ML032230319

Draft Information Input, Attachment 12, e-mailed on July 11, 2003 (50-298)

ML032230319
Person / Time
Site:	Cooper
Issue date:	07/11/2003
From:	Bhalchandra Vaidya NRC/NRR/DLPM
To:	Roger R Nebraska Public Power District (NPPD)
Shared Package
ML032260096	List: ML032230292 ML032230297 ML032230298 ML032230301 ML032230306 ML032230311 ML032230316 ML032230319 ML032230326 ML032230332 ML032230334 ML032230338 ML032230341 ML032230437 ML032230446 ML032230448 ML032230453 ML032230455 ML032230459 ML032230460 ML032230464 ML032230467
References
TAC MB5821
Download: ML032230319 (4)

Text

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Subject:

Cooper-MB6821-Request for Code Relief-RP-06-IST for Core Spray Pump Creation Date: 7/11/03 2:53PM From: Bhalchandra Vaidya Created By: BKV@nrc.gov Recipients Action Date & Time nppd.com Transferred 07/11/03 02:53PM reroger (Reroger@nppd.com) nrc.gov owf2_po.OWFNDO Delivered 07/11/03 02:53PM RAG CC (Robert Gramm) nrc.gov owf4,_po.OWFNDO Delivered 07/11/03 02:53PM MCT CC (Mohan Thadani) Opened 07/11/03 02:53PM Post Office Delivered Route nppd.com owf2_po.OWFNDO 07/11/03 02:53PM nrc.gov owf4-po.OWFNDO 07/11/03 02:53PM nrc.gov Files Size Date & Time CooperReliefRP06-RAI-071 03.wpd 8860 07/11/03 02:14PM MESSAGE 1687 07/11/03 02:53PM Options Auto Delete: No Expiration Date: None Notify Recipients: Yes Priority: Standard Reply Requested: No Return Notification:

Send Mail Receipt when Opened Concealed

Subject:

No Security: Standard To Be Delivered: Immediate Status Tracking: Delivered & Opened

I Bhalchandra VaLid -CoO er-MB6821-Request for Code Relief-RP-06-IST for Core Spiny Pump Page From: Bhalchandra Vaidya To: Reroger3 nppd.com Date: 7111/03 2:53PM

Subject:

Cooper-MB6821 -Request for Code Relief-RP-06-IST for Core Spray Pump Attached document is the list of RAIs from the Mechanical and Civil Engineering Branch (EMEB), on the subject Relief Request.

I had sent e-mails to you on 6-3-2003 and 6-5-2003 on the same subject. The attached list of RAls should be considered as the governing list of RAls. Please substitute my e-mails with the attached list.

Please acknowledge the receit of this e-mail and let me know the date when I can expect to receive the response to these RAls.

Also, please contact me, if you have any questions.

Thanks.

Bhalchandra Vaidya NRR/DLPM Licensing Project Manager, PDIV-1 Grand Gulf Nuclear Station, Unit 1 301-415-3308 M/S: 0-7D1 CC: Grarnm, Robert; Thadani, Mohan

BVaidya - CooerRelIefRP06-RAI-71 103.wpd Pan Request fo Additional Information Relief Request RP-06 Cooper Nuclear Station Docket No. 50-298 TAC No. MB6281 RP-06 requests relief from the requirements to obtain vibration measurements for Core spray Pump CS-P-B from one-third minimum pump shaft rotational speed to at least 1000 Hz.

Nebraska Public Power District (NPPD), the licensee, proposes that the vibration data be filtered, removing the measurement associated with the piping induced vibration occurring at less than 1/2 of the pump operating speed. Currently, the vibration measurements are taken from one-third of pump minimum rotational speled to 1000Hz. The proposed relief would allow exclusion of vibration data between 1/3 and 1/2 pump speed.

The licensee has provided the following statements for the relief request:

1. A similar relief request has been approved by the NRC for the Sequoyah Nuclear Plant (SNP) on October 5, 2000.

2. The relief request will restore the affected pump to Its normal testing frequency and will prevent unnecessary pump wear, potential challenges to the plant, and entry into Technical Specifications Limiting Conditions for Operation associated with the increased testing frequency.

3. Vibrations occurring at these low frequencies should not be detrimental to the long term reliability of either the pump or the motor.

With regard to Item #1, RP-06 is different from SNP's relief request in two respects.

a) At SNP, the pumps are tested quarterly using the minimum flow recirculation line.

However, during each refueling outage, the pumps are tested at full flow in accordance with Code requirements, I.e., the relief request is only applicable to quarterly mini-flow.

b) At SNP, the higher vibration only occurs during mini-flow tests, and Is primarily caused by low frequency flow pulsations combined with low structural resonant frequencies of the pump assembly. Although the pumps have experienced high vibration during previous mini-flow tests, the licensee for SNP has monitored this high vibration condition since original Installation of these pumps and was able to conclude that there has been no degradation of the pump/motor/foundation assembly from the inherent high vibration in this range during mini-flow tests. Another key element for approving SNP's relief request is that the pump operability can be demonstrated and verified each refueling outage by full flow test without the relief from Code requirements.

Therefore, the vibration data between 1/3 and 1 /2 pump speed are excluded only from mini-flow tests but the vibration between 1/3 and 1 /2 pump speed continues to be monitored by full flow tests during each refueling outage.

The licensee should address the above differences between Cooper and SNP, and determine If SNP's relief request Is applicable to Cooper. If so, the licensee should revise the relief request and resubmit It along with documentation and justification similar to SNP.

Bhalchandra Vaida- oo erReiefRP6-RA-07113. Page 2 With regard to Item #2, NPPD alludes that increased test frequency and associated high vibrations can cause unnecessary pump wear, potential challenges to the plant, and entry into Technical Specifications Limiting Conditions for Operation. If the licensee has so many concerns about mini-flow test, they need address whether (1) a mini-flow test should even be performed for the affected pump, and (2) the vibration Impact (regardless the sources of vibration) on the pump reliability of prolonged operation following a design basis accident. It should be noted that high vibration level at any frequency range (regardless it is caused by pump internals, piping, piping supports or foundation) may result in pump degradation during a prolonged operation. Therefore, the licensee should justify or provide additional information to demonstrate that high vibrations during mini-flow tests have not caused any pump degradation, and that high vibration will not occur during full flow condition as In the case at SNP.

With regard to Item #3, NPPD should address the four key components recommended by NRC NUREG/CP-0152 In order to conclude that vibrations occurring at these low frequencies should not be detrimental to the long term reliability of either the pump or the motor. The licensee may want to review more thoroughly the SNP submittal regarding how those components were addressed. The licensee should also discuss whether there are aiternative means to monitor the vibration in the excluded range so that action can be taken if they are trending higher. A review of vibration histories at Cooper indicates that the vibration data varied widely and the variation at locations 1H and 5H could be as high as .25 in/sec. The licensee should provide a justification why vibration measurements could vary so widely and discuss actions taken to reduce them. The key issue for the proposed relief request Is to provide justification along with alternative to show that doubling the test frequency does not provide any additional Information nor additional assurance as to the condition of the pump and its ability to perform its safety function.