Theron does seem an odd pairing with Viggo in this, but I thought their screen relationship seemed convincing enough.

I think the popular thinking is that cockroaches would survive a nuclear holocaust: there’s not really the suggestion that this happened, just that everything started to fall apart.

Hydroelectric is a better question, but I suspect this falls into the category of suspending disbelief. Perhaps with no viable food supply the people maintaining the equipment lost interest in it?

EDITOR: According to Dr Karl in ABC Science Online:

“the cockroach is, at least in terms of nuclear survivability, a wimp. The two Drs. Wharton had found in 1957 that it took only 1,000 rads to interfere with cockroach fertility. In 1963, Drs. Ross and Cochran found that a dose as low as 6.400 rads would kill 93% of immature German cockroaches – making cockroaches only six to fifteen times tougher than we frail humans. Sure, cockroaches survive radiation better than we do – but they curl up and die at doses than don’t even bother other insects”.

I’ve not read the book either, but felt like there was a huge amount missing from the film.

It wasn’t all bad: The acting was pretty solid throughout (although Theron was a little bit.. unlikely), the photography was suitably bleak, the script suitably sparse, and a bit part for Michael K. Williams (Omar in ‘The Wire’) was a highlight.

But some of it was: Books (for me) can focus on a really tight narrative – what’s happening, to whom, why, how, but films can’t get away with that. If you paint a dystopian future, people notice every detail and, will ask questions which they wouldn’t think of in a book.

I still think there’s enough meritworthy in here to get this out on DVD (I think you’ve missed it at the cinema), but maybe it’s that rare case where you have to have read the book to appreciate the film?

ATTENTION (a bit of a) SPOILER:
Why no cockroaches – they famously survive everything? why no rodents (no mammals at all except for humans and one dog)? why no ships ? why no hydroelectric ?