ML20246P497
| ML20246P497 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 03/20/1989 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-004, IEB-88-4, NUDOCS 8903280234 | |
| Download: ML20246P497 (3) | |
Text
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Northem States Power Company 414 Nicollet Mall Minneapoks. Minnesota 55401 Telephane (612) 330 5500 March 20, 1989 NRC Bulletin 88-04 Director of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555 PRAIRIE ISIAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Supplemental Response to NRC Bulletin 88-04 In our response to NRC Bulletin 88 ^4, " Potential Safety-Related Pump Loss", dated October 10, 1988 we provided our commitment to modify the orifices in the safety injection recirculation lines to provide the preferred balance between required saiety injection flow and miniflow.
We stated that these modifications would be completed during the next refueling outage of each unit (January 2, 1990 for Unit 1 and March 29, 1989 for Unit 2).
The purpose of this letter is to inform the Commission of a delay in the schedule we originally provided to com-plete this work in Unit 2.
The project has progressed to the point of choosing a 72-gpm orifice since only short term minimum flow protection is needed. The macimum time at minimum flow has been calculated to be 30 minutes.
The pump vendor has been given the design requirements for the mini.aum flow orifices. An estimated 8 - 12 week fabrication schedule is required following final design work, which is in progress. The pump vendor will not be able to deliver the new orifices to support installation during the Unit 2 outage next month.
For this reason, the modifica-tion in Unit 2 will not be completed until the next re ~ eling outage currently scheduled for August, 1990.
As noted in our October 10, 1988 letter, Prairie Island has experi-enced no operational problems with the existing safety injection pump miniflow rate of 47 gpm. A delay in the schedule for installing larg-er orifices in Unit Nc. 2 will not present a significant operability concern for these pumps.
l 8903280234 8903 0 g FDR ADOCK 0500
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Director'of NRR March 20, 1989 Northem States Power Company Page 2 Please contact us if you'have any questions related to our change in-schedule for completing the~ design enhancements recommended by NRC
_ Bulletin 88 04 in Unit No. 2.
e C E Larson Vice President Nuclear Generation c:' Regional Administrator, Region III,.NRC Sr Resident Inspector, NRC NRR Project Manager, NRC G Charnoff-l I
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UNITED STATES NUCLEAR REGULATORY COMMISSION NORTHERN STATES POWER COMPANY PRAIRIE ISLAND' NUCLEAR GENERATING PLANT DOCKET NOS. 50-282 50-306 SUPPLEMENTAL RESPONSE TO NRC' BULLETIN 88-04 l'
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Northern States Power Company, a Minnesota corporation, with this letter is submitting supplemental information'in response to NRC Bulletin 80-04.
This letter contains no restricted or other defense information.
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FJRTHERN STATES ER COMPANY By
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CE son Vice esi nt Nuclear Generation On this d M_ day of b d
,' /#ff before me a notary public in and for said County; personally appeared C E Larson,-Vice President Nuclear Generation, and being first duly sworn acknowl-~
edged that he is authorized to execute this document on behalf of Northern States Power Company, that he knows the contents-.there-of, and that to the best of his knowledge, information, and be-lief the statements made in it are true and that is is not inter-posed for delay.
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JUDY L KLAPPERICK NOTARY PUBtlC-MINNESOTA ANOKA COUNTY My Comnesen Expres Sept 29,1991
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