ML23235A186
| ML23235A186 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/2023 |
| From: | King D, Carla Roque-Cruz Licensing Processes Branch |
| To: | |
| References | |
| Download: ML23235A186 (1) | |
Text
Higher Burnup Workshop IV August 31, 2023
Opening Remarks Andrea Kock Deputy Office Director NRR
Agenda Time Topic Speaker 12:30 - 12:40 Welcome and Opening Remarks NRC 12:40 - 12:55 Accident Tolerant Fuel (ATF) Roadmap to Readiness NRC 12:55 - 1:05 Increased Enrichment Rulemaking Update NRC 1:05 - 1:25 Introduction to the New Fuels ATLAS NRC 1:25 - 1:45 Update on the Collaborative Research on Advanced Fuel Technologies for LWRs (CRAFT) Industry, DOE 1:45 - 2:00 Discussion NRC, DOE, Industry 2:00 - 2:15 Break All 2:15 - 2:30 Non-LOCA Release Fractions for Burn Up > 68 GWd/MTU NRC 2:30 - 2:50 Source Terms with Higher Burnup Using MELCOR NRC 2:50 - 3:10 Assess the Impact of Prototypic High Burnup Operating Conditions on Fuel Fragmentation Relocation DOE and Dispersal Susceptibility 3:10 - 3:25 Environmental Evaluation of ATF with Increased Enrichment and Higher Burnup Levels NRC 3:25 - 3:40 Discussion NRC, DOE, Industry 3:40 - 3:55 Public Comments Public 3:55- 4:00 Closing Remarks NRC Topic times are estimated based on the participation level and presentation length.
Meeting Logistics
- Meeting visuals and audio are through MS Teams.
- Participants are in listen-only mode until the discussion and public feedback period. During which, we will first allow in-person attendees to participate, then allow remote attendees to un-mute.
- Remote attendees should utilize the hand raised feature in MS Teams, if possible.
- This is an Observation Meeting. Public participation and comments are sought during specific points during the meeting.
- NRC will consider the input received but will not prepare written responses.
- No regulatory decisions will be made during this meeting.
- This meeting is being recorded.
Meeting Purpose
- Exchange information between NRC and industry on higher burnup, increased enrichment, and Accident Tolerant Fuel (ATF) activities.
- Provide an opportunity for members of the public to ask questions of the NRC staff.
ATF Roadmap to Readiness Daniel King, NRR/DORL Carla Roque-Cruz, NRR/DORL
Roadmap Overview
- Issued: June 28, 2023 (ML23158A288)
- Stakeholder Engagement: May 10, 2023, Public Meeting (ML23138A050)
- Updates: Evaluated Biannually
- Available at:
https://www.nrc.gov/reactors/pow er/atf.html
The Project Plan
- Version 1.2 of the ATF Project Plan issued September 2021 (ML21243A298).
- The NRC is implementing the strategy laid out in the ATF project plan to enable the safe and efficient use of emerging ATF fuel technologies.
Roadmap Purpose
- Provide graphical representation of the ATF Project Plan
- Enhance efficiency and reliability
- Enhance understanding of the pathways to licensing near-term ATF technology
- Clearly identify direction, challenges, and risks associated in licensing near-term ATF technology
- Depict critical milestones to maintain a mid-to-late 2020s deployment timeline to batch load near-term ATF technology
General Assumptions
- Commercial nuclear industry aims to increase operational cycle time, using a combination ATF technology.
- Increased Enrichment and Higher Burnup are included with ATF technology.
- Industry aims to batch load the suite of near-term ATF technologies in mid-to-late 2020s.
Timeline Assumptions
- Licensing timeline assumptions are from the January 2022, NRC Letter to Industry, regarding scheduling expectations and historical review timelines.
Roadmap Description
- Orientation: Left-to-Right and Top-to-Bottom.
- Sequence: Items are generally displayed in chronological sequence by start date. Of note, the previous item is not always required for the subsequent in the graphic.
- Dates: Dates are generally only provided for completed/issued actions.
