1. 1DEN/CAD/DTN/DIR Genova 2010 April 22nd LEADER WP6 Task 6.3 Assessment, validation and adaptation of oxygen control and purification strategy (CEA-5, ENEA-1, KIT-2) Christian Latgé CEA - Cadarache Department of Nuclear Technology

2. 2DEN/CAD/DTN/DIR Genova 2010 April 22nd Oxygen control is required for LFR systems. The general oxygen activity level and different technologies like gas phase control via gas plenum or using solid lead oxide particle in the liquid lead are widely explored in the last years. Several institutions in Europe were also very active in the development of lead purification systems. However, a clear route to realize oxygen control and lead purification in a real pool type reactor is not yet defined. Task responsible persons: CEA: Christian Latge, ENEA: Alessandro Gessi, KIT: Alfons Weisenburger; Deliverables: D12 - Compilation of existing data on the liquid lead oxygen control strategy (M24) – CEA, ENEA, KIT

3. 3DEN/CAD/DTN/DIR Genova 2010 April 22nd Assessment, validation and adaptation of oxygen control and purification strategy Context: For a safe and reliable reactor operation: - Structural material shall be protected controlling the amount of oxygen in the molten lead pool. - Formation of flow blockages shall be avoided in the lead molten pool (blockage of Fuel Assemblies, narrow gaps,… Consequently: Strategies developed to protect the primary vessel should be efficient and reliable: - for steady-state and transient conditions, the general oxygen activity level range at which a LFR will be operated, has to be validated. - the technologies to control O (gas phase control via gas plenum, solid PbO in lead) should be reliable in all operating conditions. - the purification systems should be reliable and operable for various conditions (start-up purification, steady-state purification or purification campaign after large pollution) - the instrumentation required to monitor the lead quality has to be validated (O activity, particles content, O content in cover gas,…)

4. 4DEN/CAD/DTN/DIR Genova 2010 April 22nd - Dedicated studies:  amount and location of oxygen sensors investigated and proposed.  position of purification systems (PS) (for efficiency) (integrated or implemented on loops; position of lead inlet inside the primary vessel,…)  PS management: ie for filters: in-situ operating duration, impact of dosimetry (Po,…), strategy for replacement and impurities removal,… (and impact on sizing)  oxygen behaviour during accident conditions: possibility to face various potential events to be investigated.  Options for lead purification during plant operation to be individuated and qualified.  Attempt to define efficient filtering system for lead and gas phase. (type of filter, flow : tangential or not, pressure drop adjustment,… Identification of clear requirements and input data with regards safe and reliable operation: O activity range versus the operating lead temperature Acceptable density of particles (from dedicated safety studies) in lead, cover gas. CFD characterization of primary vessel (Lead velocity map, « dead » zones, temperature distribution and stratification (from design studies) R&D activities to be performed:

5. 5DEN/CAD/DTN/DIR Genova 2010 April 22nd Purification systems: filtering systems