ML082340226

Summary of Conference Call with Amergen Energy Company, LLC, to Discuss Responses to Severe Accident Mitigation Alternatives Request for Additional Information

ML082340226
Person / Time
Site:	Crane
Issue date:	09/08/2008
From:	Sarah Lopas License Renewal Projects Branch 1
To:	AmerGen Energy Co
Lopas, S, DLR/REBA - 415-1147
References
TAC MD7702
Download: ML082340226 (8)

Text

September 8, 2008 LICENSEE:

AmerGen Energy Company, LLC FACILITY:

Three Mile Island Nuclear Station, Unit 1

SUMMARY

OF CONFERENCE CALL WITH AMERGEN ENERGY COMPANY, LLC, TO DISCUSS RESPONSES TO SEVERE ACCIDENT MITIGATION ALTERNATIVES REQUEST FOR ADDITIONAL INFORMATION FOR THREE MILE ISLAND NUCLEAR STATION, UNIT 1 (TAC NO. MD7702)

On August 12, 2008, the U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives from its contractor (Pacific Northwest National Laboratory) conducted a conference call (teleconference) with AmerGen Energy Company, LLC (AmerGen) staff and its contractor (ERIN Engineering and Research, Inc.), to obtain clarification regarding AmerGens responses to the NRCs request for additional information (RAIs) about the Three Mile Island Nuclear Station, Unit 1 (TMI-1) severe accident mitigation alternatives (SAMA) analysis. The NRC SAMA RAI letter was dated May 21, 2008 (ML081330714), and AmerGens response was dated July 17, 2008 (ML082040144).

NRC staff and its contractor representatives discussed their follow-up questions concerning the SAMA RAI responses with AmerGen staff and its contractor representatives. Clarification of specific line items was obtained. Enclosure A contains a list of teleconference participants.

Enclosure B contains the NRCs follow-up questions and summarizes the responses provided by AmerGen during the teleconference. No staff decisions were made during the teleconference.

\\RA\\

Sarah Lopas, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-289

Enclosure:

As stated cc: See next page

ML082340226 OFFICE LA:DLR PM:DLR:RPB1 PM:DLR:RPB1 BC:DLR:RPB1 NAME SFigueroa SLopas JRobinson DPelton DATE 8/27/08 9/2/08 9/8/08 9/8/08

Letter to AmerGen Energy Company, LLC from Sarah Lopas dated September 8, 2008

SUMMARY

OF CONFERENCE CALL WITH AMERGEN ENERGY COMPANY, LLC, TO DISCUSS RESPONSES TO SEVERE ACCIDENT MITIGATION ALTERNATIVES REQUESTS FOR ADDITIONAL INFORMATION FOR THREE MILE ISLAND NUCLEAR STATION, UNIT 1 (TAC NO. MD7702)

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PUBLIC RidsNrrDlr RidsNrrDlrRpb1 RidsNrrDlrRpb2 RdsNrrDlrRer1 RidsNrrDlrRer2 RidsOgcMailCenter JRobinson SLopas RPalla MModes, RI DKern JBrand RConte RBellamy PBamford MMcLaughlin

ENCLOSURE A LIST OF PARTICIPANTS FOR CONFERENCE CALL WITH AMERGEN ENERGY COMPANY, LLC, TO DISCUSS RESPONSES TO SEVERE ACCIDENT MITIGATION ALTERNATIVES REQUEST FOR ADDITIONAL INFORMATION FOR THREE MILE ISLAND NUCLEAR STATION, UNIT 1 August 12, 2008 PARTICIPANTS AFFILIATION Sarah Lopas U.S. Nuclear Regulatory Commission (NRC)

Steve Short Pacific Northwest National Laboratory (PNNL)

Bruce Schmitt Christopher Wilson PNNL Exelon Corporation (Exelon)

