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| number = ML12163A473
| number = ML12163A473
| issue date = 04/10/2012
| issue date = 04/10/2012
| title = 2012/04/10 Limerick Lr - Draft Request for Information
| title = Lr - Draft Request for Information
| author name =  
| author name =  
| author affiliation = NRC/NRR
| author affiliation = NRC/NRR
Line 15: Line 15:


=Text=
=Text=
{{#Wiki_filter:1 LimerickNPEm Resource From: Kuntz, Robert Sent: Tuesday, April 10, 2012 10:00 AM To: Christopher.Wilson2@exeloncorp.com
{{#Wiki_filter:LimerickNPEm Resource From:                       Kuntz, Robert Sent:                       Tuesday, April 10, 2012 10:00 AM To:                         Christopher.Wilson2@exeloncorp.com


==Subject:==
==Subject:==
DRAFT Request for Information Attachments:
DRAFT Request for Information Attachments:               DRAFT Fluence and FP RAIs.docx
DRAFT Fluence and FP RAIs.docx Chris, Attached is a DRAFT Request for Information related to the Limerick license renewal application. If Exelon would like clarification on the attached let me know and I will set up a teleconference with the NRC staff.  
: Chris, Attached is a DRAFT Request for Information related to the Limerick license renewal application. If Exelon would like clarification on the attached let me know and I will set up a teleconference with the NRC staff.
Robert Kuntz Sr. Project Manager NRR/ADRO/DLR/RPB1 (301) 415-3733 robert.kuntz@nrc.gov 1


Robert Kuntz Sr. Project Manager NRR/ADRO/DLR/RPB1 (301) 415-3733
Hearing Identifier:   Limerick_LR_NonPublic Email Number:         304 Mail Envelope Properties  (88F7F98950D94A46925CB4A4FC3BE54A07609B1F8C)
 
robert.kuntz@nrc.gov
 
Hearing Identifier: Limerick_LR_NonPublic Email Number: 304   Mail Envelope Properties  (88F7F98950D94A46925CB4A4FC3BE54A07609B1F8C)


==Subject:==
==Subject:==
DRAFT Request for Information Sent Date:   4/10/2012 10:00:26 AM Received Date: 4/10/2012 10:00:00 AM From:   Kuntz, Robert Created By:   Robert.Kuntz@nrc.gov Recipients:     "Christopher.Wilson2@exeloncorp.com" <Christopher.Wilson2@exeloncorp.com>
DRAFT Request for Information Sent Date:           4/10/2012 10:00:26 AM Received Date:       4/10/2012 10:00:00 AM From:                 Kuntz, Robert Created By:           Robert.Kuntz@nrc.gov Recipients:
Tracking Status: None  
"Christopher.Wilson2@exeloncorp.com" <Christopher.Wilson2@exeloncorp.com>
Tracking Status: None Post Office:          HQCLSTR01.nrc.gov Files                        Size                    Date & Time MESSAGE                      344                    4/10/2012 10:00:00 AM DRAFT Fluence and FP RAIs.docx                      32428 Options Priority:                    Standard Return Notification:          No Reply Requested:              No Sensitivity:                  Normal Expiration Date:
Recipients Received:


Post Office:  HQCLSTR01.nrc.gov Files    Size      Date & Time MESSAGE    344      4/10/2012 10:00:00 AM DRAFT Fluence and FP RAIs.docx    32428 Options  Priority:    Standard  Return Notification:    No  Reply Requested:    No  Sensitivity:    Normal  Expiration Date:      Recipients Received:
LIMERICK GENERATING STATION LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION DRAI 2.3.3.9-2.1
LIMERICK GENERATING STATION LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION DRAI 2.3.3.9-2.1  


