ML14227A885

E-mail P Longmire, NRC, Re e-mail Fr Samuel Chesnutt, Xcel Energy, Re Meeting Summary for the June 16, 2014 Prairie Island ISFSI License Renewal Application RAI Discussion

ML14227A885
Person / Time
Site:	Prairie Island
Issue date:	07/02/2014
From:	Pamela Longmire NRC/NMSS/SFST
To:
Longmire P
References
Download: ML14227A885 (111)

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1 PrairieIslandISFSIPEm Resource From: Longmire, Pamela Sent: Wednesday, July 02, 2014 1:05 PM To: PrairieIslandISFSIHearing Resource

Subject:

FW: Meeting Summary for the 6-16 Prairie Island ISFSI LRA RAI Discussion Attachments:Meeting Summary for the 6-16 Prairie Island ISFSI LRA RAI Discussion

Hearing Identifier: Prairie_Island_ISFSI_Public Email Number: 57 Mail Envelope Properties (A56E37EC1CBC8045910287CEF5E7AE6C0276DDA8D4A2)

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FW: Meeting Summary for the 6-16 Prairie Island ISFSI LRA RAI Discussion Sent Date: 7/2/2014 1:05:07 PM Received Date: 7/2/2014 1:05:09 PM From: Longmire, Pamela

Created By: Pamela.Longmire@nrc.gov Recipients: "PrairieIslandISFSIHearing Resource" <PrairieIslandISFSIHearing.Resource@nrc.gov> Tracking Status: None

Post Office: HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 3 7/2/2014 1:05:09 PM Meeting Summary for the 6-16 Prairie Island ISFSI LRA RAI Discussion 1622297 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:

Damiano, Debra From: Sent: Chesnutt, Samuel < Samuei.Chesn utt@xe nuclear.com > Tuesday , June 24 , 2014 4: 03 PM To: Longmire , Pamela Cc: Eckho lt , Gene F.

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Attachments

Meeting Summary for the 6-16 Prairie Island I SFSI LRA RAI D isc ussion PI LRA RAI Meeting S umma ry 6-16-2 014.pdf Dr. Longmire, Attached is our summary of l ast we e k's meeting with you a nd your s taff. For completeness , we included co pi es of all h a ndout s. As we d iscusse d after the m ee tin g, I h ave in c lud e d everyone who s i gned the at t e nd a n ce s h eet, and all of the names I cou ld identify from the ca ll-i n introductions. I know th e re w e r e 2 r e pre se ntati ves from OGC whom I do not know , but I'm hoping yo u can id entify a ny o n e I mi sse d from yo ur call-in r eq u es t li s t. It was a plea su re meeting you and your review team and we f ee l thi s was a very produ c tive exc hang e of id eas. W e are working on our RAI re s pon ses and w ill co nt act you w h en we have draft copies for your r ev i ew. If you hav e any qu est ion s, plea se feel free t o ca ll eit h e r Gen e or myself. I can be reached at my cell, 303-358-5235. Th anks, Sam Chesnutt Xcel Energy 1 Responsible By Nature Projec ts Licensing Engineer Pratrie Island Nuclear Generatmg Plant P: 651.267.7546 C: 303.358 5235 E: sam u el.ches nutt@xe nuclear.com 1 QF-0700, Rev. 1 (FP-R-LIC-013)

Page 1 of 5 Summary of Discussion with NRC Staff Regarding PI ISFSI LRA RAI Responses Date: June 16, 2014 Time: 1:00 pm CDT

Location: Telephone Conference - Call-in Participants:

NRC NSPM Dr. Pamela Longmire, Project Manager Mike Baumann, Director Nuclear Fuels Mark Lombard, SFST, Director Martin Murphy, Director Regulatory Affairs Al Csontos, SFST/SMMB Peter Glass, Counsel Zhian Li, SFST/CSDAB Terry Pickens, Director Regulatory Policy Ricardo Torres, SFST/SMMB Gene Eckholt, Manager, Projects Licensing Nate Jordan, SFST/CSDAB H. Oley Nelson, Projects Engineer Mathew Hiser, RES/DE Sam Chesnutt, Projects Licensing A.H. Hsia, SFST, Deputy Director Robert Einziger, SFST/SMMB David Pstrak, SFST/LID Greg Oberson, RES/DE Mica Baquera, RES/DE Darrell Dunn, SFST/SMMB David Tang, SFST/SMMB Tim Lupold, SFST Asud Chowdhury, CNWRA Yiming Pan, CNWRA Others Jim Wood, Exelon Philippe Pham, Areva TN Brian Gutherman, NEI John Greeves, PIIC Kimberly Harshaw, Pillsbury Law Pam Cowan, Exelon Rod McCullum, NEI By Telephone Carlyn Green, Ux Consulting Phil Mahowald, PIIC Kristina Banovac, SFST/LB OGC (2) Kyle Kriesel, NSPM, PINGP Pete Wildenborg, NSPM, PINGP

QF-0700, Rev. 1 (FP-R-LIC-013)

Page 2 of 5 Summary of Discussion with NRC Staff Regarding PI ISFSI LRA RAI Responses Topic: Discuss PI ISFSI License Renewal - 2nd Set of RAIs and NSPM Proposed Responses This category 1 public meeting was held to discuss the 12 Requests for Additional Information (RAIs) provided in Reference 3, to support NRC review of the Prairie Island ISFSI License Renewal Application (LRA). The purpose of the meeting was to exchange information, obtain clarification of the information request, and gain a better understanding of NRC expectations for RAI responses.

References:

1. NSPM letter dated October 20, 2011, PI ISFSI LRA (ADAMS ML11304A068)

2. NSPM letter dated July 26, 2013, Response to RAI (ADAMS ML13210A272) 3. NRC letter dated May 27, 2014, Second RAI (ADAMS ML14147A527) 4. NRC Meeting Notice dated June 3, 2014 (ADAMS ML14154A130)

Enclosures:

1. NSPM presentation, PI ISFSI LRA, Discussion of Requests for Additional Information, June 16, 2014 2. NSPM DRAFT AMP, High Burnup Fuel Monitoring Program 3. NRC presentation, Elements of an Aging Management Program (AMP), June 16, 2014 4. NRC presentation, Fuel Performance AMP Development, June 16, 2014 5. NRC presentation, Concrete AMP Development, June 16, 2014 6. NRC presentation, Aging Management Program for Polymer-based Neutron Shield, June 16, 2014

Main Points of Discussion:

1. Introductions Dr. Longmire began the meeting with introductions of meeting participants both in the room and on the telephone.

2. NSPM presented information in Enclosures 1 and 2, which included draft response strategies to RAIs provided in Reference 3.

3. NSPM provided an introductory overview of the process used to develop the Aging Management Program for the Prairie Island ISFSI. This process was consistent with the development of Aging Management Programs for the plant license renewal effort and included: a. Identify in-scope components

b. Identify the materials and environments for covered components c. Review aging effects using EPRI tools and reports d. Prepare an AMP - this is a program document

e. Provide appropriate acceptance criteria in implementing procedures

4. AMP Contents - Acceptance Criteria The specification of Acceptance Criteria "against which the need for corrective actions will be evaluated" is addressed in Element 6 of NUREG-1927. NSPM explained that their aging monitoring inspections are consistent with inspections that are part of aging management programs for the plant. The inspection process identifies initial indications QF-0700, Rev. 1 (FP-R-LIC-013)

Page 3 of 5 Summary of Discussion with NRC Staff Regarding PI ISFSI LRA RAI Responses of aging (e.g., any evidence of corrosion) and then ensures that these conditions are documented and evaluated in the 10 CFR 50 Appendix B Corrective Action Program (CAP). The NRC indicated that having more specific acceptance criteria in the AMP would be valuable to their review. Also, the identification of specific criteria at which corrective actions would be taken was discussed. NSPM explained that the broad range of conditions and locations of aging effects that might be observed do not support identification of specific values (e.g., corrosion depths) for initiating pre-specified corrective actions in the inspection procedures or in the AMP program level documents. In addition, it is undesirable to identify a specific value that would be considered acceptable for all cases. For example, the amount of corrosion that might be acceptable on a general surface might not be acceptable if it were all in one location.

NSPM will explain the use of the CAP program for evaluating conditions and determining corrective actions in the RAI response.

5. RAI-12, High Burnup Fuel AMP NSPM presented the Draft AMP, High Burnup Fuel Monitoring Program in Enclosure 2.

NSPM intends to submit this AMP as part of the response to RAI-12. The High Burnup Fuel AMP relies on the joint EPRI and DOE "High Burnup Dry Storage Cask Research and Development Project (HDRP)," as a surrogate program for the high burnup fuel being stored at the PI ISFSI. The Draft High Burnup Fuel AMP includes the 10 elements of an AMP identified in NUREG-1927, and also includes an eleventh element to describe "Toll Gate Assessments." The Toll Gate Assessments element recognizes that the HDRP may identify lessons learned or other aging-related impacts at some time in the future, and provides for periodic assessments of new or additional industry operating experience information.

