMS Current I~t Rati MaxlIIlum

'llowable Maximum Time Isc for Isc Available (Sec)

Clearing Time for Pri.

Device (Sec)

Clearing Time for Sec.

Device (Sec)

Clearing Time for Backup Device (Sec)

Circuit 02 ANG 21 PIN 600 V

30KA, 57.7X10+

95 9,600 0.06 0.01 0.02 0.1 Light Trans ~

480 V f8 ANG 60 PIN 600 V 1400+

3. 6X10+

40 3,500 0.029 0.018 0.002 Not Req.

Low Voltage Power 480 V CE-21 500 MCM 64KA 25.8X10 1000 20,000 3 PIN CE-25 750 MCM 64'.

58.2X10 1000 36,800 CE-27 3 PIN 6.5 4.3 0.045 0.017 26.0 0.184 0.5 0.15 Contain

-ment Air Recir.

Fan 480 V Reactor Coolant Pump 4160 V CE-18

<<2 AWG

-21 Pin 5KV 30KA 57.7X10+

95 270 79.2 0.18 0.576 Not Req.

Rod Drive Lift Coils 125V DC CE-17 N8 ANG 60 Pin 5KV 1400+

3. 6X10+

40 260 5.28 0.0004 0.0043 Not Req.

Rod Drive Gripper Coils 125V DC CE-23

$ 10 ANG 1250+ 14.1X104 30 144 PIN 600 V 600 0.392

('0.001 (0.001

)700 Emerg.

Light 125V DC Table 1 Penetration Data

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Clearing Time for Pri.

Device (Sec)

Clearing Time for Sec.

Device (Sec)

Clearing Time for Backup Device (Sec)

Circuit AE-10 516 SHZD 100+

8.7X'10 12 Twisted Prs 6 Quads 0.05 Cont.

Not Req.

Inst.

Current Loops

'E-1 516 28 SHZD Quads 100+

8.7X10 12 0.05 Cont.

Not Req.

Inst.

Current Estop

'E-8 Triaxial I.

40X10 10 Bal.

Cont.

Not Req.

Power Range De-tector Table l Penetration Data

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5.0 PENETRATION EVALUATIONS AND RECOMMENDATIONS Procedure for the penetration study consisted of the following:

a.

Establishment of circuit single line diagrams.

b.

Acquisition of protective device settings and response characteristics.

c.

Calculation of I t values.

d.

Plotting of time-current curves.

e.

Review of primary device fault current response.

f.

Review of secondary device fault current response.

g.

Determination where additional fault protection was needed.

h.

Selection and recommendation of what device was best suited to correct coverage inadequacies.

5.1 Review of Satisfactor Penetrations.

Penetrations AE-5, CE-17 and CE-18 were deemed suitable under all postulated environmental conditions during the first review for the SEP Topic VIII-4.

The I t values were recalculated for these penetrations to reflect the 140 C initial temperature found in a LOCA condition.

Maximum allowable short circuit current (Isc) times were also recalculated and compared to the clearing times for the primary and secondary protective devices.

The systems were capable of clearing all faults under the conditions postulated in Section 3.

Penetrations CE-l, CE-8 and AE-10 were also found suitable because their available Isc was less than the continuous rating of the penetration.

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5.2 Penetration Nu er AE-6.

The AE-6 penetra ion has 21-$ 2 ANG conductors and is classified as low voltage (0-1000VAC).

This particular penetration is used to supply 480VAC to a 30 KVA lighting transformer.

A single line diagram for this penetration is shown on page 11.

The continuous current rating of this penetration is 95 amperes.

Soft solder, with a melting point of 180 C was used in its construction.

Maximum short circuit current (Isc) available to this penentration is 9600 amperes.

Based on these conditions using Formula 1:

I~t at short circuit current (9,600 amps) is:

I~t =.0297 x (66360) log 180

+ 234 140

+ 234 I~t = 57.7 x 10+

(ampere) seconds t = 0.0626 seconds at 9600 amperes t = 0.23 seconds at 5000 amperes t = 5.77 seconds at 1000 amperes.

The time-current characteristic curves for the AE-6 penetration are shown on page 13.

Analysis shows that the primary protective device 4K (Curve 55),

a molded case breaker located in a motor control center, will clear fault currents from 60 amperes up to and including the Isc of 9600 amperes.

