ML031540738
| ML031540738 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 06/03/2003 |
| From: | Cora M NRC/NRR/DRIP/RLEP |
| To: | Office of Nuclear Reactor Regulation |
| Cora, MG, NRR/DRIP/RLEP, 415-3148 | |
| References | |
| Download: ML031540738 (10) | |
Text
June 3, 2003 LICENSEE: Rochester Gas and Electric Corporation (RG&E)
FACILITY: R. E. Ginna Nuclear Power Station
SUBJECT:
SUMMARY
OF MAY 22, 2003, MEETING BETWEEN THE NRC AND RG&E TO DISCUSS THE PROPOSED RESPONSE TO A REQUEST FOR ADDITIONAL INFORMATION REGARDING THE PRESSURIZER SURGE LINE 60-YEAR FATIGUE ANALYSIS FOR THE R. E. GINNA NUCLEAR POWER STATION The U.S. Nuclear Regulatory Commission staff and representatives of RG&E held a meeting on May 22, 2003, to discuss RG&Es recent analysis of the pressurizer surge line. The objective of the meeting was for RG&E to present the methodology and the results for the computations made to estimate the 60-year fatigue usage for the Ginna surge line and lower head of the pressurizer, considering the effects of "insurge/outsurge" and environmentally-assisted fatigue.
The applicant used the EPRI Fatigue Pro software to monitor fatigue at critical locations in the surge line and pressurizer lower head. The analysis was performed using the available template sets of real plant data to determine the incremental fatigue usage factor for given fatigue sensitive plant cycles. Cumulative usage factors (CUFs) for the life of the plant were computed using measured plant data, and projections of future plant operations. The results indicated that the expected CUF will be less than one for 60 years of plant operation. The applicant proposes to use Fatigue Pro as the tool for monitoring the plant future operation to confirm the projections.
The applicant has had an opportunity to review and comment on this summary. A meeting handout and a list of the meeting attendees are enclosed.
/RA/
Mario G. Cora, Project Manager License Renewal Section License Renewal and Environmental Impacts Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket No.: 50-244
Enclosures:
- 1. Participants in Meetings
- 2. Handout, Insurge/Outsurge Analysis of Ginna Surge Line and Pressurizer LowerHead.
cc w/enclosures: See next page
LICENSEE: Rochester Gas and Electric Corporation (RG&E)
FACILITY: R. E. Ginna Nuclear Power Station
SUBJECT:
SUMMARY
OF MAY 22, 2003, MEETING WITH RG&E TO DISCUSS THE PROPOSED RESPONSE TO A REQUEST FOR ADDITIONAL INFORMATION REGARDING THE PRESSURIZER SURGE LINE 60-YEAR FATIGUE ANALYSIS FOR THE R. E. GINNA NUCLEAR POWER STATION The U.S. Nuclear Regulatory Commission staff and representatives of RG&E held a meeting on May 22, 2003, to discuss RG&Es recent analysis of the pressurizer surge line. The objective of the meeting was for RG&E to present the methodology and the results for the computations made to estimate the 60-year fatigue usage for the Ginna surge line and lower head of the pressurizer, considering the effects of "insurge/outsurge" and environmentally-assisted fatigue.
The applicant used the EPRI Fatigue Pro software to monitor fatigue at critical locations in the surge line and pressurizer lower head. The analysis was performed using the available template sets of real plant data to determine the incremental fatigue usage factor for given fatigue sensitive plant cycles. Cumulative usage factors (CUFs) for the life of the plant were computed using measured plant data, and projections of future plant operations. The results indicated that the expected CUF will be less than one for 60 years of plant operation. The applicant proposes to use Fatigue Pro as the tool for monitoring the plant future operation to confirm the projections.
The applicant has had an opportunity to review and comment on this summary. A meeting handout and a list of the meeting attendees are enclosed.
/RA/
Mario G. Cora, Project Manager License Renewal Section License Renewal and Environmental Impacts Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket No.: 50-244
Enclosures:
- 1. Participants in Meetings
- 2. Handout, Insurge/Outsurge Analysis of Ginna Surge Line and Pressurizer LowerHead.
