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{{#Wiki_filter:May 2, 2007LICENSEE:Exelon Generation Company, LLC FACILITY:LaSalle County Station, Units 1 and 2
{{#Wiki_filter:May 2, 2007 LICENSEE:     Exelon Generation Company, LLC FACILITY:     LaSalle County Station, Units 1 and 2


==SUBJECT:==
==SUBJECT:==


==SUMMARY==
==SUMMARY==
OF APRIL 5, 2007, MEETING WITH EXELON GENERATIONCOMPANY, LLC (TAC NOS. MD7434 AND MD7435)On April 5, 2007, a Category 1 public meeting was held between the U.S. Nuclear RegulatoryCommission (NRC) and representatives of Exelon Generating Company, LLC (Exelon) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss regulatory resolution pathways for a proposed submittal, for the ultimate heat sink (UHS) for LaSalle County Station (LaSalle), Units 1 and 2. A list of attendees is provided as Enclosure 1. BACKGROUNDOn March 13, 2006, Exelon submitted a license amendment request (LAR) to the NRC tochange the technical specification (TS) limit of the UHS from 100 F to 101.5 F byreducing the temperature measurement uncertainty by replacing the existing thermocouples with higher precision temperature measurement equipment. On June 15, 2006, the NRC staff forwarded a request for additional information (RAI) to Exelon. Exelon responded to the RAI on July 13, 2006. After a number of telephone conferences, Exelon submitted a supplemental response to the NRC on August 4, 2006. The NRC staff reviewed the material supplied by Exelon with respect to the UHS submittal, and on November 13, 2006, the NRC staff determined that the degree of measurement accuracy that would be required to support the LAR was not adequately demonstrated and denied the LAR. In a letter to the NRC dated January 24, 2007, Exelon stated that the NRC was challenging the current design and licensing basis and that the technical basis for the denial represented a change in NRC's position on theappropriate measurement uncertainty methodology applied to non-safety related, indication only instrumentation.
OF APRIL 5, 2007, MEETING WITH EXELON GENERATION COMPANY, LLC (TAC NOS. MD7434 AND MD7435)
On April 5, 2007, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Exelon Generating Company, LLC (Exelon) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss regulatory resolution pathways for a proposed submittal, for the ultimate heat sink (UHS) for LaSalle County Station (LaSalle), Units 1 and 2. A list of attendees is provided as Enclosure 1.
BACKGROUND On March 13, 2006, Exelon submitted a license amendment request (LAR) to the NRC to change the technical specification (TS) limit of the UHS from # 100 EF to # 101.5 EF by reducing the temperature measurement uncertainty by replacing the existing thermocouples with higher precision temperature measurement equipment. On June 15, 2006, the NRC staff forwarded a request for additional information (RAI) to Exelon. Exelon responded to the RAI on July 13, 2006. After a number of telephone conferences, Exelon submitted a supplemental response to the NRC on August 4, 2006. The NRC staff reviewed the material supplied by Exelon with respect to the UHS submittal, and on November 13, 2006, the NRC staff determined that the degree of measurement accuracy that would be required to support the LAR was not adequately demonstrated and denied the LAR. In a letter to the NRC dated January 24, 2007, Exelon stated that the NRC was challenging the current design and licensing basis and that the technical basis for the denial represented a change in NRCs position on the appropriate measurement uncertainty methodology applied to non-safety related, indication only instrumentation.
On January 26, 2007, a public meeting was held between the NRC and representatives of Exelon to discuss the denial of the UHS submittal and Exelons plan for re-submittal of the proposed LAR. At that meeting a number of actions items were identified for both the NRC staff and Exelon to address before the April 5, 2007, meeting.
APRIL 5, 2007, MEETING


On January 26, 2007, a public meeting was held between the NRC and representatives of Exelon to discuss the denial of the UHS submittal and Exelon's plan for re-submittal of theproposed LAR. At that meeting a number of actions items were identified for both the NRC staff and Exelon to address before the April 5, 2007, meeting. APRIL 5, 2007, MEETING
==SUMMARY==
 
The action items discussed during the January 26, 2007, meeting and their disposition are discussed below. The NRC action items from the January 26, 2007, meeting are discussed in the body of the Exelon action items and are not covered separately.


