Of course it can, just short the generator coils and you have a free brake. The turbine should then still have resistance and shouldn't overspeed. Or just idk, use it to pump some water in a loop or discharge through some resistors. Getting rid of power isn't that hard if you want to do it. Simplest solution would I suppose be to just have an outside radiator that brings the steam to cooling tower levels of manageability so you can throttle the turbine with just a valve.
The thing is, they don't really want to do it if they can save fuel by shutting down.
The thing is, they don't really want to do it if they can save fuel by shutting down.