ML20065S042
| ML20065S042 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/04/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20065S034 | List: |
| References | |
| NUDOCS 8210290418 | |
| Download: ML20065S042 (3) | |
Text
,
. /
\\
UNITED STATES 8
i NUCLEAR REGULATORY COMMISSION g
-l WASHINGTON, D. C. 20555
\\... /
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT.NO. 42 TO FACILITY OPERATING LICENSE NO. NPF-4 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION, UNIT N0. 1 DOCKET NO. 50-338_
__Introducti_o,n:
o By letter dated June 8, 1982 (Serial No. 327), the Virginia Electric and Power Company (the licensee) requested an amendment to Facility Operating License 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 implementing a steam pressure increase to maximize the electrical output at the currently licensed thermal power level. Com-pletion of Phases I.and II would be followed by implementation of Phase III, a core thermal power uprating program.
The licensee's June 8, 1982 request would implement Phase I by revising the NA-1 Technical Specifications (NA-2 to be revised at a later date) to allow operation with a Reactor Coolant System (RCS) average temper-ature (Tav) of 582.8 degrees Fahrenheit (OF) as opposed to the cur-rently approved RCS Tav of 580.30F. This 2.50F increase in Tav Will provide an increase in the secondary side steam pressure of 18 pounds i
per square inch (psi) resulting in a higher secondary cycle thermal efficiency and a 2 Megawatt electrical (MWe) increase in electrical output.
Discussion:
The licensee has provided safety evaluations in order to provide a technical basis that the proposed increase in the RCS Tav does not involve any unreviewed safety question in accordance with 10 CFR Part 50.59. The safety evaluations included the scope of the Nuclear Steam Supply System (NSSS), the Balance of Plant (B0P), and the Turbine-Generator System.
Section 15.1.2.2 of the NA-1&2 Final Safety Analysis Report (FSAR) indicates that the original design bases for the accident analyses i
included a 2.SoF additional allowance on temperature. The additional Cortific 8210290418 821004 PDR ADOCK 05000338 P
PDR t
,,u% %
- m.,_
,m
2-r allowance, without invalidating any accideni analysis, calls for steady
(
state operation at nominal average temperatures up to 2.50F greater than the design value of 580.30F. All accident analyses were performed at either the design RCS Tav of 580.3of plus 6.50F (586.80F) or at 580.3oF -40F, whichever is more conservative.
An uncertainty of plus or minus (+) 40F is required to envelope tem-perature and control uncertainties _. Therefore, the existing FSAR analysis is adequate for operation at 582.80F + 40F. For transients postulated to initiate at "No Load" conditions, the docketed temperature of 5400F remains unchanged.
In summary, the docketed NA-1&2 FSAR accident analyses envelopes tJSSS fullpower operations at 2785 Megawatts thermal (MWt) with a RCS Tav of 582.80F.
All the TS data are appropriate for an RCS Tav of 582.8oF except for the overtemperature and overpower AT setpoints and minor changes incorporating the higher RCS Tav. The calculation of the currently licensed overpower and overtemperature AT setpoints and associated constants was based on a nominal RCS average temperature of 580.3oF at 2785 MWt. The licensee has performed analyses to determine the over-power and overtemperature AT setpoints for an RCS average temperature of 582.8aF. Also, the licensee has performed confirmatory analyses to verify that the revised constants and resulting setpoints are appropriate and provide adequate protection against Departure from Nucleate Boiling (DNB). The new setpoints and associated changes I
will be incorporated 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 2.50F increase in the RCS T that the increase is within tN. From our review we have determined 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 (2785 MWt) with an average RCS temperature of 582.8aF 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.
be a
d ek' N N
,MT, ehkQ i a*,
h
% h[ jld' " $ * %M',T ;Y a 43
4 e
~
I 3-Environmental Consideration We have determined that the amendment does not authorize a change in j
effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. 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 $51.5(d)(4), that an environmental impact statement or negative declaration and environ-mental 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) because the amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated, does not create the possibility of an accident of a type different from any evaluated previously, and does not involve a significant reduction in a margin of safety, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance f
with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense i.nd security or to the health and safety of the public.
I Date: October 4, 1982 I
Princinal Contributors:
L. Engle A. Gill G. Schwenk 5
m,,m o
.h
~ e =omm L
.. m % < #m.
,