I like reading, so longer posts are something I do enjoy, as long as they are something that I can actually enjoy reading about. To answer your question for me:
Xalium is a sort of unobtainium found only on three planets out of the many star systems that the Empire has their hands on. As you've read a simple uncontrolled detionation of a single piece of Xalium 17 forced a planet evacuation and even affected the sun with it's Xalium radiation. Xalium radiation is incredibly lethal and if the resource Xalium 17 is even affected in the slightest it will unleash incredible amounts of xalium radiation, it sort of affect's other pieces of xalium at the same time, so if one detonates and the xalium radiation spreads to other xalium 17 elements then the xalium radiation is unleashed by them also.

Xalium 17 is incredibly rare and xalium transports are far from regular. Basically the moment that it's touched outside of a controlled environment shit'll go down. To top it all of Xalium 17 is volatile, incredibly so.