Reactor

The Terran Nuclear Reactor is an add-on in StarCraft II.

Its modular design enables it to be attached to several different Terran structures which produce units.

A structure attached to a Nuclear Reactor can produce units more quickly. For instance, a Barracks attached to a Nuclear Reactor can produce Marines twice as quickly.

Note that a Terran structure cannot be attached to both a Tech Lab and a Nuclear Reactor, so it cannot enjoy the benefits of both.