1. Plans for a new large scale corium facility at CEA Cadarache: the FOURNAISE project C. Journeau, J.M. Ruggieri, P. Piluso CEA, DEN, Cadarache (FR) ERMSAR 2012, Cologne March 21 – 23, 2012

2. Outline Need for prototypic material tests FOURNAISE for SFRs FOURNAISE objectives FOURNAISE general characteristics Time schedule

3. Uranium oxide: specificity and properties Uranium and some « simulant » element-oxygen systems U-O systemZr-O system Hf-O system Many solid compounds with uranium: UO 2.00, UO 2+x, U 4 O 9, U 3 O 8 Many gaseous compounds with uranium: UO 3,UO 2,UO,U

4. Prototypic /simulant material FCI experiment corium alumina -No spontaneous steam explosion with 80%UO 2 20%ZrO 2 corium (0.1MPa, sub-cooled water) in KROTOS facility -Same conditions: very energetic steam explosion with alumina Specific melt break-up behaviour with prototypic corium: Different configurations of the pre-mixing (and thus explosion) for alumina and for corium

5. Operating international prototypic corium experimental facilities(1/2) PLINIUS FOURNAISE SICOPS COMETA RASPLAV ACE/MACE LAVA-B TROI VESTA SOFI

6. Operating international prototypic corium experimental facilities (2/2) For SFRs >SOFI: few kg SOdium Fuel Interaction test (IGCAR, India) For LWRs : >CCI (ANL, USA) : upto 1 t corium (no steel) MCCI >TROI (KAERI, Korea): 20-kg Fuel-Coolant Interaction Test >VESTA (KAERI, Korea) new built 100-kg MCCI facility (oxidic melt) >LAVA-B (NNC, Kazakhstan) : 60-kg scale corium facility. Currently working on Lower Head corium pools. >RASPLAV (NITI, Russia): 5-20-kg scale facilities: phase diagrams, corium-metal, aerosols >SICOPS (AREVA, Germany): 5-20 kg MCCI tests >COMETA (UJV, Czech Republic) : kg-scale tests on corium thermochemistry and aerosol generation >CODEX (EK, Hungary): bundle melting and corium formation >VULCANO (CEA, Cadarache) 25-80 kg facilmity for spreading, MCCI, solidification, coolability >KROTOS (CEA, Cadarache) 5 kg corium-water interaction >COLIMA (CEA, Cadarache) 2 kg crucible: aerosol generation, material interaction >VITI (CEA, Cadarache) 1-10-g small scale facility: thermophysical properties, material interactions

7. ASTRID SFR Severe Accident programme CEA is developing the ASTRID Sodium Fast Reactor (SFR) demonstrator for which ambitious goals in term of safety and operability have been set. >its safety level concerning severe accidents must be at least equivalent to that of the EPR. To reach this objective a SFR severe accident project has been launched including a large experimental program with prototypic corium. The FOURNAISE facility (Furnace for Oxides of Uranium aimed at simulating Nuclear severe Accidents In large Scale Experiments) is under study at CEA Cadarache to extend the current PLINIUS prototypical platform in order to study the issues linked to SFR severe accidents, with large masses of prototypic corium, especially : >Fuel Coolant Interaction (FCI) >corium-material interactions in the core catcher

8. Based on FARO facility at JRC Ispra 2 SFR FCI tests before 1990. TERMOS test section >Thermal protection by alumina to enable tests with Na with low undersaturation (800-900°C) >Program halted before hi temperature tests due to backfitting for LWR programme. 10s of LWR FCI tests. 2 spreading tests. Direct Electrical Heating furnace 110 and 140 kg UO2 poured into Na FARA has been dismantled and is in waste storage casks.

9. LWR Experimental Needs Since the Fukushima accident], the interest for large mass experiments for Light Water Reactors (LWR) has grown It has been proposed to design the FOURNAISE facility so that it can be applied to severe accident phenomena in both types of reactors. For LWRs (Reactor case ~100 t corium) >FCI (steady state requires M > 100 kg) -Steam explosion -Jet fragmentation and debris formation >MCCI and ex-vessel coolability -Crust anchorage issues -Surface/Volume ratio >Optimization/Qualificatiopn of mitigation devices -Core catchers,….

10. Need for large scale experiments (FARO – Large scale FCI) Formation of cake vs. Debris has only been observed in large scale experiment like FARO. In some tests, almost 100 kg remained fragmented. In 100 kg+ experiments (as FARO), steady state regime (linear pressure increase) can be achieved contrary to the case of small masses tests.

11. FOURNAISE A versatile large scale prototypic corium facility made of >A furnace able to melt large masses of corium -SFR composition: UO2, Steel, core catcher materials… -LWR composition: UO2, ZrO2, Steel, concrete and core catcher materials -Mass in the 100-300 kg range. >Transfer devices >Test sections dedicated to various objectives -Corium-sodium interaction -Corium-water inetraction -Corium-material interactions (concrete/ sacrificial material/ refractories) -Coolability issues -Melt Spreading, Debris Levelling -New applications to be determined…. For regulatory reasons, test sections with sodium must be in separate room from test sections with water, >Material preparation rooms (load, post-test) >Sodium and steam treatment installations

12. First sketch of facility

13. Melting technology Still under study >Thermitic reactions -For LWR: Zr+CrO3 + Fe2O3+ (U3O8)…. -For SFR: U+CrO3+Fe2O3 + … >Induction heating -Cold crucible seems the best option to prevent pollution by crucible material Two implementation options are considered One furnace + inclined transfer tubes to 2 rooms (sodium/water) Two furnaces sharing the same power supply and services. Induction heating will also be available to simulate decay heat in long term experiments. >Applied largely to oxidic phase.

14. Tentative time schedule Preliminary studies 2012 Detailed studies 2013 Construction 2014-2016 Commissionning and First tests 2016-2017

15. Conclusions The FOURNAISE facility, initially planned for the SFR Severe Accident program, is now being considered as a scientific experimental platform that would be useful to both LWRs and SFRs. Its general lay-out would be close to that of the FARO facility, >but it will take account of all the technological knowledge gained on corium experimentation in the last 20 years. It should be available around 2017 for experimental research programs for both Sodium Fast Reactors and Light Water Reactors on : >Fuel-Coolant Interaction, corium coolability, >Corium-Material Interaction (material being concrete, sacrificial ceramic,…). When available, this new prototypic corium facility will be an asset for the European Research Area on Severe Accidents. >Complementary to current European corium facilities.