ML112170066

SG Tube ISI Report - RAIs - ME6102

ML112170066
Person / Time
Site:	Palisades
Issue date:	08/01/2011
From:	Mahesh Chawla Plant Licensing Branch III
To:	Kuemin J Entergy Nuclear Operations
chawla M
References
TAC ME6102
Download: ML112170066 (1)

Text

From: Chawla, Mahesh Sent: Monday, August 01, 2011 10:21 AM To: KUEMIN, JAMES L Cc: DOTSON, BARBARA E

Subject:

Palisades Nuclear Plant - SG Tube ISI Report - RAIs - ME6102 On April 25, 2011, by ADAMS Accession Number ML11119A040, Entergy Nuclear Operations, Inc. (the licensee), submitted a steam generator inspection report for the Palisades Nuclear Plant Fall 2010 refueling outage in accordance with the plants technical specifications. In addition to this report, the U.S. Nuclear Regulatory Commission staff summarized additional information concerning the 2010 steam generator tube inspections at Palisades in a letter dated January 5, 2011 (ADAMS Accession Number ML103640046).

The NRC staff has reviewed the information the licensee provided and determined that additional information is required in order to complete the evaluation.

REQUEST FOR ADDITIONAL INFORMATION PALISADES NUCLEAR PLANT STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT DOCKET NO. 50-255

1. Please clarify the following sentence on page 3: No leakage was predicted for either operating or accident conditions for the 2009 to 2010 operating cycle due to observed SG [steam generator] tube degradation in the 2010 refueling outage.

2. Please confirm the Inspection Period EFPM [Effective Full Power Months] for refueling outage 21 in Table A. It would appear that the correct value is 56.0 EFPM rather than 64.2 EFPM.

3. It appears that two freespan crack-like indications were detected during the 2010 outage (SG A, row 2 column 21 and SG B row 85, column 44). These indications were presumably associated with dings. Please discuss the size (voltage amplitude) of the dings associated with these indications. If the voltage amplitude of the dings is near 5.0 volts, please discuss the basis for not expanding the rotating probe examinations to include dings whose voltage amplitude is less than or equal to 5.0 volts.

4. Please discuss the nature of the single volumetric indications listed in Table 4A. Are these wear indications attributed to loose parts?

5. In Table 4A, there are some depths that are greater than 100-percent through-wall.

Please clarify.

6. Please discuss whether any secondary side inspections other than foreign object search and retrieval were performed. If secondary side inspections were performed, please summarize the results.

7. In Table 3, there is reference to wear from tube-to-tube contact. This wear appears to be limited to the square bend region. Was any such wear observed during this inspection? If so, please discuss the extent of the degradation (number and size).