LEADER Project Overview 3th LEADER International Workshop Analysis and design issues of LFR reactor concept: ALFRED Pisa, 4th -5th September 2012; Bologna, 6th -7th September 2012 Luigi Mansani Luigi.mansani@ann.ansaldo.it

SUMMARY Introduction Nuclear Energy Sustainability Lead cooled Fast Reactors – Why? FP7 LEADER Project Roadmap towards an industrial LFR fleet in Europe ALFRED (Implementation schedule, design guideline, configuration) and ELFR (configuration) Some important facts

Introduction - Generation IV Goals & Concepts Sustainability Safety & Reliability Economics Proliferation Resistance & Physical Protection GENERATION IV SYSTEMS ACRONYM Sodium-Cooled Fast Reactor System SFR Gas-Cooled Fast Reactor System GFR Lead-Cooled Fast Reactor System LFR Molten Salt Reactor System MSR Supercritical-Water-Cooled Reactor System SCWR Very-High-Temperature Reactor System VHTR

European framework and context European energy policy, aiming at fulfilling the “20-20-20” strategy by 2020, relies on a wide implementation of nuclear technologies, including a new Generation of Fast Neutron Reactors oriented to the sustainability of nuclear energy through the actual closure of the fuel cycle The Strategic Research Agenda (SRA) of the Sustainable Nuclear Energy Technology Platform (SNE-TP) has selected three Fast Neutron Reactor systems (SFR, LFR and GFR) as a key structure in the deployment of sustainable nuclear fission energy Among the technologies under investigation in Europe Lead-cooled Fast Reactors (LFRs) represent one of the promising solutions, candidate as an alternative to the reference technology, based on Sodium-cooled Fast Reactors (SFRs)

ESNII* Roadmap from the Concept Paper Fast Neutron Reactors in the frame of the European Sustainable Nuclear Industrial Initiative (ESNII) ESNII* Roadmap from the Concept Paper (*) ESNII will address the need for demonstration of Gen-IV Fast Neutron Reactor technologies, together with the supporting research infrastructures, fuel facilities and R&D work All documents are available for download on www.snetp.eu

Sustainability: Partitioning and Transmutation (P&T) The radio-toxicity of the fission products dominates the total radio-toxicity during the first 100 years and reaches the uranium ore mine level at about 300 years The long-term radio-toxicity is dominated by the actinides (mainly by the Pu and Am isotopes) and the uranium ore mine level is reached only after more than 120,000 years By recycling and then ‘burning’ all the MA, the period over which high-level radioactive waste remains hazardous could theoretically be reduced from hundreds of thousands of years down to a few hundred years

Strategy for Sustainability of Nuclear Energy Present known resources of Uranium represent about 100 years of consumption with the existing reactor fleet Fast neutron reactors with closed fuel cycle have the potential: to multiply by a factor 50 to 100 the energy output from a given amount of uranium (with a full use of U238), To improve the management of high level radioactive waste through the transmutation of minor actinides to provide energy for the next thousand years with the already known uranium resources Both fast spectrum critical reactors and sub-critical ADS are potential candidates for dedicated transmutation systems Critical reactors, however, loaded with fuel containing large amounts of MAs pose safety problems caused by unfavourable reactivity coefficients and small delayed neutron fraction Core fuelled with only MA (Uranium free) has no Doppler nor Delayed Neutrons

Example of Closed Fuel Cycle in Fast Reactors Sustainability: Example of Closed Fuel Cycle in Fast Reactors Fabrication LFR Adiabatic Reprocessing All Actinides (Expected MA: 1% of which 20% Cm) MOX first loads (U:82.5%; Pu: 17.5%) Unat/dep: 1g/MWD + reintegration of losses FP: 1g/MWD + losses MOX equilibrium (U: 82%; Pu: 17%; MA: 1%) LFR can be operated as adiabatic: Waste only FP, feed only Unat/dep Pu vector slowly evolves cycle by cycle MA content increases and its composition drift in the time LFR is fully sustainable and proliferation resistant (since the start up) Pu and MA are constant in quantities and vectors Safety - main feedback and kinetic parameters vs MA content

Why LEAD? – Some Advantages LEAD COOLANT PASSIVE SAFETY Lead does not react with water or air Steam Generators installed inside the Reactor Vessel Very high boiling point (1745°C ), very low vapor pressure (3 10-5 Pa @ 400 °C) Reduced core voiding reactivity risk Lead has a higher density than the oxide fuel No need for core catcher (molten clad and fuel float) Lead is a low moderating medium and has low absorption cross-section. No need of compact fuel rods (large p/d defined by T/H) Very low pressure losses (1 bar for core, 1.5 bar for primary loop) Very high primary natural circulation capability natural circulation DHR LEAD COOLANT PASSIVE SAFETY

