New nuclear power plant designs propose to rely more heavily on passive systems to fulfill several safety functions. This design choice is usually driven as the passive systems relies less on human actions and support systems than active systems. Safety expectations for passive and active systems are similar and only the approaches to implement them may differ considering that passive systems operate differently.
Within this context, the WENRA Reactor Harmonization Working Group (RHWG) has developed a report that draws attention on attributes of passive systems that are worthwhile to be considered with regards to safety in view of current regulatory practices in Europe. This report reviews some of the key features of passive systems and stress on the potential need to provide the regulator with specific justifications.