ML073550079
| ML073550079 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/04/2008 |
| From: | Mahesh Chawla NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Balduzzi M Entergy Nuclear Operations |
| Chawla M, NRR/DORL/LPL3-1, 301-415-8371 | |
| References | |
| TAC MD6564 | |
| Download: ML073550079 (6) | |
Text
January 4, 2008 Mr. Michael Balduzzi Sr. Vice President, Regional Operations NE Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
SUBJECT:
PALISADES -
SUMMARY
OF CONFERENCE CALL REGARDING THE FALL 2007 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MD6564)
Dear Mr. Balduzzi:
On September 21, 2007, the Nuclear Regulatory Commission (NRC) staff participated in a conference call with Entergy Nuclear Operations, Inc. (the licensee) representatives regarding the ongoing steam generator tube inspection activities at Palisades Nuclear Plant. The conference call summary is enclosed.
The NRC staff did not identify any issues that warranted follow-up action at this time; however, the NRC staff asked to be notified in the event that any in-situ pressure testing was performed or if any unusual conditions were detected during the remainder of the outage. If you have any questions, please do not hesitate to call me at 301-415-8371.
Sincerely,
/RA/
Mahesh L. Chawla, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosures:
Summary of Conference Call cc w/encls: See next page
ML073550079 *Memo from A. Hiser OFFICE LPL3-1/PM LPL3-1/LA DCI/CSGB/BC LPL3-1/(A)BC NAME MChawla THarris AHiser CMunson DATE 1/3/08 1/3/08 10/03/07 1/4/08
SUMMARY
OF CONFERENCE CALL WITH PALISADES REGARDING THE FALL 2007 STEAM GENERATOR TUBE INSPECTION RESULTS On September 21, 2007, Nuclear Regulatory Commission (NRC) staff participated in a conference call with Palisades Nuclear Plant representatives regarding the fall 2007 steam generator (SG) tube inspection activities. Palisades has two Combustion Engineering Model 2530 replacement SGs. There are 8,219 mill annealed Alloy 600 tubes in each SG. The tubes have an outside diameter of 0.75 inches and a wall thickness of 0.042 inches. The tubes are supported at various locations by stainless steel eggcrate lattice-type tube supports, diagonal straps and vertical straps. The SG tubes were expanded through the full depth of the tubesheet using an explosive process.
Prior to the call, the licensee was provided with discussion points to help facilitate the phone conference (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072690282). In support of the phone call in an e-mail dated September 21, 2007, the licensee provided responses to the staff questions (see ADAMS Accession No. ML073331083).
At the time of this call, tube inspections were still in progress, but they were nearly complete.
Additional clarifying information or information not included in the material provided by the licensee is summarized below:
The structural limit for a through-wall crack is 0.42 inches. The cracks detected in the sludge pile were not bathtub-shaped.
The voltage of the ding associated with the axial outside diameter stress corrosion crack detected in a ding in SG B was 1 volt. This indication was initially detected with the bobbin coil.
The absolute channel is screened for flaws. No freespan crack-like indications have been detected during the outage. The data quality is comparable to the data quality in previous outages. Many manufacturing buff marks were detected in the freespan (Based on the absolute channel). If there is an indication in the absolute channel, and there was no indication at this location during the previous inspections, the indication is assigned an I-code and inspected with a rotating probe.
No SG chemical cleaning has been performed at Palisades.
The axial outside diameter stress corrosion crack indication found at a dent at a vertical strap was not detected with the bobbin coil.
The U-bend region of rows 4 through 18 are inspected with a bobbin coil.
ENCLOSURE
The two volumetric indications in the tube in row 137, column 92 in SG B, will be sized and left in service if they meet the size requirements specified in the technical specifications (TS).
If the possible loose part near the tube in row 3, column 58 is not removed (Either through sludge lancing or foreign object search and retrieval), the tube will be plugged. If the possible loose part is removed, the indication will be sized and will be left in service if it meets the size requirements specified in the TS.
No wear indications were found in the freespan. The bobbin data from the 2006 tube inspections was reviewed for indications of batwing slippage and none was detected.
A similar review is being conducted during the 2007 outage, and no batwing slippage had been detected at the time of the conference call.
Regarding the leakage past the divider plate in the channel head, the licensee indicated this leakage had not been observed in the past, but such leakage has not normally been the focus of an inspection. The increased awareness by the industry on the topic of divider plate weld cracking may be the reason this leakage was detected during this inspection (along with panning of the camera to this region of the channel head).
The licensee relies on the bobbin coil to inspect dents less than 2 volts at eggcrates, and dents less than 3.5 volts at vertical straps and diagonal bars. Similarly, the licensee relies on the rotating probe to inspect for cracking other than axially-oriented outside diameter stress corrosion cracking (e.g., circumferential primary water stress-corrosion cracking) at dented/dinged locations.
The NRC staff did not identify any issues that warranted follow-up action at this time; however, the NRC staff asked to be notified in the event that any in-situ pressure testing was performed, or if any unusual conditions were detected during the remainder of the outage.
Palisades Plant cc:
Supervisor Covert Township P. O. Box 35 Covert, MI 49043 Office of the Governor P. O. Box 30013 Lansing, MI 48909 U.S. Nuclear Regulatory Commission Resident Inspector's Office Palisades Plant 27782 Blue Star Memorial Highway Covert, MI 49043 Michigan Department of Environmental Quality Waste and Hazardous Materials Division Hazardous Waste and Radiological Protection Section Nuclear Facilities Unit Constitution Hall, Lower-Level North 525 West Allegan Street P.O. Box 30241 Lansing, MI 48909-7741 Michigan Department of Attorney General Special Litigation Division 525 West Ottawa St.
Sixth Floor, G. Mennen Williams Building Lansing, MI 48913 Mr. Michael R. Kansler President & CEO/CNO Entergy Nuclear Operations 1340 Echelon Parkway Jackson, MS 39213 Mr. John T. Herron Sr. Vice President Entergy Nuclear Operations 1340 Echelon Parkway Jackson, MS 39213 Sr. Vice President, Engineering and Technical Services Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Mr. Christopher J. Schwarz Site Vice President Entergy Nuclear Operations Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 General Manager, Plant Operations Entergy Nuclear Operations Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 Mr. Oscar Limpias Vice President, Engineering Entergy Nuclear Operations 1340 Echelon Parkway Jackson, MS 39213 Mr. John F. McCann Director, Nuclear Safety & Licensing Entergy Nuclear Operations 440 Hamilton Avenue White Plains, NY 10601 Ms. Charlene D. Faison Manager, Licensing Entergy Nuclear Operations 440 Hamilton Avenue White Plains, NY 10601 Mr. Ernest J. Harkness Director, Oversight Entergy Nuclear Operations 1340 Echelon Parkway Jackson, MS 39213
Mr. William C. Dennis Assistant General Counsel Entergy Nuclear Operations 440 Hamilton Avenue White Plains, NY 10601 Mr. Joseph P. DeRoy VP, Operations Support Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Ms. Laurie A. Lahti Manager, Licensing Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 Mr. John A. Ventosa GM, Engineering Entergy Nuclear Operations 440 Hamilton Aveune White Plains, NY 10601 Director, NSA Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 Mr. William DiProfio 48 Bear Hill Road Newton, NH 03858 Mr. William T. Russell 400 Plantation Lane Stevensville, MD 21666 Mr. Gary Randolph 1750 Ben Franklin Drive, 7E Sarasota, FL 34246