That's far, far from uncertain.
The framework for this new deal with Iran and the major six other countries involved would implement a more severe regimen of inspections than ever before.
However, even if Iran had a bomb RIGHT NOW, I sincerely doubt they would use it.
The utility in having a nuclear bomb isn't using it, it's having it.
Look at North Korea - they actually have some form of a bomb, and they could nuke Seoul tomorrow. Would they? No, because the rest of the world would 'salt their earth'...it would be game over.
You're mistaken if you think Iran would use a bomb, even if they had it.
You're also mistaken if you think Israel would nuke Iran...won't happen.