Nuclear-type question

So I was browsing the wiki and just learning tad bits of information for here and there, when I saw the Nuclear-type page. I am confused by the type weaknesses & strengths chart on the page. Maybe someone can help clarify: Are Nuclear-types super-effective against everything and other types are not effective against Nuclear-types or are Nuclear-types not effective against other types and other types are super-effective against Nuclear-types. If anyone could answer my question, it would be really appreciated.

I believe Nuclear is currently super effective against everything except Steel (not effective) and maybe Nuclear. Everything is super effective against Nuclear.

nuclear is effective against all and all is effective against nuclear ( nuclear on nuclear is normal i think)
hazma will be something else i think ... this pokemon will be immune against nuclear

Thanks for the clarification!