Have you gone to the kett base? They pull power from the radiation.
There's a really big Kett Base on the edge of a cliff, where you will come by very close to get to the lower dunes area. If you walk about the place, the local leader, one called Invictor, will speak about you or to you. The Quest with the Massani guy is basically about going there and taking that base down.
The second time you touch down Eos and activate a forward post, the first thing Sam will explain is that Kett base on the planet overview. On the map, you'll find it on the central area, a bit to the West, on a plateau.
