ML20249A867
| ML20249A867 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/06/1998 |
| From: | DUQUESNE LIGHT CO. |
| To: | |
| Shared Package | |
| ML20249A865 | List: |
| References | |
| PROC-980306, NUDOCS 9806190023 | |
| Download: ML20249A867 (5) | |
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ENCLOSUREI Beaver Valley Power Station, Unit No.1
. IST Program Proposed Revision 1H x
9906190023 99061 PDR ADOCK O P
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l DUQUESNE LIGHT COMPANY Beaver Valley Power Station 1
UNIT 1
l INSERVICE TESTING (IST) PROGRAM FOR PUMPS AND VALVES Proposed Revision _1B_
Page. lassed OSC Review /Dete LC 2
bb mS rers a m Departmasat Review /Dete 3#f0f General Manager. -
Nuclear Operettoms Approved /Dete This " Propose $ Revision" was made against Revision _1_ of the present Unit _L IST Program.
Ber.vtr Vcil;y Pcwzr Stati:n Unit 1 Issue 3 Proposed Revision 1H INSERVICE TESTING (IST) PROGRAM FOR PUMPS AND VALVES
, PUMP RELIEF REQUEST 5
Pump Mark No(s):
LEE-P-1 A Code Class:
3 IEE-P-1B IEE-P-lC IEE-P-ID System:
36 - Diesel Fuel Oil Function:
To transfer fuel oil from the underground Emergency Diesel Generator Fuel Oil Storage Tank to the Day Tank in order to provide continuous operation of the Diesel at rated load for up to 7 days during an emergency.
Test Requirement:
Per OM-6, Paragraph 5.2(d), " Pressure, flow rate, and vibration (displacement or velocity) shall be determined and compared with corresponding reference values. All deviations from the reference values shall be compared with the limits given in Table 3 and corrective action taken as specified in para. 6.1."
Basis for Relief:
In accordance with 10CFR50.55a(f)(5)(iii), ieliefis requested on the basis that compliance with the code requirement is impractical for BVPS-1.
The limits given in Table 3 for positive displacemer* pumps for discharge pressure are 0.93 to 1.10P, for the Acceptable Range and 0.90 to <0.93P, for the Alert Range Low, and for flow 0.95 to 1.10Q, for the Acceptable Range and 0.93 to <0.95Q, for the Alert Range Low. These limits are too restrictive for the Fuel Oil Transfu Pumps at BVPS-1. The baseline discharge pressures for these four pumps l
range between 7 psig and 11 psig. Applying the OM-6 limits for these values, the average allowable degradation from the reference value is only 0.8 psig. The discharge pressure indicators have graduations every 0.2 psig, however, a review of the previous data for discharge pressure since 1985 reveals that the discharge pressure has historically varied as much as 1 psig from one test to the next and between 1-3 psig over the course of a year. In addition, the allowable inaccuracy of the discharge pressure gauges would allow variations of 0.48 psig, equal to more than half of the Acceptable Ranges. The baseline flows for these four pumps range from 9 to 12 gpm. The average allowable degradation for flow is therefore only 0.7 gpm. The flow values also vary from test to test and between 1-3 gpm over the course of the year.
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Ber.v:r Wil:y Pcw r St:ti:2 Unit 1 Issus 3 Proposed Revision 1H INSERVICE TESTING (IST) PROGRAM FOR PUMPS AND VALVES The OM-6 limits are, therefore, too restrictive. Normal historic variation in discharge pressure and flow would require the pumps to i
enter the Alert or Required Action Ranges. Trends would not be l
observed because the pumps would have to be declared inoperable l
before enough data could be obtained to determine if the data obtained is a true indication of a degrading condition or data scatter. In addition, the ASME trending would also pick-up variations caused by fouling of the suction strainer or discharge filter or by chattering of the relief valve. An allowable variation larger than 0.8 psig or 0.7 gpm, therefore, is needed to trend pump performance.
NUREG-1482, Paragraph 5.6 " Operability Limits of Pumps," states i
that if expanded ranges are needed, relief must be obtained. "The request for relief must include the licensee's basis for the expanded ranges and the basis for finding that the pump performance does not demonstrate degrading conditions. The basis for acceptable pump f
performance pertains to the pump and not the system, though pump performance must meet system requirements to remain in an analyzed condition."
Therefore, BVPS-1 requests relief to use expanded ranges for discharge pressure and flow for the Fuel Oil Transfer Pumps. The ranges proposed for discharge pressure would be 0.80 to 1.20P, for the acceptable range and 0.70 to <0.80P, for the Alert Range. The function of these pumps is to be able to deliver fuel to the day tank to supply the Diesel Generator under full load. The amount of fuel that is required to be delivered is 3.6 gpm, significantly lower than the reference values for all of the pumps. In addition, due to the nature of positive displacement pumps, flow should be the more consistent parameter.
Therefore, the proposed range for flow is 0.90 to 1.15Q, for the Acceptable Range and 0.80 to <0.90Q, for the Alert Range. The proposed range for the flow value is more restrictive because the flow rate is the more critical parameter for the system. The high flow limit is based on approximately half of the allowable variation expected in pumps with this rated flow rate, from the Hydraulic Institute Test Standard for Rotary Pumps,14th edition.
These ranges would only result in an average allowed variation of-2.5 psig and +1.7 psig for pressure and -2.1 gpm and +1.5 gpm for flow. In addition, during discussions with Ingersoll-Dresser Pumps, the pump manufacturer, when questioned about a limiting value for pump
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performance, the pump manufacturer has stated that as the pump wears and the clearances open, the performance will gradually change. No limiting value for either flow or discharge pressure was provided and i
l Be:v;r Vclicy P:wer St: tin Ucit 1 Issue 3 i
Proposed Revision 1H INSERVICE TESTING (IST) PROGRAM FOR PUMPS AND VALVES sudden performance degradation is not expected. The proposed expanded ranges will allow degrading conditions to be identified and provide assurance that the Fuel Oil Transfer Pumps will be capable of l
fulfilling their safety function.
Alternate Test:
Test per IOST-36.1 and 2, " Diesel Generator Monthly Tests" using expanded ranges for flow and discharge pressure.
References:
OM-6, Paragraph 5.2(d),
NUREG-1482, Paragraph 5.6 l
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