===Background===
===Background===
The response to RAI 2.3.3.9-2, dated February 16, 2012, stated for passive components in lightning plant protection system (NFPA 78, Lightning Protection Code), that Limerick Generating Station (LGS) does not have a lightning plant protection system. Passive lightning protection components (NFPA 78) are provided for equipment and personnel protection. They are not relied upon to demonstrate compliance with 10 CFR 50.48 and as such do not perform an intended function for license renewal. Therefore, the lightning protection components are not in the scope of license renewal.
The response to RAI 2.3.3.9-2, dated February 16, 2012, stated for passive components in lightning plant protection system (NFPA 78, Lightning Protection Code), that Limerick Generating Station (LGS) does not have a lightning plant protection system. Passive lightning protection components (NFPA 78) are provided for equipment and personnel protection. They are not relied upon to demonstrate compliance with 10 CFR 50.48 and as such do not perform an intended function for license renewal. Therefore, the lightning protection components are not in the scope of license renewal.
Issues The response excluded some passive lightning protection components (NFPA 78). The response stated that the equipment passive lightning protection components have no function that supports 10 CFR 50.48 requirements; therefore, they are not within the scope of license renewal and subject to an AMR.  
Issues The response excluded some passive lightning protection components (NFPA 78). The response stated that the equipment passive lightning protection components have no function that supports 10 CFR 50.48 requirements; therefore, they are not within the scope of license renewal and subject to an AMR.
 
Request Provide clarification on how the passive lightning protection components are required per the NFPA 78 Code but are not required for compliance with 10 CFR 50.48. If the components are required for compliance with 10 CFR 50.48 then provide information to demonstrate that the effects of aging will be adequately managed so that the intended function(s) will be maintained consistent with the current licensing basis for the period of extended operation as required by 10 CFR 54.21(a)(3).
Request Provide clarification on how the passive lightning protection components are required per the NFPA 78 Code but are not required for compliance with 10 CFR 50.48. If the components are required for compliance with 10 CFR 50.48 then provide information to demonstrate that the effects of aging will be adequately managed so that the intended function(s) will be maintained consistent with the current licensing basis for the period of extended operation as required by
DRAI 4.2.1-1
 
10 CFR 54.21(a)(3).
DRAI 4.2.1-1  


===Background===
===Background===
LRA Section 4.2.1 provides the basis for deriving the 57 effective full power years (EFPY) neutron fluence values for the power operation of LGS, Units 1 and 2, through the period of extended operation. These are inputs to the neutron irradiation embrittlement time-limited aging analyses (TLAA) of the reactor pressure vessel (RPV) beltline shell, nozzle and weld components. The corresponding neutron fluence TLAAs that are derived from these neutron fluence values are in the following LRA sections: (a) Section 4.2.2, Upper Shelf Energy; (b)
Section 4.2.3, Adjusted Reference Temperature; (c) Section 4.2.4, Pressure - Temperature Limits; (d) Section 4.2.5, Axial Weld Inspection; (e) Section 4.2.6, Circumferential Weld Inspection, and (f) Section 4.2.7, Reactor Pressure Vessel Reflood Thermal [Analysis].
LRA Section 4.2.1 identifies the RAMA code was used to derive the 57 EFPY neutron fluence values for high energy neutrons with kinetic energies greater than 1.0 MeV


