ML17249A816
| ML17249A816 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 02/26/1980 |
| From: | White L ROCHESTER GAS & ELECTRIC CORP. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-79-27, NUDOCS 8004090445 | |
| Download: ML17249A816 (28) | |
Text
~
~
~,m ROCHESTER GAS AND ELECTRIC CORPORATION LEON O. WHITE. JR.
VIC! PRESIOENT ml~
TELEPRONC ARCA CONC 754 546.2700
~ 4i ~ 0 I ~
0 I
.~$,
~oaa ITAIC o
89 EAST AYENUE, ROCHESTER, N.Y. 14649 Pebruary 26, 1980 Mr. Boyce H. Grier, Director U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Subject:
IE Bulletin No. 79-27, Loss of Non-Class-1-E Instrumentation and Control Power System Bus during Operation R. E. Ginna Nuclear Power Plant, Unit 41 Docket No. 50-244
Dear Mr. Grier:
A review has been conducted at Ginna Station to identify the 120V AC buses supplying power to safety and non-safety related instrumentation and control systems, and to determine the effects, if any, on the ability to obtain a cold shutdown condition.
The buses that were identified as a result of this review are the 1A, 1B, 1C and 1D instrument buses.
Detailed des-criptionof these buses is as follows:
lA Instrument Bus:
Instrument Bus 1A is normally supplied from Safeguard Bus 14 MCC-1C via battery charger 1A, main D.C. distribution panel lA, inverter 1A and static switch 1A.
Instrument Bus 1A backup supply is supplied from Safe-guard Bus 14 MCC-1C via a regulating transformer and static switch 1A.
When the normal supply fails, the static switch automatically switches to the backup supply.
When the normal supply returns, the static swit s
manually switched from'the backup supply to the normal supply.
When inverter or static switch maintenance is required, Instrument Bus lA can manually be switched to the maintenance supply, supplied from Bus 13 MCC-1A via a.regulating transformer, by operating a mechanically inter-locked breaker in the Instrument Bus lA distribution panel located on the south wall of the main control room.
The auto-static transfer switch is initiated by any of the following: inverter failure, overcurrent beyond the static switch, inverter output undervoltage, manually, or a failure of the static switch.
80 0.4 09 0 4 4 5
~,~~ 4
ROCHESTER GAS AND ELECT~ CORP.
DATE February 26, 19M Mr. Boyce H. Grier, Director i pp~
SHEET NO.
2 f
The computer willalarm on the operation of the auto-static transfer switch, fan failure, loss of regulated output, and manual transfer to alter-nate supply.
The computer alarm directs the operator to check the inverter.
There are two AC voltmeters and a frequency meter located on the lA Instru-ment Bus distribution panel that indicates the 1A inverter output voltage and frequency and the lA Instrument Bus output voltagd.
A main control board alarm willannunciate if the 1A Instrument Bus voltage drops below 100 vac.
1B Instrument Bus:
Instrument Bus 1B is normally supplied from Safeguard Bus 14 MCC-1C via a regulating transformer.
The backup supply for Instrument Bus 1B is supplied from Bus 13 MCC-1A via a regulating transformer.
Operator action is required to switch to the backup supply by operating a mechanically interlocked breaker in Instrument Bus 1B distribution panel located on the south wall of the main control room.
There is an AC voltmeter located on the 1B Instrument Bus distribution panel which indicates the 1B Bus voltage.
A main control board alarm willannunciate if the 1B Instrument Bus voltage drops below 100 vac.
1C Instrument Bus:
Instrument Bus 1C is normally supplied from Bus 16 MCC-1D via, battery charger 1B, main D.C. distribution panel 1B, inverter 1B, and static switch 1B.
Instrument Bus 1C backup supply is supplied from Safeguard Bus 16 MCC-1D via a regulating transformer and static switch 1B.
When the normal supply fails, the static switch automatically switches to the backup supply.
When the normal supply returns, the'static switch is manually switched from the backup supply to the normal supply.
