ML18079B096
| ML18079B096 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 10/04/1979 |
| From: | Mittl R Public Service Enterprise Group |
| To: | Parr O Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7910110425 | |
| Download: ML18079B096 (5) | |
Text
PS~G Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 Phone 201 /430-7000 October 4, 1979 Director of Nuclear Reactor Regulation
- u. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Gentlemen:
Mr. Olan D. Parr, Chief Light Water Reactors Branch 3 Division of Project Management RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION NO. 2 UNIT SALEM NUCLEAR GENERATING STATION DOCKET NO. 50-311 Public Service Electric & Gas Company hereby transmits sixty (60) copies of its response to your request for additional information regarding the NPSH available for the RHR pumps during the accident recovery recirculation mode.
This in-formation supplements the May 17, 1979 submittal.
Should you have any questions, please do not hesitate to con-tact us.
Enclosure The Energy People Ver1~£--
gL. Mittl General Manager -
Licensing and Environment Engineering and Construction
"' 9 1o11 o</~
A 95-2001 (400M) 9-77
This information supplements the May 17, 1979 submittal re-garding the NPSH available for the RHR pumps during the re-circulation mode and addresses the following two open issues.
- 1.
Establish the maximum flow rate for the worst hy-draulic configuration by field test and evaluate the available NPSH based on that flow.
- 2.
Demonstrate where the velocity term (v2/2g) is con-sidered in the NPSH evaluation previously submitted to the NRC.
Maximum Flow for the RHR Pumps The worst hydraulic configuration for the NPSH evaluation of the RHR pumps, as defined by the NRC, is when one (1) RHR Pump is feeding two (2) charging pumps, two (2) safety in-jection pumps and also flowing directly into two (2) cold legs.
To establish the initial pump condition on July 13, 1979, both No. 21 and 22 RHR pumps were individually tested for the defined flow configuration using the Refueling Water Storage Tank as the water source.
The results of this test were as follows:
Pump No.
21 22 Throttle Valve Position 60%
60%
Flow {GPM) 4,132 4,686 The test was stopped after the above results were reached because it was obvious that if the throttle valves were to be opened to 100% the pump would reach high runout condi-tions and the motor current readings would exceed that which is normally desired.
This test demonstrated that the system resistance was low and that excessive pump runout conditions would be seen under this accident mode of operation.
The system resistance on the discharge side of the RHR pumps was increased by changing the orifices on the flow elements that are located both upstream and downstream of the RHR Heat Exchanger.
The revised flow orifices were sized for differential pressures of fifty (50) PSI at approximately 4500 GPM for the upstream flow element and 21 PSI for the downstream element.
The corresponding orifice diameters are 5.5 and 5.0 inches respectively.
2 -
No. 21 RHR pump was retested on August 6, 1979 with the re-sized orifices in place.
The operating flow conditions were as described above.
This test showed that with the throttle valve full open the maximum flow achieved was 4,600 GPM.
This test result is acceptable since the pump had adequate NPSH for flows up to 4,800 GPM, as indicated in our submit-tal to the NRC on May 17, 1979.
Westinghouse has evaluated this modification and has concluded tpat ECCS performance remains above the minimum required performance level.
A letter (refer to Attachment A) has been received from the RHR pump manufacturer, the Ingersoll Rand Company, indicat-ing that the certified characteristic curves submitted for these pumps and used in this evaluation are per the Hydrau2 lie Institute standard which includes the velocity term (v /2g) in specifying the NPSH required.
RWS:kd
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(IlJ Im l!9 CJtabli*l1ccl J 871 CAM~RON PUMP OIVIDION P.O. aox,qaa PHILLIPBDURG, N. J, OBBGS Mr. Menon Public Service Elec. & Gas 60 Military Rd.
Room 410 Newark, N. J.
07101
./ '.
Dear Mr. Menon:
June 28, 1979
Subject:
8X20WD S/N 0370-4S/46 016-:32294 Residual Heat Removal Pumps Characteristic Certified Curves f\\-247 A, N-2478 2
l Note that performance curve uses V /2g term to calcu ate NPSH as per the Hydraulic Institute standards.
RF/il Very truly yours.?
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R. Farrell Quality Assurance Cameron Pun'.p Division All iCRllMlNlS C1lNllNC.I NI \\Jl'llN S!Ht~IS, ACCIOINlS ANO Olltrtl CONOlllONS ll!YONO Ollfl fOllllHll.
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