LRA Section 4.2.1 provides the basis for deriving the 57 effective full power years (EFPY) neutron fluence values for the power operation of LGS, Units 1 and 2, through the period of extended operation. These are inputs to the neu tron irradiation embrittlement time-limited aging analyses (TLAA) of the reactor pressure vessel (RPV) beltline shell, nozzle and weld components. The corresponding neutron fluence TLAAs that are derived from these neutron fluence values are in the following LRA sections:  (a) Section 4.2.2, "Upper Shelf Energy"; (b) Section 4.2.3, "Adjusted Reference Temperature"; (c) Section 4.2.4, "Pressure - Temperature Limits"; (d) Section 4.2.5, "Axial Weld Inspection"; (e) Section 4.2.6, "Circumferential Weld Inspection," and (f) Section 4.2.7, "Reactor Pressure Vessel Reflood Thermal [Analysis]." 
(E > 1.0 MeV) and that the RAMA code conforms to the staffs recommended regulatory position in Regulatory Guide (RG) 1.190, Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence [March 2001], for applying neutron fluence methodologies.
Issue LRA Section 4.2.1 does not identify which industry-based RAMA code is being used in the current licensing basis (CLB) for deriving the high energy neutron fluence values (i.e., E > 1.0 MeV) for the ferritic RPV beltline components in LGS, Units 1 and 2. The LRA only references the methodology in Electric Power Research Institute (EPRI) Report No. BWRVIP-126, BWR Vessel and Internals Project, RAMA Fluence Methodology Software, Version 1.0, which represents the software that is used at LGS to derive these fluence values. However, the staff noted that it does not represent the fluence methodology used to conform to RG 1.190.
In contrast, the staff has noted that the P-T limits in the applicants CLB (refer to facility operating license amendment No. 163 to Technical Specification 3.4.6.1, which was approved by NRC safety evaluation dated January 2, 2003) used General Electric (GE) Company Report No. NEDC-32983P-A as the neutron fluence methodology for conforming to RG 1.190.
The LRA does not identify the methodology in GEs report as the basis for the 57 EFPY neutron fluences provided in LRA Section 4.2.1. Thus, the LRA does not present sufficient information to identify the neutron fluence methodology or provide a basis for concluding that the neutron fluence methodology used in the CLB conforms to RG 1.190 and bounds all RPV beltine shell, nozzle, and weld components (including associated axial welds, circumferential welds, and nozzle-to-shell welds).
LRA Section A.4.2.1, which provides the Updated Final Safety Analysis Report (UFSAR) supplement summary description for LRA Section 4.2.1, also does provide this information.
Request
: 1. Identify the document (include reference number, title, and date) and neutron fluence methodology used in the CLB to conform with RG 1.190. Clarify whether the neutron fluence methodology used has been endorsed for use by the staff. Justify the conclusion that the neutron fluence methodology currently adopted in the CLB for these TLAAs conforms to RG 1.190 and is bounding for all RPV beltine shell, nozzle, and weld components (including associated axial welds, circumferential welds, and nozzle-to-shell welds).
: 2. Update LRA Section 4.2.1 and A.4.2.1 to identify the document (including reference number, title, and date) and the neutron fluence methodology used in the CLB to conform to RG 1.190. and justify the LGS regulatory basis for using this neutron fluence methodology for the derivation of 57 EFPY neutron fluence values for the ferritic beltline shell, nozzle, and weld components in the LGS, Unit 1 and 2 RPVs.


LRA Section 4.2.1 identifies the RAMA code was used to derive the 57 EFPY neutron fluence values for high energy neutrons with kinetic energies greater than 1.0 MeV (E > 1.0 MeV) and that the RAMA code conforms to the staff's recommended regulatory position in Regulatory Guide (RG) 1.190, "Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence" [March 2001], for applying neutron fluence methodologies.
DRAI 4.2.1-2
Issue LRA Section 4.2.1 does not identify which industry-based RAMA code is being used in the current licensing basis (CLB) for deriving the high energy neutron fluence values (i.e., E > 1.0 MeV) for the ferritic RPV beltline components in LGS, Units 1 and 2. The LRA only references the methodology in Electric Power Research Institute (EPRI) Report No. BWRVIP-126, "BWR Vessel and Internals Project, RAMA Fluence Methodology Software," Version 1.0, which represents the software that is used at LGS to derive these fluence values. However, the staff noted that it does not represent the fluence methodology used to conform to RG 1.190. 
 
In contrast, the staff has noted that the P-T limits in the applicant's CLB (refer to facility operating license amendment No. 163 to Technical Specification 3.4.6.1, which was approved by NRC safety evaluation dated January 2, 2003) used General Electric (GE) Company Report No. NEDC-32983P-A as the neutron fluence methodology for conforming to RG 1.190. 
 
The LRA does not identify the methodology in GE's report as the basis for the 57 EFPY neutron fluences provided in LRA Section 4.2.1. Thus, the LRA does not present sufficient information to identify the neutron fluence methodology or provide a basis for concluding that the neutron fluence methodology used in the CLB conforms to RG 1.190 and bounds all RPV beltine shell, nozzle, and weld components (including associated axial welds, circumferential welds, and nozzle-to-shell welds).
LRA Section A.4.2.1, which provides the Updated Final Safety Analysis Report (UFSAR) supplement summary description for LRA Section 4.2.1, also does provide this information.
 