Primary clearing time at Isc is 0.01

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Backup device 22C (Curve N4) will not.clear fault currents up to 3000 amperes or between 7000 and 9600 amps before the I~t value is exceeded.

Any of these fault current could result in seal damage.

Recommendation Improved backup protection will be accomplished by the installation of a 70 ampere backup breaker installed at the motor control center.

This device will exhibit the characteristic curve N6 shown on the time-current curve for the AE-6 penetration.

This will provide backup protection for all fault currents and has a Isc clearing time of 0.0l7 seconds.

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5.3 Penetration Number CE-21.

The CE-21 penetration has three 500 KCM conductors and is classified as a low voltage (0-1000VAC) type.

The penetration is used to supply 480VAC to Containment Air Recirculating Fan lA.

The circuit single line is shown on page 16.

The continuous rating of this penetration is 1000 amperes.

Silver brazing, with a melting point of 600 C was used in its construction.

Maximum short circuit current (Isc) available to the penetration is 20,000 amperes.

Based on these conditions using Formula 1:

I~t at short circuit current (20,000 amps) is:

I~t =.0297 x (500,000) log 600

+ 234 2.

140

+ 234 I~t = 25.8 x 10 (ampere)2-seconds t = 6.5 seconds at 20,000 amperes t = 2.87 seconds at 30,000 amperes t = 25.9 seconds at 10,000 amperes The time-current characteristic curves for the CE-21 penetration are shown on page 18.

Analysis shows that the primary protective device, 23C (Curve ¹5), will clear all values of fault current from its long term setting of 450 amperes to Isc of 20,000 amperes.

Clearing time for the primary device at Isc is 0.045 seconds.

The existing backup devices, breaker 18B (Curve ¹4) and relay 50/51 (Curve ¹2), will clear fault currents between 3000 amperes

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and Isc of 20,000 amperes.

However, the backup devices fail to clear low magnitude faults up to 3000 amperes.

It is between these low magnitudes of fault current that seal overheating and damage may occur.

Recommendation To improve the low level protection, an additional secondary

relay, 51S, will be installed to trip the low side breaker 18B of transformer N14.

The relay's response curve N3 is shown on the time-current curves for the CE-21.

A set of current transformers which will be used to operate 51S will be installed on the power cables prior to penetration.

The generator, No.

1A, will not be blocked for conditions other than the penetration fault.

The addition of this secondary relay will provide a

reliable backup protection scheme which will insure the clearing of all fault currents in this circuit prior to penetration damage.

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5.4 Penetration N

ers CE-25 and CE-27.

The penetrations have three 750 KCM conductors and are classified as a

medium voltage

( )1000VAC) penetration.

They are used in parallel to supply 4160VAC to one 6000 horsepower (HP) reactor coolant pump (RCP).

The RCP elementary and single line diagrams are provided on pages 21 and 22 respectively.

The continuous current rating of these penetrations is 1000 amperes.

Silver brazing with a melting point of 600 C was used in their construction.

Maximum fault current available to the penetrations is 36,800 amperes.

Based on these conditions using Formula 1:

X~t at short circuit current (36,800 amps)

I t = (0.029)(750,000) log 600

+ 234 140

+ 234 22a

= 50.2 s

10 (amperes) seconds t = 4.3 seconds at 36,800 amperes t = 9.31 seconds at 25,000 amperes t = 25.86 seconds at 15,000 amperes is:

The time-current characteristic curves for the CE-25 and CE-27 penetrations are shown on page 24.

Analysis shows that the primary protective relay, 50P/51P (Curve 04)g will protect for all levels of fault current and will clear Xsc in 0.017 seconds.

Backup relay 51/llA (Curve N2) will also clear fault currents above 9000 amps and It ~

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clear Isc in

. 15 seconds.

However, the backup relay will not clear lower magnitude faults between 1000 and 9000 amperes.

The 51/llT relay (Curve 41) on the primary side of ll Transformer will not provide low fault protection either.

It is at these low fault current levels where there is a potential for seal damage.

Recommendation To improve the secondary relay protection for low magnitude faults, an additional relay 50S/51S will be installed with a response characteristic as shown on the time-current curves as curve 3.

This relay will be connected to a new set of current transformers installed on the power cables prior to penetration.

