ML18096B071
| ML18096B071 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 10/27/1992 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-A-30, REF-GTECI-EL, TASK-A-30, TASK-OR GL-91-06, GL-91-6, NLR-N92126, NUDOCS 9211040156 | |
| Download: ML18096B071 (10) | |
Text
Public Service Electric and Gas Company Stanley LaBruna Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1200 Vice President - Nuclear Operations OCT2'7 1992 NLR-N92126 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
REVISED RESPONSE TO GENERIC LETTER 91-06 SALEM GENERATING STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311 On April 20, 1991, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 91-06 in partial resolution of Generic Issue A-30, "Electrical Power Reliability".
Licensees were required by GL 91-06 to provide written responses to questions contained in Enclosure 1 of the letter.
These questions pertained to the adequacy of safety-related DC power supplies.
PSE&G hereby revises its original response dated October 25, 1991 (Ref: NLR-N91142).
Should you have any questions regarding this transmittal, please feel free to contact us.
Thank you.
Affidavit Attachment 030156 Sincerely,
~\\
Ref:
NLR-N92126 STATE OF NEW JERSEY SS.
COUNTY OF SALEM
- s. LaBruna, being duly sworn according to law deposes and says:
I am Vice President - Nuclear Operations of Public Service Electric and Gas Company, and as such, I find the matters set forth on our letter dated October 27, 1992, concerning the Salem Generating Station, are true to the best of my knowledge, information and belief.
My C~:nnmission expires on
ATTACHMENT 1 GENERIC LETTER 91-06 RESOLUTION OF GENERIC SAFETY A-30 SALEM GENERATING STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311
ATTACHMENT 1 GL 91-06 RESPONSE NLR-N92126
- 1.
Unit -
Salem Units 1 and 2
- 2.
- a.
The number of independent redundant divisions of Class lE or safety-related de power for this plant is three divisions of Class lE 125V DC and two divisions of Class lE 28V DC.
- b.
The number of functional safety-related divisions of de power necessary to attain safe shutdown for this unit is two divisions of Class lE 125V DC and one division of Class lE 28V DC.
- 3.
Does the control room for this unit have the following separate, independently annunciated alarms and indications for each division of de power?
- a.
alarms In addition to the alarms located on the overhead annunciator related to bus/panel voltage problems, an alarm window is provided to notify the control room operator that the auxiliary annunciator is printing.
Therefore, for those failures which are not alarmed on the overhead annunciator, the operator is referred to the auxiliary annunciator.
NOTE During the last refueling outage for both units, the overhead annunciator system has been upgraded.
This upgrade does provide significant enhancements, but does not change the response to any of the questions listed concerning alarms.
See Item 5.
- 1)
Battery disconnect/circuit breaker open? NO See Item 5.
- 2)
Battery charger disconnect/circuit breaker open (both input ac and output de)? NO See Item 5.
- 3)
De system ground? NO See Item 5.
- 4)
De bus undervoltage? YES
- 5)
De bus overvoltage? NO See Item 5.
PAGE 1 OF 6
ATTACHMENT 1 GL 91-06 RESPONSE NLR-N92126
- 6)
Battery charger failure? YES See item 3 a
- 7)
Battery discharge? No See Item 5.
- b.
Indications
- 1)
Battery float charge current? No See Item 5.
- 2)
Battery circuit output current? YES
- 3)
Battery discharge? YES
- 4)
Bus voltage? YES
- c.
Does the unit have written procedures for response to the above alarms and indications? YES Written alarm-response procedures are provided for control room overhead annunciator.
- 4.
Does this unit have indication of bypassed and inoperable status of circuit breakers or other devices that can be used to disconnect the battery and battery charger from its de bus and the battery charger from its ac power source during maintenance or testing? NO See Item 5.
- 5.
If the answer to any part of question 3 or 4 is no, then provide information justifying the existing design features of the facility's safety-related de system.
General Justification for Item 3 The 125V DC and 28V DC system at Salem Station consist of the following:
- 1. Three independent 125V DC systems (A,B, and C) each powered by its own independent battery charger.
The power supply to these battery chargers come from their associated 230V AC vital bus.
ie: A 125V DC battery charger is powered by A 230V AC vital bus and similarly for the other two 125V DC buses.
Normal alignment is for the batteries to be in a float condition, with the associated battery charger in service.
Additionally, a back up battery charger is provided for each 125V DC bus.
PAGE 2 OF 6
ATTACHMENT 1 GL 91-06 RESPONSE NLR-N92126 The back-up battery chargers are maintained out of service and their associated 230V AC breaker opened and tagged for the Nuclear Shift Supervisor.
This ensure proper breaker alignment and compliance with separation requirements since the supply breakers (to the back-up chargers) are fed from different 230V AC vital buses.
The loss of the bus/panel voltage of the DC system will be alarmed or annunciated as described within this attachment.
- 2. The 28V DC system is identical to the 125V DC described above with the exception of being only two independent systems (A and B).
Breaker and fuse position/status is controlled by the Salem Generating Station's administrative tagging procedure and the operating procedure entitled "DC Breaker Administrative Controls".
These procedures ensure proper operability and control of vital de breakers whose positions are not alarmed.
Additionally, routine control room and field indicator status/readings are performed every shift to ensure that vital batteries/chargers are in operable status.
