"Survivor" is back — and it's still one of TV's hottest shows from the moment it premieres tonight at 7 on CBS/Ch. 2.

Just moments into the telecast, there's host Jeff Probst setting up the ninth go-round — this one subtitled "Vanuatu: Islands of Fire" — as he stands in front of an active volcano.

"That was a blast," Probst said in a teleconference with TV critics. "We were surprisingly close. . . . While we were shooting that, one big kaboom went off, and rocks went past me, over my head, down the hill in front of me.

"One of the coolest things I've ever done was to be that close to a volcano while it was erupting."

As always, there's a bit of a twist to open the show. The 18 contestants (up from the usual 16) are taken to the South Seas island by natives, who "welcome" them with a ceremony that's going to shock some viewers and outrage PETA (although it's carefully edited and by no means exploitative).

But what makes "Survivor" continue to be one of TV's top reality shows — one of TV's top shows, period — is the same old formula. People "stranded" on a tropical island, competing against each other, voting each other off as each tries to outwit, outplay and outlast the others to win $1 million.

"Some of the themes that 'Survivor' is about really are epic, and they are part of our mythology, in a sense," Probst said. "I mean, being abandoned is always something that I think plays to our deeper sense of adventure.

"And then there's also the fundamental thing that the show is about — voting out people. What does it feel like to be voted off? What does it feel like to be the first guy laid off? The last kid picked in the sandlot game? Those are big themes."

Since it premiered in the summer of 2000, "Survivor" has gone from being a TV oddity to an institution, spawning lots of lesser imitations, none of which have surpassed it.

"Just this season I started wondering if 'Survivor' was becoming a little like 'Monday Night Football' in that it's familiar," Probst said. "And the music is always the same and the setting is always almost the same. And the conflicts that emerge and people starting fire and building shelter and working together — I'm wondering if that familiarity and the fact that we haven't played with the show much . . . if that's part of it."

(They have, as Probst put it, "tweaked tiny things within the show." This time around, for example, there will obviously be more tribal councils to vote out more contestants — and those can come at any time.)