R&D activities related to nuclear fuel performance and technology at the DG JRC Paul VAN UFFELEN 1
Introduction 2
JRC Core Staff (2004) Institute for Reference Materials and Measurements Institute for Transuranium Elements Institute for Energy Institute for the Protection and Security of the Citizen Institute for Environment and Sustainability Institute for Health and Consumer Protection Institute for Prospective Technological Studies DG, ISR, DPRM, ISD Total 184 220 159 215 255 160 64 374 1631 3
Main infrastructure Experimental fuel fabrication facility Post irradiation examination facilities High Flux Reactor in Petten NRG a powerful multi-purpose materials testing reactor, running an important programme on irradiation-induced ageing of components GELINA (Geel Electron Linear Accelerator) a powerful white spectrum neutron source van de Graaff accelerator Actinide laboratory 4
Projects related to nuclear fuel safety High burnup fuel characterisation TRANSURANUS projects Severe accident research Research on sustainable fuel types 5
High burnup fuel characterisation Thermophysical characterisation of UO 2 with 100 GWd/tM Commissioning tests on a shielded Secondary Ion Mass Spectrometer Matrix swelling rate and cavity volume balance of UO 2 fuels at high burnup Assess effect of stress on the high burnup structure formation 6
TRANSURANUS projects EU funded projects Shared cost actions: OMICO, MICROMOX Enlargement and integration activities: Bulgaria, Hungary, Romania, Lithuania Networks of excellence: ACTINET Consolidation of TRANSURANUS network: Institutional network TUNet, new partners (Armenia, USA) 7
International projects TRANSURANUS projects IAEA: FUMEX-II CRP OECD: HRP experiments, TFRPD MOX benchmarking USDOE: GEN IV, IFG, LANL, INL, ORNL, PNNL, UC Berkeley multi-time-scale modelling 8
Severe Accident Research PHEBUS FP PIE of degraded FPT2: Steam starvation/ H excess Zy melts and relocates at a lower temperature POLARIS: on-line monitoring of Thermal properties FGR Fuel fragmentation 9
Research on sustainable fuels Fuel developments in the frame of the Euratom framework program Thorium cycle (HFR, Obrigheim) MICROMOX (HFR) OMICO (BR2) MIMAS-PV (BR2) HTR-F (hot cells) Developments in the frame of GEN IV and USDOE/Euratom agreements Nitride and carbide fuels: fabrication, characterisation, modelling HTR fuel kernels: fabrication technology 10
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Thermal diffusivity of UO 2 irradiated to 105 GWd/t by means of laser flash Thermal diffusivity, m 2 s -1 x 10-7 8 7 25% Increase of diffusivity by high-temperature annealing 1 st run asc. 1 st run desc. 2 nd run asc. 2 nd run desc. 3 rd run asc. 3 rd run desc. 4 th run asc. 4 th run desc. 5 th run asc. 5 th run desc. 6 th run asc. 6 th run desc. Irradiation temperature 6 600 700 800 900 1000 1100 Temperature, K 12
x 10-6 Compare thermal diffusivity after irradiation / storage 2.0 1.8 1.0 thermal diffusivity at 500K (m 2 s -1 ) fresh fuel degradation by out-of-pile auto-irradiation 0.8 annealed at 700K annealed at 600K after storage degradation by in-pile burn-up end of life (model prediction) recovery by out-of-pile annealing 0.6 0.0 0.2 0.4 0.6 0.8 1.0 Radial position on the cross section of the irradiated fuel rod (r/r 0 ) 13
Commissioning test of shielded SIMS Detection of hydride phase in Zy at very high mass resolution (18000), Zr-hydride molecular species can be discriminated from Zr isotopes Analysis of oxidation layer containing Li and B oxide layer containing Li 7 Li 15 µm 14
Evolution of immersion density with burnup 15
Irradiation damage in (U 0.9, 238 Pu 0.1 )O 2 Doped material: (U 0.9, 238 Pu 0.1 )O 2 TEM dislocation characteristics DSC energy associated with defects 16
Interaction energies between dislocations b Elastic energy (J/m) l (A) pile-up of dislocations b Distance between dislocations (nm) l (B) tilt-boundary of dislocations 17
OMICO (FP5) Partners SCK CEN (B), ITU, FRAMATOME_ANP Objectives: variations of Microstructure: homogeneous vs heterogeneous Composition: UO 2, (U,Pu)O 2, (Th,Pu)O 2 Planning Design, fabrication and transport of pins completed Irradiation in BR2: automn 2004 2006 Interpretation of in-pile results PIE to be decided between ITU and SCK CEN Extended for 24 months 18
MICROMOX (FP5) Partners BN (B), BNFL (UK), ITU, IE, PSI (CH), NRG (NL) Objectives: FGR in UO 2, MOX Assess effect of high burnup and transient conditions Assess effect of composition and grains size Planning Design, fabrication and transport of pins completed Irradiation in HFR: Sep 2003? (to be decided next week) Interpretation of in-pile results PIE in Petten 19
New action for Bulgaria Objectives Help reform activities in nuclear fuel cycle (licensing process) Extend the capabilities of TRANSURANUS for VVER fuel (normal operation and storage conditions) Change of fuel rod diameter [mm] Partners of ITU 0.2 0.1 0-0.1-0.2 NRA, INRNE, TUS, PDSU, KNPP Planning 2004-2006 WWER-1000 TRANSURANUS Experimental data (IFPE) newly released 40 45 50 55 0 20 15 10 5 Change of fuel rod length [mm] 20 Rod average burn-up [MWd/kgU]
New action for Hungary Simulation of VVER fuel under accident conditions Include hydrogen uptake WP1: Out-of-pile experiments WP2: Model development WP3: OECD LOCA Benchmark K m (mg/cm 2 /s 0.5 ) 1 0.1 1100 o C 1000 o C 900 o C 658 exp(-10200/t) H content 0 v% H content 20 v% 0.01 6.5 7.0 7.5 8.0 8.5 9.0 9.5 Specific energy at failure (mj/mm) 1000 100 10 1 0.1 0 1000 2000 3000 4000 5000 10 4 /T (1/K) 21 H concentration (ppm)
100 50 0-50 -100 Benchmark for MOX thermal conductivity correlation with data from Halden ITU B correlation (laser flash) Carbajo A et al (JNM) 4026 data points 0 5 10 15 20 Difference between calculated and measured Fuel Centre Temperature (K) Rod average burnup (MWd/kgHM) 22
Steam starvation/ H excess Zy melts and relocates at a lower temperature 23
New proposed experimental approach SIMULATION OF THE IN-PILE THERMAL BEHAVIOR: LASER HEATING OF IRRADIATED FUEL Water cooled sample holder (optional) Gas Water To high-speed camera Laser beam To high-speed pyrometer Laser beam To spectropyrometer P <200 bar Fuel Cladding Radial power distribution 24
Simulation of the temperature profiles Sample thickness : 1mm Atmosphere: 200 bar of He UO 2 (radius 4mm) + cladding (radius 5mm) + ZrO 2 Laser heating on both sides (P=200 W/cm 2 ), only the UO 2 disk is heated 25
Homogenisation of MIMAS-MOX prepared by powder metallurgy bentonite 26
Effect of bentonite addition to MOX Liquid bentonite Increased grain size of (U,Pu)O 2 : 8 14 µm Homogenisation of Pu distribution 27
Modified cold finger apparatus for FGR measurement from HTR fuel spheres 28