ML18152B047
| ML18152B047 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/07/1988 |
| From: | Cruden D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 88-430, NUDOCS 8807190089 | |
| Download: ML18152B047 (2) | |
Text
D.S.CnuDEN VICE PRESIDENT-NUCLEAR e
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 July 7, 1988 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNIT I ASME SECTION XI INSERVICE PUMP TESTING INSIDE RECIRCULATION SPRAY PUMPS Serial No.88-430 PES/ISI/DJF:vlh R7 Docket No.
50-280 License No.
DPR-32 We have recently modified the Surry Power Station Unit 1 inside recirculation spray system to permit hydraulic testing of the inside recirculation spray pumps in accordance with ASME Section XI.
Flow and pressure instrumentation were installed during this modification to measure the pump hydraulic para-meters.
As a result of initial pump testing, we have determined that the +/-2%
accuracy requirement of the ASME Section XI Code for fl ow instrumentation cannot be met with the as-built piping configuration.
Additional modifica-tions of the piping system are required to achieve the +/-2% accuracy.
Recon-figuring the system at this time would significantly extend the present Unit 1 refueling outage.
We request relief from the ASME Section XI flow instrument accuracy require-ment of +/-2% for pumps 1-RS-P-IA and IB until the next Unit I refueling outage, which is scheduled for September 1989.
At that time the necessary modifica-tions will be made in the test loop to improve the flow instrument accuracy to within +/-2%.
The manufacturer's specified accuracy for flow instrumentation for this piping configuration is +/-4% of full scale.
Full scale for this instrumentation is 0 to 4,000 gpm.
Flow measurements were taken over the range of Oto 3,500 gpm thereby meeting the ASME specified range criteria for flow instrumentation.
We have refurbished both the Unit 1 inside recirculation spray pumps and have re-established the pump curve with the existing piping configuration.
Curve fit techniques were emp 1 oyed to deve 1 op the pump head-fl ow curve for the "as-left" condition for both the A and B pumps.
The data points obtained during fl ow testing fa 11 within a +/-4% dead band of the derived pump curve.
This provides reasonable assurance that the instrument performed within the manufacturers stated accuracy limits throughout the flow test.
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- r Utilizing appropriate system curves, the approximate operating point for each refurbished pump is 3250 gpm.
The LOCTIC computer program, which determines containment depressurization times, was run with an assumed IRSP flow of 3000 gpm.
The acceptance criterion for a 3600 second depressuri zat ion ti me, as required for input to the docketed existing offsite dose calculations, was satisfied witb __ _1~hi_~ a~sum~d f_l_ow._
This analytical result, _when. compared -to----
the flow test results, confirms the adequacy of the inside recirculation spray pumps to meet design basis requirements.
If you have any questions regarding this request, please contact us.
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~ru cc: U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N.W.
Suite 2900 Atlanta, GA 30323 Mr. W. E. Holland NRC Senior Resident Inspector Surry Power Station