ML18139A937
| ML18139A937 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/23/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Varga S Office of Nuclear Reactor Regulation |
| References | |
| 1014, NUDOCS 8012290268 | |
| Download: ML18139A937 (3) | |
Text
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VIRGINIA ELECTRIC AND PowER CoMPANY RICHMOND,VIROINIA 23261 December 23, 1980 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
Dear Mr. Denton:
Serial No. 1014 NO/LEN:ms Docket Nos. 50-280 50-281 License Nos. DPR-32 DPR-37 AUXILIARY FEEDWATER SYSTEM INFORMATION SURRY UNITS 1 AND 2 We have reviewed your letter dated November 17, 1980 requesting additional information on Surry's Auxiliary Feedwater System.
Vepco's response to these items is provided in Attachment 1.
We believe the attached adequately addresses the NRC concerns.
Should you have any questions or require additional information, please contact us.
Attachment
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~~ Manager - Nuclear Operations and Maintenance I
Listed below are Vepco 's responses to the recommendations found in the NRC letter dated November 17, 1980 requesting additional information for Surry's Auxiliary Feedwater System.
- 1.
Recommendation GL-3 All auxiliary feedwater flow control valves and the downstream manually operated shutoff valves are located inside containment.
We need your response as to how these valves can be utilized in an accident environ-ment.
Response
Vepco's initial response, in a letter dated November 9, 1979, to the requirements of GL-3 stated that the present design had at least one AFW system pump and flow path automatically initiated and capable of being operated independently of any alternating current power source for at least two hours.
At that time, it was stated that the essential instrumentation (AFW Flow Indication) would have to be modified to provide for a
loss of all AC because only two indicators could be independently supplied from alternate DC sources.
This was resolved by feed flow and wide range steam generator level indication being powered from diverse Class IE buses, with at least one of the buses backed by batteries for each steam generator.
Therefore, with the wide range steam generator level considered as a back-up indication, the AFW flow indica-tion is powered from a highly reliable, battery-backed non-class IE power supply.
The NRC request for additional information in their letter dated Febru-ary 8, 1980 stated that a commitment needed to be made to modify instru-mentation; such that following a complete loss of all AC power, the turbine driven AFW pumps may be operated remotely from the control room for at least two hours.
Hence, an analysis is in progress to determine the best method for providing this capability.
The analysis and sub-sequent modifications should be completed and/or implemented by January 1, 1982.
- 2.
Recommendation (Enclosure 2)
- 3.
We need your response to Enclosure 2 of our September 25, 1979 letter.
Response
Vepco's response was submitted in a letter dated December 23, 1980, Serial No. 999, AFW Design Reevaluation This reevaluation is to be provided prior to January 1, 1981 in accor-dance with your letter dated November 9, 1979.
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Response
As a result of Vepco's I.E. Bulletin 79-0lB Review for Surry Units 1 and 2, it has been determined that the AFW flow control valves have envirornnental qualification data requiring further corroborating information from the manufacturers before final judgement can be made.
These valves are of the same general type and were purchased during the same time period as those which have been determined to be qualified.
We do not foresee any problem in having these components meet IE Bulletin 79-0lB qualifications.* Futhermore, these components will have performed their accident safety function prior to receiving a radiation dose above the threshold of 2500 rads.
Since we did not receive vendor qualification documentation in time for the December 1, 1980 update to I.E. Bulletin 79-0lB, we have placed a purchase order for replacement operators.
If in the interim, prior to installation, we receive substantiation of qualification for the presently installed operators, the existing operators will not be replaced.
Therefore, only those installed operators that are proven not to be qualified will be replaced during the first outage of suffi-cient duration upon receipt of material.