Development of Molten Salt Reactor technology in the Czech Republic

1. Development of Molten Salt Reactor technology in the Czech Republic Author: Jan Uhlíř

2. Generation IV International ForumGIF

3. GIF selected 6 advanced reactor systems Very-High-Temperature Reactor (VHTR) Gas-Cooled Fast Reactor (GFR) Sodium-Cooled Fast Reactor (SFR) Supercritical-Water-Cooled Reactor (SCWR) Led-Cooled Fast Reactor (LFR) Molten Salt Reactor (MSR) Existing interest of GIF members in individual reactor systems development (EURATOM activities in MSR are represented mainly by R&D in the Czech Republic)

4. Molten Salt Reactor (MSR) Non-classical reactor system: • Nuclear fuel is dissolved in carrier coolant (fluoride molten salt) of primary circuit • Liquid (molten salt) fuel is continuously supplied into reactor, fission products are also continuously removed by on-line reprocessing of circulating fuel • Reactor can be operated either with thorium fuel (in thorium - uranium fuel cycle [MSR – Th-breeder]) or with transuranium fuel – burning plutonium and higher actinides (MSR – An-burner) (MSR operated in thorium – uranium fuel cycle does not produce any transplutonium elements, which cause the main problem of current spent nuclear fuel) The basics of MSR technology were verified in 1965 – 69 by successful operation of MSRE in ORNL (USA).

5. Position of Czech Republic within the R&D of MSR technology Czech Republic and France were leaders of MSR technology development within the frame of GIF.Czech Republic takes part in GIF activities under the EURATOM membership(EURATOM representative in GIF System Steering Committee MSR is Dr. M. Hron from NRI Řež plc) Czech republic had the most extensive experimental program in the area of MSR technology development Czech R&D was supported mainly by the Ministry of Industry and Trade (MIT), partially by the Radioactive Waste Repository Authority (RAWRA); international co-operastion was based on R&D grants of EC-EURATOM (Framework program 5 and 6). R&D in the Czech Republic was realized in the frame of special consortium constituted by: NRI Řež plc, Faculty of Nuclear Sciences and Physical Engineering of Czech Technical University, ŠKODA JS (SKODA Nuclear Machinery), Institute of Nuclear Physics of CAS, Energovýzkum Ltd. (NRI Řež plc was the leading company and coordinator of the R&D)

6. R&D project MIT „Nuclear transmuter SPHINX with liquid fuel based on molten fluorides“ (2004 – 2008) Project work-packages: • Reactor core and primary circuit • Fuel cycle technology • Experimental reactor core and reactor control • Secondary circuit and its components • Structural materials • System study • Experimental program SR-0 Inserted zone with fluoride molten salt in the LR-0 reactor (NRI Řež plc.) Special nickel alloy MONICR developed by ŠKODA JS Processing of fluoride fuel (NRI Řež plc)

7. Proposal of subsequent R&D project of MSR technology:Phase 1: (2009 – 2013) „Development of MSR Mock-up“ • Development of main components of MSR technology • Verification of the MSR technology by realization of MSR Mock-up The main aim of Phase 1 is building of MSR mock-up technology – molten salt loop, which looks like a real MSR. However the nuclear (chain) reaction is simulated by electrical heating, other systems are similar as in real MSR. (Mock-up technology is inevitable step before constructing real nuclear reactor.) Individual work-packages of the project devoted to the R&D of MSR system: • Liquid fuel processing technology • Technology of fuel salt clean-up, reactor chemistry • Molten Salt Reactor core physics • Design and construction of reactor core including the control system • Primary circuit components (pumps (impellers), valves, heat exchangers, flux and temperature measurements, etc.) • Primary and secondary circuit heating systems • Structural materials of primary and secondary circuit • Thermohydraulics of primary and secondary circuit • Nuclear reactor safety • MSR Mock-up realization • Applicability of molten-salt technology for other types of advanced reactors and for non-nuclear application

8. Preliminary proposal of subsequent R&D project of MSR technology :Phase 2: (2014 – 2020) „Realization of experimental MSR (2 – 5 MWth MSR)“ The aims of Phase 2 are realization of experimental MSR, full verification of the reactor system, verification of all structural materials, processing of liquid fuel and radioactive waste management, reactor safety (reactor control systems), proliferation resistance and physical protection and finally to create suitable conditions for full MSR technology testing by manufacturers of nuclear technologies. Successful operation of the experimental MSR is inevitable for subsequent design and deployment of power MSRs. A necessary requirement for successful realization of Phase 2 is collaboration with some “nuclear power”, preferably with USA and broad collaboration of Czech and international companies producing nuclear reactor components. The collaboration with USA will be necessary for arrangement of fissile material (nuclear fuels) and for fuel tests of MSR with all proposed fuel types (uranium, thorium, transuranium). Experimental MSR can be realized by reconstruction of LR-O reactor in the NRI Řež plc.

9. Current status of the new MSR project preparation • September 2008 – MIT and prime minister were informed about the business plan • November 2008 – SPHINX project was supplemented by new WP describing possible of future strategy in R&D of advanced reactor types • February – March 2009 – Opponents recommended to continue in R&D of MSR technology • March – April 2009 – new proposal was submitted to MIT and is waiting for decision