The Draft AMP includes toll gate assessments at least 5, 15, 25, and 35 years after license renewal. Based on the current schedule to load the HDRP cask in 2017, the initial toll gate assessment after 5 years (approximately 2019) will allow an evaluation of temperature readings from loading and initial storage of the demonstration cask, and additional data will be addressed after another 10 years. The Draft AMP also provides for evaluation of data from the examination of stored fuel when it becomes available, which is expected to occur before storage of high burnup fuel at the PI ISFSI exceeds 20 years (in 2033). Discussion topics to be addressed in the RAI response include initial design actions to establish and maintain a dry, inert environment as preventive actions to prevent cladding oxidation.

6. RAI -1, SAR Updates SAR markups regarding storage periods (e.g., 20 or 25 years) will be provided along with justification for changes.

7. RAIs 2, 3, 4, 5, 6, and 7 regarding Concrete Pad, Groundwater, and Earthen Berm NSPM explained inspections, inspection frequencies, acceptance criteria, and the use of the CAP process to determine when corrective actions would be initiated. Further QF-0700, Rev. 1 (FP-R-LIC-013)

Page 4 of 5 Summary of Discussion with NRC Staff Regarding PI ISFSI LRA RAI Responses explanations will be provided in the RAI responses. NSPM will also provide explanations of terminology based on EPRI aging management tools and reports, which have not been endorsed by NMSS.

8. RAI-8 and 9, Cask Inspections NSPM explained that any evidence of corrosion is documented and evaluated in the CAP program. Photographs from the baseline inspections (provided in Reference 2) were taken to provide a visual record as part of the CAP documentation and do not provide "conclusive evidence" that there was no observable loss of material. The CAP process is used to document inspections and determine when further actions are needed. This explanation will be provided in the RAI response.

9. RAI-11, Flammable Gas Generation NSPM explained new analysis that shows negligible flammable gas generation in neutron shield material. This analysis will be provided with the RAI response.

10. RAI-10, Neutron Shield AMP NSPM explained that new analysis shows negligible loss of hydrogen due to radiolytic degradation of neutron shield material. Quarterly surveys do not detect "any" degradation, but will identify degradation that could lead to a loss of safety function. NSPM discussed comparing survey data to a curve based on the safety analysis, and also trending of survey data as provided Reference 2. Further explanations will be considered in the RAI response.

11. NRC Presentation on Elements of an Aging Management Program (AMP) The NRC presented information in Enclosure 3, including the information and level of detail that should be provided for the 10 elements described in NUREG-1927. The overall structure of AMPs was also discussed with regards to the presentation of a "horizontal slice" of aging effects or a "vertical slice" that is more component oriented.

12. NRC Presentation on Fuel Performance AMP Development The NRC presented information in Enclosure 4, including the 10 elements of an AMP described in NUREG-1927. The use of future OE assessments that NSPM included in the Draft AMP under an eleventh element, "Toll Gate Assessments," was discussed under element 9, Administrative Controls. The NRC also discussed ISG-24, which is currently in draft form and is expected to be issued within a few weeks

13. NRC Presentation on Concrete AMP Development The NRC presented information in Enclosure 5 and noted that this is a generic presentation that includes horizontal storage modules.

14. NRC Presentation Aging Management Program for Polymer-based Neutron Shield The NRC presented information in Enclosure 6, including the 10 elements of an AMP described in NUREG-1927.

QF-0700, Rev. 1 (FP-R-LIC-013)

Page 5 of 5 Summary of Discussion with NRC Staff Regarding PI ISFSI LRA RAI Responses Actions:

NSPM Provide draft responses to RAIs as discussed.

NRC No specific actions at this time.

Summary: There was a good exchange of information between NSPM and the NRC, and the meeting was beneficial for identifying issues to be addressed in the RAI responses. Based on discussions and presentations made by both NSPM and the NRC, NSPM will prepare written responses to the 12 RAIs, including a revision to the High Burnup Fuel Monitoring Program AMP. Draft responses will be provided to the NRC Project Manager for preliminary review. Telephone conferences or other communications will be held to discuss remaining issues, so that final responses can be submitted by the July 29 schedule date.

Disposition of Summary Discussion with NRC:

1) Summary for internal use ___x__ 2) Meeting summary with copy provided to NRC ___x__ 3) Docketed letter related to meeting ______

Rockville, MarylandJune 16, 2014Prairie Island Independent Spent Fuel Storage Installation License Renewal ApplicationDiscussion of Requests for Additional InformationPrairie Island Independent Spent Fuel Storage Installation License Renewal ApplicationDiscussion of Requests for Additional Information 2Attendees -NSPMMike Baumann -Director, Nuclear Fuel SupplyMartin Murphy -Director, Nuclear Licensing and Regulatory AffairsTerry Pickens -Director, Regulatory Policy Gene Eckholt -Manager, Projects Licensing Oley Nelson -Engineer, Spent Nuclear Fuel Projects Sam Chesnutt -Engineer, Projects Licensing 3IntroductionsObjective of MeetingBackgroundDiscussion of Requests for Additional Information and NSPM Proposed ResponsesClosing Remarks Agenda 4Acronyms~!""#!#~!!$#!!#%%%%!#&!!&'%'%!%%

5Objective Of MeetingEnsure clear understanding of RAIsReach agreement on response strategies 6BackgroundISFSI Operations commenced -1995NSPM submitted PI ISFSI License Renewal Application (LRA) -October 2011Requested 40 year extension beyond October

2013Submitted Responses to Initial Round of Technical

RAIs -July 20132 n dSet of RAIs -May 2014 7Discussion of RAI-12RAI-12: Provide an AMP for high burnupfuel addressing the 10 points in NUREG-1927; the AMP should be based on the DOE Cask Demonstration test plan.

8Discussion of RAI-12 (Cont'd)Response to RAI-12Will provide an AMP based on DOE Demonstration planAMP will include Toll Gate AssessmentsAMP will be included in revision to Appendix A of

LRA, Aging Management Plan 9Discussion of RAI-1RAI-1: Identify each instance in the safety analysis report (SAR) that refers to a limited storage system period -explain and justify their disposition.

10Discussion of RAI-1 (Cont'd)Response to RAI-1:Propose to provide markups of each instance in SAR that refers to a storage system period (e.g., 20 years)SAR update categories:Delete storage period if no technical basis Revise storage period if new analysisClarify how storage period applies during PEOWill provide complete list of SAR updates and

justification of categorization 11Discussion of RAI-2RAI-2: Provide a revised Aging Management Program (AMP) for the concrete pad, or provide detailed justifications for why five listed aging effects / mechanisms do not require an AMP, for both above-grade and below-grade areas, as applicable.

12Discussion of RAI-2Response to RAI-2:Three of the listed aging effects / mechanisms for the concrete pad are addressed in the LRA, Table 3.4-1 (AMR) and A2.1-1 (AMP):Cracking, Loss of Strength from cement

aggregate reactionsIncrease in porosity/permeability and Loss of

Strength due to leaching of Ca(OH)2Cracking due to Settlement 13Discussion of RAI-2 (Cont'd)Will provide site-specific technical justification for exclusion of:Cracking, Loss of Material from chemical attackNot exposed to aggressive chemical environmentCracking, Loss of Material / Bond from corrosion

of embedded steelGood quality, well consolidated, properly

cured concrete pads.

14Discussion of RAI-3RAI-3: Specify which materials properties are covered by the aging effect "Change in Materials Properties" when referring to the aging mechanism "Leaching of Ca(OH)2" in the concrete pad and justify visual examination.

15Discussion of RAI-3 (Cont'd)Response to RAI-3:Material properties that can be affected by leaching include:Increase in porosity and permeabilityReduced strengthLower pH Visual examination can detect evidence of

leaching such as white lime deposits 16Discussion of RAI-4RAI-4: Revise the license renewal application (LRA) to include a water chemistry program as part of the AMP for the concrete pad, or provide justification for exclusion.

17Discussion of RAI-4 (Cont'd)Response to RAI-4:Will revise AMP in Appendix A to LRA, to include groundwater chemistryProposed Frequency is every six monthsProposed acceptance criteriaChloride 500 ppmSulfate 1500 ppmpH 5.5 18Discussion of RAI-5RAI-5: Revise inspection frequencies consistent with ACI 349.3R or justify discrepancies. Also, justify opportunistic inspections of below-grade areas.

19Discussion of RAI-5 (Cont'd)Response to RAI-5:Inspection frequency for ISFSI concrete pad is proposed to be the same as other PINGP concrete structuresAbove-grade -5 yearsInaccessible -inspections of opportunityWill clarify frequency in LRA Section A2.4.2Inspection frequency consistent with GALL, NUREG-1801, Rev.2,Section XI.S6, Structures Monitoring 20Discussion of RAI-6RAI-6: Describe the Corrective Action Program (CAP) and when inspection results of the concrete pad will initiate an Action Request, change to the AMP, or notification to the NRC. Also, address use of operating experience (OE) from other ISFSIs.

