I doubt that salt water is circulating in the loop between the turbine and steam generator. That’s an interesting idea. I wonder about the integrity of the tubes in the condenser. From the images, the plant doesn’t have cooling towers so sea water is probably used to condense the steam exhausted from the turbine.
Instrumentation should have spotted the change in water chemistry from salt.
I was just considering the possibility of “improvements” that may have been made that may possibly be promoting such via bonding or lightning protection without sacrificals. I’ve seen such destroy fire risers, underground water lines an structural materials when said improvements weren’t a coordinated effort etc...
Stay safe ! Hope yer well...