This is DoE I think, not any other 3 letter agency, so they're probably not too worried about it getting out after the fact. Who the hell uses an iPod anymore? Now you'd just use the CCD camera on any modern smartphone, or count DRAM bit errors or something. Then again, they could have done that with the iPod and didn't, which suggests they wanted to measure energy levels maybe. Tight integration makes a lot of sense if you want something that, when opened up and compared to an off the shelf iPod, doesn't look any different.
CCD cameras or counting bit errors doesn’t really have great sensitivity for radiation detection. This is why they are generally not used to monitoring projects and people stick with Geiger tubes. This is my understand anyway (having worked on these kinds of projects).
