ML060670480
| ML060670480 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 03/05/2006 |
| From: | Masnik M T NRC/NRR/ADRO/DLR/REBB |
| To: | AmerGen Energy Co |
| Keto E, NRR/DLR/REBB, 415-2621 | |
| References | |
| %dam200604, TAC MC7625 | |
| Download: ML060670480 (9) | |
Text
March 5, 2006LICENSEE: AmerGen Energy Company, LLC FACILITY: Oyster Creek Nuclear Generating Station
SUBJECT:
TELECOMMUNICATION WITH AMERGEN ENERGY COMPANY, LLC, TODISCUSS REQUESTS FOR ADDITIONAL INFORMATION PERTAINING TO THE NRC STAFF'S REVIEW OF THE SEVERE ACCIDENT MITIGATIONALTERNATIVE (SAMA) ANALYSIS IN THE OYSTER CREEK LICENSE RENEWAL APPLICATION (TAC NO. MC7625)On November 9, 2005, the U.S. Nuclear Regulatory Commission (NRC) staff formally sent arequest for additional information (RAI) on Severe Accident Mitigation Alternatives (SAMA) to AmerGen Energy Company, LLC (AmerGen), regarding the environmental review of the application for the license renewal of Oyster Creek Nuclear Generating Station (OCNGS). AmerGen formally replied to the RAI in a letter dated January 9, 2006. After a review of the responses provided by AmerGen in the January 9, 2006 letter, the NRC staff and its contractorfrom Information Systems Laboratory (ISL) determined that some additional clarification was necessary for several of the responses. On January 31, 2006, the NRC staff and its contractor conducted a conference call(teleconference) with representatives from AmerGen and Erin Engineering and Research, Inc.
(ERIN) to discuss AmerGen's RAI responses, dated January 9, 2006, for the Oyster Creek Nuclear Generating Station (OCNGS) license renewal (ADAMS Accession No. ML053130387). Enclosure 1 contains a listing of the teleconference participants. Enclosure 2 contains a list ofquestions and requests for clarification on specific responses contained in the January 9, 2006, RAI response, that were discussed during the January 31, 2006, teleconference. No staff decisions were made during the teleconference. AmerGen plans to provide writtenresponses to the requests for clarification./RA/Michael T. Masnik, Senior Project Manager Environmental Branch B Division of License Renewal Office of Nuclear Reactor RegulationDocket No. 50-219
Enclosure:
As statedcc w/encls: See next page
ML053130387). Enclosure 1 contains a listing of the teleconference participants. Enclosure 2 contains a list ofquestions and requests for clarification on specific responses contained in the January 9, 2006, RAI response, that were discussed during the January 31, 2006, teleconference. No staff decisions were made during the teleconference. AmerGen plans to provide writtenresponses to the requests for clarification./RA/Michael T. Masnik, Senior Project Manager Environmental Branch B Division of License Renewal Office of Nuclear Reactor RegulationDocket No. 50-219
Enclosure:
As statedcc w/encls: See next pageDISTRIBUTION: See next page ADAMS Accession Number: ML060670480DOCUMENT NAME: E:\Filenet\ML060670480.wpd OFFICEGS:REBB:DLRLA:DLR: REBBPM:DLR: REBBSC:DLR: REBBNAMEEKetoYEdmondsMMasnikRFranovichDATE3/1/063/1/063/2/06 3/5/06 Note to: Licensee: AmerGen Energy Company, LLC, Facility: Oyster Creek Nuclear GeneratingPlant, from Michael Masnik, Dated: March 5, 2006
SUBJECT:
SUMMARY
OF CONFERENCE CALL WITH AMERGEN ENERGY COMPANY,LLC (AMERGEN) TO DISCUSS AMERGEN'S SEVERE ACCIDENT MITIGATION ALTERNATIVE (SAMA) RESPONSES DATED JANUARY 9, 2006 FOR THE OYSTER CREEK NUCLEAR GENERATING STATION (TAC NO.MC7625)DISTRIBUTION
- REBB/Environmental R/F L. Gerke P. T. Kuo/F. Gillespie, (RidsNrrDlr)
R. Franovich, (RidsNrrDlrRebb)
H. Nash R. Bellamy, RI A. Hodgdon, OGC, (RidsOgcMailCenter)R. Cureton, RI M. Modes, RI
B. Pham E. Miller, DLPM J. Lilliendahl, RIK. LaGory (ANL)
F. Monette (ANL)
D. Ashley R. Bores, RI M. Ferdas RI D. Screnci, RI N. Sheehan RI LIST OF PARTICIPANTS FOR TELEPHONE CONFERENCE CALLTO DISCUSS THE SEVERE ACCIDENT MITIGATION ALTERNATIVES (SAMAS)JANUARY 31, 2006ParticipantsAffiliationsMichael MasnikU.S. Nuclear Regulatory Commission (NRC)Tom QuintenzAmerGen Energy Company, LLC (AmerGen)
