ML072330440

Prairie Island - RAIs for ISI Summary Report Steam Generator- MD3158

ML072330440
Person / Time
Site:	Prairie Island
Issue date:	08/20/2007
From:	Kivi J Nuclear Management Co
To:	Chawla M L NRC/NRR/ADRO/DORL/LPLIII-1
Chawla M L, NRR/.DLPM, 415-8371
References
TAC MD3158
Download: ML072330440 (3)

Text

From: "Kivi, Jeffrey L." <Jeffrey.Kivi@nmcco.com>To:"Chawla, Mahesh" <mlc@nrc.gov>Date: 08/20/2007 9:38:43 AM

Subject:

RE: Prairie Island - RAIs for ISI Summary Report Steam Generator -MD 3158

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Original Message-----From: Mahesh Chawla [1]

Sent: Tuesday, December 12, 2006 3:39 PM To: Kivi, Jeffrey L.

Cc: Allen Hiser; John Burke

Subject:

Prairie Island - RAIs for ISI Summary Report Steam Generator

-MD 3158By a letters dated September 1, 2006 (ML062550530), and May 25, 2006(ML061450543), Nuclear Management Company (the licensee) submitted information summarizing the results of the 2006 steam generator tube inspections at Prairie Island Unit 1. These inspections were performed during the twenty fourth refueling outage (1R24). In addition to this report, the U.S. Nuclear Regulatory Commission staff summarized additional information concerning the 2006 steam generator tube inspections at Prairie Island Unit 1 in a letter dated July 10, 2006 (ML061680006).The NRC staff has reviewed the information the licensee provided anddetermined that additional information is required in order to complete the evaluation. The additional information being requested is enclosed.

From discussions with you, the root cause evaluation is not complete.

Please provide your estimated date of completion of the root cause evaluation and arrange a teleconference to discuss the staff request upon availability of the root cause evaluation report. 1. On May 18, 2006, the Nuclear Regulatory Commission (NRC) staffconducted a phone call with representatives from Prairie Island to discuss the steam generator tube inspections during their 24th refueling outage. During the call the there was a discussion of a root cause analysis that was commenced in response to finding more wear indications than expected. Please discuss the scope and results of that analysis.

In addition, please discuss any planned corrective actions in response to the results. Also, please discuss whether there is any axial or radial pattern for the wear indications detected. If so, discuss the significance.2. During the operating cycle prior to the 24th refueling outage, pleasediscuss whether there were any chemical excursions in the steam generators (e.g., from a leaking condenser tube). If so, discuss the extent of the chemical excursion, the corrective action and any long term implications for the steam generators.Thanks