It's quite amazing what kind of bogus ideas government agencies and operators of nuclear power plants have. According to this article, the German federal environmental agency has negotiated with the operators of not airplane crash safe nuclear power plants to install GPS jammers.
The idea is to make it harder to automatically guide a passenger airplane into such a power plant (as part of a terrorist attack). It follows the same awkward logic as the already-proposed "artificial disguise in fog".
It's incredible to see what to what extent they're willing to compromise the security. Either you think an attack to such plants is a danger that needs to be avoided, then you have to shut down those (three, I think) plants. Or you think all that terrorist panicking isn't worth such a measure.
But I don't think that anyone honestly believes that a bit of fog and some GPS jamming will prevent any such attack. At aircraft speeds, it doesn't really matter whether you have GPS 1 or 2 kilometers in front of the power plant. And in a country with a population density like Germany you cannot jam the signal for 100 or even 50km - especially since the highway toll system for tracks operates on the basis of GPS ;)
Apart from that, according to the Bundesnetzagentur (formerly RegTP, similar to the FCC), it is at this point not legal to operate any such jamming devices.