ML20037A193
| ML20037A193 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/08/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Parr O Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19260G254 | List: |
| References | |
| 237D, NUDOCS 7903200284 | |
| Download: ML20037A193 (9) | |
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Ve co V4RGtNt A ELECTHIC AND POWER COMA ANY. RICH 4OND, VIRGIN 14' 2D61 March 8, 1979 Mr. Harold R. Denton, Director Serial No. 237D Office of Nuclear Reactor Regulation PSE&C/RLR:adw:mc Attention: Mr. O. D. Parr, Chief Light Water Reactors Branch No. 3 Docket Nos. 50-338 Division of Project Management 50-339 U. S. Nuclear Regulatory Commission License No. NPF-4 Washington, D. C.
20555
Dear Mr. Denton:
A comprehensive test to evaluate the thermal performance and water in-ventory characteristics of the North Anna Service Water Reservoir and spray system was conducted in July and August, 1978. The results of this test were used to verify the predictive capabilities of complex analytical models which evaluate the thermal performance and water inventory capabilities of the.sys-tem. We are submitting ten (10): copies of the final report on the testing and performance evaluation of the North Ann'a Service Water Reservoir (SWR) and spray system with this letter (see Attachment 1). This report is entitled,
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" Service Water Reservoir and Spray System Performance Testing and Evaluation".
Two independent consultants were utilized for the acquisition of test data and the data analyses / system modeling tasks.
Environmental Systems Corp-oration was responsible for all data acquisition during)the testing of the SWR and spray system.
Ford, Bacon & Davis Utah Inc. (FB&DU was responsible for final data reduction and analyses as well as system modeling at design conditions. A report on the procedures and instrumentation used in the testing of the SWR and spray system was submitted in September,1978. This report was entitled "The North Anna Power Station Ultimate Heat Sink, Interim Report of Design Verification Test'ing."
The final report contains some information relating to direct test measure-nents of the thermal efficiency of the SWR spray system. Vepco considers-this information proprietary and requests that this information be withheld under
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10CFR2.790. An affidavit to this effect is included as Attachment 2.
Also our consultant FB&DU considers the results of their proprietary computer modeling techniques as being proprietary.under 10CFR2.790. This information is addressed separately in Attachment 3.
Those portions of the report whose proprietary nature is explained in are enclosed in brackets with a @ superscript - i.e.:
[ pro-explained in Attachment 3 arednclosed in brackets with a@prietary nature is prietary materialfJ1 Those portions of the report whose pro h
superscript -
i.e.:
[ proprietary material]W Those portions of the report whose proprietary nature is explained both in Attachment 2 and'Attachmo t 3 are enclosed in brackets 3
witha@ superscript-i.e.:
[ proprietary material
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k 7903 2 0 0,2$1[
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.m.12. m a me e.o rc e.m c m mo m fir. Harold R. Denton, Director su m e 2
Figure 1 of Attachment 4 is considered proprietary and is not provided.
Hewever, this figure is completely analogous to Figure 4.4 of Attachment 1 with a peak temperature of 110 F.
The final report utilizes complex modeling techniques to ascertain the maximum Service Water temperatures which could be expected under design basis plant and meteorological conditions. This maximum SWR temperature was found to be 107.7 F for four-unit operating conditions.
Stone & Webster Engineering Corporation has performed a review of all plant safety systems on Units 1 and 2 which would be affected by increased Service Water temperatures for design basis conditions. The conclusions of this review are presented in Attachment 4.
In summary, all Units 1 and 2 systems are now acceptable for operation with 110.0 F inlet Service Water with 3 exceptions:
1.
fiodifications are required to charging pump coolers and associated Service Water piping to provide adequate flow for design basis conditions.
2.
liadifications are required to guarantee the operability of the control room air-conditioning chillers for Ser-vice Water inlet temperatures in excess of 110.0 F.
3.
Piping and pipe supports in the Service Water and Com-ponent Cooling Water Systems are being reanalyzed ar.
will be modified if required. The temperature limit considered in this effort are stated in our letter Serial flo. 656B dated January 26, 1979, to fir. James P.
O'Reilly, Director of the Office of Inspection and Enforcement, Region II.
It is our intent to complete the modifications required in items (1) and (2) prior to Unit 2 fuel load. Work is proceeding on item (3), and you will be notified as to the resolution of this item in the near future.
This notifica-tion will be in the form of a final report as required under the provisions of 10CFR50.55(e).
The design Service Water Temperatures for Units 3 and 4 will be modified as a result of the analyses presented in this report. All Service Water and Com-ponent Cooling Water systems will be reanalyzed as required using 110.0 F as the maximum Service Water inlet temperature. Any modifications required for either Unit 3 or Unit 4 will be completed prior to their respective fuel load dates. The Units 3 and 4 Service Water and Component Cooling Water piping and supports will be reanalyzed using the same temperature limits as Units 1 and 2.
The submission of this report fulfills commitments made in our letters Serial f!o. 610 dated December 28, 1977, and Serial flo. 396, dated July 13, 1978, to fir. James P. O'Reilly, Director of the Office of Inspection & Enforcement, Region II.
VmGIN4 [LECTRIC AND 00.'.TR COMPANY To dr. Harold R. Denton, Director ssect no.
3 In summary, the flovth Anna Service Uater Reservoir and spray system has been tested and the results used to verify the conservatism of analytical models of the system. These models were then used to evaluate the thermal per-formance and water inventory characteristics of the system for 4 unit design basis conditions. Some system modifications were indicated as a result of these evaluations. These modifications are now in progress on Units 1 and 2.
Studies will be performed on the Units 3 and 4 Service Water and Component Cooling Water Systems to identify any modifications which are required on these systens. These modifications will be performed on Units 3 and 4 prior to the fuel load date for each respective unit.
The florth Anna Service Water Reservoir and spray system will be qualified for the operation of florth Anna Units 1, 2, 3, and 4 with the completion of all indicated modifications.
Please contact us if you should require additional information.
Very tru,'y yours,
/
WW Sam C. Br wn, Jr.
Senior Vice President Power Station Engineering and Construction Enclosures cc: fir. James P. O'Reilly, Director Office of Inspection & Enforcement Region II