Why LEAD? – Not Only Advantages High Lead melting point (~ 327 °C) – assure Lead T above 340-350 °C Overcooling transient (secondary side) may cause Lead freezing Corrosion / erosion of structural materials - Slugging of primary coolant Seismic risk due to large mass of lead in-service inspection of core support structures fuel loading/unloading management by remote handling Steam Generator Tube rupture inside the primary system Flow blockage and mitigation of core consequences

Why LEAD? – Not Only Advantages PROVISIONS High Lead melting point (~ 327 °C) – assure Lead T above 340-350 °C heating system, design and operating procedures Overcooling transient (secondary side) may cause Lead freezing FW requirement – diversification and redundancy – Really a safety issue? Corrosion / erosion of structural materials - Slugging of primary coolant Coatings, oxygen control, limit flow velocity (Russian approach) Strategy at low oxygen content (alternative approach) Seismic risk due to large mass of lead 2-D seismic isolators, vessel hanged, specific design (EU FP7 SILER project) in-service inspection of core support structures Similar to other HLM reactors but high T, all components replaceable fuel loading/unloading by remote handling Develop appropriate cooling system (active  passive back-up) Steam Generator Tube rupture inside the primary system Show no effect on core, provide cover rupture disks to limit max pressure Flow blockage and mitigation of core consequences Hexagonal wrapped FAs – outlet temperature continuous monitoring Full unprotected flow blockage causes cladding damages to a max of 7 FAs

The FP7 LEADER Project The first step in the development of a Lead Cooled Critical Fast Reactor in Europe started in 2006 with the EU - FP6 ELSY project, on the basis of previous projects already carried out in the frame of projects dedicated to Lead-Bismuth/Lead cooled Accelerator Driven Systems (XT-ADS, EUROTRANS etc.) On March 2010 a first reference configuration of an industrial size (600 MWe) LFR was available. On April 2010 the LEADER project started its activities with the main goal to: Develop an integrated strategy for the LFR development Improve the ELSY design toward a new optimized conceptual configuration of the industrial size plant, the ELFR conceptual design. Design a scaled down reactor, the LFR demonstrator – ALFRED, using solutions as much as possible close to the adopted reference conceptual design but considering the essential need to proceed to construction in a short time frame.

Conceptual Design for Lead Cooled Fast Reactor Systems The FP7 LEADER Project Conceptual Design for Lead Cooled Fast Reactor Systems 16 European Organization are participating to the project Project Coordinator - Ansaldo Nucleare 3 year Project (2010-2013), started April 2010 LEADER Project Work Packages: WP1 - SCK CEN : Design Objectives and Specification WP2 - ENEA : Core design WP3 - ANSALDO : Conceptual design WP4 - EA : Instrumentation, control/protection systems WP5 - KIT-G : Safety and transient analysis WP6 - KIT-G : Lead Technology WP7 - KTH : Education and Training

Roadmap towards an industrial LFR fleet in Europe The main drawback facing the industrial deployment of a LFR fleet in Europe is the lack of operational experience A satisfactory technological readiness has been achieved in Russia in the past century driven by military research To fill the technology gap in Europe requires the setting up of a complete R&D roadmap, in analogy with what has been done in France for the development of the SFR technology chain, whose readiness is almost proven Nuclear submarine 705 serial (1976-1996)

Roadmap towards an industrial LFR fleet in Europe For the demonstration of the LFR technology chains, further facilities (either existing or under construction) are required to provide the overall frame for LFR technology development, like: all the existing and planned EU lead labs focused on thermal/hydraulics, materials development and corrosion testing; the zero-power facility Guinevere, already operating in Mol, Belgium, the irradiation facility and pilot plant MYRRHA, to be built and operated in Mol and, the European training facility ELECTRA, planned for realization in Sweden Guinevere MYRRHA ELECTRA

Roadmap towards an industrial LFR fleet in Europe The LFR development roadmap towards the industrial deployment of a fleet of European LFRs, requires: first a Demonstrator reactor (ALFRED) for proving the viability of reliable electricity production for LFR systems – 125 MWe second a Prototype reactor (PROLFR) is envisaged for testing the scaling laws at an intermediate step according to a common approach focused both on plant size and representativeness of the target reference system – 300÷400 MWe third a First-Of-A-Kind (ELFR-FOAK) representative of a commercial ELFR fleet – 600 MWe

