ML20149D013
| ML20149D013 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/25/1988 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20149D003 | List: |
| References | |
| NUDOCS 8802090358 | |
| Download: ML20149D013 (3) | |
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UNITED STATES e
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NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF SPECIAL PROJECTS SUPPORTING AMEN 0 MENT NO. 66 TO FACILITY OPERATING LICENSE NO. OPR-77 AND AMENDMENT NO. 58 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
By letter dated July 2, 1987 the Tennessee Valley Authority (TVA) requested arendments to the Sequoyah Nuclear Plant, Units 1 and 2 Appendix A Technical Sptcifications (TS).
The proposed amendments would modify TS Section 3/4.7.11, Fire Suppression Systems, to reflect charges in the flow and pressure requirements of the High Pressure Fire Protection System (HPFPS) pumps.
In order to meet Appenaix R requirements the licensee has significantly increased the coverage of areas in Sequoyah Units 1 and 2 by the plant's HPFPS.
The increased coverage resulted in a higher design point for the HPFPS pumps in terms of flow and system head.
The proposed change would raise the flow and pressure requirements of the design point to assure a sufficient water supply for the redifiec HPFPS during the design fire condition.
2.0 EVALUATION Water for fire protection is provided from the river by four pumps located in the irtake pumping station.
Each pump is rated at 1500 gallons per minute (gpm) at a syster head of 415 feet.
For design purposes only two pumps are assumed to be operable during a fire. The fire with the raw service water system (RSWS) protection system is also interconnected which provides system pressure from supply tanks on the roof of the auxiliary building. When the fire pumps actuate, the storage tanks are automatically isolated from the HPFPS.
There are, however, RSWS interconnections with the HPFPS that will still require a supply during a fire demard. Water for the RSWS demands is nomally supplied by three RSWS 500 gpm pumps which fill the supply tanks on the auxiliary building roof.
Because the supply tanks are isolated when the fire pumps are rterted, the RSWS demands rust be supplied by the fire pumps.
The licensee
&ternined the RSKS derard on the fire pumps to be 1635 gpm.
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The RSWS demand consists of such itens as the Makeup Water Treatment Plant (44 gpn), Office Building Chillers (660 gpm), Hot Machine Shop ((75 ppm), er.d Yard 120 gpm), Service Building Air Conditioners (141 gpm). Hypochlorite Building Sprinkling and miscellaneous uses (200 gpm).
The licensee also uses 250 gpm for backwashing the strainers.
In the existing TS a flow of 500 gpm was assumed for backwashing two strainers at a time.
This assumption was reconsidered by the licensee and it was determined to be extremely unlikely because the alignrert fer valves necessary for backwashing the strainers is operator controlled; also the strainer backwash tire is short (about 5 minutes). Hence, the flow demand en the fire pumps for strainer backwashing was reduced from 500 gpn to 250 gpm.
The fire demand flow was determined from a series of trial and error calculatiers to determine the flew to the hydraulically most remote area in accordance with National Fire Protection Association (NFPA) standards 13 and
- 15. The rrost critical fire demand was deterrined to be the opening of deluce valves 0-26-1521 and 0-26-2066 in the Reactor Auxiliery Building. The required fire demand from these valves is 1170 gpm with a required head at the pump of 338 feet.
Also included for fire fighting we.s a hose demand of 250 gpm.
The total flow to be supplied by two fire pumps in the intake Structure is then 3306 gpm er 1653 gpm per purp.
The demand point calculated by the licensee (1653 ppm, 338 ft) corresponl~ % e curve parallel to the ranufac-turer's pump curve and 10% below it (regarding head developed) at the rated capacity of 1500 sprr and 376 fert.
The staff agrees with the procedures used to determire the fire demands and the edditienal Raw Service Vrter denands on the fire purps.
Therefore, the TS as modific em tr.st.re an adequate water supply for fire fighting. Also, the margin between the marufacture's curve and the TS design poirt will allew merc9 fer maintent.rre or replacement of the pump before the TS value is violated.
3.0 ENVIRONMENTAL CONSIDERATION
These amendrerts involve a change to a requirenent with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillarce requirements.
The staff has detertnined that the amendments involve no significart increase in the amounts, and no significant change in the types, cf any effluents that may be released 4
offsite, and that there is no significant increase ir individual or cumulative occupational radiation exposure. The Comissinn has previously issued a proposed finding that these crerdments involve no significant hazards censiceraticn tr(' there has been no public connert on such finding. Accordingly.
fcrth ir 1r CFR 51.22(c)(9)gibility criteria for categorical exclusion set the anendments meet the eli l
Pursuant to 10 CFP. fl.22(b), no environrental impact staterent nor environnental essessment need be crepared in connection with the issuance of the amendrents, i
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4.0 CONCLUSION
j The staff has concluded, based on the considerations discussed above, that:
(1) there is reasorable assurance that the health and safety of the will net be endangered by operatirr in the proposed narrer, and (2) public such activities will be conducted in compliance with the Commission's regulations, l
and the issuance of these eterdments will rot be inimical to the connen defense ar.d security nor to the health and safety of the pub,lic.
,i Frincipal Certritttor:
R. Wescott Dated: January 25, 1988 l
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