They call it Renationalization. when a Government takes back the contract for public infrastructure pr public services from the private provider, but the more appropriate concept is Reversion back to the Public Sector, who always retains ultimate responsibility for public service provision.
After all, that's why it's called Public Infrastructure and Public Services.
Since the Public Sector is ultimately responsible for roads, passenger transportation and utilities, the proper word to use is Reversion, not Renationalization. Most PPP and concession
contracts have clauses providing for this.