It seems the U.S. Forces Korea has conducted an exercise last week that involved a THAAD missile defense battery... originally deployed to fend off attacks from North Korea.
According to a photo uploaded by the 35th Air Defense Artillery Brigade on its Facebook page... the week-long exercise initiated last Monday... took place at Camp Humphreys in Pyeongtaek, Gyeonggi-do Province... and not at the missile defense base in Seongju.
An official from U.S. Forces Korea says the exercise, which used inert missiles,... was aimed at mounting missiles on the launcher.