9FB/A15 single shaft. M/VIe

How or can you force cool a single shaft?

 

You need to get procedure and recommendations from GE. This would likely involve operating the unit at purge speed. However, you would also likely need vacuum and steam seals (auxiliary steam required), and you may need to monitor steam turbine internal temperatures as well as HRSG temperatures (there may be limits imposed by the HRSG supplier on how rapidly it can be cooled down).