Mike GodknechtAmerGen Bill MaherAmerGen/Erin Engineering and Research, Inc. (ERIN) Ed BurnsERIN Kiang Lee ERIN Kim GreenInformation Systems Laboratory (ISL)
Bob SchmidtISL Clarifications Needed in Oyster Creek Severe Accident Mitigation Alternative (SAMA)Request for Additional Information (RAI) ResponsesRAI 1cThe response to this RAI indicates that the results of the 2004A Probabilistic Risk Assessment(PRA) model were
?re-reviewed to establish the number of gaps that remained following theupdate" and
?the self-assessment performed for the 2004A model and documentation alsoapplies to 2004B". Was the 2004A analysis subjected to a complete self-assessment or was the focus of the re-review limited to those gaps found in the 2001 PRA? Of concern is the completeness/applicability of the self-assessment of the 2001 PRA relative to the 2004A modelconsidering the extensive changes from the 2001 model to the 2004 model not the least ofwhich is the change from support state (RISKMAN) modeling to linked fault tree (CAFTA) modeling.RAI 1eIt is implied in the response to this RAI that the self-assessment discussed in the response toRAI 1c included reviewing the Level 2 PRA. The self-assessment, however, as described, started with the 2001 PRA and this PRA did not include the complete Level 2 model. Please describe in more detail the review of the current Level 2 model.RAI 2c1.The results of the Fire PRA (FPRA) Reassessment gives a core damage frequency (CDF)for the two dominant fire areas in the individual plant examination of external events (IPEEE) of 3.5E-06/yr vs the IPEEE value of 1.37E-05/yr. The evaluation of SAMA 125 gives a CDF for these two areas of 2.11E-05/yr. Please explain the very large reduction from the SAMA 125 evaluation.2.Please provide a summary description of the FPRA Reassessment including: overallmethodology, scope, reviews and status.3.The results of the FPRA indicate a significant reduction in fire risk below that utilized in theevaluations for SAMA 125. Please discuss the impact of the revised fire risk on the SAMA 125 evaluations.4.Footnote 2 to Table 2-2 discusses cable fire scenario U and indicates that review of existingmitigating measures reduces the CDF. Please clarify what these measures are.5.Fire Area OB-FZ-4, which was the dominant contributor in the IPEEE, is now the seventhranked contributor to fire CDF. Please discuss potential for SAMAs for this zone as is done for the other top ranked fire zones. RAI 4eBased on the response, the reason for the larger reduction in CDF indicated for SAMA 125Athan for SAMA 109 is that this SAMA has a much more significant impact on the fire CDF than on the internal events CDF. If the impact of the SAMA on internal events CDF is a 15.6%
reduction, the reduction in the fire CDF must be approximately 72% to give the final SAMA 125A result.SAMA 125A CDF= Internal events contribution + Fire events contribution=(1- 0.156)
- 1.05E-05 + (1 - 0.725)
- 2.11E-05 =0.886E-05 + 0.580E-05 = 1.47E-05 The latter number is equal to the SAMA frequency given on Page F-206. This result is contraryto the general argument that the fire risk is only partially influenced by internal events SAMAs. As it turns out, SAMA 109 is cost beneficial based on the assumption that the fire risk isimpacted to the same degree as the internal event risk is impacted. If it had not been true thenthe SAMA 125A result might have changed this conclusion. Are there any other SAMAs where the impact on fire risk could be more significant than on the internal events risk and thereforechange the cost benefit result? Please discuss.RAI 4fThe analysis of Net Value in Table 4F-1 makes use of averted cost calculated on two differentbases. For SAMA 109 it is based on the internal events analysis and a factor of 2 to account for external events; for SAMAs 125B and 125C it is based on the preliminary fire risk results.
