The console is fully disabled when playing on a Survival mode save (from the beta). There is no way to enable it I've seen, either from the .ini settings or by changing the keyboard bindings or even the launch options. It seems that the console is only disabled in Survival mode -- in Normal difficulties the console is available and usable.
How can I re-enable the console in Survival mode?
To note, the Fallout 4 PC version is considerably very buggy. There are numerous spots where players can get stuck; console commands make getting out of these "traps" possible. Without console commands, it may be possible to get stuck and never get out.