No account will be safe if it has his name in any way attached to it or any of his accounts linked to it. If you want to protect yours and the children's accounts he cannot be attached or linked in any way.
Any other asset with his name on it (house, car) would not be safe either.
Make sure that your settlement goes into an account that he has zero access to. Make sure that he has no access of any kind to the children's accounts as well.

