Is there a simple way to figure out how big of a RF choke an safety gap I need for my Tesla coil?

Ive built a pretty good sized tesla coil. Problem is, I kinda of afraid to run it without some sort of protection for my NST an my house wiring. I have three other coils of varous sizes  that Ive run without any problems, but I really dont want to push my luck. So if anyone could give me a hand on how to figure this out, I would greatly appreciate it. Many thanks in advance.

The RF choke is simple these give you a good idea, I have seen them about an inch wide 3inches tall before. I use modified MOT's for HV transformers so I don't know anything about safety gaps.