So if you removed the big metal vats from the "brewery" section (whatever they are; coolant tanks? antimatter bottles? Slush hydrogen?)
Don't we see VFX of those being the specific things ejected upwards when Kirk calls for the "core" to be ejected and detonated to escape the final timehole?
Calling those the "core" is Scotty's terminology, not Kirk's, to be sure. But it would be easy to argue that the "core" is a massive and distributed thing in the 23rd century and a single compact rod in the 24th century only. And the part of it that can be "detonated" is the one with the antimatter in it. Meaning, antimatter tank ejection would meet the plot need in the 2009 film, and might still meet the dialogue specs as well.
And the matter-antimatter reaction chamber was a much smaller device built into the floor in the middle of the room.
Or a much, much larger one, simply residing on the multiple decks below...
Timo Saloniemi