When inverter or static switch maintenance is required, Instrument Bus 1C can manually be switched to the maintenance supply, supplied from Bus 13 MCC-lAvia a regulating transformer, by operating a mechanically interlocked breaker in the Instrument Bus 1C distribution panel located on the south wall of the main control room.
The auto-static transfer switch is initiated by any of the following: - inverter failure, overcurrent beyond the static switch, inverter output undervoltage, manually, or a failure of the static switch.
The computer willalarm on the operation of the auto-static transfer switch, fan failure, loss of regulated output, and manual transfer to alter-nate supply.
The computer alarm directs the operator to check the inverter.
There are two AC voltmeters and a frequency meter located on the 1C Instru-ment Bus distribution panel that indicates the lB inverter output voltage and frequency and the 1C Instrument Bus output voltage.
A main control board alarm willannunciate if the 1C Instrument Bus voltage drops below 100 vac.
ROCHESTER CAS AND ELECT~CORP.
oATE February 26, 19M Mr. Boyce H. Grier, Director SHEET NO 3
1D Instrument Bus:
Instrument Bus 1D is normally supplied from Safeguard Bus 15 MCC-
.1B via a regulating transformer.
The backup supply for Instrument Bus 1D is supplied from Bus 13 MCC-lA via a regulating transformer.
Operator action is required to switch to the backup supply by operating a mechanically inter-locked breaker in Instrument Bus 1D distribution panel located on the south wall of the main control room.
There is an AC voltmeter located on the 1D Instrument Bus distribution panel which indicates the 1D Bus voltage.
A main control board alarm willannunciate if the 1D Instrument Bus voltage drops below 100 vac.
The instrument and control system loads connected to the above buses are identified in the attached lists for each bus.
The effects of the loss of power to these loads were evaluated.
In no case did the postulated loss of power from one of the instrument buses leave the control room operator without adequate indication and control of the plant parameters, or prevent the ability of achieving a cold shutdown condition using existing approved procedures.
As a result of this review and evaluation, no potential problems have been identified and therefore no design modifications are planned.
The present existing procedures regarding the electrical supplies to the safety and non-safety related instrument and control systems have been reviewed and have been found to provide the control room operators with the necessary direction to cope with loss of power to any instrument bus.
IE Circular No. 79-02, failure of 120 volt vital AC power supplies, was again reviewed.
Based on this re-review and past operating experience, no design modifications or administrative control changes are planned.
Very truly yours, Attachments xc:
U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D. C.
20555
1.
Main control board (right section) 2.
Instrument rack R-1 (Red) 3.
Instrument rack R-2 (Red) 4.
Steam dump rack (SD) 5.
Pressurizer level and pressure rack (PLP) 6.
Feedwater control loop B (FW) 7.
Chemical and volume control rack (CVCS-2) 8.
Nuclear Instrumentation System Rack 41 9.
Rod speed control rack (RSC) 10.
Relay rack RR-1 (Red) 11.
Relay rack RR-2 (Red) 12.
Fire control panel and smoke detector 13.
Main control board (center section) heater drain pump and auxiliary feedwater pump transmitters and square root extractors 14.
First stage pressure, reheat pressure transmitters 15.
Secondary instruments supply (instrument air pressure, screen house level, etc.)
16.
Evacuation flashers 17.
RMS Rack 41 (outside temperature indication) 18.
Undervoltage alarm/Voltmeter on top of panel) 19.
Main steam header annunciator panel 20.
Spare 21.
Twinco regulator MQ-400A 22.
Twinco regulator MQ-400E 23.
Spare 24.
Power to SAFWP-C Main Normal Inverter lA MCC-1C Maintenance Emergency Instrument Transformer MCC-1A
Twinco Unit M 400-A 1.
Instrument Rack R-2 (Red) 2.
Instrument Rack R-1 (Red) 3.
Steam Dump Rack (SD) 4.