Nancy Ranek Exelon Greg Krueger Exelon David Honan Exelon Ed Fuhrer AmerGen Energy Company, LLC Don MacLeod ERIN Engineering and Research, Inc. (ERIN)

Leo Shanley ERIN

ENCLOSURE B 1

NRC FOLLOW-UP QUESTIONS AND

SUMMARY

OF AMERGEN RESPONSES August 12, 2008

1. NRC Request for Additional Information (RAI) 6f, 6h, and 7: The environmental report (ER) identifies SAMAs 2, 7, 8, 11, 12, 15, 16, 19, 21, 23, 24, 26, 27, 32, and 33 as potentially cost-beneficial and that these 15 SAMAs will be considered for implementation through the established TMI-1 work management processes. The response to RAI 7 clarified that many of these SAMAs address the same risk contributors and identified a "minimal SAMA" set composed of SAMAs 2, 12, 15, 16, 26, 27, and 32. However, the ER analyses assumed that the existing borated water storage tank (BWST) manual refill makeup capability was adequate.

A sensitivity case in the ER showed that SAMA 10 would also be cost-beneficial if BWST manual refill capability was inadequate. The response to RAI 6f further identified that the cost-benefit results for SAMAs 2, 11, 13, 16, 22, and 24 could be impacted if the analysis had assumed that BWST manual refill capability was inadequate. The RAI 6f response further identified SAMA 13 as being cost-beneficial if BWST manual refill capability was inadequate (SAMAs 2, 11, 16, and 24 were already cost-beneficial and so they were not re-analyzed with this assumption, while SAMA 22 was shown to still not be cost-beneficial for either the baseline or uncertainty analyses). Finally, the response to RAI 6h clarifies that the BWST refill capability issue has been entered in the TMI-1 Corrective Action Program and that SAMA 10, and an unevaluated option to enhance the existing manual makeup capability, will be considered when addressing this issue.

The NRC requests further clarification on AmerGen's plans for further evaluation or implementation of the original 15 cost-beneficial SAMAs and SAMAs 10 and 13, in light of the impact that the BWST refill capability assumption can have on the cost-benefit results.

AmerGen Response: SAMAs 10 and 13 will be evaluated for implementation along with the original 15 SAMAs.

2. NRC RAI 2a regarded MAAP source term calculations used to support the TMI-1 SAMA analysis. Please identify the version of the modular accident analysis program (MAAP) code used in the SAMA evaluation.

AmerGen Response: PWR MAAP 4.0.5

3. The NRC would like SECPOP corrected values for each of the elements that contribute to the Maximum Averted Cost-Risk for both internal events and external flooding events (see page E-42 of the TMI-1 ER). The contributing elements include: off-site exposure cost-risk (APE); off-site economic cost-risk (AOC); on-site exposure cost-risk (AOE); on-site cleanup cost-risk (ACC); and replacement power cost-risk (RPC).

AmerGen Response:

Maximum Averted Internal Events Cost-Risk APE: $972,461 AOC: $1,939,164

ENCLOSURE B 2

AOE: $14,670 ACC: $461,912 RPC: $125,917 Maximum External Flooding Cost-Risk APE: $5,289,732 AOC: $9,321,762 AOE: $50,177 ACC: $1,579,915 RPC: $430,685

4. Please clarify the response to RAI 3d, which asked for clarification regarding flood gate installation and the time available for operator response to a fast developing flood. Specifically, the NRC would like to know why only six flood gates are discussed in the AmerGen response.

What is their relevance with respect to the other flood gates?

AmerGen Response: The response to RAI 3d focused on the E flood gates rather than the other critical flood gates in Table 1 of Section 5.2 of the Integrated Plant Examination - External Events (IPEEE) for the following reasons. Most flood gate installation at TMI is performed incrementally based on river flow forecast. For example, certain gates are directed to be installed beginning with a 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> forecast of 640,000 cubic feet per second (cfs) and others with a 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> forecast of 900,000 cfs. However, in the case of the six E (Intake Screen Pumphouse) flood gates and the single B-2 (Control Building Doorway to BWST Tunnel) flood gate, installation is directed based on the river level rather than the river flow forecast.