Request  1. Identify the document (include reference number, title, and date) and neutron fluence methodology used in the CLB to conform with RG 1.190. Clarify whether the neutron fluence methodology used has been endorsed for use by the staff. Justify the conclusion that the neutron fluence methodology currently adopted in the CLB for these TLAAs conforms to RG 1.190 and is bounding for all RPV beltine shell, nozzle, and weld components (including associated axial welds, circumferential welds, and nozzle-to-shell welds). 
: 2. Update LRA Section 4.2.1 and A.4.2.1 to identify the document (including reference number, title, and date) and the neutron fluence methodology used in the CLB to conform to RG 1.190. and justify the LGS regulatory basis for using this neutron fluence methodology for the derivation of 57 EFPY neutron fluence values for the ferritic beltline shell, nozzle, and weld components in the LGS, Unit 1 and 2 RPVs.
DRAI 4.2.1-2  


===Background===
===Background===
 
10 CFR Part 50, Appendix H identifies that RPV surveillance programs need to be implemented for all ferritic RPV components with projected end-of-life neutron fluences in excess of 1.0 X 1017 n/cm2 (E > 1.0 MeV). The background information in RAI 4.2.1-1 is also applicable to RAI 4.2.1-2.
10 CFR Part 50, Appendix H identifies that RPV surveillance programs need to be implemented for all ferritic RPV components with projected end-of-life neutron fluences in excess of 1.0 X 10 17 n/cm 2 (E > 1.0 MeV). The background information in RAI 4.2.1-1 is also applicable to RAI 4.2.1-2.  
Issue The staff is concerned that there may be additional ferritic shell, nozzle, or weld components in the RPV that need to be added to the list of RPV beltine components because the neutron fluences would not be projected to exceed a fluence value of 1.0 X 1017 n/cm2 (E > 1.0 MeV) until some point in the proposed period of extended operation.
 
Request Clarify and justify whether there are any additional ferritic shell, nozzle, or weld components (including circumferential, axial or nozzle-to-vessel welds) in the RPV that needs to be added to the components associated with the beltine regions of the LGS, Unit 1 and 2 RPVs.
Issue The staff is concerned that there may be additional ferritic shell, nozzle, or weld components in the RPV that need to be added to the list of RPV beltine components because the neutron fluences would not be projected to exceed a fluence value of 1.0 X 10 17 n/cm 2 (E > 1.0 MeV) until some point in the proposed period of extended operation.  
If additional ferritic shell, nozzle, or weld components need to be added as RPV beltline components, identify the components and provide the 57 EFPY neutron fluences for these components. In addition, address how these components will be assessed for the neutron irradiation embrittlement TLAAs that are identified and evaluated for in Sections 4.2.2 - 4.2.7 of the LRA.
 
DRAI B.2.1.28-2
Request Clarify and justify whether there are any additional ferritic shell, nozzle, or weld components (including circumferential, axial or nozzle-to-vessel welds) in the RPV that needs to be added to the components associated with the beltine regions of the LGS, Unit 1 and 2 RPVs.  
 
If additional ferritic shell, nozzle, or weld components need to be added as RPV beltline components, identify the components and provide the 57 EFPY neutron fluences for these components. In addition, address how these components will be assessed for the neutron irradiation embrittlement TLAAs that are identified and evaluated for in Sections 4.2.2 - 4.2.7 of  
 
the LRA.  
 
DRAI B.2.1.28-2  


===Background===
===Background===
The GALL Report recommends that loss of material and degradation of the neutron absorbing material capacity be determined through coupon and/or direct in situ testing.
The response to RAI B.2.1.28-1, provided by letter dated February 28, 2012, stated that the coupons in the Limerick Generating Station (LGS), Unit 2 spent fuel pool had experienced only two cycles of high fluence from freshly discharged fuel. The response also stated that the coupons in the LGS, Unit 1 spent fuel pool had not experienced high fluence from freshly discharged fuel since re-racking.
In order for the coupons to obtain environmental conditions bounding of all Boral spent fuel pool racks, the response to RAI B.2.1.28-1 proposes to resume an accelerated exposure configuration for the Boral coupons (i.e., surround the coupons by freshly discharged fuel assemblies) at each of the next five refueling cycles, beginning with the refueling outage in 2013 and 2014 for LGS, Units 1 and 2, respectively.


