ML18153B363

Informs of Mod Made to Instrument Range for RVLIS Dynamic Head Points to Expand Range in Order to Prevent Spurious Alarms Which Resolves North Anna Emergency Response Facility Problem Rept

ML18153B363
Person / Time
Site:	Surry, North Anna
Issue date:	11/02/1993
From:	Bowling M VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
93-675, NUDOCS 9311120020
Download: ML18153B363 (15)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 November 2, 1993 United States Nuclear Regulatory Commission Serial No.93-675 Attention: Document Control Desk NL&P/CGL RO Washington, D. C. 20555 Docket Nos. 50-280 50-281 50-338 50-339 License Nos. DPR-32 DPR-37 Gentlemen: NFP-4 NFP-7 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 NORTH ANNA POWER STATION UNITS 1 AND 2 EMERGENCY RESPONSE DATA SYSTEM DATA BASE UPDATES Modifications were recently made to the instrument range for the Reactor Vessel Level Instrumentation System (RVLIS) dynamic head points. The upper instrument limits were modified slightly to expand the range in order to prevent spurious alarms. The changes were made to resolve a recent North Anna Emergency Response Facility problem report. Since the potential for this problem also exists at Surry, the changes were made at both stations and are detailed in the Data Point Library (DPL) revision summaries (change reports) contained in Attachments 1 and 2 for Surry Units 1 and 2 and North Anna Units 1 and 2, respectively. Attachments 3 and 4 provide revision summaries (change reports) for the affected points for Surry Units 1 and 2 and North Anna Units 1 and 2, respectively. The updated data base files are also provided in the dBase IV format on Attachment 5.

If you have questions regarding this information, please contact us.

Very truly yours, fi;J~

M. L. Bowling, Manager Nuciear Licensing & Programs Attachments:

1. Updated DPL Forms for Surry Units 1 and 2

2. Updated DPL Forms for North Anna Units 1 and 2

3. DPL Revision Summaries for Surry Units 1 and 2

4. DPL Revision Summaries for North Anna Units 1 and 2

5. Updated DPL Data Base Files for Surry and North Anna in dBase IV Format 9311120020 931102 PDR ADOCK 05000280 F PDR

cc: U. S. Nuclear Regulatory Commission - Attachments 1 - 4 Region II 101 Marietta Street, N. W.

Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch - Attachments 1 - 4 NRC Senior Resident Inspector Surry Power Station Mr. R. D. McWhorter - Attachments 1 - 4 NRC Senior Resident Inspector North Anna Power Station NUS Corporation/ El Division - Attachments 1 - 5 P. 0. Box 59736 Idaho Falls, Idaho 83405 Attention: Mr. Tony LaRosa

e ATTACHMENT 1 UPDATED DPL FORMS FOR SURRY UNITS 1 AND 2

STATION: Surry PRINTED UNIT: 1 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE DATE: 10/20/93 REACTOR UNIT: SUl DATA FEEDER: N/A NRG ERDS PARAMETER: REAC VES LEV POINT ID: L1RC003C PLANT SPEC POINT DESC: RVLIS DYNAMIC HEAD LEVEL GENERIC/COND DESC: REACTOR VESSEL WATER LEVEL ANALOG/DIGITAL: A ENGR UNITS/DIG STATES: PCT ENGR UNITS CONVERSION: N/A MINIMUM INSTR RANGE: 0.0 MAXIMUM INSTR RANGE: 122.0 ZERO POINT

REFERENCE:

TNKBOT REFERENCE POINT NOTES: N/A PROC OR SENS: p NUMBER OF SENSORS: 5 HOW PROCESSED: AVERAGE - SEE SYSTEM DESCRIPTION SENSOR LOCATIONS: HEAD VENT (TOP) & BOTTOM OF VESSEL ALARM/TRIP SETPOINTS: VARIABLE NI DETECTOR POWER SUPPLY CUT-OFF POWER LEVEL: N/A

'j'" NI DETECTOR POWER SUPPLY

>--' TURN-ON POWER LEVEL: N/A INSTRUMENT FAILURE MODE: N/A TEMPERATURE COMPENSATION FOR DP TRANSMITTERS:

LEVEL REFERENCE LEG: WET UNIQUE SYSTEM DESC: The 2 reactor dynamic head level signals are used in conjunction with the reactor coolant pump motor currents to calculate this value. The dynamic head readings are invalid if no RCP's are running; therefore, this process value will be set invalid if no RCP motor current is greater than 5% of it's full load value. If none of the RCP's are running, the average of the valid dynamic head level signals is used to calculate this point.

