You can buy all the essentials in these scattered shops around Chernobyl. There are no signs and everything always looks closed, so you have to know where to go. I assume that if you are coming into the area to work your two-week shift, this becomes common knowledge.
As Americans, most of us wanted water without carbonation, which is rather hard to find. Frankly, I am more concerned about untrustworthy brands than whether or not it has gas. Given what they eat around here, I wouldn't mind having a little shove in the GI to keep things moving, if you know what I mean.