This achievement may take a bit of practise its all down to learning the method and remember stick it on casual mode to make it a walk in the park.
I did this in coop so lets consider this a guide for all the coop players out there.
All you need to do is grab the orbs with your kenesis and throw them into the reactor while it is being hit with stasis, then shoot the yellow vents on the floor below you method as follows.
There are 4 massive Cysts in the room that fire homing bombs. You can get them out of the way before the timer starts. They won't die right away, though. As long as you pour a generous amount of ammo into each one before you hit the ON button, they will all die at this point.
1. Have one person as the thrower and the other as the stasis guy ( I was the stasis guy)
2. Try to stasis the reactor at a good time so your friend can throw the object into the core (it has 3 levels to it so you have plenty of choice on where to throw)
3. You need to do this three times and shoot the yellow vents below that stick out. There is always three vents I believe.
4. When you shoot the final 3 vents the achievement will unlock!
I have a video below showing this all being done just takes a bit of practise and speed. Good luck guys!