Dieselpunk/Atompunk Place Names

[TurtleSoup]

My advice, since those names don't immediately evoke the "flavor" of diesel/atom in my opinion, is that you look in to what names you find in games and novels of the style.
Of course you have to ask yourself, is the world inspired by non fiction, or is it completely fictional, are there conlangs and absolutely new cultures with no foundation in the ones we are familiar with? If it is rooted in reality, then you would have the typical racial/cultural rules for how cities/countries sound, for example in Papers Please, it follows a very Balkan/Slavic set of rules for the style, even though it is completely fictional...
If you stick with the old school fantasy formula of naming a city or place after two words (i.e brook haven, shadow vale, etc...) Then you could apply to this formula a set of words from "diesel" or "atom" glossary, for example: "Howitzer Fields" "Thorium Bayou" "Meltdown Canyon" "Disaster Depths" "Gunpowder Ranch" "Tzar Collider" whatever you feel has a cool "ring" to it, you could write a bunch of these down on a paper, recombine, recycle bits of each word and do a mashup, whatever brings you closer to the "flavor" you wish to evoke, you could do this in a number of languages, here's "расплавленный эпицентр" "Rasplavlenniy Epicentre" for example... Just use google translate and some imagination :p

Here's a few that just came to mind that I really like: "Charnel Trench", "Barbwire Ossuary" "Haunted Reactor" "Geiger facility"