Explain monitoring and trending of identified but uncorrected aging effects.

21Discussion of RAI-6 (Cont'd)Response to RAI-6:CAP Action Request initiated when acceptance criteria are exceeded:Cracking -identified size limitsChange in material properties -calcium

streaks and deposits (indicative of leaching) Loss of material -identified size limits for

surface scaling, spallingCriteria are consistent with Tier 2 criteria in ACI

349.3R for conditions requiring evaluation 22Discussion of RAI-6 (Cont'd)CAP program is 10 CFR 50 Appendix B programCAP evaluations include:Extent of condition evaluationActions to accept or repair as appropriate, including possible increase in inspection frequency or expansion of sample populationEvaluation for NRC reportabilityDetermination if AMP needs to be revised 23Discussion of RAI-6 (Cont'd)Site OE program reviews issues identified by NRC and industry (e.g., INPO, Owners groups, TN cask users group)Concrete OE issues are similar to other Plant

concrete structure issuesOE reviews could lead to a CAPCAP program evaluation will determine need

for modifying the AMPAMP includes monitoring and trending 24Discussion of RAI-7RAI-7: Provide additional information in the AMP for the berm:Define "absence of aging effects"Provide basis for inspection frequencyIdentify material properties that will change due to dessicationand explain visible signs of change 25Discussion of RAI-7 (Cont'd)RAI-7 Discussion: AMP for berm is consistent with PINGP AMP for earthen structures"Absence of aging effects" for the berm includes:

(aging effects terminology from EPRI reports)No loss of form -no indications of slope instability or settlementNo loss of material -no evidence of erosion No change in material properties -no evidence of

erosion 26Discussion of RAI-7 (Cont'd)Dessicationis a drying of soils that results in a loss of soil adhesion -visible signs would include accelerated effects of erosionInspection frequency of 5 years is based on Plant

structural inspections, also consistent with GALL report, NUREG-1801 Rev. 2 27Discussion of RAI-8RAI-8: Provide a detailed technical basis for the acceptance criteria for visual examinations of the cask: the absence of any signs of aging, as indicated in LRA Section A2.6.2.

28Discussion of RAI-8 (Cont'd)Response to RAI-8Acceptance criteria of the "absence of any of the aging effects listed in Table A2.1-1" ensures conservative initiation of an Action Request in the CAP program Aging effect listed in Table A2.1-1 for casks is

"Loss of Material" due to various corrosion mechanismsAcceptance criteria are not met if Inspector

observes any corrosion 29Discussion of RAI-8 (Cont'd)Any observed corrosion is evaluated in the CAP programCAP Program relies on engineering evaluations to

determine actions Calculation referred to in the RAI provides basis for inspection frequency -is not a quantitative or actionable operation criterion 30Discussion of RAI-9RAI-9: Provide conclusive evidence to support no observable loss of material statement regarding the lead cask examination. Also, clarify photographs of the inspection and address observations regarding pits and measurable loss of material.

31Discussion of RAI-9 (Cont'd)Response to RAI-9: Use of visual examinations is consistent with NUREG 1927, AppxE, Component Specific Aging ManagementOnly "conclusive evidence" is inspection report with

documented observationsby the inspectorInspector documented no observable depth to

corrosion (including pitting corrosion)AMP will be revised to clarify "no measureable loss of material" should be "no observable loss of material"Discussion of photos and annotations 32Discussion of RAI-11RAI-11: Provide a TLAA to support position that there will be no buildup of flammable hydrogen based on radiolytic degradation of the neutron shield polymer. Provide AMP for the relief valve if needed.

33Discussion of RAI-11 (Cont'd)Response to RAI-11: Will provide analysis:Calculation of potential flammable gas generation based on methodology in NUREG/CR-6673Conservatively includes energy deposition in resin from both gamma and neutron radiationThe amount of gas generated is less than solubility

c apacity of resinAnalysis concludes that the amount of flammable gas released from resin would be negligible 34Discussion of RAI-10RAI-10: Provide an AMP to detect degradation of cask neutron shield. The current radiation monitoring program does not adequately address detector selection, measurement location selection, resolution of measurement data, time dependency of the decaying source term, or detection of cracks or unexpected degradation of the shield.

35Discussion of RAI-10 (Cont'd)Response to RAI-10: NSPM will provide additional support for position that there is no aging effect for neutron shield that could result in a loss of shielding intended functionAging effects such as embrittlement, cracking, loss

of elasticity do not affect intended functionCalculation discussed in response to RAI 11 shows

hydrogen generated by radiolytic degradation will remain absorbed in the poly material No loss of shielding 36Discussion of RAI-10 (Cont'd)Will provide clarification that current surveys can detect degradation before loss of intended functionIntended function is to provide shielding for

compliance with offsite dose regulations, as demonstrated by Safety AnalysisLoss of intended function would be defined as a

reduction in shielding effectiveness that results in actual dose rates that exceed those based on the Safety Analysis 37Discussion of RAI-10 (Cont'd)Neutron survey metersWill discuss neutron energy spectrum used during survey meter calibrationWill explain that meter readings are conservatively

higher than actual due to different neutron energy spectra in calibration source vs. casksShielding degradation could result in a shift to

higher energy neutrons which would produce even higher measured values 38Discussion of RAI-10 (Cont'd)Measurement LocationsSurvey measurements at consistent locationsMeasurements taken approximately 2 m from casks

-at a point straight out from each cask Approximately 1 m above groundMinimizes impact of dose from adjacent casks 39Discussion of RAI-10 (Cont'd)Measurement resolutionMeter scale is analog, 1 to 10 mr/hr; data typically recorded to nearest 1 mrElevation is at point of high dose rateConsistent measurement locations provide representative sample of casks 40Discussion of RAI-10 (Cont'd)TrendingTrending of 2-meter survey data shows dose rates below dose rates based on Safety AnalysisIncreases in dose rate trends will detect

degradation before loss of intended function 41Closing Remarks 42 (l Xcel Energy@ RESPONSIBLE BY NATUREŽ Page 1 of 10 A3.0 HIGH BURNUP FUEL MONITORING PROGRAM The Prairie Island ISFSI provides for long-term dry fuel interim storage for High Burnup spent fuel assemblies, i.e., fuel assemblies with discharge burnups greater than 45 GWD/MTU, until such time that the spent fuel assemblies may be shipped off-site for final disposition. The cask system presently utilized at the Prairie Island ISFSI for the storage of High Burnup spent fuel is the Transnuclear TN-40HT which has a 40 fuel assembly capacity and is designed for outdoor storage. The first High Burnup fuel assembly was placed into storage operation at the Prairie Island ISFSI in April of 2013.

The Aging Management Review of the high burnup fuel spent fuel assemblies in a dry inert environment did not identify any aging effects/mechanisms that could lead to a loss of intended function. However, it is recognized that there has been relatively little operating experience, to date, with dry storage of high burnup fuel. Reference A5.8 provides a listing of a significant amount of scientific analysis examining the long term performance of high burnup spent fuel that provides a sound foundation for the technical basis that long term storage, i.e., greater than 20 years, may be performed safely and in compliance with regulations.

However, it is also recognized that scientific analysis is not a complete substitute for confirmatory operating experience. Therefore, the purpose of the High Burnup Fuel Monitoring Program is to confirm that the High Burnup Fuel Assemblies' intended function(s) are maintained during the period of extended operations.

A description of the High Burnup Fuel Monitoring Program is provided below. Although the program is a confirmatory program, the description below uses each attribute of an effective AMP as described in NUREG-1927 for the renewal of a site-specific Part 72 license to the extent possible. In addition to the ten elements called for in NUREG-1927, the program includes an eleventh element, Toll Gate Assessments. This element is intended to provide periodic assessments of available information relative to the storage of high burnup spent fuel.

A3.1 Scope of Program A3.1.1 NUREG-1927 Program Element NUREG-1927 Program Element 1, Scope of the Program, (Reference A5.1) states "The scope of the program should include the specific structures and components subject to an AMR."

A3.1.2 PINGP Program Element The High Burnup Fuel Monitoring Program relies upon the joint Electric Power Research Institute (ERPI) and Department of Energy's (DOE) "High Burnup Dry Storage Cask Research and Development Project" (HDRP) to monitor the condition of high burnup spent fuel assemblies in dry storage as a surrogate program for the high burnup fuel being stored at the Prairie Island ISFSI.

The HDRP is a program designed to collect data from a spent nuclear fuel dry storage system containing high burnup fuel. The program entails loading and storing a TN-32 bolted lid cask (the Research Project Cask) with intact high Page 2 of 10 burnup spent nuclear fuel with four different kinds of cladding (including cladding types used at the Prairie Island Nuclear Generating Plant) at Dominion Virginia Power's North Anna Power Station. At the end of a long-term storage period, which may be up to 10 years or longer, the Research Project Cask will be transported to an off-site Fuel Examination Facility where the cask will be reopened and the fuel examined.

