Reactor core

A reactor core was the device that powered a Romulan planetary base and Cardassian space stations.

According to false information feeded to the defector Admiral Alidar Jarok, on stardate 43462.5, it would take only 48 more hours till the reactor core on a base on Nelvana III would be online, completing the construction of the base. 

In 2369, Commander Benjamin Sisko noted that if the hull breaches continued on Deep Space 9, it could affect the reactor core and destroy half of the station. 

After been taken over by the Saltah'na energy spheres in 2369, the Klingon first officer Hon'Tihl placed a thalmerite device under a crossbeam of the reactor core of his attack cruiser, the, to destroy the ship. 

In 2372, B'Elanna Torres destroyed the Cardassian ATR-4107 missile by firing her phaser at its reactor core, which weakened the missile's containment field and blew it up in orbit of Rakosa V.