It's like the dark side of the moon, except that rather than the laws of physics preventing communication, it's something the screenwriter pulled out of his ass. The filmmakers needed a way to get the bad guys into the lab without Hunt being warned about it, so they made up the idea that radio communication doesn't work when generators are running. It may as well have been a janitor brushing his teeth or the shearing of local sheep that caused the disruption. As far as I can tell, that's the beauty of it. Movies are no longer about the needs of the characters.
Movies are all about the needs of the filmmakers.
They further made up the idea that, for no reason at all but on a predictable schedule, generators would run for eight minutes. No reason and Woo. Of course, there is a love story, which is somehow central to the plot and completely perfunctory at the same time. For her safety, Strickell tracks her with a satellite that exists for the sole purpose of tracking her and only her. There is only one PowerBook in the whole world that can link to the satellite and follow Nyah, and it gets damaged in an explosion, leaving Nyah's whereabouts unknown just when she starts coming down with the flu.