The GALL Report recommends that loss of material and degradation of the neutron absorbing material capacity be determined through coupon and/or direct in situ testing.
Issue The coupons in the LGS, Units 1 and 2 spent fuel pools have not experienced long exposure to high radiation fluence from freshly discharged fuel, making the exposure time potentially non-conservative and/or not bounding of all the LGS, Unit 1 and 2 Boral spent fuel pool racks. The current environmental conditions of the coupons are not bounding of all Boral racks and; therefore, may not provide acceptable testing data for monitoring loss of material and degradation of the neutron absorbing material capacity.
 
The response to RAI B.2.1.28-1, provided by letter dated February 28, 2012, stated that the coupons in the Limerick Generating Station (LGS), Unit 2 spent fuel pool had experienced only two cycles of high fluence from freshly discharged fuel. The response also stated that the coupons in the LGS, Unit 1 spent fuel pool had not experienced high fluence from freshly discharged fuel since re-racking. 
 
In order for the coupons to obtain environmental conditions bounding of all Boral spent fuel pool racks, the response to RAI B.2.1.28-1 proposes to resume an accelerated exposure configuration for the Boral coupons (i.e., surround the coupons by freshly discharged fuel assemblies) at each of the next five refueling cycles, beginning with the refueling outage in 2013 and 2014 for LGS, Units 1 and 2, respectively.
 
Issue The coupons in the LGS, Units 1 and 2 spent fuel pools have not experienced long exposure to high radiation fluence from freshly discharged fuel, making the exposure time potentially non-conservative and/or not bounding of all the LGS, Unit 1 and 2 Boral spent fuel pool racks. The current environmental conditions of the coupons are not bounding of all Boral racks and; therefore, may not provide acceptable testing data for monitoring loss of material and degradation of the neutron absorbing material capacity.  
 
Request Provide justification on how resuming a five cycle radiation exposure period will place the coupons in a bounding condition for all Boral spent fuel pool racks for the LGS, Units 1 and 2 now and in the future. If there is not ample justification that the coupons will be bounding of all the Boral panels in the spent fuel pool (SFP) now or in the future, discuss if another method of monitoring will be used, such as in situ testing.}}
Request Provide justification on how resuming a five cycle radiation exposure period will place the coupons in a bounding condition for all Boral spent fuel pool racks for the LGS, Units 1 and 2 now and in the future. If there is not ample justification that the coupons will be bounding of all the Boral panels in the spent fuel pool (SFP) now or in the future, discuss if another method of monitoring will be used, such as in situ testing.}}

Latest revision as of 20:16, 5 December 2019

Lr - Draft Request for Information
ML12163A473
Person / Time
Site: Limerick  Constellation icon.png
Issue date: 04/10/2012
From:
Office of Nuclear Reactor Regulation
To:
References
Download: ML12163A473 (6)
v • d • e


Text

LimerickNPEm Resource From: Kuntz, Robert Sent: Tuesday, April 10, 2012 10:00 AM To: Christopher.Wilson2@exeloncorp.com

Subject:

DRAFT Request for Information Attachments: DRAFT Fluence and FP RAIs.docx

Chris, Attached is a DRAFT Request for Information related to the Limerick license renewal application. If Exelon would like clarification on the attached let me know and I will set up a teleconference with the NRC staff.