cc w/enclosures: See next page DISTRIBUTION:
See next page *see previous concurrence DOCUMENT NAME: G:\RLEP\Cora\meetingGinna\Summary - Ginna Meeting 05-22-03 OFFICE PM:RLEP LA:RLEP PM:RLEP SC:DE:EMEB SC:RLEP NAME MCora EHylton* RArrighi KManoly SLee DATE 05/27/03 06/03/03 06/03/03 06/03/03 06/03/03 OFFICIAL RECORD COPY
DISTRIBUTION: Meeting summary between NRC and RG&E, Dated: June 3, 2003 HARD COPY RLEP RF R. Arrighi M. Cora E-MAIL:
PUBLIC W. Borchardt D. Matthews F. Gillespie C. Grimes RidsNrrDe E. Imbro G. Bagchi K. Manoly W. Bateman J. Calvo P. Shemanski H. Nieh H. Walker S. Black B. Boger D. Thatcher R. Pettis G. Galletti C. Li J. Moore R. Weisman M. Mayfield A. Murphy W. McDowell S. Smith (srs3)
S. Duraiswamy C. Munson RLEP Staff R. Clark B. Platchek (RI)
A. Fernandez (OGC)
M. Kotzalas
RG&E/NRC FATIGUE USAGE MEETING ATTENDANCE LIST MAY 22, 2003 NAME ORGANIZATION JOHN FAIR NRR/DE/EMEB SAM LEE NRR/DRIP/RLEP KEN CHANG NRR/DRIP/RLEP RUSSELL ARRIGHI NRR/DRIP/RLEP MARIO G. CORA NRR/DRIP/RLEP GERALD GEIKEN RG&E LEE ROCHINO RG&E GEORGE WROBEL RG&E DAVID GERBER STRUC. INTEGRITY ASSOC.
Enclosure 1
RG&E/NRC FATIGUE USAGE MEETING PRESENTATION HANDOUT MAY 22, 2003 Insurge/Outsurge Analysis of Ginna Surge Line and Pressurizer Lower Head Objective Compute the 60-year projected fatigue usage for the Ginna surge line and lower head of the pressurizer, considering the effects of "insurge/outsurge" and environmentally-assisted fatigue (EAF)
Background
- The EPRI FatiguePro software program was customized for the Ginna plant to monitor fatigue critical locations in the Surge Line and Pressurizer Lower Head.
- An analysis was performed based on available template sets of real plant data to determine the incremental fatigue usage factor for given fatigue sensitive plant cycles.
- Cumulative usage factors for the life of the plant were computed based on the results of the real plant data, and using projections into the future based on the expected number of cycles.
- FatiguePro will be used to monitor future operation of the plant.
Technical Approach
- The flow rate in the surge line was computed based on a mass balance approach, using the incoming spray demand and the rate of change in the pressurizer water level, taking into account temperature effects.
- A 2-dimensional model was created to take into account 1) the advance and time delay of colder water from the hot leg into the surge line and lower head of the pressurizer, and 2) the heat transfer between the fluid and the metal.
- The technical approach has been verified to be conservative based on available thermocouple data from another plant, as well as plant-specifically for Ginna by comparing the surge line temperature instrument reading with FatiguePro's calculated water temperature in the region of the surge nozzle. Note that the temperature at the nozzle and lower head are calculated in FatiguePro completely independently from the surge line temperature instrument. The figure below shows a comparison of the calculated temperature at the nozzle, and the surge line temperature instrument.
Enclosure 2
Verification of Calculated Temperature at Surge Nozzle Region During an Insurge/Outsurge
- Finite Element models were created to compute "Green's Function" stress responses to step changes in temperature at various zones in the pressurizer. Stresses were then able to be computed based on the calculated fluid temperatures at the various zones in the pressurizer and surge line.
- The stress history was used to compute fatigue usage in FatiguePro.
Projections
- Fatigue usage requires significant temperature differentials (T's) (the difference between pressurizer water temperature and RCS hot leg temperature) to produce thermal fatigue in the surge line and lower head. This occurs during plant Heatups and Cooldowns.
Other transients such as Reactor Trip do not produce stresses above the minimum fatigue threshold.
- Ginna now uses the "Water Solid" method of Heatup and Cooldown, which maintains a relatively small T during operation (typically less than 200F), having a relatively benign effect on fatigue usage.
- Real plant data from various Heatup/Cooldown cycles since 1996 were analyzed to compute incremental fatigue usage for a Cooldown/Heatup cycle.
- The maximum fatigued location was determined to be the pressurizer heater tube to vessel weld.
- Each incremental fatigue usage (for a complete Cooldown/Heatup cycle) was relatively the same magnitude with an average incremental fatigue usage of 2.42 x 10-4.
- For 200 Heatups and Cooldowns, the cumulative fatigue usage factor (without EAF) was determined to be 0.048, based on the available plant data.
