ML20078P394
| ML20078P394 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/19/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078P389 | List: |
| References | |
| NUDOCS 8311080031 | |
| Download: ML20078P394 (3) | |
Text
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- q UNITED STATES y-NUCLEAR REGULATORY COMMISSION j
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WASHINGTON, D. C. 20555 o
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SAFETY EVALUATION BY THE.0FFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 32 TO FACILITY OPERATING LICENSE NO. NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION, UNIT N0. 2 DOCKET N0. 50-339 Introduction i
By letter dated June 8,1982 (Serial No. 327), the Virginia Electric and Power Company (the licensee) requested amendments to Facility Operating Licenses No. NPF-4 and No. NPF-7 for the North Anna Power Station, Units No. 1 and No. 2 (NA-1&2).
The licensee's amendment request would implement Phase I of a Plant Upgrade Program for NA-1&2. Phases I and II of the Upgrade Program consist of im-plementing a steam pressure increase to maximize the electrical output at the currently licensed thermal power level. Completion of Phases I and II would be followed by implementation of Phase III, a core thermal power up-rating program.
The licensee's June 8,1982 request would implement Phase I by revising the NA-2 Technical Specifications to allow operation with a Reactor Coolant System (RCS) average temperature (T of 582.8 degrees Fahrenheit ( F) as opposedtothecurrentlyapprovedR8)T of 580.3 F.
This 2.5 F increase Ncondarysidesteampressureof18 poun$ will provide an increase in theper square inch (psi) resulting in a highe in T efficiency and a 2 Megawatt electrical (MWe) increase in electrical output.
On October 4,1982, Phase I of the Plant Upgrade Program was implemented at NA-1 with the issuance of Amendment No. 42 to Facility Operating License No. NPF-4. Although our Safety Evaluation supporting Amendment No. 42 stated that we found the Phase II Upgrade to be applicable to both NA-182, the issuance of a identical amendment for NA-2 was held in abeyance until the licensee could implement secondary steam line support modifications to support the 2.5 F uprating for NA-2.
By letter dated May 3, 1983 the licensee stated that the secondary steam line support modification had been completed at NA-2 to support the NA-2 Phase I Upgrade Program. Therefore, we are issuing the Phase I Upgrade for NA-2 at this time.
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Due to the passage of time since first approved for NA-182 and specifically implemented for NA-1 on October 4,1982, we are restating our safety evalua-tion as originally provided for NA-1&2 to support the Phase I Upgrade for NA-2 at this time. Our original discussion and evaluation in addition to our comments on the NA-2 secondary steam line support modifications is pro-vided below.
Discussion The licensee has provided safety evaluations in order to provide a technical t
basis that the proposed increase in the RCS T does not involve any unreviewed safetyquestioninaccordancewi,th10CFRParfV50.59.
The safety evaluations included the scope of the Nuclear Steam Supply System (NSSS), the Balance of Plant (80P), and the Turbine-Generator System.
Section 15.1.2.2 of the NA-182 Final Safety Analysis Report (FSAR) indicates that the original design bases for the accident analyses included a 2.5 F additional allowance on temperature. The additional allowance, without invalidating any accident analysis, calls for steady state operation at nominal av7 rage temperatures up to 2.5 F greater than the design value of l
580.3 F.
All accident analyses were performed at either the design RCS T
of 580.3 F plus 6.5 F (586.8 F) or at 580.3 F -4 F, whichever is more c8Xservative.
An uncertainty of plus or minus (+) 4 F is required to envelope temperature and control uncertainties. ThereTore, the existing FSAR analysis is adequate for operation at 582.8 F +4 F.
For transients postulated to initiate at "No Load" conditions, the docFeted temperature of 540 F remains unchanged.
In f
summary, the docketed NA-l&2 FSAR accident analyses envelopes NSSS full power operations at 2785 Megawatts thermal (MWt) with a RCS T of 582.8 F.
av All the TS data are appropriate for an RCS T of 582.8 F except for the overtemperature and overpower AT setpoints a63 minor changes incorporating the higher RCS T overtemperature $Y. The calculation of the currently licensed overpower and setpoints and associated constants was based on a nominal RCS average temperature of 580.3 F at 2775 MWt. The licensee has performed analyses to determine the overpower and overtemperature AT setpoints for an RCS average temperature of 582.8 F.
Also, the licensee has performed con-firmatory analyses to verify that the revised constants and resulting set-l points are appropriate and provide adequate protection against Departure from Nucleate Poiling (DNB). The new setpoints and associated changes will be incorporateJ in the utility Precautions, Limitations and Setpoints (PLS) document and plant procedures.
Evaluation We have reviewed the NA-1&2 FSAR and the licensee submittal justifying a 2.5 F increase in the RCS T,y.
From our review we have determined that
. the increase is within the limits assumed in the docketed FSAR accident and transient analyses and, therefore, is acceptable.
Thus, we find full power operation at the currently licensed thermal power level (2775 MWt) with an average RCS temperature of 582.8 F to be acceptable. Also, we have reviewed the TS changes associated with the NA-1&2 Phase I Upgrade Program and we find these changes acceptable.
By letter dated May 3,1983, the licensee stated that the main steam line monoball support modifications which were found necessary to support the 2.5 0 uprating at NA-2 had been completed. We requested that Region II inspection verify the completion of these modifications at NA-2.
Verifica-tion for completion of these modifications is so stated in Inspection Report 50-339/8-11 dated July 1, 1983.
Therefore, based on all of th'e above, we find implementation of the 2.5 F increase in T,y (Phase I Upgrade) to be acceptable for NA-2.
Environmental Consideration We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. This amendment increases the efficiency of NA-2 to produce slightly greater available electrical power without changing the authorized core thermal power. Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 651.5(d)(4), that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
Conclusion We have concluded, based 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, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the ^.7alth and safety of the public.
Date: October 19, 1983 Principal contributor:
L. Engle A. Gill G. Schwenk l
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