The scope of the High Burnup Fuel Monitoring Program includes those activities outlined in the "High Burnup Dry Storage Cask Research and Development Project Final Test Plan", February 27, 2014, (HDRPTP) prepared by the Electric Power Research Institute.

1) Monitoring temperatures inside and outside the cask. 2) Perform non-destructive and destructive examinations of sister rods to those in the Research Project Cask. These examinations include: a) Visual exams b) Cladding profilometry c) Rod internal pressure and content d) Hydride content and orientation e) Cladding mechanical testing 3) At the end of the long-term storage process, perform similar examinations of rods from the Research Project Cask.

A3.2 Preventive Actions A3.2.1 NUREG-1927 Program Element NUREG-1927 Program Element 2, Preventive Actions, (Reference A5.1) states "Preventive actions should mitigate or prevent the applicable aging effects."

A3.2.2 PINGP Program Element The High Burnup Fuel Monitoring Program consists of temperature monitoring, non-destructive examinations, and destructive examinations of fuel rods to confirm there is no degradation of a high burnup fuel assembly that would result in a loss of their intended function(s). No preventive or mitigating attributes are associated with these activities.

A3.3 Parameters Monitored or Inspected A3.3.1 NUREG-1927 Program Element NUREG-1927 Program Element 3, Parameters Monitored or Inspected, (Reference A5.1) states "Parameters monitored or inspected should be linked to the effects of aging on the intended functions of the particular structure and component."

A3.3.2 PINGP Program Element The parameters monitored by the High Burnup Fuel Monitoring Program are outlined in the HDRPTP. The principle aging effect being monitored is a change in material properties, e.g., ductility, of the cladding due to hydride reorientation.

The intended functions of the fuel cladding that are being monitored include:

Page 3 of 10

• Maintains a pressure boundary (PB)

• Provides structural/functional support (SS)

These functions combine to comply with regulations regarding the protection against degradation that leads to gross ruptures and the retrievability of the fuel.

The hydride reorientation aging mechanism is dependent upon the fuel cladding temperatures during the loading and storage operations. Hence the HDRPTP calls for monitoring of cask internal temperatures during loading and storage operations. These temperatures may then be used to infer the fuel cladding temperatures. The destructive examinations at the off-site Fuel Examination Facility will be used to determine the hydride content and orientation within the fuel cladding. The destructive examinations will also include fuel cladding ductility testing.

A3.4 Detection of Aging Effects A3.4.1 NUREG-1927 Program Element NUREG-1927 Program Element 4, Detection of Aging Effects, (Reference A5.1) states "Detection of aging effects should occur before there is a loss of any structure and component intended function. This includes aspects such as method or technique (i.e., visual, volumetric, surface inspection), frequency, sample size, data collection, and timing of new or one-time inspections to ensure timely detection of aging effects."

A3.4.2 PINGP Program Element The use of information from the surrogate program is an acceptable method to ensure that the potential aging effects of high burnup fuel are identified and managed prior to the loss of intended functions.

The HDRPTP calls for monitoring of cask internal temperatures during the initial cask drying process at one minute intervals. During the long-term storage period temperatures would be collected twice a day. These frequencies will provide data for thermal models during the larger temperature transients encountered during the drying process as well as cladding time at temperature taking into account daily and seasonal temperature fluctuations. This information will provide inputs to the evaluation of hydride reorientation and ductility testing.

The destructive examinations are intended to be performed after a long-term storage period which may be up to 10 years or longer. These examinations will provide a direct indication of the degree of hydride reorientation and ductility of the cladding.

The schedule for the HDRP as outlined in the final test plan calls for the Research Project cask to be loaded and placed in storage in 2017. Thus, information from the destructive examination of the fuel placed into storage would not be expected until after 2027. This schedule provides sufficient time to obtain, evaluate and take any necessary action prior to the high burnup fuel being stored at the Prairie Island ISFSI beyond 20 years. The "toll gate" assessments Page 4 of 10 described in program element A3.11 assure that information from the HDRP and other relevant sources will be regularly conducted in a timely manner.

A3.5 Monitoring and Trending A3.5.1 NUREG-1927 Program Element NUREG-1927 Program Element 5, Monitoring and Trending, (Reference A5.1) states "Monitoring and trending should provide for prediction of the extent of the effects of aging and timely corrective or mitigative actions."

A3.5.2 PINGP Program Element HDRPTP calls for submitting progress reports on a semi-annual basis while the Research Project Cask is in dry storage. It is expected that these reports will include trends of cask internal temperatures which may be used to infer the trend of the fuel cladding temperatures. As previously mentioned the hydride reorientation aging mechanism is dependent upon the fuel cladding temperatures during the loading and storage operations.

The destructive exams are scheduled to occur after a period of long-term storage and are expected to provide information on the extent of the hydride reorientation mechanism and its effect on the ductility of the cladding ductility prior to the high burnup fuel being stored at the Prairie Island ISFSI beyond 20 years.

A3.6 Acceptance Criteria A3.6.1 NUREG-1927 Program Element NUREG-1927 Program Element 6, Acceptance Criteria, (Reference A5.1) states "Acceptance criteria, against which the need for corrective action will be evaluated, should ensure that the particular structure and component intended functions are maintained under the existing licensing-basis design conditions during the period of extended operation."

A3.6.2 PINGP Program Element When information from the ductility testing of the fuel in the Research Project Cask becomes available, an Action Request will be initiated within the NSPM Corrective Action Program to perform a Condition Evaluation. The Condition Evaluation will determine if the results of the ductility testing indicate the need for corrective action to ensure that the fuel cladding will continue to perform its intended functions under the existing licensing-basis conditions.

A3.7 Corrective Actions A3.7.1 NUREG-1927 Program Element NUREG-1927 Program Element 7, Corrective Actions, (Reference A5.1) states "Corrective actions, including root cause determination and prevention of recurrence, should be timely."

Page 5 of 10 A3.7.2 PINGP Program Element Northern States Power Company - Minnesota (NSPM) has a single Corrective Action Program that is applied regardless of the safety classification of the structure or component. The Corrective Action Program requirements are established in accordance with the requirements of the NSPM Quality Assurance Topical Report and 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants."

The Corrective Action Program procedures require the initiation of an Action Request for actual or potential problems including failures, malfunctions, discrepancies, deviations, defective material and equipment, nonconformances, and administrative control discrepancies, to ensure that conditions adverse to quality, operability, functionality, and reportability issues are promptly identified, evaluated if necessary, and corrected as appropriate. Guidance on establishing priority and timely resolution of issues is contained within the Corrective Action Program procedure.

All corrective actions for deviating conditions that are adverse to quality are performed in accordance with the requirements of the Quality Assurance Program which complies with the requirements of 10 CFR 50, Appendix B. Any resultant maintenance, repair/replacement activities, or special handling requirements are performed in accordance with approved procedures. Corrective actions provide reasonable assurance that deficiencies adverse to quality are either promptly corrected or are evaluated to be acceptable. Where evaluations are performed without repair or replacement, engineering analysis reasonably assures that the intended function is maintained consistent with the current licensing basis. If the deviating condition is assessed to be significantly adverse to quality, the cause of the condition is determined and an action plan is developed to preclude recurrence. Corrective actions identify recurring discrepancies and initiate additional corrective actions including root cause analysis to preclude recurrence.

As stated above, when information from the ductility testing of the fuel in the Research Project Cask becomes available, an Action Request will be initiated within the NSPM Corrective Action Program. Actions that are required to resolve inspection findings will be tracked to completion and trended within the Corrective Action Program.

A3.8 Confirmation Process A3.8.1 NUREG-1927 Program Element NUREG-1927 Program Element 8, Confirmation Process, (Reference A5.1) states "The confirmation process should ensure that preventive actions are adequate and appropriate corrective actions have been completed and are effective."

Page 6 of 10 A3.8.2 PINGP Program Element The confirmation process is part of the NSPM Corrective Action Program and ensures that the corrective actions taken are adequate and appropriate, have been completed, and are effective. The focus of the confirmation process is on the follow-up actions that must be taken to verify effective implementation of corrective actions. The measure of effectiveness is in terms of correcting the adverse condition and precluding repetition of significant conditions adverse to quality. Procedures include provisions for timely evaluation of adverse conditions and implementation of any corrective actions required, including root cause evaluations and prevention of recurrence where appropriate. These procedures provide for tracking, coordinating, monitoring, reviewing, verifying, validating, and approving corrective actions, to ensure effective corrective actions are taken.

The Corrective Action Program is also monitored for potentially adverse trends. The existence of an adverse trend due to recurring or repetitive adverse conditions will result in the initiation of an Action Request.

