Unrelated to the nuclear ramjet aspect, a close high-Mach flyby has many of the same effects as an explosion. The shock wave has a pressure profile very similar to the "N wave" of an explosion -- positive overpressure followed immediately by a vacuum underpressure -- and depending on the shape of the supersonic object, there may be multiple overpressure waves.
Historically, sonic booms were fairly common when I was a child, if you lived close to an Air Force Base; I grew up about 150 km from Fairchild AFB (Spokane, Washington) and used to hear the booms once or twice a week. This was in the 1960s, before the ban on non-emergency supersonic flight over populated areas.
Even with an aircraft flying at high altitude (FL200, at a guess), these booms could and would rattle windows; they were loud enough to startle people, sometimes leading to kitchen injuries (dropping hot items, for instance) or falls. Given that the intensity of the pressure wave from a linear source like this obeys an inverse law, such a boom (from aircraft that were only low supersonic, probably Mach 1.1 to 1.2) from a hundred times closer would be a hundred times stronger -- and go from rattling windows to breaking them, flying glass injuries, many falls (people knocked off their feet by the pressure, never mind off ladders), and so on.
Look at the damage at Chelyabinsk from their bolide explosion a few years ago -- while that object was, well, rock-shaped, at high altitude and much higher speed, that's the kind of damage you might expect with a fairly close supersonic flyby of a streamlined aircraft or missile.