Nuke'em explains the entire movie. Enjoy.
In other words... I state the obvious.
THE LOCKDOWN (denial of entry to the tourists)-
The Russian Government had Pripyat locked down for a reason that I will cover later. So, I'll just note it here.
URI-
Uri, sporting the stylish "Sasha" training jacket if you didn't catch that reference in the movie, is a tour guide who has NO CLUE that there are zombie-like creatures in Pripyat because there are NOT SUPPOSED TO BE zombie-like creatures in Pripyat. He has the gun to fend off possible extortionists or wild animals seeking a meal that might be living around the area. It's as simple as that. He had no idea what was going to be going on.
THE DOGS-
The dogs around Pripyat are starving, vicious dogs that eat whatever they can to survive. Like the dead dog we saw at the apartment, these other dogs were hungry, and they were large enough to prey on human beings.
THE FORTIFIED BUS-
There are a few things surrounding the barricaded bus that I'm not entirely sure on how to cover. I do, however, know everything else. Remember when one of the characters said "It's part of a guards uniform" regarding the torn fabric... Well, the guard, too, wasn't expecting zombies to come out for him. Assumably, other people were killed (like the guy hanging from the ceiling) during that timeframe. How he barricaded that bus alone? Hell if I know, let's just go with it.
THE VAN BEING TIPPED OVER-
Ok. I'll admit, this is where I started hating the movie. The van is attacked, Chris and slut #3 dragged off. Slut #3 had no idea how to use a gun, so that's why she didn't get off any shots...
FINDING SLUT #3-
I have no idea how they found Slut #3. I guess the directors decided not to kill her off so soon. Oh well.
THE LITTLE GIRL-
This character's existence actually goes against a lot of what the movie is supposed to be about. Either A) she's just some radiated survivor (which would make little sense, considering what's coming up), or B) she's directly linked to what's coming up.
THE BUNKER AND THE REACTORS-
The bunker that the remaining idiots ran into (excluding Michael.. since he died) served as both a radiation bunker (with the inoculation chambers inside) and also as a tunnel to access the reactors.. which is how they went from the apartments to the nuclear reactors.
THE SOLDIERS AND THE APC-
The soldiers and their armored fighting vehicle who ended up shooting Paul were assigned by the government to "clear out" the area of the creatures that resided. The next point, I'll explain the whole existence of the zombies, and why they are not survivors.
THE END-
The ending of the movie is simple.
The Russians had been experimenting on creating monstrous cannibals, and used radiation as an aid in creating them. Because of this, they were immune to the radiation. The thing is... They managed to escape from containment. They ambushed the guard whose AK-47 you saw earlier, and managed to find places to hide inside of the old city.
Uri was so unprepared because he had never known about these things, because they were a top-secret russian experiment. As far as he knew, the fish were radiated and a few dogs ran around. Gotta P99, No big deal, right?
The Soldiers were sent to kill these creatures because if someone saw them, they'd know that some serious Area-51 Russia stuff was going down. That, and they were dangerous!
Slut #1 was killed because she knew about the Russian experiment.. which was mentioned by one of the doctors... in russian.
So. There's Chernobyl diaries. The plot isn't hard to understand, but most of you had no idea what was going on. I solved your problem.
I have balls of steel.