Experimental analysis of stationary and transient scenarios of alfred steam generator bayonet tube in circe-hero facility

One of the most promising Generation IV nuclear concept, fostered by GIF (Generation IV International Forum), is constituted by the innovative heavy liquid metal coolant systems, complying with all GIF requirements: sustainability, economics, safety, reliability and proliferation-resistance. The technological development and safety evaluation of the Advanced Lead Fast Reactor European Demonstrator (ALFRED) are supported by national and European research projects. In particular, the European HORIZON2020 project SESAME (Simulations and Experiments for the Safety Assessment of MEtal cooled reactors) financed a series of experimental and numerical analysis oriented to this reactor type. In this framework, an experimental campaign was performed at ENEA research centre of Brasimone in the large pool integral test facility CIRColazione Eutettico (CIRCE), implementing the dedicated Heavy liquid mEtal pRessurized water-cOoled tubes (HERO) test section, for characterizing ALFRED Steam Generator Bayonet Tube (SGBT) behaviour in both stationary and transient scenarios.HERO test section was obtained implementing, in the pre-existing Integral Circulation Experiments (ICE) TS, a new heat exchanger composed by 7 bayonet tubes with geometry (scale 1:1) and operating conditions (liquid water inlet at 335°C and steam outlet of about 180 bar) coherent with ALFRED SGBT. HERO test sectionmaintained the configuration of the Fuel Pin Simulator (FPS), fitting volume, riser and separator of ICE test section.The performed experimentalcampaign consists of three Transient Tests (TTs), starting from the same steady state condition (as ALFRED) and reproducing Protected Loss Of Flow Accident (PLOFA) events. In steady-state conditions, the LBE mass flow rate is promoted by the injection of argon in the riser simulating the behaviour of the primary pump, while the thermal power is supplied with an electrically heated fuel pin simulator. The transients areobtained reducing the FPS power according to a characteristic heat decay curve, while the loss of the primary pump is reproduced by the reduction of the gas injection. The loss of the heat sink is simulated managing the HERO feedwater in the secondary loop.The present work also reportsthe pre-test analysis carried out by RELAP5-3D simulations, for evaluating CIRCE LBE pool dynamics/stratification during TTs