I'll give the easier answer first...nuclear technology as a power source can be VERY useful and 'clean' compared to fossil fuels. It's not renewable like hydroelectricity, wind farms, or solar panels but like was said previously it can be VERY efficient. The problem comes in how to protect it as there is an inherent danger to it as seen in the tragedies that have occurred - most recently the damage to the plant in Japan. However, that case is such a rare condition it is hard to design a protection system for that...two natural disasters occurring at the same time? Ouch...
Nuclear technology as a weapon? That one is much harder for me to answer. Part of that stems from the history of my country (USA) in how the shock values of the first bombs used against Japan brought a more abrupt end to the last world war. Yet...the damage potential of it is so devastating with how it destroyed the lives of all those people. I suppose the weapons have their uses as deterrents, but honestly...I wish we never had them in the first place. Still...if the scientists hadn't run to the US then Germany might have had the first bombs and then who knows what would have happened?
~tWS