NASA announces nuclear robotic submarine to explore Titan’s ocean

I sure hope the idea of Jupiter and Saturn moon missions captures the public's eye and become economically feasible in my lifetime. In the spectrum of space missions that might actually happen someday, they have the most manageable timeline for a single generation and are easily the most exciting. I'm much more interested in reading about an analysis of a Europan water sample than than about a human setting foot on Mars.

The problems associated with operating a submersible are formidable, even in the best cases here on Earth. Coupling this engineering problem with the one of sending a spacecraft to safely Saturn seems a daunting but noble task to me!

Here's the 46th Lunar and Planetary Science Conference PDF source:

http://www.hou.usra.edu/meetings/lpsc2015/pdf/1259.pdf

And here is a video NASA released regarding the subject:

https://www.youtube.com/watch?v=NnKxbdpLP5E

I'm more concerened with a rocket launch failing spectacularly when the payload includes a nuclear reactor.

Has anything like this been attempted before?

As the only planet on the solar system with stable bodies liquid and atmosphere, this is got to be the ultimate frontier in exploration.