Used Fuel Disposition Campaign DOE R&D in Support of Transportation

Used Fuel Disposition Campaign
DOE R&D in Support of
High Burnup Spent Fuel Dry Storage and
Transportation
Ned Larson, Office of Nuclear Energy
U.S. Department of Energy
U.S.NRC RIC
March, 2016
Rockville, MD
Used
Fuel
Disposition
Used Fuel Disposition Campaign
(UFDC) Storage and Transportation
R&D Objectives
1. Support the
development of
the technical
bases to
demonstrate used
fuel integrity for
extended storage
periods
2. Develop the
technical bases
for fuel
retrievability and
transportation
after long term
storage
3. Develop the
technical bases
for transportation
of high burnup
fuel
2
Used
Fuel
Disposition
Performance of the Storage and
Transportation Systems
Material Strength
Stress Profiles
 Cladding Structural Integrity
 Storage Stresses
–
Hydride re-orientation
• Thermal profile
• Internal rod pressure
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Drying & corrosion
Fatigue during transport
Creep
̶ Annealing
Oxidation
̶ Brittle behavior
 Canister Structural Integrity
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Tipping over
Routine handling
Dropping
Gravity
 Transportation Stresses
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Road and rail vibrations
Road and rail shocks
Cracking of canister welds from
Acqueous corrosion (drying)
Fatigue in shipping
 Cask Structural Integrity
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Bolted lids
̶ Poison Creep
Metallic lid seals
Concrete weathering
Lifting hardware
Overpack corrosion / Freeze-Thaw
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1
Used
Fuel
Disposition
Gap Prioritization (1) – 2014
Comprehensive technical gap analyses have been
performed to identify and rank data needs
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Used
Fuel
Disposition
Cladding Strength
Cyclic Integrated Reversible-Bending
Fatigue Tester (CIRFT)
 Follow on from NRC work
 Tested M5® and Zr-2 clad
 Determine the load,
curvature, # of cycles for
failure
 Pellet-clad and pellet-pellet
bonding provides additional
stiffness → increase the load
and # of cycles for failure
 Debonding → shift loadcarrying capacity from fuel
pellets to clad and reduce
composite flexural rigidity
 FY15-16 support NRC test for
CIRFT after RHT
Used
Fuel
Disposition
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Cladding Strength
Ring Compression Tests
 Hoop stress key at 350-400°C
RHT
– Appears more important than
temperature
 KAERI has shown minimal
reorientation at lower
temperatures (unirradiated)
– Hydride re-orientation
– FY15-16 ANL will focus on 350°C
RHT
 Temperature cycling
– Need additional cycling data
 High hydride concentration
may cause brittle without
reorientation
 Expected temperatures over
extended periods
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2
Used
Fuel
Disposition
Cladding Strength
Hoop Stress
 Hoop Stress during drying
and cool-down a function of
– End of Life Rod Internal
Pressure
• Temperature
• Initial He pressure
• Fission gas release
• Creep down/swelling
– Cladding inner diameter
– Cladding thickness
• Minus corrosion layer
 Limited EOL RIP public
database
 Populating database
– FRAPCON modeling
– Collaboration with EPRI and
international partners
– Sister rod examination
 What fraction of PWR fuel rods have a
high enough EOL RIP and high
temperature during drying to have
radial-hydride-induced embrittlement?
 Newer BWR cladding is thinner, still
7
larger diameter
Used
Fuel
Disposition
Canister Strength
Atmospheric Corrosion
 Site examinations have shown
deposition of salts can occur
quickly; temperatures low
enough in areas of canister early
on
 Residual stress measurements
on full-scale (diameter) mock-up
show through-wall tensile stress
in the welds
 Effect of sensitization vs. weld
residual stress?
 Experiments under relevant
conditions
– Magnitude of residual stress
– Salt composition and loading
– Temperature/humidity
 Focus on crack growth rates
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Canister Strength
Stainless Steel Corrosion
Purpose: Better understand
canister degradation, support
Aging Management Plans, and
license extensions.
Collecting dust
samples at
Diablo Canyon
 Develop data to understand
initiating conditions for corrosion
conditions and progression of
SCC-induced crack growth
Sea Salt crystal with MgCl inside found on
Diablo Canyon Canister
Conceptual design
for full-scale
(diameter) SS
welded canister
 Obtain site data to assess
atmospheric conditions and
compare with initiating conditions.
 Procure a full scale (diameter)
welded SS canister to investigate
residual stresses due to plate
rolling and welding.