Also, rather than providing the net values for implementing the SAMAs individually, the netvalue provided for SAMA 125B reflects the combined benefit of SAMAs 125A and 125B, and the net value provided for SAMA 125C reflects the combined benefit of SAMAs 125A, 125B, and 125C. The results provided do not appear to be the most appropriate estimates to use.
Please discuss.RAI 4hBased on the wind speed probabilities cited in RAI 4h, the pr obability curve would shift upwardby about one to two orders of magnitude at low and high wind speeds. This would increase both the baseline risk contribution from high winds and the risk reduction from each SAMA. Since the slope of the curve is similar to that on which the SAMA evaluation was based, it wasexpected that this shift would increase the net value of these SAMAs by one to orders of magnitude. While, as described in the RAI response, the probability curve on which the SAMAanalysis is based is higher than used in the IPEEE, it is still lower than suggested in the staff'sreview of the IPEEE (by about one decade). Further, the reanalysis described in the RAI response did not change the base line risk to be more consistent with the higher frequency of low wind speeds suggested by the staff's IPEEE comments. Use of the higher frequencies indicates an 85 MPH wind speed frequency of 1 to 2 E-02/yr, implying that there may be some probability of Combustion Turbine or Fire Pump House failure in the severe weather category ofLoss of Offsite Power events. The net values based on the "NRC Recommended RevisedEvaluation" may therefore be underestimated. Discuss the impact on the baseline risk and the risk reduction for each of these SAMAs if the curve were shifted consistent with the staffcomments on the IPEEE.RAI 5aAs commented above for RAI 4f, the response to this RAI involves combining the results of twodifferent determinations of benefit. How does this inconsistency impact the response to this RAI?
Oyster Creek Nuclear Generating Station cc:
Site Vice President - Oyster Creek Nuclear Generating Station AmerGen Energy Company, LLC
P.O. Box 388 Forked River, NJ 08731Senior Vice President of Operations AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348Kathryn M. Sutton, EsquireMorgan, Lewis, & Bockius LLP 1111 Pennsylvania Avenue, NW Washington, DC 20004Kent Tosch, ChiefNew Jersey Department of Environmental Protection Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625Vice President - Licensing and Regulatory Affairs AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555Regional Administrator, Region IU.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415Mayor of Lacey Township818 West Lacey Road Forked River, NJ 08731Senior Resident InspectorU.S. Nuclear Regulatory Commission
P.O. Box 445 Forked River, NJ 08731Director - Licensing and Regulatory AffairsAmerGen Energy Company, LLC Correspondence Control
P.O. Box 160 Kennett Square, PA 19348Manager Licensing - Oyster CreekExelon Generation Company, LLC Correspondence Control
P.O. Box 160 Kennett Square, PA 19348Regulatory Assurance Manager Oyster Creek AmerGen Energy Company, LLC
P.O. Box 388 Forked River, NJ 08731Assistant General CounselAmerGen Energy Company, LLC 200 Exelon Way Kennett Square, PA 19348Ron Bellamy, Region IU.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415Correspondence Control DeskAmerGen Energy Company, LLC 200 Exelon Way, KSA 1--1 Kennett Square, PA 19348Oyster Creek Nuclear Generating StationPlant Manager AmerGen Energy Company, LLC
P.O. Box 388 Forked River, NJ 08731License Renewal ManagerExelon Generation Company, LLC 200 Exelon Way, Suite 210 Kennett Square, PA 19348 Oyster Creek Nuclear Generating Station cc:
Mr. James RossNuclear Energy Institute 1776 I Street, NW, Suite 400 Washington, DC 20006-3708