SK Fun Fact®: Venusians, like Kyzok (or like these guards), live closer to the sun (and all of its radiation) than we do. Therefore they are more naturally resistant to radiation than human beings are. This is why they tend to get chosen for tasks which involve high radiation risks — such as guarding nuclear reactors.
So when Space Kid sees that HISS has placed Venusians to guard the central reactor, he is not at all surprised. 😉