Dust on top surface of
SS canister
Enos, et al., Data Report on Corrosion Testing of Stainless Steel SNL
Storage Canisters, FCRD-UFD-2013-000324
Dust particles
on filter
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3
Transport Stresses
Laboratory Shock and Vibration
Normal Conditions of Transport
Used
Fuel
Disposition
 A surrogate assembly was
subjected to truck data from a
700 mile trip on a shaker table
and 50 miles on a real truck
with representative weight.
– Data results were >10 times
below yield strength.
– The strains measured in both
were an order of magnitude
lower than either an irradiated
or unirradiated Zircaloy rod
yield strength.
 If high burnup fuel can maintain its
integrity during transport, pressure
will be taken off experimental R&D
efforts associated with hydride
effects on cladding strength and
ductility.
7000 - 9000 μϵ @ yield
Data collection
and analysis for NCT
loads on a surrogate
fuel assembly
Sorenson, K., Determination of Loadings on Spent
Fuel Assemblies During Normal Conditions of Transport,
SAND2014-2043P.
Used
Fuel
Disposition
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Transport Stresses
Over the Road Shock and Vibration
 External loads as a
result of Normal
Conditions of
Transport (NCT)
 Simplified Truck Test
 Analyses for 30 cm
drop
 Full-scale rail test
being planned with
ENSA
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Used
Fuel
Disposition
Transport Stresses
Compared to Material Properties
 Brittle clad still
needs an external
stress to cause
failure
 SNL Shaker Table
and Truck tests
– Measured and
modeled strains are
well below yield
 Planned rail test with
ENSA
 External loads appear
well below limits to
cause cladding
failure
–
How much degradation
can occur and still
have SSCs meet all
safety functions?
Variation of flexural rigidity (EI) by up to a factor of 4 showed
at most a 50% increase in strain to 1144 micro-strain, still
a factor of ~7 below yield for unirradiated cladding
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4
Numerical Modeling
Develop predictive models of material
behavior to establish the technical bases
for extended storage and transportation
CFD Thermal Analysis of Dry Storage Casks
Suffield, et al, PNNL‐21788
Model for Simulation of Hydride Precipitation, Tikare et al, FCRD‐UFD‐2013‐000251.
 Predictive modeling
 Thermal Analysis (PNNL) to predict cool down,
Ductile to Brittle Transition, deliquescence, etc.
– HBU Demonstration fuel selection and cool down
– Modern, high heat load, high capacity systems
– In-service inspections validation data
 Hydride reorientation model (SNL)
 Structural uncertainty analysis at assembly
and canister level (PNNL)
 Finite element analysis validation with CIRFT
and application to out-of-cell testing (ORNL)

Thermal profile analyses
 Detailed thermal analyses for 2-3 licensed dry
storage systems (PNNL FY15)
FE Model of Rod Bend Tests
FE Models of Assembly
Klymyshyn, et al, PNNL, FCRD‐UFD‐
2013‐000168 Jy‐An Wang et al, ORNL
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High Burn‐up Confirmatory Data Project:
Dry Storage R&D Project
 Major Steps
 Loading a commercial storage cask with high burn‐up fuel in a utility storage pool
– Well understood fuel
– Cask outfitted with additional instrumentation for monitoring
 Drying of the cask contents using typical process  Housing cask at the utility’s dry cask storage site
– Monitored and externally inspected until the first internal inspection at 10 years
 Determining details of where and how the cask will be opened will be solved at a later date. Picture from North Anna ISFSI
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High Burn‐up Confirmatory Data Project:
Data to be Monitored
 Fuel cladding temperature (indirect via thermocouple lances)
 Cavity gas monitoring is being evaluated
 Temperature
 Composition
– Fission gasses
– Moisture
– Hydrogen
– Oxygen
 Pressure
 Active methods for sampling the gas were analyzed
 Use of remote sensors was evaluated to gather the needed data
 Gas sampling on the pad is still to be investigated
Picture from North Anna ISFSI
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5
Used
Fuel
Disposition
Sister Rod Selection
 Individual rods have been pulled to
perform characterization and material
property tests to obtain initial cladding
conditions prior to storage
 25 fuel rods from representative fuel
assemblies
 These rods will form the baseline for
pre- storage characterization
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–
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Nine Areva M5™ rods
Nine Westinghouse Zirlo™ rods
Four Westinghouse Low-tin zircaloy-4 rods
Three Westinghouse standard zircaloy-4
rods
NAC LWT basket for shipping rods
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Used
