ML18016A543

Submits Response to Request for Addl Info Re Auxiliary Feedwater Sys Surveillance Requirements at Plant

ML18016A543
Person / Time
Site:	Harris
Issue date:	08/31/1998
From:	Scarola J CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HNP-98-120, NUDOCS 9809040061
Download: ML18016A543 (6)

Text

CATEGORY 2 REGULATORY INFORMATION DISTRIBUTIO SYSTEM (RIDS)

'ACCESSXON NBR:9809040061 DOC.DATE: 98/08/31'OTARIZED: NO DOCKET ¹ FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTg.NAME AUTHOR AFFILIATION SCAROLA,J. Carolina Power &. Light Co.

RECIP;NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Submits response to request for addi info re auxiliary feedwater sys surveillance requirements at plant.

DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: OR Submittal: General Distribution T NOTES:Application for permit renewal filed. 05000400E RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL 0

PD2-1 LA 1 1 PD2-1 PD 1 1 FLANDERS,S 1 1 INTERNAL: ACRS 1 E 1 1 NRR/DE/ECGB/A 1 1 CENSER'RR/DE/EMCB 1

NRR/DRCH/HICB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 OGC/HDS2 1 0 EXTERNAL: NOAC 1 1 NRC PDR 1 1 E

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM~DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK tDCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 14 ENCL 13

li Carolina Power & Ught Company James Scarola PO Box 165 Vice President New Hill NC 27562 Harris Nuclear Plant SERIAL: HNP-98-120 AUG 31 1998 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 RESPONSE TO REQUEST FOR ADDITIONALINFORMATIONREGARDING THE AUXILIARYFEEDWATER SYSTEM LICENSE AMENDMENTREQUEST

Dear Sir or Madam:

Per a telephone call on August 7, 1998, the NRC requested additional information on a Carolina Power & Light Company (CP&L) request for a license amendment regarding the Auxiliary Feedwater (AFW) System surveillance requirements at the Harris Nuclear Plant (HNP). By letter dated December 16, 1997, CP&L submitted a request to revise HNP Technical Specification (TS) 4.7.1.2.1.a.2.a. This TS revision would change the differential pressure and flow requirements of the turbine-driven AFW pump to allow testing of the pump at a lower speed than is currently performed. The additional information was requested to be provided within three weeks of the date of the telephone call.

A written response providing the requested information is provided in the enclosure to this letter.

Questions regarding this matter may be referred to Mr. J. H. Eads at (919) 362-2646.

Sincerely, y/':

AEC/aec Enclosure Mr. J. B. Brady (NRC Senior Resident Inspector, HNP)

Mr. L. A. Reyes (NRC Regional Administrator, Region II)

Mr. S. C. 'Flanders (NRR Project Manager, HNP) 98090400&i 98083i PDR ADQCK 05000400 P PDR 5413 Shearon Harris Road New Hill, NC Tel 919 362-2502 Fax 919 362-2095

Enclosure to SERIAL: H 120 Page 1 of 2 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 RESPONSE TO REQUEST FOR ADDITIONALINFORMATIONREGARDING THE AUXILIARYFEEDWATER SYSTEM LICENSE AMENDMENTREQUEST Re uested Information Item 1:

Please describe the conditions under which the turbine-driven auxiliary feedwater pump (TDAFWP) would operate at 4100 rpm.

Res onse1:

The current setpoint of the TDAFWP differential pressure controller is 28 psig. As a result, the controller will maintain pump discharge pressure 28 psig greater than steam inlet pressure. The controller will vary pump speed with steam generator (SG) pressure to maintain the required 28 psig. Therefore, as steam generator pressure increases, pump speed (and hence pump discharge pressure) will increase. The maximum pump flowrate at a controller setpoint of 28 psig is approximately 550 gpm. As stated in the Harris Nuclear Plant (HNP) Final Safety Analysis Report, the highest steam generator pressure at which the AFW pumps are required to inject water into the SGs is 1205 psig (the first safety valve setpoint of 1170 psig plus 3% accumulation, which equals 1205 psig). This combination of approximately 550 gpm and steam generator pressure of 1205 psig results in the pump running at a pump speed of less than 4100 rpm, but greater than 3700 rpm. The pump's original design point is 900 gpm and 1265 psig (2940 ft) at a speed of 4100 rpm. Therefore, with the exceptions of the TDAFWP runout case during a MSLB or FWLB accident, or manual adjustment to 4100 rpm, the current HNP design does not require the TDAFWP to run at 4100 rpm.

During a Main Steam Line Break (MSLB) or Feedwater Line Break (FWLB) accident, between the time the Main Steam Isolation Valves (MSIVs) close and the time the AFW isolation signal occurs, the pump will be operating at maximum speed (4125 rpm) for approximately 60 seconds.

This is due to high steam generator pressure and low pump discharge pressure. Under these circumstances, the controller cannot maintain the discharge pressure 28 psig higher than steam inlet pressure, therefore, the turbine goes to maximum speed.

J Re uested Information Item 2a:

Please provide any test data that supports the new surveillance ciiteria values that were derived using the pump affinity law.

Res onse2a:

The calculated numbers in the engineering evaluation were veiified by Inservice Testing (IST).

Enclosure to SERIAL: H 120 Page 2 of 2 The reference values for IST are as follows:

Set Speed: 3715 rpm (range 3700 - 3725)

SetFlow: 90gpm (range 89-91)

Calculated dP: 1233.5 psid (range 1167 - 1356.85)

The calculated numbers in the engineering evaluation are as follows:

Set Speed: 3700 rpm Set Flow: 81 gpm Calculated dP: 1216 psid (4% degraded value = 1167 psid)

Speed and flow values are set and the pump dP is calculated. The IST reference value of 1233.5 psid is greater than the calculated value in the engineering evaluation because the IST reference speed is 3715 rpm. In addition, the calculated values in the engineering evaluation are based on the original pump curves.

The minimum value for IST takes into account the HNP Technical Specification (TS) degradation allowance of 4%. The reference value for IST would normally range from .9 - 1.1 of the calculated dP value, or 1110.15 - 1356.85 psid. However, to meet TS requirements, the minimum range value was set at 1167 psid .

Re nested Information Item 2b:

Describe how this test data (from 2a) justifies the scaling factors (significant digits) of these derived values.

Res onse2b:

The significant digits used in the engineering evaluation were consistent with the original TS values approved by the NRC. Also, the basis calculation for the old and new TS numbers used the same significant digits. IST data uses one more significant digit than that of TS. This is consistent with IST data taken at HNP.

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