Spooky...

In the space just before the bundles of the boiler.
In the back behind the scaffold is the exhaust of the gasturbine.
In here a temperature of appr. 620deg C (1148 F) can be reached.
At first the exhaust was only isolated at the outside but after a few years we discovered several severe cracks in the duct.
It occurred at all the units.
The cause was a change in how the units were used; the were designed for almost continuous service but after a few years that changed to to run at daytime and stop at night.
So the duct was subjected to tremendous changes in temperature; from ambient temperature to 400 deg C in about 10 minutes....
The material was worn out in no-time.
So now "cladding" insulation at the inside with ceramic wool and strong metal sheets prevents the main material from the heat changes.

Nice to know: at the outside of the manhole (the entry to this space) a board is placed where I put my badge to let everybody know someone is inside.
Imagine that board would not be there and I'm inside for a check just before the unit is ready to start and someone closes the door and the unit starts......
Spooky thought.
Same can be applied for the coolingwatersystem...
Safety is essential, that's why the board is there.