- Color-Coding: Utilized to differentiate near-term technologies only.
- Hyperlinks: Text is hyperlinked to associated NRC webpage or to download associated document from ADAMS.
Discussion Questions
- Are additional Phenomena Identification and Ranking Table (PIRT) exercises needed for ATF, increased enrichment, and higher burnup?
- Is the Roadmap to Readiness still an accurate representation of the strategy to license ATF?
References Document Title ADAMS Accession Number/ FR Citation Overview of Accident Tolerant Fuels Commission Meeting, January 24, 2023 Transcript: ML23026A288 Meeting SRM: ML23030A013 Accident Tolerant Fuel Project Plan (Version 1.2) ML21243A298 Scheduling Expectations Regarding the Licensing of Accident Tolerant, Increased ML22003A168 Enrichment, and Higher Burnup Fuels Regulatory Framework Applicability Assessment and Licensing Pathway Diagram for ML22014A112 Licensing ATF-Concept, Higher Burnup, and Increased Enrichment Fuels SECY-21-0109, Rulemaking Plan on use of Increased Enrichment of Conventional ML21232A237 and Accident Tolerant Fuel Designs in Light Water Reactors SRM-SECY-21-0109, Rulemaking Plan on use of Increased Enrichment of ML22075A103 Conventional and Accident Tolerant Fuel Designs in Light Water Reactors NRC Regulations Title 10, Code of Federal Regulations Volume 1 (Parts 1-50)
Volume 2 (Parts51-199)
Increase Enrichment Rulemaking Update 8/31/2023 Carla Roque-Cruz, NRR/DORL Philip Benavides, NMSS/REFS
Status of Rulemaking Activity
- The NRC staff is preparing the IE rulemaking regulatory basis to support its recommendation on whether it should pursue rulemaking to support industry interest in the use of fuel enriched to greater than 5.0 weight percent U-235.
- The regulatory basis stakeholder comment period will be 75 days.
- NRC will hold a public meeting during the stakeholder comment period.
Next Steps Public Comment Commission Public Comment SRM Period Review Period 3/16/22 9/16/23-12/1/23 12/16/24-3/16/25 4/17/25-6/30/25 2022 2023 2024 2025 2026 Revise Proposed Final Rule to Regulatory Basis Proposed Rule Package Rule Commission 3/16/22-9/15/23 12/2/23-12/16/24 3/17/25- 6/30/26 4/16/25 Note: Dates listed are estimates only, and thus are subject to change.
Stay Updated on IE Rulemaking Go to https://www.regulations.gov/ and search for docket ID NRC-2020-0034
References References
Introduction to Chris Markley the New Fuels NMSS/DFM Atlas High Burnup Workshop August 31, 2023 24
New Fuels Environment New fuels arena is evolving quickly
Purpose:
Enhance ability to identify and process information Outcome: New Fuels Atlas Enhanced communications
- Infographic
- New Fuels Website Enhanced organization
- Regulatory Planner 25
New Fuels Infographic Looks at all phases of the front and back end of the fuel cycle Provides the who, the what, and the how Highlights information for public stakeholders Framework supports current environment NRC has tools available to regulate 26
NEW FUELS Readiness for new non-light water reactor FUELS the Who -
The Nuclear Regulatory Commission (NRC) is an independent agency that oversees the civilian use of nuclear materials.
Regulatory tools include:
- Licensing - adequate protection
- Oversight - to ensure compliance the What -
- Research - to support Industry is expected to deploy new nuclear development of technical bases fuel technologies. Here we focus on
- International Activities -
advanced non-light water reactor fuel like multilateral and bilateral metals and salts. information exchanges the How -
- Rulemaking - to codify safety requirements The NRCs current regulatory framework can support deployment of anticipated the Who, the What, and the How... new nuclear fuels.
The existing tools can accommodate new fuels!
