今はどうにか爆発だけは抑えてるわ
They're talking about a weird monster trapped in a tank.
I don't get how だけは works here after a noun and with 抑える
I thought it said something like "Explosions are the only thing holding it back" but that didn't quite make sense so I went for the official translation:
We've managed to keep it from exploding. For now.