Justification for Item 3.a.l No battery disconnect or circuit breaker open alarms are provided in the control room.
The batteries (28V and 125V DC) are connected to their respective de bus switchgear via fuses in lieu of breakers.
A blown fuse on a DC main bus is indicated by a red indicator lights in the control room RP-9 panel.
Additionally, blown fuse indication (separate from the control room indication) is also provided locally at the D.C. Buses Main Fuses Alarm Cabinets.
NOTE The Unit 1 blown fuse indication in the control room was not connected at the time of the original response.
However, local indication was (is) still available via the field operator rounds, which check this indicator every shift.
Workorders were initiated to reconnect the Unit 1 control room indicating lights.
The blown fuse indication in the Unit 1 control room was reconnected during the 10th refueling outage.
Justification for Item 3.a.2 No position alarms are provided for battery charger 230V AC breaker (at associated 230V AC bus switchgear) or battery charger ac breaker (on charger); however, auxiliary annunciator alarms (Unit 1 only) are provided for battery charger ac input power failure.
No position alarms are provided for the DC breaker (on charger) or the de non-auto output breakers (at DC bus).
PAGE 3 OF 6
ATTACHMENT 1 GL 91-06 RESPONSE NLR-N92126 NOTE Due to differences in wiring the Unit 1 and Unit 2 battery charger auxiliary alarms are different.
These relays are wired in parallel in Unit 1 and in series in Unit 2.
Therefore, since the alternate 125V/28V DC battery charger is normally cleared and tagged (due to bus separation concerns) the alarm for loss of power is always up on Unit 2.
This difference in wiring is presently scheduled to be corrected during the next scheduled seventh refueling outage Justification for Item 3.a.3 No DC system ground alarms are provided; however, positive/negative DC bus ground resistances are indicated locally and in the control room.
(A,B and C 125V DC, and A and B 28V DC)
Justification for Item 3.a.5 No DC bus overvoltage alarms are provided; however, a battery charger overvoltage condition is sensed and will automatically trip open the 125 V DC charger's output breaker.
An overvoltage condition for the 28 V DC charger will result in the disconnecting of the auxiliary voltage transformer which results in no control power for the charger.
With no control power for the control circuit the 28V DC charger shuts down.
Justification for Item 3.a.7 No battery discharge alarm is provided; however, if a battery is providing power to the de bus, the respective battery ammeter, located in the control room, will indicate amperes.
There are ammeters for each of the DC Vital bus trains. (A,B and C 125V DC, and A and B 28V DC)
Justification for Item 3.b.l Battery float charge is not indicated; however, the respective battery ammeter, located in the control room, will indicate zero amperes when the battery is receiving float charge.
If the float charge is lost, the ammeter will now show an ampere reading, indicating loss of battery charger.
PAGE 4 OF 6
ATTACHMENT 1 GL 91-06 RESPONSE NLR-N92126 Justification for Item 4.
No alarm or indication is provided if a battery charger's DC output breaker is opened, nor is there an alarm or indication if a battery charger's non-auto output breaker at the DC bus is opened.
When a battery charger's input ac power breaker is opened, the charger ac power failure alarm will energize (local indication).
Battery output blown-fuse indicators are provided locally and in the control room.
See response to item 3.a.1.
- 6.
(1)
Have you conducted a review of maintenance and testing activities to minimize the potential for human error causing more than one de division to be unavailable? YES (2)
Do procedures prohibit maintenance or testing on redundant de divisions at the same time? YES Present maintenance and testing (18 month service testing and 60 month discharge testing) procedures specify "Only one (1) vital battery of the same voltage and unit may be serviced/tested at a time.
Prior to any battery work, verify that all other batteries of the same voltage and unit are in service to meet technical specification requirements."
- 7.
Salem Generating station, Units 1 and 2 Technical Specifications are equivalent to Westinghouse Standard Technical Specifications and specify weekly, quarterly, 18 month, and 60 month battery maintenance and surveillance requirements that meet the intent of NRC Generic Letter 91-06.
Therefore, question 7 is not applicable to Salem Units 1 and 2.
- 8.
Does this plant have operational features such that following loss of one safety-related de power supply or bus:
- a.
Capability is maintained for ensuring continued and adequate reactor cooling? YES
- b.
Reactor coolant system integrity and isolation capability are maintained? YES
- c.
Operating procedures, instrumentation (including indicators and annunciators), and control functions are adequate to initiate systems as required to maintain adequate core cooling? YES Abnormal and Emergency Operating Procedures are provided to direct operators to initiate systems as required to maintain adequate core cooling in the event that one vital de bus is lost.
PAGE 5 OF 6
ATTACHMENT 1 GL 91-06 RESPONSE NLR-N92126
- 9.
If the answer to any part of question 6, 7 or 8 is no, then provide your basis for not performing the maintenance, surveillance and test procedures described and/or the bases for not including the operational features cited.
Refer to answers to question 6, 7, and 8 above.
PAGE 6 OF 6
Document Control Desk
. NLR-N92126 c
Mr. J. c. Stone Licensing Project Manager -
Salem Mr. T. P. Johnson Senior Resident Inspector Mr. T. T. Martin Administrator -
Region 1 Mr. Kent Tosch 0CT2'7 1992 Chief -
New Jersey Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625