==SUMMARY==
Exelons action items:
The action items discussed during the January 26, 2007, meeting and their disposition arediscussed below. The NRC action items from the January 26, 2007, meeting are discussed in the body of the Exelon action items and are not covered separately. Exelon's action items:*Assess the acceptability of inserting a table in the LaSalle TS to address the loss ofthree out of four temperature detectors.Exelon determined this approach was not desirable and inconsistent with the integratedTSs and that this issue would be handled in the Bases section and maintained through their bases control program. The NRC staff agreed this was an acceptable approach.
* Assess the acceptability of inserting a table in the LaSalle TS to address the loss of three out of four temperature detectors.
Exelon determined this approach was not desirable and inconsistent with the integrated TSs and that this issue would be handled in the Bases section and maintained through their bases control program. The NRC staff agreed this was an acceptable approach.
* Correct the discrepancy in the updated final safety analysis report (UFSAR) that describes the post accident temperature limit of 102 EF versus the stated LAR value of 104 EF.
Exelon stated this would be accomplished in the next UFSAR update.
* Verify the level of accuracy of the original thermocouple measurement uncertainty and the basis for it.
Exelon stated that when the plant was initially licensed, the licensing basis for LaSalle, with respect to UHS, was a nominal plant value, and as such no measurement uncertainty calculations were performed in the initial treatment of non-safety instruments such as the UHS thermocouples. This was the basis for Exelons statement in their January 24, 2007, letter responding to the NRC denial of the UHS LAR that the NRC challenged the current design and licensing basis of the LaSalle circulating water system. NRC Deputy Director, Ken OBrien informed Exelon that the only aspect of the design basis being reviewed was the design limit of 102 EF for the UHS and not any associated uncertainty calculations. After the discussion, Exelon stated they no longer considered that the NRC challenged the LaSalle licensing or design basis.
* Determine if the NRC had approved a graded approach to setpoint methodology for other licensees.
NRC has not approved the graded approach for setpoint methodology at LaSalle. In addition, the NRC staff has not approved a license amendment for other licensees, using the graded approach. This was also an issue in the Exelon letter of January 24, 2007. Exelons position that the technical basis for the denial, as described in the NRC staffs safety evaluation (SE), represented a change in the NRC position on the appropriate measurement uncertainty methodology being applied to non-safety related, indication only instrumentation. The NRC staff informed Exelon that the graded approach was not approved nor accepted, and that if Exelon wished to use this approach, they would have to supply all supporting documentation for the NRC staffs review which would support their calculations and their approach to measurement uncertainty.
* Describe the industry standard for a graded approach to setpoint methodology Exelon presented the graded approach to setpoint methodology used by the industry.
The NRC staff acknowledged that the industry may use the graded approach for some systems, however, for setpoint methodology, the NRC evaluates the information based on a two sigma (2) uncertainty analysis. The NRC staff discussed the Agencys


