SPENT FUEL CHARACTERIZATION Approach in the Belgian industry · ⚫Tractebel has developed...
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CONFIDENTIAL RESTRICTED PUBLIC INTERNAL 12 th of November 2019 SPENT FUEL CHARACTERIZATION Approach in the Belgian industry 8
Transcript of SPENT FUEL CHARACTERIZATION Approach in the Belgian industry · ⚫Tractebel has developed...
CONFIDENTIALRESTRICTEDPUBLIC INTERNAL
12th of November 2019
SPENT FUEL CHARACTERIZATIONApproach in the Belgian industry
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Presentation outline
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⚫Overview of the current status of nuclear power in Belgium
⚫Approach followed by the Belgian industry for spent fuel characterization
⚫Current needs of the industry
⚫Some words on data/people management
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Current status of nuclear power in Belgium
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Current status of nuclear power in Belgium
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⚫ The 7 Belgian PWR are currently between
their 30’s and 40’s
⚫ Doel 1 & 2, Tihange 1 commissioned in 1975
— Life extension until 2025
⚫ Tihange 2, Doel 3 commissioned in 1982/3
— Due to shut down in 2022/3 (flake issues)
⚫ Tihange 3, Doel 4 commissioned in 1985
⚫ Nuclear phase-out in 2025 out is written in the
Law
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Current status of nuclear power
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⚫ Discharged assemblies are currently stored on-site
— Few thousands of assemblies
⚫ Wet storage in Tihange
⚫ Dry storage in Doel
⚫ New dry storage facilities foreseen for both sites
⚫ Reprocessing currently stopped (memorandum)
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Current status of nuclear power in Belgium
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⚫ The assemblies will stay on site until ~ 2050
⚫ In the current scenario, they will be moved
eventually to geological disposal
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Current approach for fuel characterization
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⚫ The spent fuel characterization capabilities at the plants are currently limited
— Logbook approach (centralized database)
⚫ Modelling capabilities have been built at Tractebel
— Properties of the assemblies, including burnup, are calculated
⚫ SCK-CEN in charge of the experimental characterization
— Programs have been conducted by SCK-CEN and other partners with ENGIE as sponsor
— Aimed at testing new fuel design in reactor conditions and validating codes
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Characterization by computer codes
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⚫ Tractebel has developed throughout the years an expertise in the use of fuel codes
— Reactor physics: WIMS, PANTHER, RABBIT
— Neutronics: MCNP, Scale, ORIGEN.
— Fuel behavior: Frapcon, Fraptran, Copernic (Framatome), Treq (ENUSA)
⚫ These codes are extensively validated
⚫ These codes are useds to evaluate the fuel properties
— Burnup, Source terms, FGR, …
⚫ Uncertainty quantification
— Dakota
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Radiochemical analyses (SCK-CEN)
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⚫ Local (pellet level) measurement of isotopic concentrations
⚫ Purpose: validation of neutronic/evolution codes
— Source term evaluation (heat, n/g)
— Reactivity evaluation (BUC)
⚫ Typical RCA include the following measurements:
— Thermal Ionisation Mass Spectrometry (U’s, Pu’s, …)
— Alpha spectroscopy (Cm-244, Cm-242 )
— Gamma spectroscopy (Cs-137, Ce-144, …)
Destructive
measurements
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Fuel analyses (SCK-CEN)
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⚫ Assessment of the physical and chemical
properties of irradiated fuel
⚫ Demonstration of fuel integrity
⚫ Validation of fuel performance codes
⚫ Most common techniques
— Optical microscope
— Electron microscope
— Electron Probe Micro-Analysis
Destructive
measurements
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Industry’s current needs/concerns (1)
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⚫ Need for a reduction of uncertainties on source terms, especially decay heat
⚫ Typical uncertainties range from 5 to 10% (applied at 2-s)
— High economical stake !
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Dec
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Decay time [years]
Best estimate Best Estimate +5% "Best Estmate +10%"
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Industry’s current needs/concerns (1)
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⚫ Need for a reduction of uncertainties on source terms, especially decay heat
⚫ Typical uncertainties range from 5 to 10% (applied at 2-s)
— High economical stake !
⚫ Best way to reduce uncertainties is by direct DH measurements
— Accurate to few % (cf CLAB program)
⚫ No measurements available in public literature for measurements for “hot” assemblies
(couple of kW’s)
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Industry’s current needs/concerns (2)
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⚫ The long-term behavior of the discharged fuel is little known
⚫ Confinement must be insured on the long term (interim storage)
⚫ Current research activities
— Evolution/migration of hydrides
— Evolution of oxide layer
— Creep
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Knowledge/data management
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⚫ Data
— All data on the fuel is stored in a unique database shared by all Engie entities
— All the data relative to fuel characterization program is stored in Tractebel’s document management
system
⚫ People/skills management
— Staff is trained to the use of codes
— Young engineers welcome to participate to new XP programs
⚫ Potential risk: what will happen at the time of the plant closure ?
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⚫ Current industry approach for spent fuel characterization relies on computer models
⚫ The codes are validated by comparison to the experiment
⚫ We benefit from the expertise of labs (SCK-CEN)
⚫ Current needs:
— Reducing decay heat uncertainties
— Understanding long term fuel behaviour
⚫ Mature data management system
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Summary
14/11/2019 Spent fuel characterization - Approach in the Belgian Industry
