ML092310120

Summary of Tele Conf Call with Nebraska Public Power Districts to Discuss Clarifications for the Severe Accident Mitigation Alternative Documented in the NRC Request for Additional Information Letter Dated May 1, 2009

ML092310120
Person / Time
Site:	Cooper
Issue date:	09/17/2009
From:	Bennett Brady License Renewal Projects Branch 1
To:	Nebraska Public Power District (NPPD)
Bennett Brady, DLR/NRR
References
Download: ML092310120 (9)

Text

September 17, 2009 LICENSEE: Nebraska Public Power District FACILITY: Cooper Nuclear Station

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON JULY 23, 2009, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION STAFF AND NEBRASKA PUBLIC POWER DISTRICT, RELATED TO CLARIFICATIONS ON REQUEST FOR ADDITIONAL INFORMATION, FOR COOPER NUCLEAR STATION LICENSE RENEWAL The U.S. Nuclear Regulatory Commission (NRC) staff and representatives of Nebraska Public Power District held a telephone conference call on July 23, 2009, to discuss clarifications for the severe accident mitigation alternative documented in the NRC request for additional information letter dated May 1, 2009 (Accession Number ML091240344). provides a listing of the participants and Enclosure 2 contains a brief description of the telephone conference call.

The applicant had an opportunity to comment on this summary.

/RA/

Bennett Brady, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-298

Enclosures:

As stated cc w/encls: See next page

ML092310120 OFFICE PM:RPB1:DLR LA:DLR PM:RPB2:DLR BC:RPB1:DLR PM:RPB1:DLR NAME B. Brady I. King T. Tran D. Pelton B. Brady DATE 09/02/09 08/25/09 09/03/09 09/17/09 09/17/09 Memorandum to Nebraska Public Power District from B. Brady dated September 17, 2009 DISTRIBUTION:

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON JULY 23, 2009, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION STAFF AND NEBRASKA PUBLIC POWER DISTRICT, RELATED TO CLARIFICATIONS ON REQUEST FOR ADDITIONAL INFORMATION, FOR COOPER NUCLEAR STATION LICENSE RENEWAL HARD COPY:

DLR RF E-MAIL:

PUBLIC RidsNrrDlrResource RidsNrrDlrRpb1 Resource RidsNrrDlrRpb2 Resource RidsNrrDlrRer1 Resource RidsNrrDlrRer2 Resource RidsNrrDlrRerb Resource RidsNrrDlrRpob Resource RidsNrrDciCvib Resource RidsNrrDciCpnb Resource RidsNrrDciCsgb Resource RidsNrrDraAfpb Resource RidsNrrDraApla Resource RidsNrrDeEmcb Resource RidsNrrDeEeeb Resource RidsNrrDssSrxb Resource RidsNrrDssSbpb Resource RidsNrrDssScvb Resource RidsOgcMailCenter Resource T. Tran C. Casto (RIV)

E. Sayoc B. Maier (RIV)

B. Brady V. Dricks (RIV)

F. Lyon D. Chamberlain (RIV)

D. Roth (OGC) A. Vegel (RIV)

A. Jones (OGC) W. Walker (RIV)

N. Taylor (RIV) G. Miller (RIV)

E. Collins (RIV)

G. Pick (RIV)

S. Burnell (RIV)

Cooper Nuclear Station cc:

Mr. Ronald D. Asche P.O. Box 176 President and Chief Executive Officer Jefferson City, MO 65102-0176 Nebraska Public Power District 1414 15th Street Senior Resident Inspector Columbus, NE 68601 U.S. Nuclear Regulatory Commission P.O. Box 218 Mr. Gene Mace Brownville, NE 68321 Nuclear Asset Manager Nebraska Public Power District Regional Administrator, Region IV P.O. Box 98 U.S. Nuclear Regulatory Commission Brownville, NE 68321 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 Mr. John C. McClure Vice President and General Counsel Director, Missouri State Emergency Nebraska Public Power District Management Agency P.O. Box 499 P.O. Box 116 Columbus, NE 68602-0499 Jefferson City, MO 65102-0116 Mr. David Van Der Kamp Chief, Radiation and Asbestos Licensing Manager Control Section Nebraska Public Power District Kansas Department of Health P.O. Box 98 and Environment Brownville, NE 68321 Bureau of Air and Radiation 1000 SW Jackson Mr. Michael J. Linder, Director Suite 310 Nebraska Department of Environmental Topeka, KS 66612-1366 Quality P.O. Box 98922 Ms. Melanie Rasmussen Lincoln, NE 68509-8922 Radiation Control Program Director Bureau of Radiological Health Chairman Iowa Department of Public Health Nemaha County Board of Commissioners Lucas State Office Building, 5th Floor Nemaha County Courthouse 321 East 12th Street 1824 N Street Des Moines, IA 50319 Auburn, NE 68305 Mr. Keith G. Henke, Planner Ms. Julia Schmitt, Manager Division of Community and Public Health Radiation Control Program Office of Emergency Coordination Nebraska Health & Human Services R&L 930 Wildwood P.O. Box 570 Public Health Assurance Jefferson City, MO 65102 301 Centennial Mall, South P.O. Box 95007 Lincoln, NE 68509-5007 Deputy Director for Policy Missouri Department of Natural Resources

Cooper Nuclear Station cc:

Mr. Art Zaremba, Director of Nuclear Garry Young Safety Assurance License Renewal Manager Nebraska Public Power District Entergy Nuclear P.O. Box 98 1448 S.R. 333, N-GSB-45 Brownville, NE 68321 Russellville, AK 72802 Mr. John F. McCann, Director Alan Cox Licensing, Entergy Nuclear Northeast License Renewal Technical Manager Entergy Nuclear Operations, Inc. Entergy Nuclear 440 Hamilton Avenue 1448 S.R. 333, N-GSB-45 White Plains, NY 10601-1813 Russellville, AK 72802 Stewart Minahan Dave Lach Vice President LRP Entergy Project Manager Nuclear and Chief Nuclear Officer Entergy Nuclear Cooper Nuclear Station 1448 S.R. 333, N-GSB-45 72676 - 648A Avenue Russellville, AK 72802 Brownville, NE 68321 Mike Boyce Cooper Strategic Initiatives Manager Cooper Nuclear Station 72676 - 648A Avenue Brownville, NE 68321 Dave Bremer License Renewal Project Manager Cooper Nuclear Station 72676 - 648A Avenue Brownville, NE 68321 Bill Victor License Renewal Project Licensing Lead Cooper Nuclear Station 72676 - 648A Avenue Brownville, NE 68321 Jim Loynes License Renewal Project Engineer Cooper Nuclear Station 72676 - 648A Avenue Brownville, NE 68321

TELEPHONE CONFERENCE CALL COOPER NUCLEAR STATION LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS July 23, 2009 PARTICIPANTS AFFILIATIONS Bennett Brady U.S. Nuclear Regulatory Commission (NRC)

Bob Palla NRC Jon Young Pacific Northwest National Laboratories (PNNL)

Steve Short PNNL Dave Bremer Nebraska Public Power District (NPPD)

Steve Nelson NPPD Alan Cox Entergy ENCLOSURE 1

TELEPHONE CONFERENCE CALL COOPER NUCLEAR STATION LICENSE RENEWAL APPLICATION BRIEF DESCRIPTION July 23, 2009 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Nebraska Public Power District (NPPD) held a telephone conference call on July 23, 2009, to discuss the Cooper Nuclear Station (CNS) responses to NRC requests for additional information (RAIs) on the CNS license renewal application Environmental Report severe accident mitigation alternatives (SAMA) in a letter dated July 1, 2009 (Accession Number ML091880319).