*Correct the discrepancy in the updated final safety analysis report (UFSAR) thatdescribes the post accident temperature limit of 102 F versus the stated LAR value of 104 F. Exelon stated this would be accomplished in the next UFSAR update.*Verify the level of accuracy of the original thermocouple measurement uncertainty andthe basis for it. Exelon stated that when the plant was initially licensed, the licensing basis for LaSalle,with respect to UHS, was a nominal plant value, and as such no measurement uncertainty calculations were performed in the initial treatment of non-safety instruments such as the UHS thermocouples. This was the basis for Exelon's statement in their January 24, 2007, letter responding to the NRC denial of the UHS LAR that the NRC challenged the current design and licensing basis of the LaSalle circulating water system. NRC Deputy Director, Ken O'Brien informed Exelon that the only aspect of the design basis being reviewed was the design limit of 102 F for the UHS and not anyassociated uncertainty calculations. After the discussion, Exelon stated they no longer considered that the NRC challenged the LaSalle licensing or design basis.*Determine if the NRC had approved a graded approach to setpoint methodology forother licensees.NRC has not approved the graded approach for setpoint methodology at LaSalle. Inaddition, the NRC staff has not approved a license amendment for other licensees, using the graded approach. This was also an issue in the Exelon letter of January 24, 2007. Exelon's position that the technical basis for the denial, as described in the NRC staff's safety evaluation (SE), represented a change in the NRC position on the appropriate measurement uncertainty methodology being applied to non-safety related, indication only instrumentation. The NRC staff informed Exelon that the graded approach was not approved nor accepted, and that if Exelon wished to use this approach, they would have to supply all supporting documentation for the NRC staff's review which would support their calculations and their approach to measurement uncertainty.*Describe the industry standard for a graded approach to setpoint methodologyExelon presented the graded approach to setpoint methodology used by the industry. The NRC staff acknowledged that the industry may use the graded approach for some systems, however, for setpoint methodology, the NRC evaluates the information based on a two sigma (2) uncertainty analysis. The NRC staff discussed the Agency's  position on the graded approach to setpoint methodology as well as the position inRegulatory Guide 1.105, "Setpoints for Safety Related Instrumentation."*The NRC staff discussed the value of completing the UHS uncertainty calculations usingthe 95/95 tolerance limit (2) as an acceptable method for uncertainties. This methodensures that there is a 95 percent probability that the constructed limits contain 95 percent of the population of interest for the surveillance interval selected. Exelon proposed that since the area of concern only relates to high temperature (notexceeding the design limit of 102 F), they plan to use single sided uncertainty in theirevaluation using the 95/95 tolerance limit which results in the uncertainty of about 0.49F. This should be within the calculated range for uncertainty for it to be below the 102 F design limit. The NRC staff pointed out that a licensee, with justification, maypropose an alternative calculation other than the 95/95 tolerance limit, based on its particular setpoint methodology or license.*A review of NRC's uncertainty calculation was discussed. The NRC's alternativecalculation identified a possible discrepancy between the calibration data and some assumptions in the Exelon calculation. The alternative calculation also addressed possible discrepancies between the assumed and derived resistance-temperature detector characteristics, but because the discrepancies may be related to differing definitions or other conditions, the alternative calculation did not address them directly.
position on the graded approach to setpoint methodology as well as the position in Regulatory Guide 1.105, Setpoints for Safety Related Instrumentation.
Exelon indicated they would review the alternative calculations in detail, and plans to resubmit the amendment request by the end of May 2007.Exelon presented information (See Enclosure 2 or the Agencywide Documents Access andManagement System Accession No. ML071090218). Exelon's presentation provided a time line for the UHS as well as a listing of action items resulting from the previous public meeting on January 26, 2007. Members of the public were not in attendance. Public Meeting Feedback forms were notreceived. Please direct any inquiries to me at 301-415-3154, or sps1@nrc.gov
* The NRC staff discussed the value of completing the UHS uncertainty calculations using the 95/95 tolerance limit (2) as an acceptable method for uncertainties. This method ensures that there is a 95 percent probability that the constructed limits contain 95 percent of the population of interest for the surveillance interval selected.
.  /RA by RKuntz for/Stephen P. Sands, Project ManagerPlant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-373 and 50-374
Exelon proposed that since the area of concern only relates to high temperature (not exceeding the design limit of 102 EF), they plan to use single sided uncertainty in their evaluation using the 95/95 tolerance limit which results in the uncertainty of about 0.49EF. This should be within the calculated range for uncertainty for it to be below the 102 EF design limit. The NRC staff pointed out that a licensee, with justification, may propose an alternative calculation other than the 95/95 tolerance limit, based on its particular setpoint methodology or license.
* A review of NRCs uncertainty calculation was discussed. The NRCs alternative calculation identified a possible discrepancy between the calibration data and some assumptions in the Exelon calculation. The alternative calculation also addressed possible discrepancies between the assumed and derived resistance-temperature detector characteristics, but because the discrepancies may be related to differing definitions or other conditions, the alternative calculation did not address them directly.
Exelon indicated they would review the alternative calculations in detail, and plans to resubmit the amendment request by the end of May 2007.
Exelon presented information (See Enclosure 2 or the Agencywide Documents Access and Management System Accession No. ML071090218). Exelons presentation provided a time line for the UHS as well as a listing of action items resulting from the previous public meeting on January 26, 2007.
Members of the public were not in attendance. Public Meeting Feedback forms were not received.
Please direct any inquiries to me at 301-415-3154, or sps1@nrc.gov.
                                        /RA by RKuntz for/
Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374


==Enclosures:==
==Enclosures:==
: 1. List of Attendees2. Licensee Handoutcc w/encls: See next page   position on the graded approach to setpoint methodology as well as the position inRegulatory Guide 1.105, "Setpoints for Safety Related Instrumentation."*The NRC staff discussed the value of completing the UHS uncertainty calculations usingthe 95/95 tolerance limit (2) as an acceptable method for uncertainties. This methodensures that there is a 95 percent probability that the constructed limits contain 95 percent of the population of interest for the surveillance interval selected. Exelon proposed that since the area of concern only relates to high temperature (notexceeding the design limit of 102 F), they plan to use single sided uncertainty in theirevaluation using the 95/95 tolerance limit which results in the uncertainty of about 0.49F. This should be within the calculated range for uncertainty for it to be below the 102 F design limit. The NRC staff pointed out that a licensee, with justification, maypropose an alternative calculation other than the 95/95 tolerance limit, based on its particular setpoint methodology or license.*A review of NRC's uncertainty calculation was discussed. The NRC's alternativecalculation identified a possible discrepancy between the calibration data and some assumptions in the Exelon calculation. The alternative calculation also addressed possible discrepancies between the assumed and derived resistance-temperature detector characteristics, but because the discrepancies may be related to differing definitions or other conditions, the alternative calculation did not address them directly.
: 1. List of Attendees
Exelon indicated they would review the alternative calculations in detail, and plans to resubmit the amendment request by the end of May.Exelon presented information (See Enclosure 2 or the Agencywide Documents Access andManagement System Accession No. ML071090218). Exelon's presentation provided a time line for the UHS as well as a listing of action items resulting from the previous public meeting on January 26, 2007. Members of the public were not in attendance. Public Meeting Feedback forms were notreceived. Please direct any inquiries to me at 301-415-3154, or sps1@nrc.gov
: 2. Licensee Handout cc w/encls: See next page
.  /RA by RKuntz for/Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-373 and 50-374
 