The new current transformers will give total redundancy in that the new secondary protective device has no dependency on any component in the primary scheme.

This new relay will add the additional protection needed to provide adequate clearing times for the backup protective devices to prevent seal damage under the conditions postulated.

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MOHAMMED, ZAHEER 5.4. 2 ST@. 13 cE-zs $ cE-27 Sl NGLE LINE

'I 5.4.2 PROTECTIVE DEVICE SETTINGS CE-25 & CE-27 Ref. No. ~on Gra h Circuit 11 TRANSFORMER 11 TRANSFORMER 11A BUS 11A BUS REACTOR COOLANT PUMP NO. 1A REACTOR COOLANT PUMP NO. 1A REACTOR COOLANT PUMP NO. 1A Device 51/1 1T 51N/1 1T 51/1 1A 51N/1 1A 50S/51S 50P/51P 50G Rela T e CO-8 CO-8 CO-8 CO-8 CO-5 COM-5 ITH CT Ratio 1200/5 300/5 3000/5 3000/5 1200/5 1200/5 100/5 Rancae 4-12A 0.5-2. 5A 4-12A 0.5-2.5A 4-12TOC 20-80IIT 2-6TOC 4-8ITH 20-8IIT 1-2A ~Settin 10A-3TLS 1A-6TZ S 12A-0.5TLS 0.5A-0.5TLS 6A-llTZS 35A 4A-8TZ S 5A 35A 1A r I II II tl II t 1 tI It n Ee ~ S.d.TS.SI I SCC 700 ecc CURRENI'N AMPERES 2 2 e 9 d 7 99IC 20 20 40 ICS0709090 II 5 ct 5 555 In ~ ) I ~ 'I ~"' I I 1'I Tfl I' ~ 4 I I I ~ '. I ! TC SC, 1 .'I j" i: I ~ I ~ 4~," ~ ~ I I.. I $ 4C<< FEllst.3'NR,:.:...i I COOQAQT:PQAP, '. MOTOR Il ~ ~ '<< I ~" 1 OI<<I ~ I 1 ~ ~ ~ I ll ~ ~ 22 I ~ I I IC w'I 2 I I I 1 ~ ~ - 55 ~ ~ ~ (CL I I ~- I I ~ ..Ic I. I. ', A. I I

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'5.d.7 4.9 I 2 2 ~ 9 C 2 9910 20 20 40 ~ - v."I.W CE 2~5CE-BASIS fOR DATA Stenos!de I. Tests modest 2. Cufves sf~ ptotted to TIMMVRRENT CHARACTERISTIC CURVES Fuse Un!Is. In Doted Votts ec e't p.t stsfting et 2SC nttn no In!I!st toed es'I poults SO vs ltepons shoutd be No. Dote 544 TIIIcv'unncuT cIIAnscfenlsTIc Ac 0200 kluffss s esses co <<w 1 II ~ ~ g f 5.5 Penetration Number CE-23. This penetration has 144-510 conductors and is classified a direct current (125VDC) type. This particular penetration is used to supply 125VDC for emergency lighting. The single line is shown on page 27. The continuous current rating of the penetration is 30 amperes. Soft solder with a melting point of 180 C was used in the construction of the penetration. Maximum short circuit current (Isc) available to the penetration is 600 amperes DC. Based on these conditions using Formula 1: I~t at I~t = ( short circuit current (600 amps) 0.0297)(10380) log 180 + 234 1s0 140 + 234 I t = 'l4.1 x 10 (ampere) seconds 0.392 seconds at 600 amperes 0.883 seconds at 400 amperes 3.53 seconds at 200 amperes The time-current characteristic curves for the CE-23 penetration are shown on page 29. Analysis shows that the, primary protective device, an amptrap OT30 fuse (Curve g2) will clear Isc (600 amps) and all values above continuous current rating.

