Looks like Multiple plumes
Video Russian arms depot in Tver region Explodes after Ukrainian attack
https://rumble.com/v5fetd1-ukraine-attacks-russian-arms-depot-in-the-tver-region.html
It is possible the Russians stuffed the Toropets ammo dump with North Korean missiles beyond its ability to safely store them. The bunkers were too close together. The Russians may not have had any place relatively close to Ukraine to store them. Another possibility is that they ran out of space underground, and munitions were sitting above ground at the time of the drone attack.