position on the graded approach to setpoint methodology as well as the position in Regulatory Guide 1.105, Setpoints for Safety Related Instrumentation.
* The NRC staff discussed the value of completing the UHS uncertainty calculations using the 95/95 tolerance limit (2) as an acceptable method for uncertainties. This method ensures that there is a 95 percent probability that the constructed limits contain 95 percent of the population of interest for the surveillance interval selected.
Exelon proposed that since the area of concern only relates to high temperature (not exceeding the design limit of 102 EF), they plan to use single sided uncertainty in their evaluation using the 95/95 tolerance limit which results in the uncertainty of about 0.49EF. This should be within the calculated range for uncertainty for it to be below the 102 EF design limit. The NRC staff pointed out that a licensee, with justification, may propose an alternative calculation other than the 95/95 tolerance limit, based on its particular setpoint methodology or license.
* A review of NRCs uncertainty calculation was discussed. The NRCs alternative calculation identified a possible discrepancy between the calibration data and some assumptions in the Exelon calculation. The alternative calculation also addressed possible discrepancies between the assumed and derived resistance-temperature detector characteristics, but because the discrepancies may be related to differing definitions or other conditions, the alternative calculation did not address them directly.
Exelon indicated they would review the alternative calculations in detail, and plans to resubmit the amendment request by the end of May.
Exelon presented information (See Enclosure 2 or the Agencywide Documents Access and Management System Accession No. ML071090218). Exelons presentation provided a time line for the UHS as well as a listing of action items resulting from the previous public meeting on January 26, 2007.
Members of the public were not in attendance. Public Meeting Feedback forms were not received.
Please direct any inquiries to me at 301-415-3154, or sps1@nrc.gov.
                                        /RA by RKuntz for/
Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374


==Enclosures:==
==Enclosures:==
: 1. List of Attendees2. Licensee Handout cc w/encls: See next page Distribution
: 1. List of Attendees 2. Licensee Handout cc w/encls: See next page Distribution:
:PUBLICTLiu, NRRTBloomer, EDODRahn, RES LPL3-2 R/FRidsNrrDorlRidsRgn3MailCenterRidsNrrDe RidsNrrDorlLpl3-2PRebstock, RESRidsNrrLAEWhittRidsOgcRp RidsNrrPMSSandsRidsNrrDeEicb RidsAcrsAcnwMailCenter Package Accession No. ML071090184Meeting Summary Accession No. ML071090180License Handouts Accession No. ML071090218OFFICELPL3-2/PMLPL3-2/LADE/EICB/BCLPL3-2/BCNAMESSandsEWhittAHoweRGibbsDATE 05/02/07 05/02/07 04/ 25 /07 05/02/07 OFFICIAL RECORD COPY LaSalle County Station, Units 1 and 2 cc:
PUBLIC                          TLiu, NRR            TBloomer, EDO                  DRahn, RES LPL3-2 R/F                      RidsNrrDorl          RidsRgn3MailCenter            RidsNrrDe RidsNrrDorlLpl3-2                PRebstock, RES        RidsNrrLAEWhitt                RidsOgcRp RidsNrrPMSSands                  RidsNrrDeEicb        RidsAcrsAcnwMailCenter Package Accession No. ML071090184              Meeting Summary Accession No. ML071090180 License Handouts Accession No. ML071090218 OFFICE    LPL3-2/PM        LPL3-2/LA      DE/EICB/BC      LPL3-2/BC NAME      SSands          EWhitt        AHowe          RGibbs DATE      05/02/07         05/02/07     04/ 25 /07       05/02/07 OFFICIAL RECORD COPY
Site Vice President - LaSalle County StationExelon Generation Company, LLC 2601 North 21st Road Marseilles, IL 61341-9757Plant Manager - LaSalle County StationExelon Generation Company, LLC 2601 North 21st Road Marseilles, IL 61341-9757Manager Regulatory Assurance - LaSalleExelon Generation Company, LLC 2601 North 21st Road Marseilles, IL 61341-9757U.S. Nuclear Regulatory CommissionLaSalle Resident Inspectors Office 2605 North 21st Road Marseilles, IL 61341-9756Phillip P. Steptoe, EsquireSidley and Austin One First National Plaza Chicago, IL 60603Assistant Attorney General100 W. Randolph St. Suite 12 Chicago, IL  60601ChairmanLaSalle County Board 707 Etna Road Ottawa, IL  61350Attorney General500 S. Second Street Springfield, IL  62701ChairmanIllinois Commerce Commission 527 E. Capitol Avenue, Leland Building Springfield, IL  62706Robert Cushing, Chief, Public Utilities DivisionIllinois Attorney General's Office 100 W. Randolph Street Chicago, IL  60601Regional Administrator, Region IIIU.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4352Illinois Emergency Management  Agency Division of Disaster Assistance &
 