Specifically, installation of the E and B-2 gates is directed when the river reaches 302 mean sea level (msl). Because installation of the E and B-2 gates is not directed until water level is nearing the point where water incursion is possible, rapid river level increases are more challenging to successful installation for these gates. Even so, note that while gate B-2 must be in place before the water level reaches 305 msl, compared with 308 msl for the E flood gates, it is a single 3.5x5.3 gate that is stored locally. Hence, installation of the single B-2 gate does not present the same challenge as installing the six E flood gates, which is why only the six E flood gates, and not also the B-2 gate, were the focus of the response to RAI 3d.

Three Mile Island Nuclear Station, Unit 1 cc:

Site Vice President - Three Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC P.O. Box 480 Middletown, PA 17057 Senior Vice President - Operations, Mid-Atlantic AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Vice President - Licensing and Regulatory Affairs AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Regional Administrator Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Chairman Board of County Commissioners of Dauphin County Dauphin County Courthouse Harrisburg, PA 17120 Chairman Board of Supervisors of Londonderry Township R.D. #1, Geyers Church Road Middletown, PA 17057 Senior Resident Inspector (TMI-1)

U.S. Nuclear Regulatory Commission P.O. Box 219 Middletown, PA 17057 Eric Epstein TMI Alert 4100 Hillsdale Road Harrisburg, PA 17112 Director - Licensing and Regulatory Affairs AmerGen Energy Company, LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Director Bureau of Radiation Protection Pennsylvania Department of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 Plant Manager - Three Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC P. O. Box 480 Middletown, PA 17057 Regulatory Assurance Manager - Three Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC P.O. Box 480 Middletown, PA 17057 Ronald Bellamy, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Ronnie Gardner, PMP Manager, Site Operations and Corporate Regulatory Affairs AREVA NP Inc.

3315 Old Forest Road OF-16 Lynchburg, VA 24501 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803

Three Mile Island Nuclear Station, Unit 1 cc:

Correspondence Control Desk AmerGen Energy Company, LLC 200 Exelon Way, KSA 1-N-1 Kennett Square, PA 19348 Manager Licensing - Three Mile Island Nuclear Station, Unit 1 Exelon Generation Company, LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Christopher M. Crane President and Chief Executive Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Mr. Charles G. Pardee Chief Nuclear Officer AmerGen Energy Company, LLC 200 Exelon Way Kennett Square, PA 19348 Associate General Counsel AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Chief Operating Officer (COO)

AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President - Operations Support AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Frederick W. Polaski Manager License Renewal Exelon Nuclear 200 Exelon Way Kennett Square, PA 19348 Albert A. Fulvio, Senior Project Manager License Renewal Exelon Nuclear 200 Exelon Way Kennett Square, PA 19348 Rich Janati, Chief Division of Nuclear Safety Bureau of Radiation Protection Pennsylvania Department of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 Michael Murphy Bureau of Radiation Protection Pennsylvania Department of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 Michael G. Brownell, Chief Water Resources Management Susquehanna River Basin Commission 1721 N. Front Street Harrisburg, PA 17102 Rachel Diamond, Regional Director Southcentral Regional Office Pennsylvania Department of Environmental Protection 909 Elmerton Avenue Harrisburg, PA 17110 Nancy Ranek Environmental Lead, License Renewal Exelon Nuclear 200 Exelon Way, KSA/2-E Kennett Square, PA 19348

Christopher Wilson KSQ License Renewal Exelon Nuclear 200 Exelon Way, KSA/2-E Kennett Square, PA 19348 Mr. Michael P. Gallagher Vice President License Renewal Projects AmerGen Energy Company, LLC 200 Exelon Way Kennett Square, PA 19348