Anyone know what hot shutdown mode is? Is it like sleep on a computer vs shutdown? I assume from the name that a hot shutdown state still requires cooling.
Since shutdown, one of the reactors has been run in a mode where it is generating some steam (but I believe no or not enough electricity – this is supplied by external power lines) for safety and maintenance purposes. Currently this is reactor 5. The russians are now switching it to reactor 4 (this being the one that Ukranian Intelligence alleged was rigged with explosives, and the one the russians won’t let the IAEA fully inspect).
The site uses the steam generated from one reactor unit in hot shutdown for various nuclear safety purposes including the processing of liquid radioactive waste collected in storage tanks. IAEA Website
From the context provide in the article I surmise that ‘Hot Shutdown’ is a condition where a reactor is on and generating steam for use with plant processes only and not producing power for external use. It is unnecessary to have any of the reactors in a Hot Shutdown state as the steam needed can be generated via mundane boilers (which would be safer and is the IAEA’s recommendation).