I think we've learned that nuclear power has risks but is still much safer and efficient than most of the other possibilities.
On a related note do nuclear plants have the capability to shutdown cleanly? Otherwise the upcoming zombie apocalypse means I need to get the fuck away from any nuclear plants since zombies usually don't make good nuclear engineers.
Unfortunately they do enhance security a little, although I strongly believe the enhanced security doesn't actually make anyone safer. I look at this way I could hire a virtual army of body guards to patrol outside my house and I'll be pretty safe from a break in. But that level of protection against something that's extremely unlikely to happen is just retarded. Terrorist some day will probably succeed in killing more Americans in our home country... however spending billions of dollars and completely destroying our privacy isn't justified by the possible death of even a couple of thousand people.
Oh and what these devices are really meant to detect are deadly things that a metal detector or sniffer can't detect. Such as broken glass, a true ceramic knife (most of them have metal in them purely to be detectable by metal detectors), or even a sharp stick (or pencil... wonder when they'll be banned). Keep in mind that any of these items could have been used by the 911 terrorist and would have been almost effective (if not as effective) as the box cutters they used.
The feds and specifically TSA are really just trying to see how much they can get away with before the public complains. I fully expect, (if these things are allowed to stay) that in five years you won't be allowed to have any liquids (acid can be really dangerous), batteries, pencils, pens or, shoelaces (can be very effective to strangle someone with). What we'll be left with eventually will be a plane full of people in their underware reading books... oh wait... I've had some nasty paper cuts before