A3.9 Administrative Controls A3.9.1 NUREG-1927 Program Element 9, Administrative Controls NUREG-1927 Program Element 9, Administrative Controls, (Reference A5.1) states "Administrative controls should provide a formal review and approval process."

A3.9.2 PINGP Program Element The NSPM Quality Assurance Program, associated formal review and approval processes, and administrative controls applicable to this program and Aging Management Activities, are implemented in accordance with the requirements of the NSPM Quality Assurance Topical Report and 10 CFR Part 50, Appendix B. The administrative controls that govern AMAs at PINGP are established in accordance with the PINGP Administrative Control Program and associated Fleet Procedures.

A3.10 Operating Experience A3.10.1 NUREG-1927 Program Element NUREG-1927 Program Element 10, Operating Experience, (Reference A5.1) states "Operating experience involving the AMP, including past corrective actions resulting in program enhancements or additional programs, should provide objective evidence to support a determination that the effects of aging will be adequately managed so that the structure and component intended functions will be maintained during the period of extended operation."

A3.10.2 PINGP Program Element It is recognized that there has been relatively little operating experience, to date, with dry storage of high burnup fuel. Hence this element is focused on the principle aging effect being monitored, e.g., ductility, of the cladding due to hydride reorientation.

Page 7 of 10 Ductility tests performed at the Argonne National Laboratory Reference A5.7 describes the results of tests performed by Argonne National Laboratory that examined the possible effects of hydride reorientation on high burnup fuel cladding. The tests involved cladding segments of high burnup spent fuel rods that were subjected to a temperature transient to simulate bounding drying and storage operations. After the temperature, the radial-hydride reorientation was characterized and ring compression tests were performed. Test results show that the trend of the data generated clearly indicates that failure criteria for high-burnup cladding need to include the embrittling effects of radial-hydrides for drying-storage conditions that are likely to result in significant radial-hydride precipitation.

The cladding material used in the test is the same as most of the high burnup fuel cladding stored at the Prairie Island ISFSI. While the burnup of the cladding segments was higher than that allowed to be stored at the Prairie Island ISFSI it is reasonably close. The temperature transient heated the cladding to 400 °C which corresponds to the cladding temperature limit for the fuel stored at the Prairie Island ISFSI. The cooldown rate was conservatively slower than what would be expected for the fuel stored at the Prairie Island ISFSI. For these reasons the cladding used in the ring compression test should be a reasonable representation of the potential condition of the cladding of the fuel stored at the Prairie Island ISFSI.

While the tests were performed on defueled irradiated fuel rod segments, there was no information in Reference A5.7 of the potential gap between the cladding and the fuel pellets. The size of this gap and the presence of the fuel pellets could have a significant impact on the ductility of a fuel rod to pinch type loads. Thus, the results of the ring compression tests may not be applicable to fuel rods in dry storage.

The ring compression test was used as a ductility screening test and to simulate pinch-type loading during cask transportation or cask drops from rod/grid-spacer and rod/rod mechanical interactions. This type of pinch load would occur when a cask is dropped horizontally or when a cask tips over. The current licensing basis for the cask stored at the Prairie Island ISFSI is that the loaded casks are always in the vertical position and cask tip over events are not credible. Thus, the results of the ring compression tests may not be applicable to fuel rods stored at the Prairie Island ISFSI.

A3.11 Toll Gate Assessments

A3.11.1 NUREG-1927 Program Element It is understood that licensees will have formal operating experience assessment programs that evaluate the impact of applicable industry operating experience to their operation. Hence, NUREG-1927 does not include a separate program element for a formal periodic assessment of any new or additional information. When NUREG-1927 was finalized, the need to formally address degradation mechanisms characterized by little to no prior operating experience through future surrogate monitoring programs, such as the HDRP, was not anticipated.

Given the unique nature of this confirmatory program, NSPM is electing to go Page 8 of 10 beyond the guidance of NUREG-1927 and will periodically perform formal assessments of aggregated feedback from the HDRP, along with other information that may be available in the future at specific points in time during the period of extended operations. NSPM is aware that industry and NRC are engaged in public discussions about augmenting NUREG-1927 for this purpose and that the term "toll gates" has been coined to describe such intended periodic assessments. Accordingly, this element is being added to the program to describe specific periodic future assessments that will be conducted as part of this confirmatory program.

A3.11.2 PINGP Program Element

Formal evaluations of the aggregate feedback from the HDRP and other sources of information will be performed at the specific points in time during the period of extended operation delineated in the table below. These evaluations will include an assessment of the continued ability of the High Burnup Fuel Assemblies to continue to perform their intended function(s) at each point.

Toll Gate Year* Assessment 1 5 Evaluate, if available, information obtained from the HDRP loading and initial period of storage (during which the highest temperatures are likely to be observed) along with other available sources of information. If the HDRP cask has not been loaded at this point and no other information is available, move the next Toll Gate assessment forward 5 years. 2 15 Complete any outstanding evaluations from Toll Gate 1. Evaluate, if available, information obtained from the destructive examination of the fuel placed into storage in the HDRP along with other available sources of information. If the aggregate of this information confirms ability of the High Burnup Fuel Assemblies to continue to perform intended function(s) for the remainder of the renewal period, subsequent toll gate assessments may be cancelled. If the HDRP fuel has not been examined at this point and no other information is available, move the next Toll Gate assessment forward 5 years. 3 25 Complete any outstanding evaluations from Toll Gates 1 & 2 and evaluate any other new information. If the aggregate of this information confirms ability of the High Burnup Fuel Assemblies to continue to perform intended function(s) for the remainder of the renewal period, subsequent toll gate assessments may be cancelled. If the information is inconclusive, move the next Toll Gate assessment forward 5 years 4 35 Complete any outstanding evaluations from Toll Gates 1-3 and evaluate any other new information. *Calculated from the effective date of the renewed license

Page 9 of 10 At each of these toll gates, the impact of the aggregate feedback will be assessed and actions taken when warranted. The toll gates amplify the existing practice of continuously evaluating site-specific and industrywide operational experience for impacts on aging management. These evaluations will address any lessons learned and take appropriate corrective actions, including:

• Perform repairs or replacements

• Modify this confirmatory program in a timely manner

• Adjust age-related degradation monitoring and inspection programs (e.g., scope, frequency)

The above toll gates are not, by definition, stopping points. No particular action other than performing an assessment is required to continue cask operation. To proceed through a toll gate, an assessment of aggregated available operating experience (both domestic and international), including data from monitoring and inspection programs, NRC-generated communications, and other information will be performed. The evaluation will include an assessment of the ability of the High Burnup Fuel Assemblies to continue to perform their intended function(s) until the next toll gate is approached. The above toll gates also represent formal opportunities for NSPM to take corrective actions, such as repairs or replacements, and to make adjustments to this program in support of operations through the period of extended operations.

The evaluations and assessments will be retained as records within NSPM's record management system.

A5.0 References (Appendix A, Aging Management Program) A5.1 NUREG-1927, Standard Review Plan for Renewal of Spent Fuel Dry Cask Storage System Licenses and Certificates of Compliance, March 2011. A5.2 EPRI Report 1002882, Dry Cask Storage Characterization Project, Final Report, September 2002. A5.3 Letter from D.A. Christian, Virginia Electric and Power Company to D.A. Cool (NRC), Surry Independent Spent Fuel Storage Installation License Renewal Application, dated April 29, 2002, ADAMS Accession Number ML021290068. A5.4 Transnuclear Information Bulletin, April 2001. A5.5 Letter from G. L. Stathes, Exelon Generation Company to Director Spent Fuel Project Office (NRC), Submittal of Independent Spent Fuel Storage Installation (ISFSI) Cask Event Report, dated December 01, 2010, ADAMS Accession Number ML110060275. A5.6 American Concrete Institute, ACI 349.3R-96, Evaluation of Existing Nuclear Safety-Related Concrete Structures, January 1996. A5.7 M.C. Billone, T.A. Burtseva, and R.E. Einziger, "Ductile-to-Brittle Transition Temperature for High-Burnup Cladding Alloys Exposed to Simulated Drying-Storage Conditions," in the Journal of Nuclear Materials, Volume 433, Issues 1-3, pages 431-448, February 2013. A5.8 Letter from R. McCullum (NEI) to M. Lombard (NRC), dated March 22, 2013, "Industry Analysis and Confirmatory Information Gathering Program Page 10 of 10 to Support the Long-Term Storage of High Burnup Fuel (HBF)," (ADAMS Accession No. ML13084A045).

Elements of anAging Management Program (AMP)Division of Spent Fuel Storage and TransportationOffice of Nuclear Material Safety and SafeguardsU.S. Nuclear Regulatory CommissionPINGP ISFSI Public MeetingJune 16, 2014 Regulatory Basis

• 10 CFR 72.42(a), 72.240(c): TLAAs that demonstrate that ITS SSCs will continue to perform their intended function for the period of extended operation.A description of the AMP for management of issues associated with aging that could adversely affect ITS SSCs.