Preparedness 110 East Adams Street Springfield, IL 62701-1109Document Control Desk - LicensingExelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555Senior Vice President - Operations SupportExelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555Director - Licensing and Regulatory AffairsExelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555Vice President - Regulatory AffairsExelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555Associate General CounselExelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 LaSalle County Station, Units 1 and 2 cc:Manager Licensing - Braidwood, Byron, and LaSalle Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555Senior Vice President - Midwest OperationsExelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555Mr. Christopher M. Crane, President   and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL   60555 ATTENDANCE LISTMEETING WITH EXELON GENERATING COMPANYPRE-APPLICATION MEETING TO DISCUSS THE ULTIMATEHEAT SINK (UHS) AMENDMENT REQUESTNAMEORGANIZATIONPHONE NUMBER Stephen P. SandsNRC/NRR/DORL/LPLIII-2301-415-3154Kenneth G. O'BrienNRC/NRR/APES/DE301-415-3300 Russell GibbsNRC/
LaSalle County Station, Units 1 and 2 cc:
NRR/DORL/LPL III-2301-415-2988Paul RebstockNRC/RES301-415-3295 Allen HoweNRC/NRR/EICB301-415-1351 John LubinskiNRC/NRR/DORL301-415-1453 Hukam GargNRC/NRR/DE301-415-2929 David RahnNRC/RES/ERA/IEEB301-415-5216 Wes BowersExelon610-765-5456 Vikram ShahExelon/LaSalle/I&C Design 815-415-3828 Terrence SimpkinExelon/LaSalle815-415-2800 Darin M. BenyakExelon/Corp. Licensing630-657-2811 Alison MackellarExelon/Corp. Licensing630-657-2817 Jerry VossExelon Services Corp.301-984-4400}}
Site Vice President - LaSalle County Station Robert Cushing, Chief, Public Utilities Division Exelon Generation Company, LLC               Illinois Attorney General's Office 2601 North 21st Road                         100 W. Randolph Street Marseilles, IL 61341-9757                    Chicago, IL 60601 Plant Manager - LaSalle County Station      Regional Administrator, Region III Exelon Generation Company, LLC               U.S. Nuclear Regulatory Commission 2601 North 21st Road                         Suite 210 Marseilles, IL 61341-9757                    2443 Warrenville Road Lisle, IL 60532-4352 Manager Regulatory Assurance - LaSalle Exelon Generation Company, LLC               Illinois Emergency Management 2601 North 21st Road                           Agency Marseilles, IL 61341-9757                    Division of Disaster Assistance &
Preparedness U.S. Nuclear Regulatory Commission          110 East Adams Street LaSalle Resident Inspectors Office           Springfield, IL 62701-1109 2605 North 21st Road Marseilles, IL 61341-9756                    Document Control Desk - Licensing Exelon Generation Company, LLC Phillip P. Steptoe, Esquire                  4300 Winfield Road Sidley and Austin                           Warrenville, IL 60555 One First National Plaza Chicago, IL 60603                            Senior Vice President - Operations Support Exelon Generation Company, LLC Assistant Attorney General                   4300 Winfield Road 100 W. Randolph St. Suite 12                Warrenville, IL 60555 Chicago, IL 60601 Director - Licensing and Regulatory Affairs Chairman                                    Exelon Generation Company, LLC LaSalle County Board                        4300 Winfield Road 707 Etna Road                                Warrenville, IL 60555 Ottawa, IL 61350 Vice President - Regulatory Affairs Attorney General                            Exelon Generation Company, LLC 500 S. Second Street                        4300 Winfield Road Springfield, IL 62701                        Warrenville, IL 60555 Chairman                                    Associate General Counsel Illinois Commerce Commission                Exelon Generation Company, LLC 527 E. Capitol Avenue, Leland Building      4300 Winfield Road Springfield, IL 62706                        Warrenville, IL 60555
 
LaSalle County Station, Units 1 and 2 cc:
Manager Licensing - Braidwood, Byron, and LaSalle Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President - Midwest Operations Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Mr. Christopher M. Crane, President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
 
