ML19294A811
| ML19294A811 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 03/14/1979 |
| From: | Groce R YANKEE ATOMIC ELECTRIC CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TASK-08-04, TASK-8-4, TASK-RR WYR-79-32, NUDOCS 7903220221 | |
| Download: ML19294A811 (22) | |
Text
Telephono 6 7 365-9011 TWX 780- 3 90-C ?3 9 YAlliWE AT0aHC ELECTRIC 000iPAllY
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20 Turnpako Road Westborough, Massachusetts 0158Pt
,YAN K EE,/
WYR 79-32
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Parch 14, 1979 i
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3 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Of fice of Nuclear Reactor Regulation
References:
( a) License No. DFR-3 (Docket No. 50-29)
(b) UShTIC L'tter to YAEC, datcci Deccaber 8, 1978
Dear Sir:
Subject:
Systematic Evaluation Program (SEP)
In your letter, reference (b), you requested that we provide additional intoruation relative to SEP Topic Vill-4, " Electrical Penetrations o f Reac to r Containments".
In respanse to this request, we hereby subait the attached information. The information items have been numbered to correspond to the numbers in your request and have been listed separately for the three catagories of penetration circuits.
We trust thic information is accpetable to you; however, should you have any questions, plesse contact lir. David A. Hansen of this of fice.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY la lL&~
Robert H. Groce Licensing Engineer 790333ogg[
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Yankee Atomic Electric Company SEP Topic VIII-4 Electrical Penetrations of Reactor Containment TYPICAL LOW VOLTAGE PENETRATION CIRCULT A.
Circuit Information 1.
Since most of the 480V circuits penetrating the reactor containment of the Yankee Rowe Plant are motor-operated valve (MOV) circuits, a MOV circuit has been chosen as the typical low voltage penetration circuit. The circuit chosen is the circuit to the Low Pressure Safety Injection Path Valve (MOV-535). This circuit is on 480V Emergency MCC-1 which is normally supplied power from 480V Bus 6-3 via 480V Emergency Bus 1.
(See drawing No. 9699-FE-lJ and drawing No. 9699-FE-lG).
2.
The primary protective devices for the MOV-535 circuit are a Westinghouse type F molded case circuit breaker located in 480V Emergency MCC-1 and a reversing starter located nearby in a separate 'EMA 1 enclosure.
The circuit breaker is equipped with a 30 ampere trip coil and the, tarter is equipped with s
two Westinghouse Code BCl2 overload heaters.
(See enclosed Westinghouse Curve for Type F,15-40A molded case circuit breakers and Westinguouse Instruction Sheet 1.L.12477-B for Type MW-21 Thermal Overload Relay).
The secondary protective device is a General Electric type AK-2A-25-1 air circuit oreaker located in 480V Emergency Bus 1.
This circuit breaker is equipped with an EC-1 series trip device with a 150A trip coil. The 1C (long time) and 2C (short time) trip characteristics are used.
(See General Electric Curve No. GES-6000A). Trip device adjustments are:
long time (IC) - 100% pickup setting short time (2C) - 10X 3.
tbximum short circuit currents available to the MOV-535 power circuit depend on the fault location and are as follows:
liaximum R'IS Symmetrical Fault Location Short Circuit Current 480V Bus 6-3 20,M 5A 480V Emergency Bus 1 15,730A' Emergency MCC-1 6,780A At the Penetration 1,350A
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At MOV-535 455A It should be noted that the maximum short circuit current listed above for Bus 6-3 includes 7,310A contribution from plant induction motors.
All other values also. include an induction motor contribution.
4.
The conductor sizes and cable lengths applicable to the MOV-535 circuit are as follows:
Conductor From H
Size Length (feet)
Bus 6-3 Emer. Eus 1 2-350 M(31 Cu 280 Emer. Bus 1 Emer. MCC-1
'/0 AUG Cu 300 Emer. MCC-1 Penetration J12 AWG Cu 106 Penetration MOV-535
- 12 AWG Cu 245 B.
Electrical Penetration Information 1.
(a) The electrical penetrations at the Yankee Rowe Plant were field fabricated and have no manuf acturer's identification numbers.
(b) The MOV-535 power circuit passes through its penetration via a 3-conductor #8 AWG mineral insulated (MI) cable.
