When is a NIMBY attitude correct?

Only when there is an issue of above normal public safety.

So a nuclear power plant that cannot store its spent fuel in a permanent safe manner or operate while keeping radiation inside is a NIMBY situation that I support.

The following NIMBY situations do not make sense to me.

You support non-fossil fuel energy but do not want a wind mill, solar panel or waste to energy plant in your vicinity.  You do not want a hydro-electric dam with fish ladders built.  Give me a break.  Do you want everyone to go back to farming with horses; or rice farming like Chinese peasants and bartering the output for other things.  I forgot how to weave wool fibers into cloth and cut them into clothes.  Not to mention forgetting any number of other things involved in being a farmer.

I am all in favor of limiting hydraulic fracking for shale gas until you have a sound disposal plan for the waste water which can contaminate drinking water for who knows how long and drinking water is essential for living in any one specific location.  However, disposing of it deeply underground makes sense to me as long as you understand what will happen to dangerous components over time.  I do not think that 4.0 earthquakes constitute a reason to stop deep underground disposal unless that means bad things are migrating up (and the issue is how far up can then come).  People all over the world live with earthquakes bigger than 4.0 so living with them at 4.0 and under seems like an acceptable situation to me to get all this domestic natural gas.  So people of Ohio and Oklahoma, study the issue like NY is doing, but make sure to differentiate between true danger and a NIMBY perception of danger.

I am not a big fan of NIMBY's as they are usually being selfish about their specific location and would support the same thing somewhere else.  If it is good somewhere else, it is good near you.