ATTENDANCE LIST MEETING WITH EXELON GENERATING COMPANY PRE-APPLICATION MEETING TO DISCUSS THE ULTIMATE HEAT SINK (UHS) AMENDMENT REQUEST NAME                    ORGANIZATION      PHONE NUMBER Stephen P. Sands            NRC/NRR/DORL/LPLIII-2    301-415-3154 Kenneth G. OBrien          NRC/NRR/APES/DE          301-415-3300 Russell Gibbs                NRC/NRR/DORL/LPL III-2    301-415-2988 Paul Rebstock                NRC/RES                  301-415-3295 Allen Howe                  NRC/NRR/EICB              301-415-1351 John Lubinski                NRC/NRR/DORL              301-415-1453 Hukam Garg                  NRC/NRR/DE                301-415-2929 David Rahn                  NRC/RES/ERA/IEEB          301-415-5216 Wes Bowers                  Exelon                    610-765-5456 Vikram Shah                  Exelon/LaSalle/I&C Design 815-415-3828 Terrence Simpkin            Exelon/LaSalle            815-415-2800 Darin M. Benyak              Exelon/Corp. Licensing    630-657-2811 Alison Mackellar            Exelon/Corp. Licensing    630-657-2817 Jerry Voss                  Exelon Services Corp. 301-984-4400 Enclosure 1}}

Revision as of 08:15, 23 November 2019

04/05/2007, Meeting Summary with Exelon Generation Company, LLC to Discuss Regulatory Resolution Pathways for a Proposed Submittal, for the Ultimate Heat Sink for LaSalle, Units 1 and 2
ML071090180
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Site: LaSalle  Constellation icon.png
Issue date: 05/02/2007
From: Sands S
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To:
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ML071090184 List:
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Download: ML071090180 (7)
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Text

May 2, 2007 LICENSEE: Exelon Generation Company, LLC FACILITY: LaSalle County Station, Units 1 and 2

SUBJECT:

SUMMARY

OF APRIL 5, 2007, MEETING WITH EXELON GENERATION COMPANY, LLC (TAC NOS. MD7434 AND MD7435)

On April 5, 2007, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Exelon Generating Company, LLC (Exelon) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss regulatory resolution pathways for a proposed submittal, for the ultimate heat sink (UHS) for LaSalle County Station (LaSalle), Units 1 and 2. A list of attendees is provided as Enclosure 1.

BACKGROUND On March 13, 2006, Exelon submitted a license amendment request (LAR) to the NRC to change the technical specification (TS) limit of the UHS from # 100 EF to # 101.5 EF by reducing the temperature measurement uncertainty by replacing the existing thermocouples with higher precision temperature measurement equipment. On June 15, 2006, the NRC staff forwarded a request for additional information (RAI) to Exelon. Exelon responded to the RAI on July 13, 2006. After a number of telephone conferences, Exelon submitted a supplemental response to the NRC on August 4, 2006. The NRC staff reviewed the material supplied by Exelon with respect to the UHS submittal, and on November 13, 2006, the NRC staff determined that the degree of measurement accuracy that would be required to support the LAR was not adequately demonstrated and denied the LAR. In a letter to the NRC dated January 24, 2007, Exelon stated that the NRC was challenging the current design and licensing basis and that the technical basis for the denial represented a change in NRCs position on the appropriate measurement uncertainty methodology applied to non-safety related, indication only instrumentation.

On January 26, 2007, a public meeting was held between the NRC and representatives of Exelon to discuss the denial of the UHS submittal and Exelons plan for re-submittal of the proposed LAR. At that meeting a number of actions items were identified for both the NRC staff and Exelon to address before the April 5, 2007, meeting.

APRIL 5, 2007, MEETING

SUMMARY

The action items discussed during the January 26, 2007, meeting and their disposition are discussed below. The NRC action items from the January 26, 2007, meeting are discussed in the body of the Exelon action items and are not covered separately.

Exelons action items:

  • Assess the acceptability of inserting a table in the LaSalle TS to address the loss of three out of four temperature detectors.

Exelon determined this approach was not desirable and inconsistent with the integrated TSs and that this issue would be handled in the Bases section and maintained through their bases control program. The NRC staff agreed this was an acceptable approach.

Exelon stated this would be accomplished in the next UFSAR update.

  • Verify the level of accuracy of the original thermocouple measurement uncertainty and the basis for it.

