Passive safety is one of Generation IV nuclear plants leading pillars. In this perspective, several new passive safety systems have been proposed and tested to demonstrate their inherence passive safety features for the GEN IV reactor technologies under development.
For Lead Fast Reactor (LFR), a self-regulating system, referred to as Isolation Condenser (IC) passive safety system, is considered to ensure long-term safe state without needs for external actions or energy supply. The IC concept is able to remove the decay heat, in order to both reach a safe shutdown state and reduce the power removal capabilities over time delaying primary cooling freezing. This IC devoted safety function is achieved by allowing the Decay Heat Removal system (DHR) loop to be flooded by Non-Condensable (NC) gases when needed (at low pressure) to passively control the rate of energy transfer via condensation in the heat exchange components. The concept is applicable to water-cooled reactors as well, to limit the temperature decrease rate during accidental events, hence reducing the thermal stresses on the primary and secondary system components.
The HORIZON 2020 Passive IsolAtion CondEnser (PIACE) project, started in 2019, aims at testing the IC passive safety system in a new experimental facility, at SIET premises in Piacenza (Italy). An experimental program is defined to test the applicability of the IC concept for selected reactor technologies: LFR, MYRRHA ADS, PWR, BWR, PHWR.
Pre-test simulations were run to provide a comprehensive evidence of the applicability of the IC solution for these technologies, and confirmed its efficiency. Test matrices have been defined for the SIRIO experimental campaign.
The paper presents the pre-test simulations performed with system thermal-hydraulic codes to demonstrate that the proposed DHR solution is able to accomplish the DHR safety function for the particular case of liquid metal fast reactors technologies: ALFRED and MYRRHA ADS.
|Conference||2022 - IAEA Technical meeting on state-of-the-art thermal hydraulics of fast reactors|
|Period||2022-09-26 → 2022-09-30|