Holy shit, wikipedia says it handles transients of up to 19 GW. They don't say for how long, but the transient control rod actuators take a quarter second to cover their full range, so I'm guessing that means 19 GW for up to a quarter second. That's about 4.5 gigajoules. As it happens, that's roughly the explosive energy of 1 ton of TNT. From a reactor core the size of a small closet. Makes me wonder, in fascinated terror, what power output we're seeing in that video.

Wikipedia says it can simulate six different reactor loop types. This is a seriously impressive facility.