Gen IV - Improved safety, cost, sustainability and efficiency have been set out as motivations. With less than expected electricity demand (and other reasons) the development of gen iv has not been put on fast track. However, the situation now looks different. Final energy consumption might not increase in OECD countries, but electrification of transport, heating and the hydrogen option in the steel industry (a.o.) drive electricity consumption up, while at the same time fossil-fuel powerplants should shut down asap and nuclear power plants might not be replaced, largely due to the high unit costs. I am aware that the future energy system will look pretty different to what we have today (and also depending where on this planet one lives) and there are quite a few pathways this could take - but for this thread I would like to kindly ask the audience to share their knowledge about the status quo of gen iv reactors. Which of the initially proposed 6 types are most promising to deliver, or are there other more promising technologies evolving, SMR? When will we see commercialization? To what cost? Many thanks in advance.