Within the R&D program of Generation IV lead fast reactors and Accelerator-Driven Systems, a new project named PATRICIA (EC – H2020) has been launched by the European Commission to support innovative solutions for the development of MYRRHA ADS concept and lead fast reactor technologies in general. In this framework, the ENEA Brasimone Research Centre (Italy) supports such research activities through experimental campaigns, involving CIRCE, a large scale pool-type facility using lead-bismuth eutectic as the primary coolant and pressurized water as the secondary fluid.
A new test section named THETIS is currently under design and it will be installed in the main vessel of the CIRCE facility. The test section will include a vertical mechanical pump for the primary coolant circulation and a new prototypical helical coil steam generator (HCSG). This type of steam generator turns out to be very interesting for nuclear power plants, since the helical geometry is very compact and it assures a high power removed, taking up the minimum amount of space.
The experimental tests will aim at: (i) investigating the thermal-hydraulic behavior of the system in steady state operation (forced circulation regime), during operational and accidental transients (postulated scenarios) and in natural circulation regime, considering as heat sink the HCSG (acting as Decay Heat Removal system, DHR) and the reactor vessel auxiliary cooling system, in stand-alone or coupled operation, (ii) characterizing the performances of the helical coil steam generator.
The present paper aims at presenting the preliminary layout of the THETIS test section, describing in details the main components, the instrumentation installed and the main operating conditions of the facility.