However, the circuit backup device, a

amptrap A2Y-400 ampere fuse (Curve gl), will not clear for any value of fault current up to and including Isc. 0 V Ir v A' pI Failure of the primary protective device, however remote, could result in damage to the seal should a fault occur. Recommendation To insure adequate backup protection, an additional fuse-an OT-25, will be installed as a new primary device. The OT-30 will become the backup fuse. The 25 amp fuse curve is labeled N3 on the time-current characteristic curve for the CE-23 penetration. The addition of the 25 amp fuse will provide the primary and backup protection required to insure seal protection for all postulated fault conditions. ~ - 1 + 'tl l29 VVC= tB 'Q5o AH tzoa 400 SHOW'T ClZCUIT CUPIZBhJ T lv1AXI MLJ~ AL( &WAN! F TlP E, FOG C,L.FAKl~l& Yt~<~ FC)P 2 gC. >4.. l x i'd&+ choo +MP5 O. 9 tZ &PC. I. F'l2 lMAIRY Z. 6E,cQ NOAE'Y 3, &AcKu& Fu+~ = (C.ocoi WK( ~ = 4o.aoi eeC. ) lOG SEC 27 O'RAWA E5Y: BARRAGATQ E&GR

MOHAMMED, ZAHEER Sl N GLE LtNE 5.5. I CE= 25

~ o~ 5.5.2 PROTECTIVE DEVICE SETTINGS CE-23 Ref. No. ~on Gra h Circuit Emergency Lights Location Fuse T e Shawmut Form-600 Type 3 A2Y Continuous Ratin 400 Emergency Lights Shawmut OT Class K-5 30 Emergency Lights Shawmut OT Class K-5 25 A 4' 9 JS.74.9 I Ioob 2 2 ~ 5 5 799IO <<J ~- I fj - I"=~ I I ~ ~ I(te I ~ SNI".I. -L I 7 I '. t ~ .Vt I 2 l a + ~ I I I I io I I 7" I tso I I I I 57 ~ 7'i 9 s =t [ ~ e ~ I I ' ~4 I'I" 7 ~ I -e I t, I ~ I ~ s I ~ I,= I rt* '1 I 4 Zsc le io C s 2 It S. II I ~ ~ ~ e 4 4 ~ 9 I I I , ~ I 4 I e 4 2 2 ~ s a 7 solo 25 so so soso7oeoooy y y y y yyjjyjj CIIRRENT IN AMPERES X i O For C""25 BASIS FOR DATA Stenderds I. Testslrledsst 2 Cundes ere plotted 10 TIMEWURRENT CHARAC'TERISTIC CURVES Fuse Unks. In Dated Volts eC et Ief storting st 25C with no Inltisl loco Teel points so vs ristdons should be No.

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Cr fV. }, t, 6. 0 REFERENCES 1. NRC letter, Dennis L. Ziemann to Mr. Leon D. White, Jr., Vice President

RGGE, SEP Topic VIII-4, Request for Information, Docket No. 50-244, Dec. 8, 1978.

2. RGGE letter, Harry G. Saddock, Systematic Evaluation Program Topic VIII-4, "Electrical Penetrations of Reactor Containment", R. E. Ginna Nuclear Power Plant, Unit No. 1, Docket No. 50-244, April 12, 1979. 3. NRC letter, Dennis L. Ziemann to Mr. Leon D. White, Jr., Vice President

RG6E, "SEP Topic VIII-4 Electrical Penetration of Reactor Containment",

March 24, 1980. 4. RG&E letter, L. D. White, Jr., to Director of Nuclear Reactor Regulations, U.S.

NRC, "SEP Topic VIII-4 Electrical Penetration of Reactor Containment", July 21, 1980.

5. NRC letter to Mr. John E. Maier, Vice President

RGGE, "SEP Technical Evaluation Topic VIII-4 Electrical Penetrations of Reactor Containment, Final Draft, R.

E. Ginna Unit No. 1 Docket No. 50-244",

November, 1980.

6. IPCEA Publication P-32-382, "Short Circuit Characteristics of Insulated Cable". 7. General Design Criterion 16, "Containment Design" of Appendix A, "General Design Criteria of Nuclear Power Plants", 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities". 8. Nuclear Regulatory Commission Standfard Review Plan, Section 8.3.1, "AC Power Systems (onsite)". 9. Regulatory Guide 1.63, Revision 2, "Electrical Penetration Assemblies in Containment Structures for Light-Water-Cooled Nuclear Power Plants". 10. IEEE Standard 317-1976, "IEEE Standard for Electric Penetration Assemblies in Containment Structures for Nuclear Power Generating Stations". 0 <<k ~ r I ~ I% C Jp S I tI