Analysis of ESFR Decay Heat Removal Systems in Protected Station Blackout

Abstract

Abstract As part of the European sodium fast reactor (ESFR)-safety measures assessment and research tools (SMART) project, safety assessments are being conducted on the updated ESFR design. An important part of the study is the evaluation of the reactor's behavior within hypothetical accidental conditions to assess and ensure that the accident would not lead to unexpected and disastrous events. In this paper, the analyzed accidental scenario is the so-called protected station blackout (PSBO), where the offsite power is lost for the power plant, simulated by using the TRACE and simulator-sodium fast reactor (SIM-SFR) system codes. The assessment started from the simulation of the reactor behavior without the decay heat removal systems (DHRSs). Following this, calculations of multiple DHRS arrangements have been performed to evaluate the individual and combined efficiency of the systems. Where it was possible, the results from the two system codes have been compared to show the consistency of the separate calculations. Through this study, the design of the DHRSs proposed at the beginning of the project has been investigated, and certain recommendations have been made for further improvement of the DHRS systems performance.