ML12338A420
| ML12338A420 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 02/21/2008 |
| From: | Gosselin S Battelle Memorial Institute, Pacific Northwest National Laboratory |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| References | |
| RAS 22101, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML12338A420 (9) | |
Text
Fatigue in Operating Nuclear Power Plants Components after 60 years Fatigue in Operating Nuclear Power Plants Components after 60 years Steve Gosselin Pacific Northwest National Laboratory 509-375-4463 stephen.gosselin@pnl.gov Joint U.S. Nuclear Regulatory Commission (NRC) and U.S.
Department of Energy (DOE)
Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues Bethesda, MD, February 19-21, 2008 ENT000040 Submitted: March 28, 2012 United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of:
Entergy Nuclear Operations, Inc.
(Indian Point Nuclear Generating Units 2 and 3)
ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #:
Identified:
Admitted:
Withdrawn:
Rejected:
Stricken:
Other:
ENT000040-00-BD01 10/15/2012 10/15/2012
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 2 Summary
Service Experience
Component Fatigue Qualification and Serviceability
Challenges and Directions for the Future
Questions and Discussion
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 3 U.S. Failures by Degradation Mechanisms 21.4%
0.1%
0.3%
0.4%
0.7%
0.8%
0.8%
1.4%
1.5%
6.5%
14.8%
18.7%
32.5%
0%
5%
10%
15%
20%
25%
30%
35%
Severe Weather (Freezing)
Corrosion Fatigue Unreported Human Error Water Hammer Over-stressed / Over-pressurized Erosion-Cavitation Thermal Fatigue Design & Construction Corrosion (Crevice, MIC, Pitting)
Vibration Fatigue (incl. Fretting)
Stress Corrosion Cracking Flow Accelerated Corrosion 5164 reported failures Source: PIPExp Database Data from 1970-2007 10,000 reactor years of service experience with commercial LWR nuclear power plant piping systems
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 4
Fatigue accounts for 21% of all reported failures in domestic operating NPPs
Vibration Fatigue
90% of the reported fatigue failures
Most all in small bore socket weld connections
2% of all reported failures
Thermal Stratification
Turbulent Penetration Effects
Hot/Cold Mixing
Generally the occurrence of these failures has not significantly changes in the last 35 years Fatigue Failure Experiance
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 5 Vibration Fatigue Socket Weld Failures Source: PIPExp Database Data from 1970-2007 0
10 20 30 40 50 60 70 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 No. Socket Weld Failures Socket Weld Failures (601 Records as of 12/31/2007)
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 6 Thermal Fatigue Failures Source: PIPExp Database Data from 1970-2007 0
2 4
6 8
10 12 14 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Number of Thermal Fatigue Failures BWR (77 Events)
PWR (101 Events)
LWGR+PHWR (8 Events)
All Plant Types (186 Records)
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 7 Fatigue Qualification and Serviceability
Component design and operation will be limited to prevent fatigue crack initiation
Component is designed and operated in a manner that will tolerate fatigue accumulation and crack growth without reducing the structural integrity below acceptable limits - 'damage tolerant
Component design and operation will be limited so that component failure probability/frequency is within established component reliability goals.
Joint U.S. NRC -DOE Workshop on U.S. Nuclear Power Plant Life Extension Research and Development Issues, Bethesda, MD, February 19-21, 2008 Slide 8
Environmental fatigue effects make it more difficult to rely base serviceability on traditional ASME Class 1 analyses
Synergistic effects of other mechanisms (e.g., corrosion, cast stainless steel thermal embrittlement, etc.)
Advanced reliability models consider all relevant design, operation and maintenance practices, surveillances, etc, so that ensure that fatigue sensitive components will continue to operate with established reliability goals
Expand application of damage tolerant and PFM methods for component fatigue qualification and fitness for continued service beyond 60 years.
Component weld fabrication flaw size and density distributions
Uncertainties in material properties, weld residual stresses, and NDE detection and flaw characterization capabilities Challenges and Directions for the Future
Questions and Discussions Questions and Discussions