Gas-cooled Fast Reactor Status and program Pascal ANZIEU Commissariat à l énergie atomique Atomic Energy Commission France Nuclear Energy Division P. Anzieu - GFR Status 1
GFR: an alternative Fast Neutrons Reactor to SFR A significant past experience and innovation objectives SFR Reduction of investment cost Safety level comparable to 3 rd generation LWRs Potential for integral recycling of actinides GFR An alternative FR track based on: Benefits from helium as a coolant Robust fuel (including severe accident conditions) Potential for high temperature applications Milestone 2020: prototype (250-600 MWe) Milestone 2020: experimental reactor ALLEGRO 75 MWt Nuclear Energy Division P. Anzieu - GFR Status 2
The GFR is a fast spectrum system Fast spectrum favours: the full use of uranium resources the actinides fissions (versus captures) reduction of heavy atoms production transmutation of minor actinides wastes minimization Isotope Thermal spectrum reactor (PWR) Fast spectrum reactor (SFR) σ f σ c α = σ c / σ f σ f σ c α = σ c / σ f 235 U 38,8 8,7 0,22 1,98 0,57 0,29 238 U 0,103 0,86 8,3 0,04 0,30 7,5 238 Pu 2,4 27,7 12 1,1 0,58 0,53 239 Pu 102 58,7 0,6 1,86 0,56 0,3 240 Pu 0,53 210,2 396,6 0,36 0,57 1,6 241 Pu 102,2 40,9 0,40 2,49 0,47 0,19 242 Pu 0,44 28,8 65,5 0,24 0,44 1,8 237 Np 0,52 33 63 0,32 1,7 5,3 238 Np 134 13,6 0,1 3,6 0,2 0,05 241 Am 1,1 110 100 0,27 2,0 7,4 242 Am 159 301 1,9 3,2 0,6 0,19 242m Am 595 137 0,23 3,3 0,6 0,18 243 Am 0,44 49 111 0,21 1,8 8,6 242 Cm 1,14 4,5 3,9 0,58 1,0 1,7 243 Cm 88 14 0,16 7,2 1,0 0,14 244 Cm 1,0 16 16 0,42 0,6 1,4 245 Cm 116 17 0,15 5,1 0,9 0,18 He coolant is almost inert to neutrons : no parasitic capture, potential for spectrum hardening Nuclear Energy Division P. Anzieu - GFR Status 3
GFR applies the related GEN IV closed fuel cycle Natural or depleted U Used fuel Fuel treatment and Re-fabrication Final Wastes Fission Products GEN IV Fast Spectrum Reactor Actinides Plutonium is the fissile species Self-sustainability Grouped extraction Proliferation resistance All the actinides (U, Pu, Np, Am, Cm) are recycled together and not separated (integral actinide recycling) The use of fertile sub-assemblies is minimized : search for self-sustaining cores with a breeding gain close to zero The fuel cycle is only fed by natural or depleted U On site integration of fuel treatment and re-fabrication Nuclear Energy Division P. Anzieu - GFR Status 4
Back to old GCFRs projects In reference they were considering cores of sodium cooled fast reactor technology : Pin bundle Oxide fuel Metallic materials High volume power But with two innovations : Roughened clads to enhance heat transfer to the He: core pressure drop A pressure equalization system (PES) Nuclear Energy Division P. Anzieu - GFR Status 5
GFR Current R&D : challenges Self-sustainable cores A robust safety approach An attractive power density ~100 MW/m 3 An innovative fuel (FPs confinement, fast neutrons, high HM content, high temperature) Reactor design and safety systems / management of the decay heat removal In common with the VHTR : And together with the SFR: Fuel recycling technologies And possibly : Power conversion, Fuel materials and design? Technology of He circuits and components High temperature materials Power conversion Nuclear Energy Division P. Anzieu - GFR Status 6
