I did see the video, although I haven't taken the time to watch the entire thing yet as it was pretty long. Pretty incredible that he was able to do that.
Unprocessed Uranium ore itself is plenty radioactive to get picked up on the CDV-700 (I've tried it with some small pieces from a lab on campus that are easily detected by the device). Unfortunately I don't think there are very significant uranium deposits here in central CA, or at least not enough to go out and find some myself. I'll need to do some more research into possible spots up in the mountains perhaps where there are a lot of exposed rocks. For finding uranium though these Civil Defense Geiger counters are about as good as it gets when it comes to cost to performance ratio.