The conductors are solid copper. Details of this Type 1 penetration are shown on drawing No. 9699 FE-29B.
(c) Rated continuous current for each l!8AWG conductor in the penetration is 45 amperes. This value is based on National Electric Code Table 310-16 corrected for a 40 C ambient temperature.
2.
The rated short circuit current for the conductors in the penetration is:
12, 281 amperes for 0.033 sec (2 cycles) or 288 amperes for 60 sec.
These values were calculated by using the following formula:
T2 + 23i 1
t = 0.0297 log 10
_A_
_T1 + 234, where A = conductor area in circular mils t=
time in seconds Ti = rated continuous temperature T2 = rated maximum temperature
. t
t
/
The values used in arriving at the above results are:
A = 16,510 circular mils t = 0.033 and 60 seconds Ti = 85 C T2 = 1080 C 3.
Electrical testing of low voltage ac penetrations consists of insulation resistance tests of the pressurizer heater circuits, including the penetration conductors, performed at each refueling outage. Other 480V circuits are tested when maintenance work has been performed on that specific circuit.
The test results to date do not indicate degradation of ins ulation.
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TYPICAL MEDIUM VOLTAGE PENETRATION CIRCUIT A.
Circuit Information 1.
The only 2400V electrical penetrations are those used for the four main coolant pump mo to rs. The 2400V circuit chosen is that to Main Coolant Pump P-14-2.
This circuit is on 2400V Bus No. I which was chosen because it has the highest fault duty of the three 2400V buses.
(See drawing No. 9699-FE-lC and drawing No. 9699-FE-1B).
2.
The primary protective device for the main coolant pump is a Westinghouse type 50-DH-250E, 1200A air circuit breaker with a Westinghouse type CO-9 overcurrent relay.
(See Westinghouse Curve #418266). The current transformer ratio is 600:5A.
Relay settings are:
Tap: 8A Time Dial: 9 Instantaneous: 27 The secondary protective device is the Bus. No. 1 feeder breaker which is a Westinghouse type 50-DH-250E, 2000A air circuit breaker with a Westinghouse type Co-9 overcurrent relay. (See Westinghouse Curve #418266). The current transformer ratio is 2000:5A.
Relay settings are:
Tap: 8A Time Dial: 3 3.
Maximum short circuit currents available to the P-14-2 circuit depend on the fault location and are as follows:
Maximum RMS Symmetrical
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Fault Location Short Circuit Current 2400V Bus 1 27,630A At the Penetration 25,260A At P-14-2 22,605A It should be noted that the maximum short circuit current listed above for Bus 1 includes 4,550A contribution from induction motors connected directly to Bus 1.
This current does not pass through the secondary protective device.
The total induction motor contribution to the maximum short circuit current listed for Bus 1 from all sources is 5,375A.
The short circuit values for faults at other locations also include an induction motor contribution.
4.
The conductor sizes and cable lengths applicable to the Main Coolant Pump P-14-2 circuit are as follows:
Conduc to r From
))1 Size Lengt'h (feet)
Bus. No. 1 Penetration 2-350 MCM Cu 243 Penetration P-14-2 2-4/0 AWG Cu 282 B.
Electrical Penetration Information 1.
(a) The electrical penetrations at the Yankee Rowe Plant were field fabricated and have no manufacturer's identification numbers.
(b) The F-14-2 circuit is routed through two Type IV penetration assemblies as shown on drawing No. 9699-FE-29C.
Each phase uses two penetration conductors. Each conductor is a solid 5/8 inch diameter tinned copper rod insulated with 17/64 inch Buna Rubber for service at 2400V ac.
(c) Each 2400V penetration conductor is a solid 5/8 inch diameter copper rod with a cross sectional area of 390,625 circular mils. The conductors are insulated with Buna Rubber and have a temperature rating of 600C. The current rating of each penetration conductor is 224 amperes.
This value is based on National Electric Code Table 310-16 corrected for a 40 C ambient.
Since two penetration conductors are used per phase, the phase current rating is 448A.
' 2.
The rated short circuit current for the conductors in the 2400V voltage penetration is 27,686 amperes for 1 second.
This value was calculated by using the formula given in Part B.2 for the low voltage penetration.
In this case:
A = 390,625 circular mils t = 1 second Tg = 60 C T2 = 200 C 3.