GFR assets Safety No cliff edge effect due to gas Gas voiding effect < 1$ Thermal-hydraulics and neutronics are decoupled Good in service inspection (optical transparency) Low inertia, needs a fuel that resists to high T Competitiveness High temperature Net efficiency >45% Industrial application of high temperature heat Easy to repair Coolant is inert, transparent, non active No specific washing Fissile material management Plutonium breeding Minor actinides transmutation Aqueous process of the fuel cycle Nuclear Energy Division P. Anzieu - GFR Status 7
Plate or pin fuel element: a first design SiC fiber Mixed carbide pellets SiC/SiC f clads Plate fuel element Nuclear Energy Division P. Anzieu - GFR Status 8
Irradiation program Fissile Compounds Inert Materials 2005 2009 2012 PHENIX NIMPHE 1&2 1600 C, 7 At% ATR GFR-F1 OSIRIS REA1 Liners CMC welding R&D fuel PHENIX FUTURIX-MI 1000 C, 42 dpa R&D Materials OSIRIS OSIRIS REA2 REA3 Fibers Composite Interphase multi layers HFR, JOYO? Optim. UPuC Swelling, FGR,creep, effect of MA in (UPuAM)C JOYO GFR-MI? 500-1000 C, 80 dpa Fuel Element PHENIX FUTURIX-Concepts 1200 C, 2 at% R&D processes BR2 IRRDEMO 1 1300 C, 1-2 at% Pin & plate prototypes Nuclear Energy Division P. Anzieu - GFR Status 9
FUTURIX-MI in PHENIX (2007-2009) Material behaviour under representative operating conditions High temperature : 1000 C with temp. detectors Fast neutron fluence : close to 10 27 n/m 2, dose max. 42 dpa SiC CEA/DOE Carbides SiC (5 types), ZrC, TiC Nitrides ZrN(2), TiN (2) Refractory metals NbZr, MoZrB, Mo alloys Ceramic composite SiC-SiCf (9) Sample geometry adapted to PIE Nuclear Energy Division P. Anzieu - GFR Status 10
FUTURIX-CONCEPTS in PHENIX (2007-2009) Thermo-mechanical mechanical & thermo-chemical behavior of GFR fuel concepts Power density: 85-95 W/g of fuel, Max. temp. : 700-1000 C, Burn-up : 3.6-4 at. %, Dose max. <42 dpa SiC UPuC / SiC UPuN / TiN SiC welding: BRASIC TiN welding : metal diffusion Nuclear Energy Division P. Anzieu - GFR Status 11
Fuel fabrication : the IRRDEMO experiment Plate fuel and pin fuel elements. Composite Matrix Ceramic clads Metallic clad for plate Irradiation in BR2 at MOL, Belgium From 2010 to 2011, 1.0 at% (U,Pu)C Metal plate Centreur SiC/SiCf mono. SiC Inner Liner Outer Liner Outer clad CMC mini-pin 6 CMC plates 10 CMC pins Metallic Liner 4 metal plates Nuclear Energy Division P. Anzieu - GFR Status 12
Ceramic core - Loading Map 246 fuel sub-assemblies (2 zones) 18 control rods (2 systems) 6 scram rods Equilibrium Unit Power (MWth) 2400 Power density (MW/m 3 ) 91,5 H/D ratio 0,62 R c (cm) H f (cm) 188.6 236 Average enrichment Pu (%) 18,2 Pu+M.A mass (t) /GWe 11,0 dont 0,6 A.M Residence time (BU max =10 at %) BU average BU max ( at %) 4 600 = 1800 JEPP 6.7 10.4 He void effect (BOL, EOL) (pcm) Doppler Constant (BOL, EOL) (pcm) Delayed neutrons fraction (BOL, EOL) (pcm) 309 307-1283 -837 355 342 Material balance (kg) Equilibrium BOL EOL U 53407 48957 Np 72 77 Pu 12029 12106 Am 524 457 Cm 134 155 TOTAL 66166 61753 TOTAL Pu9 Equiv. 8140 8277 TOTAL Pu9 Equiv. (EOL+3years) 8156 Nuclear Energy Division P. Anzieu - GFR Status 13
Decay Heat Removal loops 3 loops 100%, moderate pumping power: 300 kwe Natural circulation under pressure 1 emergency low pressure loop A spherical guard containment Gas injectors Nuclear Energy Division P. Anzieu - GFR Status 14
