ML22083A007
| ML22083A007 | |
| Person / Time | |
|---|---|
| Issue date: | 03/30/2022 |
| From: | Joseph Donoghue NRC/NRR/DSS |
| To: | |
| Joe Donoghue NRR/DSS 301-415-1193 | |
| Shared Package | |
| ML22083A005 | List: |
| References | |
| Download: ML22083A007 (10) | |
Text
ATF/HBU/IE Fuel Licensing Challenges EPRI-DOE HBU WS Joe Donoghue, NRC March 30, 2022 We make SAFE use of nuclear technology POSSIBLE.
We make SAFE use of nuclear technology POSSIBLE.
Near-Term ATF Technologies 2
Coated Cladding
- A thin chromium-based layer is applied to the cladding outer diameter
- NRR staff have issued Interim Staff Guidance ATF-ISG-2020-01 to support reviews
- Currently awaiting topical reports Doped Pellets
- UO2 pellets contain small amounts of added materials that improve performance through larger grain sizes
- No foreseen licensing challenges FeCrAl Cladding
- Iron-Chromium-Aluminum based alloy fuel cladding
- Commercialization is a few years away
We make SAFE use of nuclear technology POSSIBLE.
Longer Term ATF Technologies 3
High Density (Uranium Nitride)
Pellets
- Ceramic composite-woven fibers around a monolithic tube Extruded Metallic Fuel
- Extruded metallic bar composed of a Zirconium-Uranium matrix within a zirconium alloy cladding
We make SAFE use of nuclear technology POSSIBLE.
Increased Enrichment and Higher Burnup 4
Higher Burnup
- Currently limited to 62 gigawatt days per metric ton of Uranium (GWd/MTU) rod-average burnup
- BU limits defined in analysis methods - not in regulation
- Industry goal to reach 75 to 80 GWd/MTU Increased Enrichment
- Enrichment currently limited to 5 weight percent 235U.
- Industry goal up to 10 weight percent 235U
We make SAFE use of nuclear technology POSSIBLE.
Higher Burnup 5
Challenges
- Higher burnup effects - fragmentation, relocation, and dispersal (FFRD)
- Updates to spent fuel storage and transportation requirements
- Potential impact on source term
- HBU Designs may need increased enrichment
We make SAFE use of nuclear technology POSSIBLE.
Increased Enrichment 6
Challenges
- 10 CFR 50.68 and 71.55 contain a 5% limit - exemptions may be required - Pursuing rulemaking
- Criticality will need to be evaluated in fabrication, transportation, and storage
- Fuel fabrication facilities originally licensed for 5% - some recently approved to increase enrichment
We make SAFE use of nuclear technology POSSIBLE.
Future
- Combinations of these concepts are possible (and expected) in future licensing requests
- Applicants need to ensure that proposed design is safe and satisfies regulations 7
We make SAFE use of nuclear technology POSSIBLE.
Guidance 8
Advanced Feature Available Guidance and Discussion Chromium-Coated Zirconium Cladding ATF-ISG-2020-01, Interim Staff Guidance, Chromium-Coated Zirconium Cladding Vendor proprietary fuel properties and performance Doped UO2 Fuel Pellets New guidance not required GNF, Framatome, and Westinghouse doped UO2 fuel concepts already NRC approved Vendor proprietary fuel properties and performance Application methodology well defined FeCrAl Cladding Technology is not mature enough GNF proprietary Is guidance needed for a single-vendor proprietary concept?
We make SAFE use of nuclear technology POSSIBLE.
Guidance (cont.)
9 Advanced Feature Available Guidance and Discussion Extended Burnup (up to 68 GWd/MTU)
RG 1.236 CRE/CRD Accidents DG-1389 AST Radiological Impacts on fuel properties well characterized What, if any, further guidance is needed?
Increased 235U Enrichment (Beyond 5.0 wt%)
50.68 rulemaking begun Impacts on fuel properties well characterized Framatome topical report under review What, if any, further guidance is needed?
High Burnup (beyond 68 GWd/MTU)
Data gaps exist FAST validation identified extend of public empirical database Vendor proprietary fuel properties and performance databases What, if any, further guidance is needed?
We make SAFE use of nuclear technology POSSIBLE.
Guidance (cont.)
10 Advanced Feature Available Guidance and Discussion Fuel Fragmentation and Dispersal Regulatory & guidance implications Vendor proprietary analytical models, methods, and approaches Technical challenges (e.g., size distribution, transport, coolant interaction, and decay heat removal) understood Need to solve technical challenges which would allow fuel dispersal Are planned activities sufficient?