Electrical testing consists of insulation resistance tests of the main coolant pump motor circuits. These tests are performed during each refueling outage as part of the maintenance performed on the associated 2400V air circuit breakers. The test results to date do not indicate degradation of insulation.
s TYPICAL DIRECT CURRENT POWER PENETRATION CIRCUIT A.
Circuit Informatio2 1.
There are only a few de power circuits penetrating the reactor containment. The circuit chosen provides powpr to the solenoid operated pressurizer relief valve PR-SOV-90.
This circuit originates at circuit No. 3 of 125V de Bus No.1 and runs to a fuse block (Fil) located in the Nuclear Section of the Main Control Board. From the Main Control Board the circuit continues through an electrical penetration to the solenoid operated valve.
(See drawing number 9699-FE-lH).
2.
The primary protective device is a 10A, 250V, BUSSMAN FRN FUSETRON, dual element fuse.
(See Fusetron characteristic curve #249).
The secondary protective device is a 100A, 250V, Shawmut Tri-onic, dual element fuse type TR-100.
(See Tri-onic characteristic curve #36717-F).
3.
125V de Battery No.1 is a 60 cell battery made up of Exide type FOP-15 cells.
Maximum short circuit currents available to the PR-SOV-90 de power circuit depend on the fault location and are as follows:
Fault Location Maximum Short Circuit Current 125V de Bus 1 8900A (at 0.02 sec); 7420A (at 1 sec)
Main Control Panel 5195 (at 0.02 sec); 4820A (at I sec)
At Penetration 555A At PR-SOV-90 220A 4.
The conductor sizes and cable lengths applicable to the PR-SOV-90 y
circuit are as follows :
Conduc to r From To Size Length (feet) 125V de Bus No. 1 Main Control Board
- 2 AWG Cu 70 Main Control Board Penetration
- 12 AWG Cu 116 Penetration PR-SOV-90
- 12 AWG Cu 180
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B.
Penetration Information 1.
(a) The electrical penetrations at the Yankee Rowe Plant were field fabricated and have no manufacturer's fientification nunbers.
The penetrations used for the direct current circuits are of identical construction to those used for 480V ac circuits.
(b) The PR-SOV-90 circuit passes through the penetration utilizing 2 conductors of a 7-conductor #12 AWG mineral insulated (MI) cable. The conductors are solid copper.
Details of this Type I penetration are shown on drawing No. 9699 FE-29B.
(c) Rated continuous current for each #12 AWG conductor in the penetration is 19 amperes based on National Electric Code Table 310-16 corrected for 400C ambient temperature and derated as required for a 7-conductor cable.
2.
The rated short circuit current for each #12 conductor in the penetration is:
882A for 1 second or 590A for 3 second.
These values were calculated by using the formula given in Part B.2 for the low voltage penetration.
In this case:
6530 circular mils A
=
1 and 3 seconds t
=
Ti = 85 C T2 = 1080 C
' 3.
Electrical testing of de penetrations consists of insulation
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resistance tests of the control rod drive circuits performed during each refueling outage. Other de circuits are tested
' when any maintenance work has been performed on that specific circuit. The test results to date do not indicate degradation of insulation.
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,e ENCLOSED DP_AWINGS Drawing No.
Title 9699-FE-1B Schematic Diagram - Me ters, Relays & Synchronizing 9699-FE-lC 2400V One Line Diagram 9699-FE-lG a80V One Line Diagram - Sh. 3 9699-FE-1H 125V DC One Line Diagram 9699-FE-lJ 480V One Line Diagram - Sh. 4 9699-FE-29B Electrical Fenetrations - Sh. 2 9699-FE-29C Electrical Penetrations - Sh. 3 Characteristic Curves Westinghouse Curve for Type F, 15 to 40 amperes - 2 and 3 pole - 600V molded case circuit breakers. (Redrawn)
Westinghouse I.L. 12477-B, Type MW-21 Thermal Overload Relay, Description, Operation, and Maintenance Instructions General Electric Curve No. CES-6000A (for EC-1 Series Trip Devices)
- Westinghouse Curve No. 418266 (for Type CO-9 Overcurrent Relay)
Bussman Form 249, Ibiting Time Current Characteristic for FRN FUSETRON dual-element fuses Shawmut Curve No. 36717-F, Characteristic Melting Time-Current Curves,
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Tri-onic dual-element fuses i
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