ALFRED - Implementation schedule The realization of ALFRED will allow: the European scientific nuclear community to maintain the leading position in fast reactors design, construction and licensing, the industries to advance in the field of fast reactor components and systems design and manufacturing, preparing to the advent of a new Generation of nuclear systems for the sustainable energy future of Europe ALFRED is a Fundamental Step in the Development of Lead Fast Reactor ALFRED Implementation schedule consortium Basic Design, Siting and pre-licensing Detailed design & licensing construction Conceptual design (LEADER)

ALFRED - Design Guidelines ALFRED will be connected to the electrical grid Power close to 125 MWe (300 MWth) The LFR Demonstrator design should be based as much as possible on available technology to speed up the construction time Design solution (especially for Safety and Decay Heat Removal function) should be characterized by very robust and reliable choices to smooth as much as possible the licensing process Decay Heat Removal System based on passive technology to reach the expected high Safety level DHRs based on Active actuation and Passive operation

ALFRED - Reactor Configuration MAIN COOLANT PUMP FUEL ASSEMBLIES Power: 300 MWth Primary cycle: 400-480 °C Secondary cycle: 335-450 °C STEAM GENERATOR MAIN COOLANT PUMP STEAM GENERATOR REACTOR CORE REACTOR VESSEL SAFETY VESSEL

ELFR - Reactor Configuration Pumps integrated in the SGs Spiral SGS (8) – once through Hexagonal Wrapped FAs FAs extended to cover gas Core Bottom grid Inner shroud – lateral restraint FAs weighted down by Tungsten ballast (pumps off) FAs kept in position by top springs (pumps on) 4 Isolation condenser connected to SGs (DHR1) 4 Dip coolers immersed in the main vessel (DHR2) Power: 1500 MWth Primary cycle: 400-480 °C Secondary cycle: 335-450 °C

Main Parameters Emergency conditions Parameter ELFR ALFRED Primary Coolant Pure Lead Electrical Power/Efficiency, MWe/% 632 / 42 125 / 41 Primary System Pool type, Compact Primary Coolant Circulation: Normal operation Emergency conditions Forced by mechanical pumps Natural Core Inlet/outlet Temperature, °C 400 / 480 Fuel Assembly Hexagonal, wrapped, weighted down by ballast with pumps off, Forced by springs with pumps on Max Clad Temperature, °C 550 Max. core pressure drop, MPa 0.1 (30 min grace time for ULOF) 1st System for Shutdown/control Buoyancy Absorbers Rods: control/shutdown system passively inserted from core bottom 2nd System for Shutdown Pneumatic Inserted Absorber Rods: shutdown system passively inserted from core top Secondary System Pressure/steam temp, MPa / °C 18 / 450 Steam generators integrated in the reactor vessel Spiral type integrated in the reactor vessel Double wall Bayonet tubes DHR System 2 Passive DHRs (Actively actuated, Passively operated) DHR N°1 based on ISOLATION CONDENSER concept; DHR N°2 based on deep cooler 2 Passive DHRs (Actively actuated, Passively operated) based on ISOLATION CONDENSER concept

Last but not least …. some important facts for ALFRED GUINEVERE is operating FEED contract for MYRRHA – Offers delivered Experimental work on-going, spread over EU research Labs An MOU between Romania/Italy Organizations has been signed in February 2012 to define the steps and rules to be followed to form an international consortium for ALFRED Design and Construction. Intended location of ALFRED is Romania Romania’s Prime Minister, Mr. Victor Ponta, participating to “Nuclear 2012” hosted by INR in May, has acknowledged the importance of ALFRED and committed, on behalf of his Government, to ask the Commission to host ALFRED in Romania STRONG SYNERGIES have been identified between SFR and LFR technologies (HeliMNet meeting – Aix en Provence – October 2011 – www.helimnet.eu)

GIF LFR Reference Concepts LFR MOU signed by Japan and Euratom October 2010 LFR MOU signed by Russia July 2011 Presentation to the GIF Symposium in San Diego – November 2012 Development of a position paper on LFR safety System Research Plan will be revised – expected issue end of 2012 LFR Reference concepts: SSTAR, BREST 300, ELFR SSTAR (10 - 100 MWe) BREST 300 (300 MWe) ELFR (600 MWe)

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