ML031480529
| ML031480529 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 05/15/2003 |
| From: | Cooper D Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML031480529 (6) | |
Text
NuK Committed to Nuclear ExceIlen Palisades Nuclear Plant Operated by Nuclear Management Company, LLC May 15, 2003 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 10 CFR 50.4 PALISADES NUCLEAR PLANT DOCKET 50-255 LICENSE No. DPR-20 STEAM GENERATOR TUBESHEET INSPECTION PRACTICES Nuclear Management Company, LLC is providing the subject information for the Palisades Nuclear Plant. The attached information was requested by the Nuclear Regulatory Commission (NRC) and is provided in accordance with Enclosure 2 of Nuclear Energy Institute letter "Steam Generator Tubesheet Inspections," dated February 28, 2003.
SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
Douglas E. Cooper Site Vice-President, Palisades Cc Regional Administrator, USNRC, Region IlIl Project Manager, USNRC, NRR NRC Resident Inspector-Palisades Attachment 27780 Blue Star Memorial Highway
- Covert, Ml 49043 Telephone: 616.764.2000
- oq-
ATTACHMENT I NUCLEAR MANAGEMENT COMPANY PALISADES NUCLEAR PLANT DOCKET 50-255 INDUSTRY TEMPLATE FOR SUBMITTAL OF INFORMATION ON STEAM GENERATOR INPSECTION WITHIN THE TUBESHEET 4 Pages Follow
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Nuclear Management Company Palisades Nuclear Plant Tubesheet Inspection Practices Plant Information Plant Name: NMC Palisades Nuclear Plant Model of Steam Generator: Combustion Engineering CE 2530 Tube Material: Mill Annealed Alloy 600 Tube Diameter: 0.750 inch Tube Wall Thickness: 0.042 inch Nominal Expansion Process and Extent: Full depth explosive and rolled at both ends Tubesheet Thickness: 20.5 inches with 0.25 cladding Historical Inspection Practices and Results Most recent outage:
2003 Refueling Outage (Mar-Apr)
Operational Cycle #16 Inspection techniques used: Bobbin and plus point rotating pancake coils.
Extent of inspections (be specific on landmarks used to determine inspection extent):
Bobbin extent is full length of all active tubes including the hot leg and cold leg tubesheet.
Plus Point Rotating Pancake Coil (RPC) extent is +3 inches above and -5 inches below (minimum) of all active tubes from the top of the hot leg tubesheet.
Results (degradation mechanisms identified and orientation):
Identified one axial primary water stress corrosion cracking (PWSCC) indication in the tubesheet (2 inches below top of tubesheet completely bounded by inspection area).
Identified two axial PWSCC indications at the end of tubesheet in the tack roll of a non-expanded tube.
Identified seven outside diameter stress corrosion cracking (ODSCC) circumferential indications at the top of the tubesheet.
Identified two ODSCC axial indications at the top of the tubesheet.
Identified nineteen loose part wear indications at the top of the tubesheet.
Identified three volumetric indications at the top of the tubesheet.
Bases for inspection technique and inspection extent:
EPRI Qualified & Site Validated Techniques.
CEOG Task 1154 WCAP-1 5720, Rev. 0,"NDE Inspection strategy for the Tubesheet Region in CE Designed Units." WCAP-1 5720, Revision 0, "NDE Inspection Strategy for the Tubesheet Regions in CE Designed Units," provides a test program and technical basis for application of supplemental inspections in the tubesheet region of the steam generators at Palisades. The test program defines an inspection extent for supplemental inspections that ensures tube
structural and leakage integrity in accordance with the requirements of NEI 97-06 (Steam Generator Program Guidelines) and the licensing basis for Palisades.
The program does not provide a basis for leaving detected flaws in service inside or outside the tube length. As such, the current Palisades steam generator degradation assessment defines the inspection extent with expansion criteria but does not constitute an alternate repair criteria (ARC).
Technical Document reference (Generic or Plant Specific?):
Generic CEOG Task 1154 WCAP-1 5720, Rev. 0, NDE Inspection strategy for the Tubesheet Region in CE Designed Units.
If generic, provide statement that plant conditions and design are bounded by Technical:
Document inputs and assumptions: Generic CEOG Task 1154 WCAP-1 5720, Rev. 0 bounds Palisades operating conditions and inspection experience.
Historical Inspection Practices and Results Past outage:
2001 Refueling Outage (Mar-Apr)
Operational Cycle #15 Inspection techniques used: Bobbin and plus point rotating pancake coils.
Extent of inspections (be specific on landmarks used to determine inspection extent):
Bobbin extent is full length of all active tubes including the hot leg and cold leg tubesheet.
Plus Point RPC extent is +3 inches above and -5 inches below (minimum) of all active tubes from the top of the hot leg tubesheet.
Results (degradation mechanisms identified and orientation):
Identified two loose part wear indications at the top of the tubesheet.
Identified three volumetric indications at the top of the tubesheet.
Bases for inspection technique and inspection extent:
EPRI Qualified & Site Validated Techniques. CEOG Task 1154 WCAP-1 5720, Rev. 0 "NDE Inspection strategy for the Tubesheet Region in CE Designed Units."
Technical Document reference (Generic or Plant Specific?):
Generic CEOG Task 1154 WCAP-1 5720, Rev. 0, NDE Inspection strategy for the Tubesheet Region in CE Designed Units.
If generic, provide statement that plant conditions and design are bounded by Technical Document inputs and assumptions:
Generic CEOG Task 1154 WCAP-1 5720, Rev. 0 bounds Palisades operating
conditions and inspection experience.
Historical Inspection Practices and Results Past outage:
1999 Refueling Outage (Oct -Nov)
Operational Cycle #14 Inspection techniques used: Bobbin and plus point rotating pancake coils.
Extent of inspections (be specific on landmarks used to determine inspection extent):
Bobbin extent is full length of all active tubes including the hot leg and cold leg tubesheet.
Plus Point RPC extent is +3 inches above and -3 inches below (minimum) of all active tubes from the top of the hot leg tubesheet.
Results (degradation mechanisms identified and orientation):
Identified one axial PWSCC indications at the end of tubesheet in the tack roll of a non-expanded tube.
Bases for inspection technique and inspection extent:
EPRI Qualified & Site Validated Techniques.
Technical Document reference (Generic or Plant Specific?):
EPRI Qualified Techniques and accepted Industry practice regarding extent of rotating probe inspection within the tubesheet.
Historical Inspection Practices and Results Most recent outage:
1998 Refueling Outage (Apr-May)
Operational Cycle #13 Inspection techniques used: Bobbin and plus point rotating pancake coils.
Extent of inspections (be specific on landmarks used to determine inspection extent):
Bobbin extent is full length of all active tubes including hot leg and cold leg tubesheet.
Plus Point RPC extent is +2 inches above and -2 inches below (minimum) of all active tubes from the top of the hot leg tubesheet.
Results (degradation mechanisms identified and orientation):
Identified four loose part wear indications at the top of the tubesheet.
Prior to 1998 all three indications (2 volumetric and 1 axial) plugged were above the top of the hot leg tubesheet. These results are from the initial base line
inspection for Plus Point RPC and a possible result of the initial steam generator manufacturing process.
Bases for inspection technique and inspection extent:
EPRI Qualified & Site Validated Techniques.
Technical Document reference (Generic or Plant Specific?):
EPRI Qualified Techniques and accepted Industry practice regarding extent of rotating probe inspection within the tubesheet.