China's reliance upon nuclear energy left them with a growing supply of depleted uranium. Their solution to this build-up was to use the extremely dense element in their tank shells. Compared to more conventional tank shells, depleted uranium shells had more penetrating power and were overall more effective in combat. In order to gain access to depleted uranium shells, the uranium shells upgrade needed to be researched from the nuclear missile silo. The upgrade made all Battlemaster and Overlord tanks deal 25% more damage with their main guns.