[bananabreakfast]

You have your terms backwards.

Fusion is what they are doing here. Fission we have already figured out and have been generating power from for decades.

Fusion does not have the runaway reaction safety issues that fission has.

Also, what you're describing is what we've known since we fairly easily harnessed fusion to make a hydrogen bomb.

Controlling the reaction rate so it doesn't explode is metastable with fission, and nearly impossible with fusion. This solution is basically just using tiny explosions.