• Guidance: NUREG-1927 AMP Elements:

• Increased efficiency and reduced number/rounds of Requests for Additional Information with complete AMPs1.Scope of the Program2.Preventive Actions 3.Parameters Monitored/Inspected 4.Detection of Aging Effects 5.Monitoring and Trending6.Acceptance Criteria 7.Corrective Actions 8.Confirmation Process 9.Administrative Controls 10.Operating Experience 2

AMP Elements1.Scope of the ProgramNUREG-1927:The scope should include the specific SSCs subject to an AMRComponent and subcomponent Material of constructionEnvironmentAging mechanisms for material/environment combinationAging effects corresponding to the aging mechanism2.Preventive ActionsNUREG-1927:Preventive actions should mitigate or prevent the applicable aging effectsActions to minimize, control, or prevent the degradation mechanism (e.g. peak cladding temperatures below ISG-11, rev. 3 limit during drying) 3 AMP Elements3.Parameters Monitored or InspectedNUREG-1927:Parameters monitored or inspected should be linked to the effects of aging on the intended functions of the particular structure and componentParameters (e.g. cracking, loss of material, temperature, fluence, etc.)Location (e.g. at highest heat location, at 1 m from cask)4.Detection of aging effectsNUREG-1927:Detection of aging effects should occur before there is a lossof any structure and component intended functionMethod/technique (e.g. visual, volumetric, and/or surface inspections or surveys)*Justification & qualification that technique can achieve proposed acceptance criteria for detecting potential aging effects to be monitored or inspectedFrequency of inspection (e.g. inspection intervals)Sample size (dependent on operational experience trending)Data collection (clearinghouse for operational experience)Timing (new or one-time inspections) 4 AMP Elements5.Monitoring & TrendingNUREG-1927: Should provide for prediction of the extent of the effects of aging and timely corrective or mitigativeactionsAssess effects per prior inspections and industry-wide operational experienceTrack trending of aging effects (e.g. corrosion rate, crack growth rate, etc.)6.Acceptance CriteriaNUREG-1927:Acceptance criteria, against which the need for corrective action will be evaluated, should ensure SSC intended function is maintained under the existing licensing-basisdesign conditions during the renewal periodCriteria for evaluating inspection results for operable aging effectsDomestic and International consensus codes and standards, or previously used criteria if relevancy is justified and establishedTechnical basis for these criteria should be providedSeparate criteria should be provided for each aging effect 5

AMP Elements7.Corrective ActionsNUREG-1927: Corrective actions, including root cause determination andprevention of recurrence, should be timelyCAP commensurate with 10 CFR 71 Subpart G, or 10 CFR 50 Appendix BMaintenance plans, corrective actions for the specific degradation effects (e.g. repair, replacement, mitigation activities, and extent of condition)Actions to prevent reoccurrenceJustification for repair, replace, and/or mitigate deferralAnalysis of how action may affect other subcomponentsConsideration of corrective actions on other componentsPlans for OE incorporation into the remediation plan8.Confirmation ProcessNUREG-1927:Confirmation process should ensure that preventive actions are adequate & appropriate corrective actions have been completed & are effectiveQA Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix BMethod to confirm actions required are takenFollow up action to determine success (e.g. effectiveness of repair) 6 AMP Elements9.Administrative ControlsNUREG-1927:Administrative controls should provide a formal review and approval processCAP commensurate with 10 CFR 71 Subpart G, or 10 CFR 50 Appendix BInspector requirementsRecord retention requirementsReview process of examination resultsFrequency/methods for reporting inspection results to NRCFrequency for updating AMP based on industry-wide operational experience10.Operating ExperienceNUREG-1927:Include past corrective actions resulting in program enhancements; objective evidence to support a determination that the effects of aging will be adequately managed so that the structure and component intended functions will be maintained during the period of extended operationProvide specific industry-wide operational experience that supports the use of an examination method, inspection frequency, and/or inspection criteria 7

Path Forward 8*Staff developed generic AMP guidance for specific near-term aging effects:-Fuel performance-Concrete

-Polymer-based neutron shielding Fuel Performance AMP DevelopmentRobert E. Einziger, Ph.D.Division of Spent Fuel Storage and TransportationOffice of Nuclear Material Safety and SafeguardsU.S. Nuclear Regulatory CommissionPINGP ISFSI Public MeetingJune 16, 2014 1

AMP Element 1:Scope of the Program 2*Components/Materials of Construction

-Spent Fuel with maximum burnupof XXX-Cladding types XXX with maximum cladding temperature of XXX*Environment-Dry helium*Aging effects for material/environment combinations-DOE Cask Demo Project:*Fuel cladding breach*Assembly distortion

• Residual moisture after drying

• Changes in the hydride structure of the claddingNUREG-1927:

The scope of the program should include the specific structures and components subject to an AMR AMP Element 2:Preventive Actions 3*NRC considerations:

-Casks/Canisters dried per the accepted procedure in NUREG -1536, Standard Review Plan for Dry Cask Storage Systems-Backfilled with helium cover gas-Maximum cladding temperature is maintained below the recommended ISG-11 Rev 3 limitsNUREG-1927:

Preventive actions should mitigate or prevent the applicable aging effects AMP Element 3:Parameters Monitored/ Inspected 4*Surveillance demonstration program meeting ISG-24:

-Maximum cladding temperature-Inspection for the presence of fission gas in the cover gas-Inspection for presence of water vapor in the cover gas

-Inspection for hydrogen to determine that any radiolysis of residual or bound water does not produce a flammable condition-Profilometryat the completion of the storage period to determine creep deformation -Gas puncturing at completion of storage to determine cladding stress for creep calculations-Cladding metallography at the completion of storage to determine condition of cladding hydridesNUREG-1927:

Parameters monitored or inspected should be linked to the effects of aging on the intended functions of the particular structure and component AMP Element 4:Detection of Aging Effects 5*Surveillance demonstration program meeting ISG-24:

-Calibrated thermocouple lances to measure the radial and axial temperature profile-Fission gas analysis technique for the cover gas with sensitivity to detect release of 1% of the fission gas produced in 1% of the cask rods with the lowest burnupin the demonstration-Residual moisture detection technique with sensitivity to detect the vapor pressure at the bottom of the demonstration system-Hydrogen detection technique with sensitivity to detect 2% hydrogen in the cover gas of the demonstrationNUREG-1927:

Define method or technique, frequency, sample size, data collection, and timing to ensure timely detection of aging effects AMP Element 5:Monitoring & Trending 6*As information/data from a fuel performance surveillance demonstration program becomes available, the licensee will monitor, evaluate, and trend the information via their Operating Experience Program and/or the Corrective Action Program to determine what actions should be taken to manage fuel and cladding performance, if any *Similarly, the licensee will use its Operating Experience Program and/or Corrective Action Program to determine what actions should be taken if it receives information/

data from other sources than the demonstration program on fuel performance NUREG-1927:

Should provide for prediction of the extent of the effects of aging and timely corrective or mitigativeactions AMP Element 6:Acceptance Criteria 7*ISG-24 acceptance criteria provide detailed guidance

• Cask internals and fuel performance criteria:-Temperature: spatial distribution and time history accurately determined necessary since the behavior of the rods in the demonstration to the behavior expected of the rods in storage is temperature dependent. -Cladding Creep: total creep strain extrapolated to the total approved storage duration based on the best fit to the data, accounting for initial condition uncertainty shall be less than 1% -

ISG-11 temperature limits are based on limiting creep to <1%NUREG-1927:

Acceptance criteria, against which the need for corrective action will be evaluated; should ensure that SSC functions are maintained AMP Element 6:Acceptance Criteria 8*Cask internals and fuel performance criteria:

-Hydrogen -maximum hydrogen content of the cover gas over the approved storage period shall be extrapolated from the gas measurements to be less than 5% -limit for precluding possible flammable mixture-Drying -The moisture content in the cask , accounting for measurement uncertainty, shall indicate no greater than one liter of residual water after the drying process is complete -Drying limit, in terms of residual moisture, in the SRP NUREG-1536-Fuel rod breach -fission gas analysis shall not indicate more than 1% of the fuel rod cladding breaches. -Recommended maximum number of cladding breaches during normal conditions of storage for containment analysis by ISG-5NUREG-1927:

Acceptance criteria, against which the need for corrective action will be evaluated; should ensure that SSC functions are maintained AMP Element 7:Corrective Actions 9*Licensee Corrective Action Program commensurate with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B*Licensee Corrective Action Program to capture and evaluate surveillance demonstration program data, other information/data, and additional operating experience to initiate corrective and/or preventative actions:-Corrective actions to prevent reoccurrence

-Extent of condition to other susceptible components

-Timely corrective actionsNUREG-1927:

Corrective actions, including root cause determination and prevention of recurrence, should be timely AMP Elements 8:Confirmation Process 10*Licensee Quality Assurance Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B*Follow up action to determine success*Method to confirm any actions required are takenNUREG-1927:

Confirmation process should ensure that preventive actions are adequate & appropriate corrective actions have been completed & are effective AMP Elements 9:Administrative Controls11*Licensee Quality Assurance Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B*Training requirements for inspectors*Records retention requirements

• As specified in the DOE Cask demonstration Project Plan or alternate surveillance demonstration program meeting the ISG-24 guidance*Frequency for updating AMP based on industry-wide operational experienceNUREG-1927:

Administrative controls should provide a formal review and approval process AMP Element 10:Operating Experience 12*Surrogate surveillance demonstration programs with storage conditions and fuel types similar to those in the dry storage system that satisfies the ISG-24 acceptance criteria is a viable method to obtain operating experience*Licensee intends to rely on the information from the Department of Energy (DOE) High BurnupFuel Cask Research and Development program with similar types of HBU fuel as provided in the response to RAI 3-2*DOE Dry Cask Storage Demonstration Project is viable as a surrogate surveillance program for the industry*Additional data/research to assess fuel performanceNUREG-1927:

Include past corrective actions; provide objective evidence to support a determination that the effects of aging will be adequately managed so that the SSC intended functions will be maintained during the period of extended operation Concrete AMP DevelopmentRicardo D. Torres, Ph.D.Division of Spent Fuel Storage and TransportationOffice of Nuclear Material Safety and SafeguardsU.S. Nuclear Regulatory CommissionPINGP ISFSI Public MeetingJune 16, 2014 1

Concrete AMP Criteria

• Valid criteria include applicable consensus codes/standards and/or NUREG guidance, e.g.:ACI 349.3R, "Evaluation of Existing Nuclear Safety-Related Concrete Structures"ASME Code Section XI, Subsection IWL, "Requirements for Class CC Concrete Components of Light-Water-Cooled Plants"NUREG-1801, "Generic Aging Lessons Learned (GALL) Report"

• Applicant may propose AMPs based on alternate criteria:Exclusion of aging effects/mechanisms in the above codes/standards should be justified with a site-specific technical basis (e.g., engineering analysis, operational experience data).Justification should demonstrate that the excluded aging mechanisms will not adversely affect the ability of the in-scope structure to perform its intended ITS function during the license period of extended operation.

2 Aging Effects/MechanismsMechanismEffectFreeze-thawCracking, loss of material (spalling,scaling)Chemical attack [Cl, SO 4]Cracking, loss of material (spalling,scaling)

Aggregate reactions/expansionCrackingand loss of strengthCorrosion of embedded steelCracking, loss of material (spalling,scaling) and loss of bondLeaching of Ca(OH) 2 CaCO 3Increasein porosity/permeability, loss of strengthSettlementCracking,distortionGamma irradiationCracking, reduction in strength (change in mechanicalproperties)High temperaturedehydrationCracking, reduction in strength (changein mechanical properties) 3Not necessarily all-inclusive Gamma Radiation /Thermal Dehydration*Reductions in strength and elastic modulus not managedby this AMP -visual examination not sufficient*TLAA may be used to demonstrate that no part of the concrete exceeds critical cummulativefluencesper ACI 349.3R:1017neutrons/m 2; 1010rad (gamma dose)"Change in Materials Properties"*Definition per either ASTM C1562 or EPRI 1002950 not implicit, i.e.:increases in permeability and porosityreduction in pH value, tensile strength, compressive strength, modulus of elasticity, and bond strength*Reference to this "aging effect" must include proper definitionin the LRA 4

AMP Element 1:Scope of the ProgramNUREG-1927:

The scope of the program should include the specific structures and components subject to an AMR1.Visual inspection of all above-grade (accessible, inaccessible) and below-grade (underground) concrete areasACI 349.3R: "All safety-related structures should be visually inspected at intervals not to exceed 10 years"2.Groundwater chemistry programto manage below-grade (underground) effectsCorrosion of embedded steelChemical attack (chloride, sulfate induced degradation)3.Periodic radiation surveysControlled Area:Compliance with 10 CFR 72.104.Near cask (1m):Monitor effectiveness as neutron shield; SAR validation 5

AMP Element 2:Preventive ActionsNUREG-1927:

Preventive actions should mitigate or prevent the applicable aging effects*Program is for Condition Monitoring*Design in accordance to ACI 318 or ACI 349, as applicable.Otherwise,For locations in moderate (100-500 day-inch/yr) and severe (>500 day-inch/yr) weathering conditions, concrete mix design must meet the air content & water-to-cement ratio requirements of ASTM C260 or ASME Sect. III, Div. 2.Petrographic examination (ASTM C295 or equivalent) must demonstrate reactive aggregates do not lead to loss of function.*Site-specific AMP required if:Dewatering system used to prevent settlementEmbedded aluminum components without protective insulating coating 6

AMP Element 3:Parameters Monitored/ InspectedNUREG-1927:

Parameters monitored or inspected should be linked to the effects of aging on the intended functions of the particular structure and component

• Quantify effects including cracking, material loss (spalling, scaling), loss of bond, increased porosity/permeability.*ACI 201.1R and SEI ASCE 11-99: exemplary visuals of effects.

• Evaluation should identify, e.g:*Contributing factors should be documented, e.g.:affected surface areageometry/depth of defectcracking, crazing, curlingdelaminations, deflectionshoneycombing, bug holespopouts,voidsexposure of embedded steelstaining/ evidence of corrosiondusting, efflorescence of any colorsurface geometry supporting pondingwidening due to abrasion/ other weather effects 7

AMP Element 4:Detection of Aging EffectsNUREG-1927:

Define method or technique, frequency, sample size, data collection, and timing to ensure timely detection of aging effects

• Method/techniqueAMP must include justification that the technique can achieve the acceptance criteriaABOVE-GRADE (accessible): visual (e.g., feeler gauges, crack comparators)ABOVE-GRADE (inaccessible)/ BELOW-GRADE (underground)*Visual: site-qualified system with valid sensitivity/resolution (e.g., video/ fiber optic camera)*Ground water monitoring program: qualified chemical analysis method (e.g. ICP-MS, IC)*Radiation surveys: calibrated detector for expected energy range

• Frequency of Inspection(commensurate with ACI 349.3R)ABOVE-GRADE (accessible and inaccessible): 5 yearsBELOW-GRADE (underground): 10 yearsUse of opportunistic inspections in lieu of planned inspections must include valid technical basis (engineering justification, operational experience data).

8 AMP Element 4:Detection of Aging Effects (cont.)NUREG-1927:

Define method or technique, frequency, sample size, data collection, and timing to ensure timely detection of aging effects

• Frequency of Inspection(cont.)Water chemistry program/ radiation survey measurements: 5 years, or justifiedDaily inspections of inlet/outlet vents to ensure ACI 349.3R temperature limits (or technical specifications) are not exceeded.

• Sample size:All surface areas as stated in scope, or justified sizeLocations justified by application

• Data collectionCommensurate with ACI 562, ACI 224.1R guidelines for quantitative crack analysis (width, depth, extent)

• TimingLead canister inspection / frequency specified by AMPInspection frequencies may be accelerated per site CAP

• Inspector QualificationsCommensurate with ACI 349.3R 9

AMP Element 5:Monitoring & TrendingNUREG-1927:

Should provide for prediction of the extent of the effects of aging and timely corrective or mitigativeactions

• Commensurate with:Defect evaluation standards/references (e.g. ACI 201.1R, ACI 562, ACI 224.1R for crack evaluation)Acceptance criteria and inspector qualifications (e.g., ACI 349.3R, ASME Code Section XI)

• AMP should describe CAP components/procedures used to:Update a given SSC baseline based on previous inspectionsTrack trending of parameter, or effect not corrected in a previous inspection, i.e.:*Crack growth rates*Corrosion rates*Pore density/ affected areas

• Radiation data 10 AMP Element 6:Acceptance CriteriaNUREG-1927:

Acceptance criteria, against which the need for corrective action will be evaluated; should ensure that SSC functions are maintained

• Visual:Commensurate with ACI 349.3R (3-Tier Quantitative Criteria):Acceptance without further evaluationAcceptance after reviewAcceptance requiring further evaluation

• Groundwater Chemistry Program:ASME Code Section XI, NUREG-1801Aggressive below-grade environment: pH < 5.5, chlorides > 500 ppm, or sulfates > 1500 ppm

• Radiation SurveysControlled area: 10 CFR 72.104Near cask (1 m): Per bounding value/ justified variance (fluence, energy range)

• Alternative acceptance criteria may be provided, but must:Include a quantitative basis (justifiable by OE, engineering analysis/standards)Avoid use of non quantifiable phrases (e.g. significant, moderate, minor, little, slight, few, etc.)Be achievable -Method/technique must be able to meet the stated values (i.e. sufficient resolution/sensitivity)11 AMP Element 7:Corrective ActionsNUREG-1927:

Corrective actions, including root cause determination andprevention of recurrence, should be timely

• CAP commensurate with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B.Justification for non-repairs (e.g., engineering analysis)Cracking: ACI 224.1R, ACI 562 and ACI RAP BulletinsSpalling/scaling: ACI 562, ACI 506R, and ACI RAP Bulletins

• AMP should provide criteria applied to determine which inspection results will require either:An Action Request (e.g, Tier 2 Acceptance per ACI 349.3R)Modification to the existing AMPNotification to the NRC (e.g., Tier 3 Acceptance per ACI 349.3R)

• AMP should provide details on how CAP will capture and evaluate operating experience from other ISFSIs with similar in-scope SSCs.Clarify how external OE will initiate any of the above action items 12 AMP Elements 8/9:Confirmation Process/Admin ControlsNUREG-1927:The confirmation process should ensure that preventive actions are adequate and appropriate corrective actions have been completed and are effectiveAdministrative controls should provide a formal review and approval process*Licensee's Quality Assurance Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B.

