ML20209H198

Amended Final Deficiency Rept Re Inadequate Flow Rate for Hydrogen Recombiners Supplied by Rockwell.Blower Impeller Orientation for Both Trains Corrected & Tested. Cause of Improper Installation Will Be Submitted by 870213

ML20209H198
Person / Time
Site:	Nine Mile Point
Issue date:	01/31/1987
From:	Mangan C NIAGARA MOHAWK POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
(NMP2L-0988), (NMP2L-988), NUDOCS 8702050548
Download: ML20209H198 (3)

Text

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NMMEIA NIAGARA MOHAWK POWER CORPORATION /301 PLAINFIELD ROAD. SYRACUSE, N.Y.13212/ TELEPHONE (31s) 474-1511 S January 31, 1987 (NMP2L 0988)

U.S. Nuclear Regulatory Commission Attn: Documerit Control Desk Washington, D.C. 20555 Re: Nine Mile Point Unit 2 Docket No. 50-410 Gentlemen:

Niagara Mohawk subraitted its final report in accordance with 10CFR50.55(e) for the problem concerning inadequate flow rate for the Hydrogen Recombiners (55e-86-22) on January 6, 1987. This letter amends information transmitted in that r4 port.

In Section 3 of the above report, we stated that verification of the impeller orientation of the Hydrogen Recombiner blower had been performed and based upon this verification, we had concluded that the impeller was properly oriented. We also indicated that a review of data recorded during testing showed that the measured niotor/ blower performance was consistent with the vendor qualification program. This verification was based on the following:

1. A review with the vendor (Rotron) of the pressure, flow, and motor current data obtained during preoperational testing. The vendor indicated that based on their experience, the data was representative of a properly oriented impeller.

2. A comparison of field test measurements of winding amperage versus flow to vendor (Rockwell) qualification report data.

3. Remote manual inspection of the blower assembly using a boroscope.

Although the boroscope inspection was not 100% conclusive, the data of the vendor qualification report indicated that there was an acequate margin between operating and rated conditions, and it was accordingly felt that disassembly of the blower assembly was not necessary.

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Page Two The Recombiner vendor, Rockwell, was requested to verify'the vendor qualification report section which addressed the motor horsepower requirements. They subsequently advised that actual LOCA motor load was 9.9 hp rather than 8.6 hp as originally indicated, and that the qualification report needed correction. They also advised that if the impeller was improperly installed, the motor load could exceed the motor rating of 10 hp.

In conjunction with a continued Engineering evaluation of the Hydrogen Reconbiners, the blower manufacturer, Rotron, was contacted. They indicated that a factory test should be conducted with the impeller installed with a forward pitch and then with a reverse pitch to record performance data for each design. This test was performed and the data was compared with previous site data and it was determined that the blower. impellers were installed -

incorrectly. Therefore, the hydrogen recombiner blower for train A was disassembled for direct visual verification of impeller orientation. This inspection has verified that the blower impeller was, in fact, incorrectly orientated.

The blower impeller orientation for both trains has been corrected and

-appropriate tests performed to verify proper performance with respect to flow and proper motor loading diring rated conditions. Investigation into the root cause of the improper installation of the blower impeller and the incorrect qualification report is also in progress. Niagara Mohawk will subn.it a summary of the results of the root cause investigation to you by February 13, 1987.

Very truly yours, NIAGARA M0 HAWK POWER CORPORATION C. V. Mangan Senior Vice President TS/pns 2491G xc: Regional Administrator, Region I Ms. E. G. Adensam, Project Director Mr. W. A. Cook, Resident Inspector Project File (2)

MS

UNITED STATES OF AMERICA NUCLEAR REGULATORY C00011SSlON In the Matter of ]

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Niagara Mohawk Power Corporation ] Occket No. 50-410

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(Nine Mlle Point Unit 2) ]

AFFIDAVIT C. V. Mangan , being duly sworn, st President of Niagara Mohawk Power Corporation,ates  ; that that he isheauthorized is Senior Vice on the part of said Corporation to sign and file with the Nuclear Regulatory Commission the documents attached hereto; and that all such documents are true and correct to the best of his knowledge, information and belief.

fO M.ALAAM Subscribed and sworn to efore me, a Notary Public in and for the State of New York and County of /hdulAga , this O / day o 4/JaLa ,)987.

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%, '0 V //lAkb tary Public in and for M1/ b4 A County, New York 1 '

My Commission expires:

JANIS M. MACRO q $??,1la"u,,?l$$ <

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