Fuel
Disposition
Sister Rod Data Gaps to be Filled by
Lab Testing
 Subcriticality (burn-up credit and moderator exclusion) – radionuclide
inventory in fuel rods
 Stress profiles – mechanical strength of the fuel rod
 Fuel Transfer Options – ensure fuel is handled in a prototypic manner
 Cladding – annealing of radiation damage
 Cladding – H2 effects, reorientation and embrittlement
 Cladding – H2 effects, delayed hydride cracking
 Cladding – oxidation
 Cladding – creep
 Fuel Assembly Hardware – stress corrosion cracking (SCC) of lifting
hardware and spacer grids
Used
Fuel
Disposition
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Receipt Visual Inspection
Visual Examination
Rod Profilometry
Eddy Current Examination
Gamma Scanning
Metrology
Neutron Radiography
Destructive Post-Irradiation
Examination
Gas Pressure
Fission Gas Sampling
Free Volume Determination
Fuel Microstructure
Optical Microscopy
Hydrogen in Cladding
Sister Rod Testing
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Rod Bow Determination
Microhardness Testing
Electro-Optical Examinations
Radio-Analytical Chemistry
Microchemistry
Micromechanical Testing
Fuel Fines Capture and
Analysis
Thermal Treatment to Mimic
Drying
Retained Water on Clad
Ring Compression Test
CIRFT
4 Pt. Bent Test
Fuel Density
6
Used
Fuel
Disposition
NE University Programs (NEUP)
Funding for Storage and
Transportation
Total Available
Budget Area and Fiscal Year Award
Total
Storage & Transportation
$27,433,384
(11-2987) Anisotropic azimuthal power and temperature distribution on impact on hydride distribution - PSU
(11-3117) Life Prediction of Spent Fuel Storage Canister Material - MIT
(11-3278) Fuel Aging in Storage and Transportation (FAST): Accelerated Characterization and Performance - TAMU
$631,957
$899,826
$4,500,000
(12-3374) Validation Experiments for Spent-Fuel Dry-Cask In-Basket Convection - USU
$690,000
(12-3528) Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms - UTK
$770,000
(12-3545) Concrete Materials with Ultra-High Damage Resistance Capacity For Extended Storage Systems - UH
$800,000
(12-3660) Simulations to Predict Used Nuclear Fuel Cladding Temperatures during Drying and Transfer Ops - UNR
$745,000
(12-3730) Probabilistic Multi-Hazard Assessment of Dry Cask Structures - UH
$865,000
(12-3736) Nonlinear Ultrasonic Diagnosis and Prognosis of ASR Damage in Dry Cask Storage - NU
$885,000
(12-3756) Seismic Performance of Dry Casks Storage for Long-Term Exposure - UU
$873,320
(13-4840) Development of a nano-modified concrete for next generation of storage systems - VU
$795,153
(13-5106) Risk Assessment of Structural Integrity of Transportation Casks - UU
$740,296
(13-5178) Structural Health Monitoring of Nuclear Spent Fuel Storage Facilities - USC
$597,832
(13-5365) Doubling the Life of Concrete Structures - UI
$640,000
(14-7356) Multi-Sensor Inspection and Robotic Systems for Dry Storage Casks - PSU
$3,000,000
(14-7730) Experimental and Modeling of Used Fuel Drying by Vacuum and Gas Circulation for Dry Storage - USC
$4,000,000
(15-9231) Multimodal Nondestructive Dry Cask Basket Structure and Spent Fuel Evaluation - UM
$3,000,000
(15-9318) Innovative Approach to SCC Inspection and Evaluation of Canister in Dry Storage - CSM
$3,000,000
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Grand Total
Used
Fuel
Disposition
$27,433,384
NEUP IRP
Canister Strength Drying Issues
 HBU Demonstration cask will be
sampled and analyzed for
moisture
 A three year investigation has
been awarded to investigate
drying of used fuel canisters
for dry storage.
 Objectives:
•
This investigation will address
questions surrounding the amount,
form, and location of water remaining
in dry casks/canisters.
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Used
Fuel
Disposition
NEUP IRP
Cask Strength
Monitoring Cask System Performance
 Monitoring and observing existing
welded canisters
 Stress corrosion cracking (SCC) and
precursor detection
 Remaining water in a dried system
 Using remote sensors for measuring
existing conditions
 Placing the sensors so they can
gather needed data
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Used
Fuel
Disposition
Technical Direction
Summary
Partnerships
 Industry
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Utilities
Cask manufacturers
Fuel suppliers
Rail and trucking companies
 National Laboratories
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11 National Labs
Principal Investigators with needed
expertise have been identified
Specialized facilities and equipment
are available
 Universities
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More than 18 universities are working
with UFD
Numerous students and professors
are involved ($27M)
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