Exelon stated that when the plant was initially licensed, the licensing basis for LaSalle, with respect to UHS, was a nominal plant value, and as such no measurement uncertainty calculations were performed in the initial treatment of non-safety instruments such as the UHS thermocouples. This was the basis for Exelons statement in their January 24, 2007, letter responding to the NRC denial of the UHS LAR that the NRC challenged the current design and licensing basis of the LaSalle circulating water system. NRC Deputy Director, Ken OBrien informed Exelon that the only aspect of the design basis being reviewed was the design limit of 102 EF for the UHS and not any associated uncertainty calculations. After the discussion, Exelon stated they no longer considered that the NRC challenged the LaSalle licensing or design basis.

  • Determine if the NRC had approved a graded approach to setpoint methodology for other licensees.

NRC has not approved the graded approach for setpoint methodology at LaSalle. In addition, the NRC staff has not approved a license amendment for other licensees, using the graded approach. This was also an issue in the Exelon letter of January 24, 2007. Exelons position that the technical basis for the denial, as described in the NRC staffs safety evaluation (SE), represented a change in the NRC position on the appropriate measurement uncertainty methodology being applied to non-safety related, indication only instrumentation. The NRC staff informed Exelon that the graded approach was not approved nor accepted, and that if Exelon wished to use this approach, they would have to supply all supporting documentation for the NRC staffs review which would support their calculations and their approach to measurement uncertainty.

  • Describe the industry standard for a graded approach to setpoint methodology Exelon presented the graded approach to setpoint methodology used by the industry.

The NRC staff acknowledged that the industry may use the graded approach for some systems, however, for setpoint methodology, the NRC evaluates the information based on a two sigma (2) uncertainty analysis. The NRC staff discussed the Agencys

position on the graded approach to setpoint methodology as well as the position in Regulatory Guide 1.105, Setpoints for Safety Related Instrumentation.

  • The NRC staff discussed the value of completing the UHS uncertainty calculations using the 95/95 tolerance limit (2) as an acceptable method for uncertainties. This method ensures that there is a 95 percent probability that the constructed limits contain 95 percent of the population of interest for the surveillance interval selected.

Exelon proposed that since the area of concern only relates to high temperature (not exceeding the design limit of 102 EF), they plan to use single sided uncertainty in their evaluation using the 95/95 tolerance limit which results in the uncertainty of about 0.49EF. This should be within the calculated range for uncertainty for it to be below the 102 EF design limit. The NRC staff pointed out that a licensee, with justification, may propose an alternative calculation other than the 95/95 tolerance limit, based on its particular setpoint methodology or license.

  • A review of NRCs uncertainty calculation was discussed. The NRCs alternative calculation identified a possible discrepancy between the calibration data and some assumptions in the Exelon calculation. The alternative calculation also addressed possible discrepancies between the assumed and derived resistance-temperature detector characteristics, but because the discrepancies may be related to differing definitions or other conditions, the alternative calculation did not address them directly.

Exelon indicated they would review the alternative calculations in detail, and plans to resubmit the amendment request by the end of May 2007.

Exelon presented information (See Enclosure 2 or the Agencywide Documents Access and Management System Accession No. ML071090218). Exelons presentation provided a time line for the UHS as well as a listing of action items resulting from the previous public meeting on January 26, 2007.

Members of the public were not in attendance. Public Meeting Feedback forms were not received.

Please direct any inquiries to me at 301-415-3154, or sps1@nrc.gov.

/RA by RKuntz for/

Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosures:

1. List of Attendees
2. Licensee Handout cc w/encls: See next page

position on the graded approach to setpoint methodology as well as the position in Regulatory Guide 1.105, Setpoints for Safety Related Instrumentation.

  • The NRC staff discussed the value of completing the UHS uncertainty calculations using the 95/95 tolerance limit (2) as an acceptable method for uncertainties. This method ensures that there is a 95 percent probability that the constructed limits contain 95 percent of the population of interest for the surveillance interval selected.

Exelon proposed that since the area of concern only relates to high temperature (not exceeding the design limit of 102 EF), they plan to use single sided uncertainty in their evaluation using the 95/95 tolerance limit which results in the uncertainty of about 0.49EF. This should be within the calculated range for uncertainty for it to be below the 102 EF design limit. The NRC staff pointed out that a licensee, with justification, may propose an alternative calculation other than the 95/95 tolerance limit, based on its particular setpoint methodology or license.

  • A review of NRCs uncertainty calculation was discussed. The NRCs alternative calculation identified a possible discrepancy between the calibration data and some assumptions in the Exelon calculation. The alternative calculation also addressed possible discrepancies between the assumed and derived resistance-temperature detector characteristics, but because the discrepancies may be related to differing definitions or other conditions, the alternative calculation did not address them directly.

Exelon indicated they would review the alternative calculations in detail, and plans to resubmit the amendment request by the end of May.

