Our "safety analysis for nuclear power plants" professor asked for an FMEA worksheet and i used some of the malfucntions mentioned here, but i don't really get what was meant by the turbine runback, and hence i don't get the fault here. And i've searched google, but it was really tiring cause i didn't manage to extract some definition. I've been searching all the morning for malfunctions, circumstances, causes, effects...etc. And i'm almost done. Also I have another question that might be regarded as an OT question, it's about the criticality rank in an FMEA sheet, the professor asked us to rate it as L, M, H...I was wondering if the c.r. norm corresponded to the environment?? Because I think it could be relative to personnel, system & the environment but that's not what is demanded obviously. Thank you in advance.