Rod Speed Control Rack (RSC) 5.
Feedwater Control Loop B (FW) 6.
Pressurizer Pressure and Level Rack (PLP) 7.
Chemical and Volume Control Rack (CVCS-2) 8.
Reactor Coolant System Rack (RCS-2)
Spare 10.
Spare 11.
Spare
Twinco Unit M 400-E 1.
Radiation Monitoring System Rack 41 2.
Nuclear Instrumentation System Rack Ol 3.
4.
Spare 5.
Spare 6.
Spare 7.
Spare 8.
Spare 9.
Spare 10.
Spare ll.
Spare
INSTRUMENT BUS 1B 1.
Main Control Board (Right Section) 2.
Instrument Rack W-1 (White) 3.
Instrument Rack W-2 (White) 4.
Rod insertion limit rack (RIL) 5.
Reactor Coolant System Rack (RCS-2) 6.
Nuclear Instrumentation System Rack 42 7.
Reference Junction Box incore thermocouples 8.
Safeguard Rack (S lAl) 9.
Reactor Protection Rack (RLTRl) 10.
Miscellaneous Rack (M1) 11.
Relay rack (RW-1) 12.
Relay rack (RW-2) 13.
LlT 1090 and LlT-1093 14.
Instrument Shop 5% Regulated Power 15.
Spare 16.
Spare 17.
Spare 18.
Under voltage alarm/voltmeter on top of panel 19.
Spare 20.
Spare 21.
Twinco Regulator MQ-400-B 22.
Twinco Regulator Mg-400-F 23,.
Spare 24.
Spare Main Normal - Instrument Transformer lA MCC-1C Maintenance Emergency Instrument Transformer MCC-1A
t t
Twinco Unit M 400-B 1.
Instrument Rack W-2 (White) 2.
Instrument Rack W-1 (White) 3.
Reactor Coolant System Rack (RCS-2) 4.
Rod Insertion Limit Rack (RlL) 5.
Spare 6.
Spare 7.
Spare 8.
Spare 9.
Spare 10.
Spare ll.
Spare
t t
Twinco Unit M 400-F 1.
Radiation Monitoring System Rack g2 2.
Nuclear Instrumentation System Rack 42 3.
Meter Shop 2% Power 4.
Spare 5.
Spare 6.
Spare 7.
Spare 8.
Spare 9.
Spare 10.
Spare ll.
Spare
1.
Main control board (right section) 2.
Instrument rack B-1 (Blue) 3.
Instrument rack B-2 (Blue) 4.
Pressurizer pressure and level rack (PLP) 5.
Feedwater control loop A (FW) 6.
Rod position indication (RP1) 7.
Nuclear Instrumentation System Rack 43 8.
Auxiliary coolant rack (SA) 9.
Recirculation fans vibration switch cabinet 10.
Smoke detector (emergency) 11.
Relay rack 'RB-1 (Blue) 12.
Relay rack RB-2 (Blue) 13.
Condensate storage tank level transmitter 14.
Spare 15.
MCB Controllers and Recorders 16.
Spare 17.
Spare 18.
Undervoltage alarm/Voltmeter on top of panel 19.
Main steam heater annunciator panel 20.
Power to SAFWP-D 21.
Twinco Regulator Mg-400-C 22.
Twinco Regulator MQ-400-G 23.
Spare 24.
-. Twinco Regulator Mg-400-H Main Normal - Inverter 1B - MCC-1D Maintenance Emergency Instrument Transformer MCC-1A
0
~
Twinco Unit MO400-C 4
1.
Instrument Rack B-2 (Blue) 2.
Instrument Rack B-1 (Blue) 3.
Feedwater Control Loop A (FW) 4.
Pressurizer Pressure 6 Level Rack (PLP)
S.
Auxiliary Coolant Rack (SA) 6.
Spare 7.
Spare 8.
Nuclear Instrumentation System Rack 43 9.
Spare ll.
Spare
INSTRUMENT BUS 1D 1.
