Kerbal Space Program

The fairings on the nuclear engines are different from the others in such a way that they split in half vertically, while fairings for other engines are hollow cylinders that are left behind when separated. These vertically splitting fairings consistently break nuclear engines off. There are ways around it, such as using a weaker, smaller separator, or separating while throttled up a certain amount, but these methods are not to be relied on. If the engines do survive the separation, one half of a fairing is often caught in between multiple engines. I consider this to be of high priority as it severely limits the usability of these engines, and because these engines are unparalleled with their fuel efficiency at this time.