Robert Kuntz Sr. Project Manager NRR/ADRO/DLR/RPB1 (301) 415-3733 robert.kuntz@nrc.gov 1

Hearing Identifier: Limerick_LR_NonPublic Email Number: 304 Mail Envelope Properties (88F7F98950D94A46925CB4A4FC3BE54A07609B1F8C)

Subject:

DRAFT Request for Information Sent Date: 4/10/2012 10:00:26 AM Received Date: 4/10/2012 10:00:00 AM From: Kuntz, Robert Created By: Robert.Kuntz@nrc.gov Recipients:

"Christopher.Wilson2@exeloncorp.com" <Christopher.Wilson2@exeloncorp.com>

Tracking Status: None Post Office: HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 344 4/10/2012 10:00:00 AM DRAFT Fluence and FP RAIs.docx 32428 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

LIMERICK GENERATING STATION LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION DRAI 2.3.3.9-2.1

Background

The response to RAI 2.3.3.9-2, dated February 16, 2012, stated for passive components in lightning plant protection system (NFPA 78, Lightning Protection Code), that Limerick Generating Station (LGS) does not have a lightning plant protection system. Passive lightning protection components (NFPA 78) are provided for equipment and personnel protection. They are not relied upon to demonstrate compliance with 10 CFR 50.48 and as such do not perform an intended function for license renewal. Therefore, the lightning protection components are not in the scope of license renewal.

Issues The response excluded some passive lightning protection components (NFPA 78). The response stated that the equipment passive lightning protection components have no function that supports 10 CFR 50.48 requirements; therefore, they are not within the scope of license renewal and subject to an AMR.

Request Provide clarification on how the passive lightning protection components are required per the NFPA 78 Code but are not required for compliance with 10 CFR 50.48. If the components are required for compliance with 10 CFR 50.48 then provide information to demonstrate that the effects of aging will be adequately managed so that the intended function(s) will be maintained consistent with the current licensing basis for the period of extended operation as required by 10 CFR 54.21(a)(3).

DRAI 4.2.1-1

Background

LRA Section 4.2.1 provides the basis for deriving the 57 effective full power years (EFPY) neutron fluence values for the power operation of LGS, Units 1 and 2, through the period of extended operation. These are inputs to the neutron irradiation embrittlement time-limited aging analyses (TLAA) of the reactor pressure vessel (RPV) beltline shell, nozzle and weld components. The corresponding neutron fluence TLAAs that are derived from these neutron fluence values are in the following LRA sections: (a) Section 4.2.2, Upper Shelf Energy; (b)

Section 4.2.3, Adjusted Reference Temperature; (c) Section 4.2.4, Pressure - Temperature Limits; (d) Section 4.2.5, Axial Weld Inspection; (e) Section 4.2.6, Circumferential Weld Inspection, and (f) Section 4.2.7, Reactor Pressure Vessel Reflood Thermal [Analysis].

LRA Section 4.2.1 identifies the RAMA code was used to derive the 57 EFPY neutron fluence values for high energy neutrons with kinetic energies greater than 1.0 MeV

(E > 1.0 MeV) and that the RAMA code conforms to the staffs recommended regulatory position in Regulatory Guide (RG) 1.190, Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence [March 2001], for applying neutron fluence methodologies.

Issue LRA Section 4.2.1 does not identify which industry-based RAMA code is being used in the current licensing basis (CLB) for deriving the high energy neutron fluence values (i.e., E > 1.0 MeV) for the ferritic RPV beltline components in LGS, Units 1 and 2. The LRA only references the methodology in Electric Power Research Institute (EPRI) Report No. BWRVIP-126, BWR Vessel and Internals Project, RAMA Fluence Methodology Software, Version 1.0, which represents the software that is used at LGS to derive these fluence values. However, the staff noted that it does not represent the fluence methodology used to conform to RG 1.190.

In contrast, the staff has noted that the P-T limits in the applicants CLB (refer to facility operating license amendment No. 163 to Technical Specification 3.4.6.1, which was approved by NRC safety evaluation dated January 2, 2003) used General Electric (GE) Company Report No. NEDC-32983P-A as the neutron fluence methodology for conforming to RG 1.190.

The LRA does not identify the methodology in GEs report as the basis for the 57 EFPY neutron fluences provided in LRA Section 4.2.1. Thus, the LRA does not present sufficient information to identify the neutron fluence methodology or provide a basis for concluding that the neutron fluence methodology used in the CLB conforms to RG 1.190 and bounds all RPV beltine shell, nozzle, and weld components (including associated axial welds, circumferential welds, and nozzle-to-shell welds).