New Fuels Licensing Activities Inspection &
Enforcemen Regulatory Inspection Regulatory Related Information: t Framework & Oversight Framework
Cr, Ch, MC&A Cr, M, T Cr, M,
- NEIMA Review Schedules WM
- Hearing Opportunities
- Public Involvement Ch: Chemical Analysis, Cr: Criticality Analysis, M: Materials Properties & Compatibility, MC&A: Material Control and Accounting, T: Thermal Analysis, WM: Waste
New Fuels Website Enrichment Fabrication Transportation Utilization Safety Environmental Protection Security and Safeguards Stakeholder Engagement 25 https://www.nrc.gov/materials/new-fuels.html
The Regulatory Planner Organizational tool For each technology Fuel cycle phase Programmatic area 29
The Regulatory Planner: Research Fuel Cycle Phase Standard Review Plan Subtopic 27
Any Questions?
30
Industry Presentation:
Update on the Collaborative Research on Advanced Fuel Technologies for LWRs (CRAFT)
Discussion Period Break Non-LOCA Release Fractions for Burn Up > 68 GWd/MTU NRC HBU Workshop IV - August 31 Joseph Messina, James Corson
Background
- The Non-LOCA release fractions in RG 1.183 Rev. 1 are applicable if operation remains below the power history provided in the RG.
- The power history curve extends to 68 GWd/MTU (rod-average)
- An appendix provides an analytical procedure to calculate release fractions for other power histories, fuel designs, etc. DG-1389 Figure 1
Challenges for Non-LOCAs Above 68 GWd/MTU
- Generating non-LOCA gap fractions > 68 GWd/MTU poses a challenge:
- ANS-5.4 (2011) Standard is not applicable for BUs > 70 GWd/MTU
- Limited data exists at moderate rod powers for rods at high burnup
- NRC does not plan to be responsible for necessary experiments to generate data to update regulatory guidance to support industrys higher burnups targets
- The NRC does not have representative power Figure 1 from NUREG/CR-7003, Background and Derivation of ANS-5.4 Standard Fission Product Release Model histories up to 75 GWd/MTU, therefore any gap fractions the NRC calculates may not be useful
Possible Paths Forward The NRC staff is considering several actions for non-LOCA gap fraction guidance for BUs > 68 GWd/MTU:
- Reconvene the inactive ANS-5.4 Working Group to discuss expanding applicability
- Provide a rod power limit at HBUs for ANS-5.4 application given the available data
- Provide an analytical procedure to calculate non-LOCA gap fractions using an approved fuel performance code instead of a table of non-LOCA gap fractions to address issue of having non-representative power histories and gap fractions
Questions/Feedback?
Source Terms with Higher Burnup Using MELCOR 2023 Containment Source Term and Peer Review NRC HBU Workshop IV - August 31 Michael Salay
Source Term Regulatory Basis
- Footnote to 10 CFR 100.11(a) (Siting: Exclusion Area, Low population zone, )
The fission product release assumed for these calculations should be based upon a major accident hypothesized for purposes of site analysis or postulated from consideration of possible accidental events, that would result in potential hazards not exceeded by those from any accident considered credible. Such accidents have generally been assumed to result in substantial meltdown of the core with subsequent release of appreciable quantities of fission products.
