Quote Originally Posted by Philipvs Vallindervs Calicvla View Post
2. Cosmic rays - Extremely high energy particles (orders of magnitude above the LHC) coming from outer space are incident on upper atmosphere where they collide with the nuclei of gas molecules. We see the showers resulting from these collisions at sea level. This is appears to be safe, so we can be confident that the LHC will be."

Doesn't look like "zero" chance to me, bolded the last bit for you. Like I said, I want a copper-bottomed garantee, not, "almost certainly".
It appears to be safe to take trains that to go faster than 100 km/h without getting turned into a frog. The guarantee you seek is in principle impossible to give.