Environmental Effects
- The effects of environmentally-assisted fatigue are a function of several parameters, including material type, temperature, and dissolved oxygen content.
- These effects on individual CUF load pairs can be as high as a factor of 15.35 for stainless steel when all relevant conditions are present.
- However, it is typical for the overall effects for all load pairs for a given component location to be a factor of four or less, since environmental effects do not affect all individual load pairs (due to thresholds beyond which environmental effects are negligible).
- A factor of four is considered to be a conservative estimate of the maximum overall impact of environmental effects, based on the overall factor of 1.4 to 1.6 obtained from EPRI Report No. TR-107515, "Evaluation of Thermal Fatigue Effects on Systems Requiring Aging Management Review for License Renewal for the Calvert Cliffs Nuclear Plant," plus an additional adjustment multiplier of 2.0 to accommodate more recent laboratory data that was not available at the time of the evaluation contained in EPRI Report No. TR-107515.
- However, even applying the absolute maximum factor of 15.35 provides adequate margin with respect to projected fatigue usage.
- For 200 Heatups and Cooldowns, the cumulative fatigue usage factor including maximum possible environmental effects was determined to be 0.74 (0.048 x 15.35),
based on the available plant data.
Accounting for Early Operation
- For the time period 1975 through to about 1992 the Ginna plant sometimes operated Heatups and Cooldowns at higher maximum T's than current operation.
- Historical data was reviewed by RGE to determine the maximum T's for cycles in the past history.
- The charts below summarize the differences in operation.
- A sensitivity analysis was performed by running simulated data with higher T's (by lowering the hot leg temperature) to determine a correlation between maximum T and an increased fatigue usage factor. On the average, this resulted in an approximately 50% increase from the current operation's average incremental fatigue usage. This factor was assumed to apply to the first 59 cycles.
- In reality, only approximately 111 Heatup/Cooldown cycles are expected for the life of the plant based on the frequency of past Heatup/Cooldown occurrences. Assuming the first 59 cycles from 1975-1992 operated at the 50% increase in usage from current peration, the cumulative usage factor including maximum environmental effects is expected to be 0.52.
- Assuming the full design cycles of 200, and taking into account an assumed 50%
increase in usage in the earlier years, the expected fatigue usage with maximum environmental effects is expected to be 0.85.
- The application of FatiguePro in the future will be used to monitor the projections.
Conclusion The water solid operation of Heatup and Cooldown employed by Ginna is relatively benign with respect to fatigue usage because of low system DTs. Even considering the maximum possible environmental effect, the fatigue usage for the life of the plant in the surge line and lower head of the pressurizer is not expected to exceed 1.0.
R.E. Ginna Nuclear Power Plant cc:
Kenneth Kolaczyk, Sr. Resident Inspector Dr. Robert C. Mecredy R.E. Ginna Plant Vice President, Nuclear Operations U.S. Nuclear Regulatory Commission Rochester Gas and Electric Corporation 1503 Lake Road 89 East Avenue Ontario, NY 14519 Rochester, NY 14649 Regional Administrator, Region I Mr. Paul Eddy U.S. Nuclear Regulatory Commission New York State Department of 475 Allendale Road Public Service King of Prussia, PA 19406 3 Empire State Plaza, 10th Floor Albany, NY 12223 Mr. William M. Flynn, President New York State Energy, Research, Mr. Fred Emerson and Development Authority Nuclear Energy Institute Corporate Plaza West 1776 I Street, NW., Suite 400 286 Washington Avenue Extension Washington, DC 20006-3708 Albany, NY 12203-6399 Charles Donaldson, Esquire George Wrobel Assistant Attorney General Manager, License Renewal New York Department of Law R.E. Ginna Nuclear Power Plant 120 Broadway 1503 Lake Rd.
New York, NY 10271 Ontario, NY 14519 Daniel F. Stenger Mr. Denis Wickham Ballard Spahr Andrews & Ingersoll, LLP Sr. Vice President Transmission & Supply 601 13th Street, NW., Suite 1000 South Energy East Management Corporation Washington, DC 20005 P.O. Box 5224 Binghampton, NY 13902 Ms. Thelma Wideman, Director Wayne County Emergency Management Mr. David F. Wilson Office R.E. Ginna Nuclear Power Plant Wayne County Emergency Operations 1503 Lake Rd.
Center Ontario, NY 14519 7336 Route 31 Lyons, NY 14489 Ms. Mary Louise Meisenzahl Administrator, Monroe County Office of Emergency Preparedness 1190 Scottsville Road, Suite 200 Rochester, NY 14624