ML20245H334
| ML20245H334 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 08/08/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20245H333 | List: |
| References | |
| NUDOCS 8908170009 | |
| Download: ML20245H334 (3) | |
Text
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UNITED STATES
'e NUCLEAR REGULATORY COMMISSION I
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l
RELATED TO AMENDMENT NO.
22 TO FACILITY OPERATING LICENSE NPF-68
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AhD AMENDMENT N0 3 TO FACILITY OPERATING LICENSE NPF-81 GEORGI A POWER COMPANY, ET AL.
DOCKET N05. 50-424 AND 50-425 V0GTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2
1.0 INTRODUCTION
By letter dated April 6',1989, Georgia Power Company, et al., (the licensee) requested a change to the Technical Specifications for Vogtle Electric Generating Plant (VEGP), Units 1 and 2.
The proposed change would change the lechnical Specification (TS) to increase for Unit I the maximum total pump flow rate for the centrifugal charging pump lines with a single pump running from 550 gpm to 555 gpm. This change was approved for Unit 2 on an emergency basis on March 6, 1989, by the NRC staff.
2.0 EVALUATION The VEGP 1 & 2 centrifugal charging pumps (CCP) are from Pacific Pump. A Pacific Pump outline drawing recommends a maximum pump runout flow rate of 550 gpm.
It has been identified that the Vogtle pumps may have to operate at up to 555 Spm. The two considerations that must be evaluated for this increased runout limitation are the horsepower capability of the motor and the margin between the available and required net positive suction head (NPSH). The licensee's evaluation follows:
The pump performance curves indicate that the operation of the Vogtle charging pumps at 555 gpm will require a maximum brake horsepower of 680 HP. The charging pump motors are rated at 600 HP with a service factor of 1.15, thus the maximum horsepower for which the motor is designed is 690 HP. Therefore, the motor is capable of providing the horsepower required for pump operation at 505 gpm. The motor qualified life is based on continuous operation at 690 HP, therefore, this operation does not reduce the motor qualified life.
The charging pump performance curves provide net positive suction head (NPSH) requirements to a maximum flow rate of 555 gpm for pump #52233 and to approximately 550 gpm for the other three pumps. These performance curves show that the NPSH required at 550 gpm is approximately 22 feet for the most limiting pump.
Pacific Pump has performed additional testing of this model pump which has demonstrated that the NPSH requirements remain i
stable through flow rates as high as 555 gpm.
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' By extrapolation of the performance curves, the required NPSH at 555 gpm will not exceed 22 feet. The available NPSH at 555 gpm has been calculated to be in excess of 83 feet. Therefore, there is substantial NPSH margin, and pump operation at 555 gpm is acceptable.
Based on the evaluation of the CCP motor horsepower capabilities and the available NPSH margin, the licensee concluded that the centrifugal charging pumps are capable cf operating at 555 gpm with no damage to the pumps or degradation of pump performance.
No special operating precautions or maintenance requirements are necessary to support operation of the pumps at 555 gpm.
The NRC staff has reviewed the above evaluation and concurs with it.
'The licensee evaluated loss of coolant accident (LOCA) analyses and determined that the large break LOCA is the limiting LOCA with regard to increased CCP flow. The licensee then evaluated their large break LOCA analysis assuming an additional 5 gpm flow from each of.2 CCPs. The licensee determined that the peak cladding temperature (PCT) would increase approximately 2' F above its value of 1995.8* F.
This is a small increase and below the requirement of 2200* F.
The licensee has evaluated the effect of increased CCP flow to 555 gpm on containment response following a large break LOCA. The licensee found an insignificant increase in mass and energy that does not affect the acceptability of the containment response following a large break LOCA. Therefore, the licensee has concluded that LOCA analyses are still acceptable with an increased CCP ficw.
The'NRC staff has reviewed the above evaluation and finds that increased CCP flow to 555 gpn is acceptable with regards to LOCA analyses.
The licensee has also reviewed non-LOCA analyses and determined that increased CCP runout flow to 555 gpm does not affect them. The NRC staff finds this acceptable.
In conclusion, the licensee has evaluated the effect of increasing CCP flow from 550 gpm to 555 gpm on CCP performance, LOCA analyses, and non-LOCA analyses and finds the increase acceptable The NRC staff has reviewed the licensee's evaluations and finds them acce table. Therefore, the NRC staff finds the proposed change to TS 4.5.2.h.1) ) to be acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change in surveillance requirements. The 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 exposure.
The NRC staff has made a determination that the amendments involve no significant hazards consideration, and there has been no public coment on such finding.
Accordingly, the amendments meet the eli criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9)gibility Pursuant to 10 CFR 51.22(b,, no environmental igact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
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4.0 CCHCLUSION l
The Comission made a proposed determination that the amendments involve no significant hazards consideration which was published in the. Federal Register on May 31,1989 (54 FR 23314), and consulted with the state of Georgia. No public comments were received, and the state of Georgia did not have any comments.
The' staff 'has' concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safet endangered by operation in the proposed manner, and (2)y of the public will not be such activities will be conducted in compliance with the Commission's regulations, and the issuance of L
these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Jon B. Hopkins, PDII-3/DRP-I/II Dated: August 8, 1989
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