I think a plausible timeline for Australia is to install some SMRs after they have been accepted in the northern hemisphere. Hopefully no later than the early 2030s. Rather than a gigawatt plant some large retiring coal stations could be replaced by several SMRs of 300 MW or 470 MW each.

Australia is 70% desert full of old mines so could store spent nuclear fuel for reprocessing say after 2050. The idea is for the public to adapt its thinking in easy stages. Firstly fast build standalone light water SMRs then SMR clusters to produce over a gigawatt. Much later high burnup 4th generation reactors. What will propel this in Australia is high population growth, electric transport, desalination, gas depletion in the southern states, lack of baseload for heavy industry and 'demand management' = energy rationing.