Discussion:

1. RAI 2.c It is still not clear to the staff why the three cited success events in the large early release probability risk reduction worth (LERF RRW) table (Table E.1-5) have such high RRW values (2.181). While it appears that the complement events were considered in the computation of the RRW values, it does not seem logical that reducing a success event likelihood to zero would reduce risk. If that were the case, a severe accident mitigation alternative (SAMA) eliminating containment inerting should have been considered.

Additional discussion is needed to clarify how RRW for success events is calculated. After discussion, the staff was satisfied that the applicants assumptions were correct. Below is a brief summary of the basis for closure of this question:

Clarification NPPD responded that:

The first part of this question is discussing events with RRW values of 2.181 from Table E.1-5:

• These are failure events (not success events) with high probability of failure (as already described in response to RAI 2.c).

• These 3 basic events are under "and" gates feeding a drywell shell melt through gate.

Due to their high probabilities they show up in a large number of cutsets for a LERF model.

• The original RAI 2.c response discusses how these events are utilized in the model.

The second part of this question is concerned with the method for RRW calculation:

• RRW was calculated and reported for both failure and success events from the CAFTA output for the LERF model - RRW for success events would be calculated the same way as failure events, but wouldn't mean any actual risk reduction would occur by reducing these event probabilities.

• Table E.1-5 is LERF model importance measures extracted from the CAFTA Level 2 one top model results.

• Success events were included in the table for completeness, not to imply a risk reduction by lowering their likelihoods. The handling of SAMAs for success events was addressed in response to RAI 5.a.

RAI 6.h The staff notes that the RAI response indicates that SAMA 70 reduces release frequency but does not reduce core damage frequency (CDF). The staff asked that NPPD:

a. Explain what is meant by reducing release frequency, since implementation of a SAMA would generally result in a reallocation of release frequency among the release categories rather than a reduction in release frequency. Clarify if this relates to the accident frequency that is reallocated to release category NCF.

b. Describe the process for calculating the reduction factors for SAMA 70 (i.e., 11.59%

reduction in release frequency, 40.19% reduction in population dose, and 40.66%

reduction in OECR). Explain the significance of the estimated reduction in release frequency for this SAMA since the reduction in population dose and in OECR would seem to be all that is needed to quantify the benefit for this SAMA.

c. Based on independent calculations, it appears that the estimated Internal and External Benefit for SAMA 70 ($227K) assumes an 11.59% reduction in CDF.

Explain why any reduction in CDF was assumed since the RAI response states that this SAMA does not reduce CDF. Identify any other SAMAs that are impacted by this same assumption/treatment. Confirm inputs and outputs to SAMA-70 and why it produce this apparent reduction.

d. Discuss how the reduction in CDF reported in Table E.2-2 was calculated for other SAMAs. Specifically address the estimation of benefits (reduction in CDF, population dose, and OECR) for SAMAs that affect sequences which result in core damage but no containment release (i.e., release category NCF). Confirm that all averted onsite costs (including cleanup and replacement power costs) are appropriately treated for these SAMAs.

Clarification The staff was satisfied that the correct methodology appears to have been applied and achieved results appear conservative. Concerns persist regarding the anomaly on SAMA-70 and its potential impact on the evaluation of other SAMAs. However, these concerns do not or would not necessarily result in altering the final analysis.

Additional clarifications requested It was agreed that NPPD would respond electronically to a slightly revised form of the question "2c" above for consideration in the SAMA review:

Regarding the estimated Internal and External Benefit for SAMA 70 ($227K) which assumes an 11.59% reduction in CDF.

a. Explain why any reduction in CDF was assumed since the RAI response states that this SAMA does not reduce CDF.

b. Confirm inputs and outputs to [the evaluation of] SAMA-70 and [determine] why it produce[s] this apparent reduction [in CDF].

c. Identify any other SAMAs that are impacted by this same assumption/treatment and provide an assessment of the impact on the cost-benefit evaluation results of each identified.

Following the telephone conference, NPPD determined that the applicant would need at least two weeks and up to 30 days to respond.