LRA Section A.4.2.1, which provides the Updated Final Safety Analysis Report (UFSAR) supplement summary description for LRA Section 4.2.1, also does provide this information.

Request

1. Identify the document (include reference number, title, and date) and neutron fluence methodology used in the CLB to conform with RG 1.190. Clarify whether the neutron fluence methodology used has been endorsed for use by the staff. Justify the conclusion that the neutron fluence methodology currently adopted in the CLB for these TLAAs conforms to RG 1.190 and is bounding for all RPV beltine shell, nozzle, and weld components (including associated axial welds, circumferential welds, and nozzle-to-shell welds).
2. Update LRA Section 4.2.1 and A.4.2.1 to identify the document (including reference number, title, and date) and the neutron fluence methodology used in the CLB to conform to RG 1.190. and justify the LGS regulatory basis for using this neutron fluence methodology for the derivation of 57 EFPY neutron fluence values for the ferritic beltline shell, nozzle, and weld components in the LGS, Unit 1 and 2 RPVs.

DRAI 4.2.1-2

Background

10 CFR Part 50, Appendix H identifies that RPV surveillance programs need to be implemented for all ferritic RPV components with projected end-of-life neutron fluences in excess of 1.0 X 1017 n/cm2 (E > 1.0 MeV). The background information in RAI 4.2.1-1 is also applicable to RAI 4.2.1-2.

Issue The staff is concerned that there may be additional ferritic shell, nozzle, or weld components in the RPV that need to be added to the list of RPV beltine components because the neutron fluences would not be projected to exceed a fluence value of 1.0 X 1017 n/cm2 (E > 1.0 MeV) until some point in the proposed period of extended operation.

Request Clarify and justify whether there are any additional ferritic shell, nozzle, or weld components (including circumferential, axial or nozzle-to-vessel welds) in the RPV that needs to be added to the components associated with the beltine regions of the LGS, Unit 1 and 2 RPVs.

If additional ferritic shell, nozzle, or weld components need to be added as RPV beltline components, identify the components and provide the 57 EFPY neutron fluences for these components. In addition, address how these components will be assessed for the neutron irradiation embrittlement TLAAs that are identified and evaluated for in Sections 4.2.2 - 4.2.7 of the LRA.

DRAI B.2.1.28-2

Background

The GALL Report recommends that loss of material and degradation of the neutron absorbing material capacity be determined through coupon and/or direct in situ testing.

The response to RAI B.2.1.28-1, provided by letter dated February 28, 2012, stated that the coupons in the Limerick Generating Station (LGS), Unit 2 spent fuel pool had experienced only two cycles of high fluence from freshly discharged fuel. The response also stated that the coupons in the LGS, Unit 1 spent fuel pool had not experienced high fluence from freshly discharged fuel since re-racking.

In order for the coupons to obtain environmental conditions bounding of all Boral spent fuel pool racks, the response to RAI B.2.1.28-1 proposes to resume an accelerated exposure configuration for the Boral coupons (i.e., surround the coupons by freshly discharged fuel assemblies) at each of the next five refueling cycles, beginning with the refueling outage in 2013 and 2014 for LGS, Units 1 and 2, respectively.

Issue The coupons in the LGS, Units 1 and 2 spent fuel pools have not experienced long exposure to high radiation fluence from freshly discharged fuel, making the exposure time potentially non-conservative and/or not bounding of all the LGS, Unit 1 and 2 Boral spent fuel pool racks. The current environmental conditions of the coupons are not bounding of all Boral racks and; therefore, may not provide acceptable testing data for monitoring loss of material and degradation of the neutron absorbing material capacity.

Request Provide justification on how resuming a five cycle radiation exposure period will place the coupons in a bounding condition for all Boral spent fuel pool racks for the LGS, Units 1 and 2 now and in the future. If there is not ample justification that the coupons will be bounding of all the Boral panels in the spent fuel pool (SFP) now or in the future, discuss if another method of monitoring will be used, such as in situ testing.

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