Transient example: Loss of power grid 80 s Mass flow rate (kg/s) 1200 1000 800 600 400 200 Core mass flow rate and blower rotation speed Primary valve closure DHR valves opening Mass Flow rate Blower rotation speed DHR blowers start-up 500 400 300 200 100 Rotation speed (rad/s) Power (W) 3.E+09 2.E+09 2.E+09 1.E+09 5.E+08 Core power Neutron power Power transfered to helium 0 0 0 10 20 30 40 50 60 70 80 Time (s) 0.E+00 0 10 20 30 40 50 60 70 80 Time (s) Temperature ( 1200 1100 1000 900 Core temperature (z=4.05m) Maximum fuel Clad Helium Fuel T combustible decrease from 1375 C to 980 C in 50s Clad T increase from 985 C to 1000 C 800 0 20 40 60 80 Time (s) Nuclear Energy Division P. Anzieu - GFR Status 15
Large Components Helium blower for DHR loop High T heat exchanger Fuel handling Control rods He+N2 400 C He+N2 800 C Flo pat He 850 C He 450 C Nuclear Energy Division P. Anzieu - GFR Status 16
Power Conversion System A power conversion system with gas Indirect combined cycle 3 secondary loops 3 SG et 1 tertiary turbine 565 C 535 C 850 C 820 C He 70 bar He-N2 65 bar H2O 150 bar 400 C 362 C 178 C 32 C Electrical grid Efficiency 45% Possible optimization Up to 48% Nuclear Energy Division P. Anzieu - GFR Status 17
Reactor design & GFR2400MWth Plant PRIMARY CIRCUIT + DHR POOL + SECONDARY LOOP & ISOLATION VALVES Nuclear Energy Division P. Anzieu - GFR Status 18
Reactor design & GFR2400MWth Plant STEAM GROUP + HE/N2 GROUPS + TERTIARY WATER SYSTEM Nuclear Energy Division P. Anzieu - GFR Status 19
Reactor design & GFR2400MWth Plant REINFORCED CONTROL STATION BUILDING Nuclear Energy Division P. Anzieu - GFR Status 20
An Experimental Prototype ALLEGRO A loop type 50-80 MWth reactor; No electricity generation Two core configurations MOX core: T in /T out = 260/560 C Ceramic core: T in /T out = 400/850 C Secondary circuit: pressurised water To avoid materials for HT heat exchanger Possible link to a test loop for high T heat applications, 10 MWth AHX1-2-3 1,5 MWth DHR loops He H2O AC 850 C 560 C ETDR CORE (startingand demo) 50 MWth 400 C 100 MW/m3 Main cooling system Hélium primaire Secondaire eau sous pression Refroidisseur à air 260 C He 35 kg/s MC MHX ~51 MWth ~41 MWth MP 130 C 197 C H2O 175 kg/s AIRC ~51 MWth ~41 MWth He AIR IHX"HTTR" 0 MWth ~10 MWth Test loop for heat applications AC M C Nuclear Energy Division P. Anzieu - GFR Status 21
ALLEGRO: GFR demonstration & experimental facility 75 MW Core Fast neutron Φ Dose In core vol. Loading 25% Pu 9 10 14 n/cm 2 /s 13 dpa/an 6 x 5 litres 8 d Experimental S/A Fuel Control (CSD) Fuel 245 195 165 Shutdown (DSD) Reflector Shield 80 50 0 Diagrid Nuclear Energy Division P. Anzieu - GFR Status 22
Fuel handling Main Handling arm through peripheral access Three accesses à 120 (one for emergency) Optical fibre for inspection on arm extremity Loading / unloading using a 2nd peripheral arm Three S/As are grouped Core loading 75 MW = 52 days 5 days Pmax S/A 1 MW 6 kw 45 days for 84 S/As 2 days to switch operation handling Estimated performance >250 EFPD/y Nuclear Energy Division P. Anzieu - GFR Status 23
Technology R&D for Gas-cooled Reactors HECO Qualification of DHR Circulator He TRIBOMETER Materials for junctions and contact surfaces DHR Valves development SALSA DHR loop system HETHIMO Thermal insulation systems HELAN Thermal insulation conductivity HETIQ Study of static He tightness CIGNE/HPC Helium quality management HEDYT Helium loop 10 MPa, 0.2 kg/s, 850 C Thermal-hydraulic studies, Erosion of SiC, Heat exchanger qualification Nuclear Energy Division P. Anzieu - GFR Status 24