STATION: Surry PRINTED UNIT: 2 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE DATE: 10/20/93 REACTOR UNIT: SU2 DATA FEEDER: N/A NRG ERDS PARAMETER: REAC VES LEV POINT ID: L2RC003C PLANT SPEC POINT DESC: RVLIS DYNAMIC HEAD LEVEL GENERIC/COND DESC: REACTOR VESSEL WATER LEVEL ANALOG/DIGITAL: A ENGR UNITS/DIG STATES: PCT ENGR UNITS CONVERSION: N/A MINIMUM INSTR RANGE: 0.0 MAXIMUM INSTR RANGE: 122.0 ZERO POINT

REFERENCE:

TNKBOT REFERENCE POINT NOTES: N/A PROC OR SENS: p NUMBER OF SENSORS: 5 HOW PROCESSED: AVERAGE - SEE SYSTEM DESCRIPTION SENSOR LOCATIONS: HEAD VENT (TOP) & BOTTOM OF VESSEL ALARM/TRIP SETPOINTS: VARIABLE NI DETECTOR POWER SUPPLY CUT-OFF POWER LEVEL: N/A I-' NI DETECTOR POWER SUPPLY I

N TURN-ON POWER LEVEL: N/A INSTRUMENT FAILURE MODE: N/A TEMPERATURE COMPENSATION FOR DP TRANSMITTERS:

LEVEL REFERENCE LEG: WET UNIQUE SYSTEM DESC: The 2 reactor dynamic head level signals are used in conjunction with the reactor coolant pump motor currents to calculate this value. The dynamic head readings are invalid if no RCP's are running; therefore, this process value will be set invalid if no RCP motor current is greater than 5% of it's full load value. If none of the RCP's are running, the average of the valid dynamic head level signals is used to calculate this point.

ATTACHMENT 2 UPDATED DPL FORMS FOR NORTH ANNA UNITS 1 AND 2

STATION: North Anna PRINTED UNIT: 1 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE DATE: 10/20/93 REACTOR UNIT: NAl DATA FEEDER: N/A NRG ERDS PARAMETER: REAC VES LEV POINT ID: LlRC003C PLANT SPEC POINT DESC: RVLIS DYNAMIC HEAD LEVEL GENERIC/COND DESC: REACTOR VESSEL WATER LEVEL ANALOG/DIGITAL: A ENGR UNITS/DIG STATES: PCT ENGR UNITS CONVERSION: N/A MINIMUM INSTR RANGE: 0.0 MAXIMUM INSTR RANGE: 122.0 ZERO POINT

REFERENCE:

TNKBOT REFERENCE POINT NOTES: N/A PROC OR SENS: p NUMBER OF SENSORS: 5 HOW PROCESSED: AVERAGE - SEE SYSTEM DESCRIPTION SENSOR LOCATIONS: HEAD VENT (TOP) & BOTTOM OF VESSEL ALARM/TRIP SETPOINTS: VARIABLE NI DETECTOR POWER SUPPLY CUT-OFF POWER LEVEL: N/A N NI DETECTOR POWER SUPPLY I

I-' TURN-ON POWER LEVEL: N/A INSTRUMENT FAILURE MODE: N/A TEMPERATURE COMPENSATION FOR DP TRANSMITTERS:

LEVEL REFERENCE LEG: WET UNIQUE SYSTEM DESC: The 2 DYNAMIC HEAD level signals are used in conjunction with the reactor coolant pump (RCP) breaker statuses to calculate this value. The dynamic head readings are invalid if no RCP's are running; therefore, this point will be set invalid if no RCP breakers are closed. If any of the RCP breakers are closed, the average of the valid dynamic head level signals is used to calculate this point.