13 AMP Element 10:Operating ExperienceNUREG-1927:

Include past corrective actions; provide objective evidence to support a determination that the effects of aging will be adequately managed so that the SSC intended functions will be maintained during the period of extended operationSource Review:

• Internal/External Condition ReportsIdentify age-related degradation*Include justification for CRs not identified as age-related degradationConsider CARs for proposed:*Acceptance criteria*Frequency of inspection

• Information Notices

• Acceptable Industry Initiatives (e.g. DOE cask demo, EPRI-sponsored inspections)

• OE presented in LRA should support the proposed AMP 14 Additional Slides 15 Radiation Acceptance CriteriaNUREG-1536 (SRP Spent Fuel Dry Storage Systems/ General License)Section 6.5.4.3 -Dose RatesGuidance for the selection of points at which the dose rates should be calculated.*For normal and off-normal conditions, applicant should indicate the dose rate at all locations accessible to occupational personnel during cask loading, transport to the ISFSI, and maintenance and surveillance operations.Locations include points at or near various cask components and in the immediate vicinity of the cask and the bottom of the transfer cask.*e.g.: vent areas, trunnionareas, peak side of the cask, peak top of the cask, the canister-gap regionCalculate dose rates at 1m from these locationsNUREG 1567 (SRP Spent Fuel Dry Storage Facilities)Section 11.4.3 -Dose Assessment*Estimated dose rates should be provided for representative pointswithin the restricted areas as well as on and beyond the perimeter of the controlled area.

16 Aging Management Program forPolymer-based Neutron ShieldZhian Li, Ph.D.Sr. Criticality and Shielding EngineerDivision of Spent Fuel Storage and TransportationOffice of Nuclear Material Safety and SafeguardsU.S. Nuclear Regulatory CommissionPINGP ISFSI Public MeetingJune 16, 2014 1

Bases10 CFR 72.42(a), 240(c)(2), and 240(c)(3) require for licenserenewal to include:1)TLAAs that demonstrate that important to safety (ITS) SSCs will continue to perform their intended functions for the requested period of extended operation; and 2)A description of the AMP for management of issues associated with aging that could adversely affect ITS SSCs.Neutron shield is identified as an ITS component that requires an aging management program

-NUREG-1927: Standard Review Plan for Renewal of Spent Fuel Dry Cask Storage System Licenses and Certificates of Compliance 2

Polymer-based Neutron Shield Intended FunctionNeutron shield achieves its safety function by:-slowing down neutrons to reduce their energies and hence radiation -absorbing neutrons (primarily low energy) by boron-10 in the polymer to reduce the intensity of neutron radiation 3 Polymer-based Neutron Shield degradationPolymer will degrade due to exposure to heat (thermolysis) or high level radiation(radiolysis)Aging effects-Cracking-Loss of material, shrinkage and loss of polymer chemical bond due to thermolysisand radiolysis -Loss of B-10 content due to neutron depletion 4

Polymer-based Neutron Shield degradation (Cont.d)Loss of shielding function because of:-Formation of neutron streaming paths due to cracking-Loss of neutron moderation and absorption capacity due to:*Reduction in polymer material thickness and effective density *Loss of B-10 5

Polymer-based Neutron Shield AMP Elements1. Scope of Program: This program monitors the performance of the polymer-based neutron shield for spent fuel cask during the extended period of operation of an ISFSI2. Preventive Actions: This AMP is a condition monitoring program. No preventative actions are needed.

6 Polymer-based Neutron Shield AMP Elements (Cont.d)3. Parameters Monitored/Inspected: -One intuitive way to monitor the performance of the neutron shield is to monitor neutron radiation outside the cask-The parameter to be monitored is the difference between measured and calculated neutron radiations 7

Polymer-based Neutron Shield AMP Elements (Cont.d)4. Detection of Aging Effects: -Persistent unexpected difference between measured and calculated neutron radiation levels-Shift in spectrum of the neutrons measured outside the cask-Change in the radiation profile in either axial and/or azimuthal directions 8

Polymer-based Neutron Shield AMP Elements (Cont.d)5. Monitoring and Trending: -Monitor the radiation measurement results, including radiation intensity and neutron spectrum -Trend the difference between measured and calculated neutron radiations -For trending analyses:*Neutron source as a function of time should be determined via calculation*Expected polymer shrinkage should be determined via TLAA*The measured radiation should factor out the background radiation 9

Polymer-based Neutron Shield AMP Elements (Cont.d)6. Acceptance Criteria:-No unexpected increase in neutron radiation intensity-No apparent neutron spectrum shift

-No change in the neutron axial radiation profile

-Neutron radiation measurement locations must be comprehensive to ensue any neutron shield degradation is detected -Neutron detector(s) must be appropriate for detecting the neutrons at all energy levels-Neutron detector(s) must be calibrated following appropriate QA program 10 Polymer-based Neutron Shield AMP Elements (Cont.d)6. Acceptance Criteria (cont.d):-A baseline should be established for the difference between measured and calculated neutron radiations -Expected polymer shrinkage should be determined via TLAA-The measured radiation should factor out the background radiation -Measurement personnel should be qualified for the measurement task including operation of the detectors 11 Polymer-based Neutron Shield AMP Elements (Cont.d)7. Corrective Actions:-Corrective actions must be taken if loss of intended function or potential loss of intended function is determined-Corrective action(s) must be effective and long lasting, temporary neutron shield is not acceptable as a solution-A TLAA demonstrating that there is no longer a need for the neutron shielding function due to neutron source decay is an acceptable option 12 Polymer-based Neutron Shield AMP Elements (Cont.d)8. Confirmation Process:-Site quality assurance (QA) procedures, review and approval processes, and administrative controls should be implemented in accordance with the requirements of 10 CFR Part 72, Subpart G9. Administrative Controls: Programs implemented to meet the requirements of 10 CFR Part 72, Subpart G, are acceptable for addressing this element 13 Polymer-based Neutron Shield AMP Elements (Cont.d)10. Operating Experience (OE):-OE is a critical component of an AMP-The effectiveness of an AMP is verified by OE

-AMP should be updated and improved based on site-specific and industry OE events-A periodic review and revision of the AMP should be made based on tollgate schedule -AMP should include specific requirement for implementing the above-mentioned items 14 References*NUREG-1801, Generic Aging Lessons Learned, Rev. 2, December 2010.*Y. Liu, et. al., Managing Aging Effects on Dry Storage Systems for Extended Long-Term Storage and Transportation of Used Fuel, Rev. 1, Argonne National Laboratory, Sept. 2013*H. L. McManus, et., al., Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures, NASA Technical Memorandum 4682, Massachusetts Institute of Technology, 1996 *L. Fu, et, al, An Investigation of Radiation Damage in Cured Epoxy Resin System Using Regression Experiment Design, Electrical Insulation and Dielectric Phenomena, 1988. Annual Report, Conference on Date 16-20 Oct. 1988.*S. S. Cota, et. al, Changes in mechanical properties due to gamma irradiation of high-density polyethylene, Brazilian Journal of Chemical Engineering, Vol. 24, No. 02, pp. 259 -265, April -

June, 2007 *SCALE: A Comprehensive Modeling and Simulation Suite for Nuclear Safety Analysis and Design, ORNL/TM-2005/39, Oak Ridge National Laboratory, June, 2011.*MCNP -A General Monte Carlo N-Particle Transport Code, Version 5, Los Alamos National Laboratory, LA-UR-03-1987, April 24, 2003 (Revised 2/1/2008). *D.V. Jordan, et al, Methods and Instruments for Fast Neutron Detection, PNNL-15214, Pacific Northwest National Laboratory, May 2005.*M.L., Johnson, Radiation Protection Instrument Manual, PNL-MA-562, PNNL-14135-Rev. 1, Pacific Northwest National Laboratory, August 2009 15