Main Control Board (Right Section) 2.
Instrument Rack Y-1 (Yellow) 3.
Instrument Rack Y-2 (Yellow) 4.
Reactor Coolant System (RCS-1) 5.
Chemical and volume control rack (CVCS-1) 6.
Nuclear Instrumentation System Rack f4 7.
Reference junction box incore thermocouples 8.
Part-length rod control 9.
Safeguard rack (S 1 Bl) 10.
Reactor protection rack (RLTL-2) 11.
Miscellaneous rack (M-2) 12.
Relay Rack RY-1 (Yellow) 13.
Relay Rack RY-2 (Yellow) 14.
Spare 15.. Turbine gauge panel 16.
Feedwater transmitter panel 17.
Turbine "E.H." panel 18.
Undervoltage alarm/Voltmeter on top of panel 19.
S pare 20.
LlT 1091 and L1T 1092 21.
Twinco regulator MQ-400-D 22.
Spare 23.
Spare 24.
Spare Main - Normal - Instrument Transformer 1B MCC-1B Maintenance - Emergency Instrument Transformer MCC-1A
i(,
1.
~ t
t 1
Tvrinco Unit M 400-D l.
Instrument Rack Y2 (Yellow) 2.
Instrument Rack Yl (Yellow) 3.
Reactor Coolant System Rack (RCS-1) 4.
Chemical & Volume Control Rack (CVCS-1)
S.
Radiation Monitoring System Rack g3 6.
Nuclear Instrumentation System Rack g4 7.
Spare 8.
Spare 9.
Spare 10.
Spare ll.
Spare
t l
I I,
I(
'i l
J
Docket No. 50-244 Hr. Leon D. White, Jr.
Vice,President Electric and Steam Production Rochester Gas and Electric Corporation 89 East Avenue Rochester, New York 14649
Dear Hr. White:
On December 28, 1979 the NRC Office of Inspection and Enforcement issued Information Notice No. 79-37 that presented infoeretion available to the staff related to the discovery of cracks in the keyway and bore sections of Mestinghouse 1800 rpm low pressure turbines.
A copy of
- this Information Notice with errata sheet is enclosed.
Westinghouse notified utility users of this potential problem on October 30, 1979 and was requested by the staff to present a similar briefing in
- Bethesda, Maryland on December 17, 1979.
You were contacted on December 14, 1979 and invited to send representatives to the staff briefing and also
'were requested to advise the staff of the actions being taken in regard to this potential problem at your operating nuclear power plant.
Westinghouse was later requested to meet again with the staff and licensee-users on January 8, 1980 to supplement the information provided in the earlier meeting and in interim correspondence with the staff.
On the basis of'nformation provided by Westinghouse and recent indications from turbine disc inspections now undenvay at Arkansas Nuclear One Unit 1, Beaver Valley Unit 1'nd Indian Point Unit 2, it is evident that the probability of crack formation in these turbine discs is significantly greater than, previously assumed by the vendor.
In light of this information and the actions being taken by the licensee-users, we consider this warrants your prompt full UT inspection of LP rotor discs, especially the keyways and bore areas, and documentation to the NRC of your justification for continued operation until such inspections are made and all defects thus identified are corrected.
Therefore, in accordance with 10 CFR 50.54(f), you are requested to provide within 20 days of the date of this letter, or in any event prior to restart if your unit is not operating, written statements, signed under oath or affirmation, which will enable the staff to determine whether or not your license to operate R. E. Ginna Nuclear Power Plant should be modified, suspended, or revoked.
As part of your statement, you should provide and address the safety significance of the information requested in Enclosure 2
to this letter.
SC~
2 SVRNAME
~
~
~
~
~
~ ~
~
~
~
~
~
~
~
~
~
r
~
QATEP'......
NRC FORM 318 (9.76) NRCM 0240 4 V.S. GOVERNMENT PRINTING OFFICE: 1979 289 369
r 1
,J r