ML20133Q066

Safety Evaluation Supporting Amends 203 & 184 to Licenses NPF-4 & NPF-7,respectively

ML20133Q066
Person / Time
Site:	North Anna
Issue date:	01/17/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20133Q056	List: ML20133Q066
References
NUDOCS 9701270213
Download: ML20133Q066 (3)

Text

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NUCLEAR REGULATORY COMMISSION f

WASHINGTON, D.C. 20666-0001

%)*****+0 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 203 AND 184 TO FACILITY OPERATING LICENSE NOS. NPF-4 AND NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY OLD DOMINION ELECTRIC COOPERATIVE NORTH ANNA POWER STATION. UNITS NO. 1 AND NO. 2 DOCKET NOS. 50-338 AND 50-339

1.0 INTRODUCTION

By letter dated January 31, 1996, the licensee (Virginia Electric & Power Company) of North Anna Power Station (NAPS) requested amendments to Appendix A of Facility Operating Licenses NPF-4 and NPF-7 for NAPS Units 1 and 2, respectively. The amendments, which proposed changes to Section 3.8.1 and Section 4.8.1 of the Technical Specifications (TS) and their associated TS Bases Section 3/4.8, would revise the current minimum emergency diesel generator (EDG) fuel oil day tank volume and allow credit to be taken for i

surveillance testing performed on the EDGs while the unit is at power to satisfy portions of those surveillance requirements required during shutdown.

Subsequently, by letter dated November 26, 1996, the licensee withdrew the part of the amendment request relating to surveillance tests being performed while the unit is at power.

Our evaluation of the proposed change in the EDG fuel oil day tank volume from 750 to 450 gallons is discussed below.

2.0 EyALUATION NAPS is a dual unit site with four EDGs. Two EDGs are dedicated for each unit. The EDG fuel oil transfer and storage system at NAPS contains two underground 50,000-gallon storage tanks, each of which is designed to provide sufficient fuel oil supply to operate one EDG at full load for 7 days.

Each EDG has an independent 1,000-gallon day tank and two 100% capacity fuel oil transfer pumps (one lead pump and one backup pump).

The day tank is normally maintained at more than 800 gallons, which is sufficient for approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> of EDG operation at full load. Level controls are provided for each EDG day tank to control the operation of the two transfer pumps. The lead transfer pump will start when the tank level decreases to 700 gallons and will stop when the day tank level reaches 820 gallons. The backup fuel transfer 9701270213 970117 DR ADOCK 0500 8

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2 pump will start when the tank level decreases to 580 gallons and will stop when the tank level reaches 830 gallons.

Fuel oil is supplied to the underground storage tanks from one aboveground 210,000-gallon capacity, non-seismic fuel oil storage tank. The underground stcrage tanks, day tanks, pumps and connecting piping are seismic Category I design.

Current TS require that each EDG day tank contains a minimum of 750 gallons of fuel oil. Since the level control points in the day tank allow the fuel oil to drop below 750 gallons during EDG operation, there will be inability of the fuel oil transfer system to automatically maintain the day tank level above 750 gallons during EDG operation without operator intervention. The proposed TS change will revise the minimum volume from 750 gal %s to 450 gallons.

The proposed TS will provide an acceptable EDG day tat F.iimum volume which is more than adequate to support one hour EDG operatior 'c full load plus 10%

margin and will eliminate the need for operators to manually override the automatic level control system to maintain the current TS minimum volume of 1

750 gallons of fuel oil during operation of EDG. We find the proposed TS and its assoc.iated surveillance requirements to maintain the minimum volume of 450 gallons of fuel oil in each EDG day tank are consistent with the guidance described in ANSI N195-1976, " Fuel Oil Systems for Emergency Diesel Generators," and therefore, are acceptable.

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SUMMARY

The proposed TS changes do not. change the design aspects and operations of EDGs and their associated systems at NAPS. The EDG fuel oil transfer and storage systems will continue to provide adequate fuel oil supply for EDG operation following a loss-of-coolant accident. We, therefore, find them acceptable.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Virginia State official was notified of the proposed issuance of the amendments. The State official had no comment.

5.0 fNVIRONMENTAL CONSIDERATION These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public comment on such finding (61 FR 7559). Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental essessment need be prepared in connection with the issuance of the amendments.

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6.0 CONCLUSION

The Commission has concluded, b. sed on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to che health and safety of the public.

Principal Contributor:

D. Shum Date:

January 17, 1997 i

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