Hacking a nuclear power plant is a violation of private property rights and a crime itself.
Code allowing people to transact privately, isn't inherently a crime.
Discussion
I’m talking about the person who wrote the code to meltdown the reactor. Not the person who executed the code. Is that speech yes or no.
In order to write that code you would have to commit other crimes, like theft, fraud, trespassing, etc.
Not at all. You’re not answering the question because you know your argument doesn’t hold water.
Then explain how ypu would write code to do such a thing without violating the law. The code itself would be speech, but would put you in jail because it would be the confession of a crime(s).