38
History of Containment Source Term (1/2)
- TID-14844 (1962)
- Based on furnace heating of irradiated fuel chips
- Instantly available in the containment at the start of an accident
- NUREG-1465 (1995) (& RG1.183 rev 0)
- Result of post-Three Mile Island Accident severe-accident research effort
- Development Source Term Code Package (STCP) used in NUREG-1150 risk analysis
- Representative set of unmitigated accident sequences
- Timing and release fractions for accident phases
- Based on analyses of plants with fuel used to burnups < 40 GWd/t (regulatory limit is 62 GWd/t) 39
History of Containment Source Term(2/2)
- Impact of High Burnup and MOX fuel (2011)
- Burnups up to 62 GWd/t
- SAND2011-0128 Accident Source Terms for Light-Water Nuclear Power Plants Using High-Burnup or MOX Fuel
- Representative accident sequence similar to those selected for NUREG-1465 with insights from the Individual Plant Examinations NUREG-1560
- Peer review found methodology appropriate for containment source terms
- Technical basis for RG 1.183 Rev. 1
- Impact of Higher Burnup and Enrichment (2023)
- Burnups up to 80 GWd/t
- Near-term ATF analyses ongoing 40
Containment Source Term Development 41
2023 Source Term: Higher Burnup/Enrichment
- Extend Source Terms to 80 GWd/MTU and 10 w/o enrichment High Burnup Fuel Source Term Accident Sequence Analysis, SAND2023-01313, Sandia national Laboratories, ML23097A087, April 2023
- Similar objectives and approach to the NUREG-1465 and SAND2011-0128 source terms
- Incorporation of insights from SOARCA, post-Fukushima studies, and international experimental programs
- Evolution of severe accident modeling best-practices
- Peer review found methodology appropriate for containment source terms Peer Review of the In-Containment Source Term Study for High-Burnup and High-Assay Low Enriched Uranium Fuels, ERI/NRC 23-201, Energy Research Inc., ML23097A086, April 2023 42
Key Severe Accident Knowledge Evolution Since NUREG-1465
- Evolution of severe accident state-of-knowledge
- Improved understanding of fission product chemistry affecting I, Cs, Te release and transport (e.g., Phébus FP Program, VERCORS, VERDON)
- Insights from SOARCA and post-Fukushima studies
- MELCOR modeling enhancements
- Refined modeling of core damage progression leads to extended core degradation and delayed lower head failure
- Induced failure of reactor systems following core damage leads to lower pressure
- PWR simulations consistently predict hot leg creep rupture
Key Findings PWR Gap Release Early In-vessel
- Moving to higher burnup does Study 2023 2011 NUREG-1465 2023 2011 NUREG-1465 not significantly change the Phase Duration 1.3 0.22 0.50 4.0 4.5 1.3 source term to containment Halogens 0.007 0.004 0.050 0.58 0.37 0.35
- Increase in halogen releases 0.003 0.003 0.050 0.50 0.23 0.25 Alkali Metals from NUREG-1465 due to Te Group 0.006 0.004 0.0 0.55 0.30 0.050
- enhanced knowledge of FP release and transport BWR Gap Release Early In-vessel NUREG- NUREG-
- higher proportion of low-pressure 2023 2011 2023 2011 Study 1465 1465 scenarios 0.70 0.16 0.50 6.7 8.0 1.5 Phase Duration
- Suppression pool can impact 0.005 0.002 0.050 0.71 0.47 0.25 Halogens 0.005 0.002 0.050 0.32 0.13 0.20 BWR containment source terms Alkali Metals Te Group 0.003 0.002 0.0 0.56 0.39 0.050
DOE Presentation:
Assess the Impact of Prototypic High Burnup Operating Conditions on Fuel Fragmentation Relocation and Dispersal Susceptibility
Environmental Evaluation of ATF with Increased Enrichment and Higher Burnup Levels Donald Palmrose, Ph.D.
