ML20249C740

Submits Response to 980529 RAI Re GL 97-04, Assurance of Sufficient NPSH for ECC & Containment Heat Removal Pumps. Clarification of Licensee Response to Question 2,provided

ML20249C740
Person / Time
Site:	Waterford
Issue date:	06/29/1998
From:	Ewing E ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-97-04, GL-97-4, TAC-MA0060, TAC-MA60, W3F1-98-0115, W3F1-98-115, NUDOCS 9807010140
Download: ML20249C740 (5)

Text

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y EntIrgy Operations,Inc.

Killona. LA 70066 Tel 504 739 6242 C. Ewing, lll Judear Safety & Regulatory Affairs l

W3F1-98-0115 A4.05 PR June 29,1998 l

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555

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Subject:

Waterford 3 SES Docket No. 50-382 License No. NPF-38 Request for Additional Information Regarding Response to Generic Letter 97-04 for the Waterford Steam Electric Station, Unit 3 (TAC NO. MA0060) l Gentlemen:

On January 5,1998, via Letter Number W3F1-97-0287, Waterford 3 provided the requested 90-Day response to NRC Generic Letter (GL) 97-04, "Msurance of 8

Sufficient Net Positive Suction Head for Emergency Core Cooling 'nd Containment Heat Removal Pumps." On May 29,1998, the NRC requested aaanionalinformation on the Waterford 3 response to this GL.

The Request for Additional Information (RAI) requested further clarification of our j

response to Question 2: Identify the required NPSH and the available NPSH.

i Specifically, the NRC requested the following information:

(1) Provide a description of the inconsistencies between the design basis ca!culations and other plant documents involving some of the parameter 5 used in the NPSH calculations that were identified as part of Waterford's ongoing l/

l design basis verification program; j

I (2) Provide the expected date of resolution of the NPSH calculations and the design basis; and j

(3) Provide an updated response to GL 97-04 after the resolution.

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9907010140 990629 l

PDR ADOCK 05000382 l

P

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Request for Additional Information Regarding Response to Generic Letter 97-04 for Waterford Unit 3 (TAC NO. MA0060)

W3F1-98-0115 Page 2 l

June 29,1998 The requested information is provided in the attachment to this letter. If you have any questions regarding this RAI response, please contact Mr. M.K. Brandon at (504) 739-6254 or me at (504) 739-6242.

Very truly yours,

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I E.C. Ewing Director Nuclear Safety & Regulatory Affairs l

l ECE/RLWhtk Attachment - Response to the Request for Additional Information l

Regarding Response to Generic Letter 97-04 i

cc:

E.W. Merschoff, NRC Region IV C.P. Patel, NRC-NRR j

J. Smith N.S. Reynolds j

NRC Resident inspectors Office t

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ATTACHMENT to W3F1-98-0115 Page 1 of 3 6

9 Response to the Request for Additional Information Regarding Response to Generic Letter 97-04 for l

Waterford Unit 3 (TAC NO. MA0060)

I ITEM 1 1

Provide a description of the inconsistencies between the design basis calculations and j

other plant documents involving some of the parameters used in the NPSH calculations that were identified as part of Waterford's ongoing design basis verification program.

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- RESPONSE The inconsistencies identified between the design basis calculations and other plant documents involved the High Pressure Safety injection (HPSI) and Containment Spray (CS) pump maximum flowrates and Safety Injection sump water levels during recirculation. These values were used to calculate the minimum net positive suction l

head available (NPSHA) to the HPSI and CS pumps. NPSHA must be greater than net

' positive suction head required (NPSHR) to ensure the pumps do not experience cavitation. These HPSI and CS pump runout flowrates and sump levelinconsistencies

- were extracted from the design basis calculations and various other plant documents' j

and are presented below.

Maximum Flowrate inconsistencies:

l CS Maximum Reference Document Description Flowrate (gpm)

Document 2250 1564.116 Design Specification 2510 LP&L Memo RWSP Volume for 20 min. operation 2510 EC-M97-026 Vortex Height Calculation 2250 MN(Q)-6-27 CS & HPSI NPSH Calculation 2250 EC-M91-011 NPSH for Safeguard Pumps w/

SI-106 Open HPSI Maximum Reference Document Description Flowrate (gpm)

Document 910 SAR Table 6.3-2 890 CE Spec Project Specification 910

- LP&L Memo RWSP Volume for 20 min. operation _

985 DBD-001 -

Safety injection Design Basis Document 910 EC-M97-026 Vortex Height Calculation 890 MN(Q)-6-27 CS & HPSI NPSH Calculation 890 EC-M91-011 NPSH for Safeguard Pumps w/

Sl-106 Open

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ATTACHMENT to W3F1-98-0115 Page 2 of 3 Safety injection Sump Water Level Inconsistencies:

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1. Engineering Calculation MN(Q)-6-27, "HPSI & CS NPSH Calculation," assumed a Safety injection sump water level of (-)3.67 ft to determine NPSH. The (-)3.67 ft was based on Engineering Calculation MN(Q)-6-4, " Water Level inside Containment," which assumed a total volume of 446,500 gallons was discharged into the containment (old SAR assumption). The 446,500 gallon volume consisted of 383,000 gallons from the RWSP,42,000 gaHons from the Safety injection Tanks, and 21,500 gallons from the Reactor Coolant System.

2. Engineering Calculation MN(Q)-6-1,"NPSH Determination (HPSI & CS),"

assumed a Safety injection sump water level of (-)5.64 ft to determine NPSH.

The (-)5.64 ft was based on Engineering Calculation MN(Q)-6-19, " Level of Water inside Containment," which assumed only 383,000 gallons from the RWSP (current SAR assumption).

An operability determination was performed, which considered the above data inconsistencies, to assure continued safe operation of the plant. Engineering evaluated the design basis NPSH calculations, assuming the maximum possible pump runout flowrates and minimum Safety injection sump water level [(-)5.64 ftj, and determined that sufficient NPSH would be available to the HPSI and CS pumps under all design basis conditions. That is, NPSHA was greater than NPSHR in all cases.

ITEM 2 Provide the expected date of resolution of the NPSH calculations and the design basis verification.

RESPONSE

The expected date for resolution of the NPSH calculations and the design basis verification is January 15,1999. The corrective action plan developed for this condition is being tracked by Condition Report (CR) 97-0806. The corrective action plan consists of the following actions:

1. Containment sump level design basis calculations will be revised to conservatively and consistently calculate minimum sump water level during recirculation. The sump water level vill be based on the current UFSAR assumption of 383,000 gallons.

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ATTACHMENT to W3F1-98-0115 Page 3 of 3

2. Design basis pump runout flows for HPSI and CS will be identified and all affected design calculations revised to consistently utilize these flows and the minimum sump water level during recirculation (determined in corrective action 1 above), as design inputs.

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3. HPSI and CS pump design basis runout flows and NPSHA will be documented in l

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the applicable design basis documents.

4. Based on the revised design calculations indicated above, the UFSAR will be l

updated as appropriate. These changes will be evaluated in accordance with 10CFR 50.59.

ITEM 3 -

Provide an updated response to GL 97-04 after the resolution.

RESPONSE

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- An updated response to GL 97-04 will be provided by March 2,1999.

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