There are two control rooms where the meltdown can be initiated - the locations of both are clearly marked on your map. Kutkin's men appear to have radios and are checking in with each other on a regular basis, so time your assault carefully not to tip them off. Some plant workers may still be in the area, so watch out for innocent bystanders. Be aware that interference from the generating equipment may disable your heartbeat sensors in some areas of the plant.