Exelon presented information (See Enclosure 2 or the Agencywide Documents Access and Management System Accession No. ML071090218). Exelons presentation provided a time line for the UHS as well as a listing of action items resulting from the previous public meeting on January 26, 2007.

Members of the public were not in attendance. Public Meeting Feedback forms were not received.

Please direct any inquiries to me at 301-415-3154, or sps1@nrc.gov.

/RA by RKuntz for/

Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosures:

1. List of Attendees 2. Licensee Handout cc w/encls: See next page Distribution:

PUBLIC TLiu, NRR TBloomer, EDO DRahn, RES LPL3-2 R/F RidsNrrDorl RidsRgn3MailCenter RidsNrrDe RidsNrrDorlLpl3-2 PRebstock, RES RidsNrrLAEWhitt RidsOgcRp RidsNrrPMSSands RidsNrrDeEicb RidsAcrsAcnwMailCenter Package Accession No. ML071090184 Meeting Summary Accession No. ML071090180 License Handouts Accession No. ML071090218 OFFICE LPL3-2/PM LPL3-2/LA DE/EICB/BC LPL3-2/BC NAME SSands EWhitt AHowe RGibbs DATE 05/02/07 05/02/07 04/ 25 /07 05/02/07 OFFICIAL RECORD COPY

LaSalle County Station, Units 1 and 2 cc:

Site Vice President - LaSalle County Station Robert Cushing, Chief, Public Utilities Division Exelon Generation Company, LLC Illinois Attorney General's Office 2601 North 21st Road 100 W. Randolph Street Marseilles, IL 61341-9757 Chicago, IL 60601 Plant Manager - LaSalle County Station Regional Administrator, Region III Exelon Generation Company, LLC U.S. Nuclear Regulatory Commission 2601 North 21st Road Suite 210 Marseilles, IL 61341-9757 2443 Warrenville Road Lisle, IL 60532-4352 Manager Regulatory Assurance - LaSalle Exelon Generation Company, LLC Illinois Emergency Management 2601 North 21st Road Agency Marseilles, IL 61341-9757 Division of Disaster Assistance &

Preparedness U.S. Nuclear Regulatory Commission 110 East Adams Street LaSalle Resident Inspectors Office Springfield, IL 62701-1109 2605 North 21st Road Marseilles, IL 61341-9756 Document Control Desk - Licensing Exelon Generation Company, LLC Phillip P. Steptoe, Esquire 4300 Winfield Road Sidley and Austin Warrenville, IL 60555 One First National Plaza Chicago, IL 60603 Senior Vice President - Operations Support Exelon Generation Company, LLC Assistant Attorney General 4300 Winfield Road 100 W. Randolph St. Suite 12 Warrenville, IL 60555 Chicago, IL 60601 Director - Licensing and Regulatory Affairs Chairman Exelon Generation Company, LLC LaSalle County Board 4300 Winfield Road 707 Etna Road Warrenville, IL 60555 Ottawa, IL 61350 Vice President - Regulatory Affairs Attorney General Exelon Generation Company, LLC 500 S. Second Street 4300 Winfield Road Springfield, IL 62701 Warrenville, IL 60555 Chairman Associate General Counsel Illinois Commerce Commission Exelon Generation Company, LLC 527 E. Capitol Avenue, Leland Building 4300 Winfield Road Springfield, IL 62706 Warrenville, IL 60555

LaSalle County Station, Units 1 and 2 cc:

Manager Licensing - Braidwood, Byron, and LaSalle Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President - Midwest Operations Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Mr. Christopher M. Crane, President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

ATTENDANCE LIST MEETING WITH EXELON GENERATING COMPANY PRE-APPLICATION MEETING TO DISCUSS THE ULTIMATE HEAT SINK (UHS) AMENDMENT REQUEST NAME ORGANIZATION PHONE NUMBER Stephen P. Sands NRC/NRR/DORL/LPLIII-2 301-415-3154 Kenneth G. OBrien NRC/NRR/APES/DE 301-415-3300 Russell Gibbs NRC/NRR/DORL/LPL III-2 301-415-2988 Paul Rebstock NRC/RES 301-415-3295 Allen Howe NRC/NRR/EICB 301-415-1351 John Lubinski NRC/NRR/DORL 301-415-1453 Hukam Garg NRC/NRR/DE 301-415-2929 David Rahn NRC/RES/ERA/IEEB 301-415-5216 Wes Bowers Exelon 610-765-5456 Vikram Shah Exelon/LaSalle/I&C Design 815-415-3828 Terrence Simpkin Exelon/LaSalle 815-415-2800 Darin M. Benyak Exelon/Corp. Licensing 630-657-2811 Alison Mackellar Exelon/Corp. Licensing 630-657-2817 Jerry Voss Exelon Services Corp. 301-984-4400 Enclosure 1

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