ML18142A504
| ML18142A504 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 06/21/1985 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Varga S Office of Nuclear Reactor Regulation |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 85-123AA, NUDOCS 8507010415 | |
| Download: ML18142A504 (4) | |
Text
U'.1LLL-IM L STEWART Vice President Nuclear Operations June 21, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation Attn:
Mr. Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:
VIRGINIA POWER Nuclear Operations Department Post Office Box 26666 One fames River Plaza Richmond, Virginia 23261 VIRGINIA POWER Serial No. 85-123AA NO/JDH:acm Docket Nos. 50-280 50-281 License Nos. DPR-32 DPR-37 SURRY POWER STATION, UNITS 1 AND 2 CONFORMANCE WITH REGULATORY GUIDE 1.97 Virginia Power letter, Serial No.85-123 dated May 10, 1985, provided a partial response to your letter of February 19, 1985 which requested additional information concerning conformance with Regulatory Guide l.97~
The attachment to this letter addresses four of the remaining six items.
The responses to items 1 and 3 are undergoing additional review to insure technical correctness and to provide a clear, concise discussion of each item. Responses for items 1 and 3 will be presented by August 2, 1985.
Concurrently, we are reviewing both our January 31, 1984, submittal and your contractor 1 s report (attached to the February 19, 1985 letter) so that we can provide comments if the report includes incorrect assumptions or reflects a commitment beyond the intent of our responses. The results of this validation process will be forwarded separately.
If you have any questions, or need additional information to complete your review, please contact us.
Very truly yours, Ql~
W. L. Stewart Attachment
e cc:
Dr. J. Nelson Grace Regional Administrator Region II Mr. D. J. Burke NRG Resident Inspector Surry Power Station e
SURRY POWER STATION REGULATORY GUIDE 1.97 RESPONSE TO NRC LETTER DATED FEBRUARY 19, 1985 NRC letter, dated February 19, 1985, on conformance with Regulatory Guide 1.97 identified fifteen open items and requested a Virginia Power response to each item.
Responses to nine of these items, were provided in Virginia Power letter Serial 85-123 dated May 10, 1985.
Four of the remaining six items are addressed below.
Item 4 RHR system flow -- environmental qualification should be addressed in accordance with 10 CFR 50.49 (Section 3.3.3).
Virginia Power Response The Residual Heat Removal (RHR) system at Surry does not serve as an Engineered Safety Feature. Unlike most other Westinghouse plants, the RHR and Low Head Safety Injection systems are separate and independent.
RHR is not a safety grade system and is not required to bring the plant to a design base safe shutdown condition. Since the RHR system is not designed to remain operable during post-accident conditions, we believe that the variable of RHR flow should be reclassified as a Category 3 variable for Surry and the present instrumentation accepted without modification.
Item 5 RHR heat exchanger outlet temperature environmental qualification should be addressed in accordance with 10 CFR 50.49 (Section 3.3.3).
Virginia Power Response As discussed in Item 4
- above, we believe this variable should be reclassified as a Category 3 variable consistent with the qualification of the RHR System as specified in UFSAR, Section 9.3.
The RHR System and accordingly the variable of RHR heat exchanger outlet temperature is not required post-accident.
Item 6 Accumulator level the licensee should install Category 2
instrumentation with the recommended range; environmental qualification should be addressed in accordance with 10 CFR 50.49 (Section 3.3.4).
Virginia Power Response The present accumulator level indication is adequate for its design function of confirming that accumulator contents are available for discharge during an accident.
During power operation the accumulator isolation valve is open, power to the valve is removed, and during start-up the breaker is verified locked open in accordance with the
e Technical Specifications. With the isolation valve open and the breaker locked open, two check valves in series in the accumulator discharge line prevent the tank from being discharged until RCS pressure is less than the accumulator pressure.
In this arrangement the operator has no direct control over accumulator tank level in accident conditions. During rapid RCS depressurization, the level in the accumulator decreases based on the differential pressure between the RCS and the accumulators.
Complete discharge of the accumulator is therefore determined by the primary system pressure.
Furthermore, no subsequent post-accident operator actions are taken based on accumulator level.
Based on a range consistent with Technical Specifications and the accumulator design function, no discharge control function, and no identified post-accident operator use in the Emergency Procedures, we believe the existing instrumentation to be adequate and that accumulator tank level should be reclassified as Category 3 instrumentation for Surry.
Item 7 Accumulator isolation valve position environmental qualification should be addressed in accordance with 10 CFR 50.49 (Section 3.3.4).
Virginia Power Response The present accumulator isolation valve indication is adequate for its design function of confirming that accumulator contents are available for dis.charge prior to an accident.
During power operation the accumulator isolation valve is open, power to the valve is removed, and during start-up the breaker is verified locked open in accordance with the Technical Specifications. With the isolation valve open and the breaker locked open, two ccyeck valves in series in the accumulator discharge line prevent the tank from being discharged until RCS pressure is less than the accumulator pressure. During rapid RCS depressurization, the level in the accumulator decreases based on the differential pressure between the RCS and the accumulators.
Complete discharge of the accumulator is therefore determined by the primary system pressure.
Furthermore, no subsequent post-accident operator actions are taken based on the accumulator isolation*valve position.
Based on the Technical Specifications and the accumulator design function, no discharge control function, and no identified post-accident operator use in the Emergency Procedures, we believe the existing instrumentation to be adequate and that accumulator tank isolation valve position indication should be reclassified as Category 3 instrumentation for Surry.