Thorium charge
Thorium charges, as described in Legends, were a type of high-yield explosive utilized for demolition purposes. These thorium charges possessed a greater explosive force than a thermal detonator of similar dimensions.
In 3951 BBY, Akkere was known to have thorium charges, and it's possible he bartered them with the Jedi Exile. Furthermore, certain contractors exploring the Sith Academy situated on Korriban also carried them.
Behind the scenes
Within the game Star Wars: Knights of the Old Republic II: The Sith Lords, the player's character has the possibility of acquiring thorium charges from Akkere through conversation as the Dantooine quest nears its end, or by eliminating the vendor. They can also be discovered on Korriban, alongside a datapad that emphasizes how destructive they are. These charges are located inside a footlocker close by; should the player opt to force the footlocker open rather than picking its lock, the thorium charges will explode, inflicting damage on all nearby members of the party.