Three Mile Island - The Disaster (cont.)
 
 Three Mile Island - The Disaster (cont.)
- When the steam generators boiled dry standby pumps began to operate, as they should 
- Operators turned down the flow thinking enough coolant was available - kept problem growing.
 
 - Practically an accidental turning on of the standby pumps by a supervisor averted the accident.
 
- Human intervention was primary cause of accident 
 - The Human Error was principally due to design of the control room