STATION: North Anna PRINTED UNIT: 2 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE DATE: 10/20/93 REACTOR UNIT: NA2 DATA FEEDER: N/A NRG ERDS PARAMETER: REAC VES LEV POINT ID: L2RC003C PIANT SPEC POINT DESC: RVLIS DYNAMIC HEAD LEVEL GENERIC/COND DESC: REACTOR VESSEL WATER LEVEL ANALOG/DIGITAL: A ENGR UNITS/DIG STATES: PCT ENGR UNITS CONVERSION: N/A MINIMUM INSTR RANGE: 0.0 MAXIMUM INSTR RANGE: 122.0 ZERO POINT

REFERENCE:

TNKBOT REFERENCE POINT NOTES: N/A PROC OR SENS: p NUMBER OF SENSORS: 5 HOW PROCESSED: AVERAGE - SEE SYSTEM DESCRIPTION SENSOR LOCATIONS: HEAD VENT (TOP) & BOTTOM OF VESSEL AI.ARM/TRIP SETPOINTS: VARIABLE NI DETECTOR POWER SUPPLY CUT-OFF POWER LEVEL: N/A N NI DETECTOR POWER SUPPLY r!.., TURN-ON POWER LEVEL: N/A INSTRUMENT FAILURE MODE: N/A TEMPERATURE COMPENSATION FOR DP TRANSMITTERS:

LEVEL REFERENCE LEG: WET UNIQUE SYSTEM DESC: The 2 DYNAMIC HEAD level signals are used in conjunction with the reactor coolant pump (RCP) breaker statuses to calculate this value. The dynamic head readings are invalid if no RCP's are running; therefore, this point will be set invalid if no RCP breakers are closed. If any of the RCP breakers are closed, the average of the valid dynamic head level signals is used to calculate this point.

e ATTACHMENT 3 DPL REVISION SUMMARIES FOR SURRY UNITS 1 AND 2

STATION: Surry PRINTED UNIT: 1 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE CHANGE REPORT CHANGED POINT LlRG003C AT 08:21 ON 10/20/93. CHANGES WERE AS FOLLOWS:

DATE: WAS: 05/20/91 IS: 10/20/93 MAXIMUM INSTR RANGE: WAS: 120.0 IS: 122.0 w

.....I

STATION: Surry PRINTED UNIT: 2 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE CHANGE REPORT CHANGED POINT L2RC003C AT 08:22 ON 10/20/93. CHANGES WERE AS FOLLOWS:

DATE: WAS: 05/20/91 IS: 10/20/93 MAXIMUM INSTR RANGE: WAS: 120.0 IS: 122.0 w

I N

ATTACHMENT 4 DPL REVISION SUMMARIES FOR NORTH ANNA UNITS 1 AND 2

STATION: North Anna PRINTED UNIT: 1 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE CHANGE REPORT CHANGED POINT L1RG003G AT 08:20 ON 10/20/93. CHANGES WERE AS FOLLOWS:

DATE: WAS: 03/21/91 IS: 10/20/93 MAXIMUM INSTR RANGE: WAS: 120.0 IS: 122.0

STATION: North Anna PRINTED UNIT: 2 10/20/93 PWR DATA POINT LIBRARY REFERENCE FILE.

CHANGE REPORT CHANGED POINT L2RC003C AT 08:21 ON 10/20/93. CHANGES WERE AS FOLLOWS:

DATE: WAS: 03/21/91 IS: 10/20/93 MAXIMUM INSTR RANGE: WAS: 120.0 IS: 122.0

-Po I

N

e ATTACHMENT 5 UPDATED DPL DATA BASE FILES FOR SURRY AND NORTH ANNA IN dBASE IV FORMAT (Diskette to NUS Corporation / El Division)