If the Australian Government were to contract say SK, then SK...

If the Australian Government were to contract say SK, then SK will supply all of the engineering to design/construct/commission the reactor. Local contractors and engineering firms can then be used to undertake the construction. This sort of turn key engineering on large projects is common.

Operating a reactor is something completely different and today, most of its operation is done through control systems engineering, that the NK will provide. Then all you need to do is buy in expertise as required, with NK to supply full time systems engineers until such time as the in-house expertise can be developed. Sounds like such a project would take 8-10 years, plenty of time for expertise to be developed and plenty of time for Universities to start offering nuclear engineering for next generation engineers.

They seem to be managing just fine at Lucas Heights???

Its certainly not such a big ask as the scare mongers would suggest.