Senior Reactor Engineer Office of Nuclear Material Safety and Safeguards (NMSS)
Co-Authors: Rao Tammara (NMSS) and Ken Geelhood (PNNL)
Key Points
- Evaluate environmental impacts of deployment and use of near-term ATF with increased enrichment (IE) and higher burnup (HBU) levels to support future licensing reviews
- Evaluation of impact in the uranium fuel cycle (UFC),
transportation of fuel and waste, and decommissioning
- Table S-3, Table S-4, and Decommissioning GEIS still bounding for deployment and use of ATF with up to 8 wt %
U-235 and 80 GWd/MTU
- Address release fraction uncertainty at HBU levels Higher Burnup Workshop IV August 31, 2023
Impacts of ATF Technologies
- Focus is on near-term ATF technologies
- Coated cladding, doping, FeCrAl cladding
- Longer-term ATF technologies not covered
- UN pellets, SiC cladding, and extruded metallic fuel
- Near-term ATFs do not significantly change fuel fabrication impacts, radiological inventory, and releases fractions
- IE and HBU being part of the deployment and use of ATF are the key factors for impacts Higher Burnup Workshop IV August 31, 2023
Uranium Fuel Cycle Changes
- Analysis for Table S-3 from the 1970s but UFC changes have reduced environmental impacts
- Replaced deep and pit mining with in-situ uranium recovery technology
- Gaseous diffusion enrichment replaced with gaseous centrifuge enrichment
- Table S-3 emission impacts based on all electricity from coal but now significantly reduced
- Most fuel fabrication facilities (FFF) have moved from a wet to a dry process with less environmental impacts
- Slightly higher enrichments (4% to 5%) and higher burnup levels (33 to 62 GWd/MTU)
Higher Burnup Workshop IV August 31, 2023
Uranium Fuel Cycle
- The greater amount of yellowcake to support IE would not cause a significant change in related Table S-3 impacts
- Gaseous centrifuges use less electricity for 10 wt % U-235 than gaseous diffusion did for 4 wt % U-235
- Longer refueling cycles would reduce the rate of spent nuclear (used) fuel generation
- Spent ATF management would still be similar to Continued Storage (CS) GEIS (NUREG-2157)
- Table S-3 and CS GEIS would bound or still apply to deployment and use of ATF with IE & HBU levels Higher Burnup Workshop IV August 31, 2023
Transportation
- Use of DOE & NRC guidance & the code NRC-RADTRAN (radiological transportation risk) with WebTRAGIS (routing)
- Six sites selected by regions
- Parameter values for fuel shipments from prior analyses and new sources for incident-free and accident risk impacts
- Some are very conservative, for example, vehicle accident rates based on commercial shipping and least capacity in a transport package
- Sensitivity cases for rail shipments and release fraction uncertainty at HBU levels Higher Burnup Workshop IV August 31, 2023
Transportation (cont.)
- Normalized annual truck shipments of spent ATF of 30 for PWRs and 52 for BWRs based on 2-yr refueling cycle for 1100 MWe reference NPP of WASH-1238 and Table S-4
- Normal, incident-free, conditions are bounded by Table S-4
- Worker doses less than the 4 person-rem of Table S-4
- Cumulative public doses, while generally higher than 3 person-rem of Table S-3, not a significant impact
- Average individual doses were very low (<<1 mrem) and within the Table S-4 ranges of doses for onlookers and along route populations
- Radiological accident effects still small as in Table S-4
- Non-radiological accident risk (fatalities/injuries) greater than radiological risks but also bounded by Table S-4 Higher Burnup Workshop IV August 31, 2023
Transportation Sensitivity Cases
- Rail shipments
- Less than 2 shipments per year
- With greater capacity, normal conditions and accident impacts are significantly reduced
- Many rail packages utilize an inner sealed canister such that no accident releases would be expected as assessed in NUREG-2125
- Radiological release fractions due to HBU levels
- Uncertainty noted in NUREG/CR-6703 by Ramsdell et al. (2001)
- Concerns such as cladding embrittlement, fuel fragmentation, and diffusional releases
- Noticeable increase in particulates release fractions over values in NUREG/CR-6672 by Sprung et al. (2000)
- While accident risks do increase (~10-6 to ~10-4), still a small impact Higher Burnup Workshop IV August 31, 2023
Decommissioning
- Decommissioning GEIS is NUREG-0586 Supplement 1
- Extensively discussed in 2013 License Renewal GEIS (NUREG-1437 Rev 1) and in past new reactor EISs
- ATF deployment, use, and subsequent termination of operations would only affect human health and waste management
- All other resource areas would be the same or slightly less
- ATF deployment affects on decommissioning:
- Effluent releases would still be lower after cessation of ops
- Worker doses still controlled per 10 CFR Part 20
- Would not alter the practices employed to manage the wastes
- Would need less ISFSI capacity than staying with current fuels
- Decommissioning GEIS would bound deployment and use of ATF with IE and HBU levels Higher Burnup Workshop IV August 31, 2023
Discussion Period Public Comment Period Adjourn How did we do?
https://feedback.nrc.gov/pmfs/
Meeting Code: 20230872