Most remaining humans reside in small settlements spread out in the wild, sometimes salvaging buildings from the old world or building walled off shelters to protect themselves from the dangers in the zone. Many settlements are practically self sufficient, growing fungi farms for food and filtering water from rain or flowing rivers, usually not having more than 100 settlers.
More than most humans born exposed to the unclean air riddled with glass particles showed signs of zoomorphic mutations, caused by the genetic splicing from animals previously infected by the glass and pulverized. Generally only one mutation os dominant, but sometimes more than one can be expressed.
When bigger settlements started to form, bigger problems started to arise. Heating, filtering the air and water and even growing food for an entire colony began to cost more resources than manpower could provide. That’s when the advancements in nuclear power of the Kurchatov Institute came to save the day.
Most larger arcs rely on Micro Nuclear Reactors (MNRs) to keep the lights running (although a few can manage with other sources), at the cost of having to periodically send their brightest minds to serve as recruits for the institute. Most other tech are either salvaged from the old world or haphazardly put together by savy survivors.
When it comes to appliances, improvised lightbulbs from car headlights, salvaged fairy tubes and light bulbs are commonplace in settlements with electricity, along with fan-powered air filters, old school radio equipment and even some CRT TVs and cassette players. Most other tech salvaged from the old world could be reasonably adapted to work.