After receiving great answers on my previous question, I've thought hard, how to create a story, in which there is a large-enough group of people (at least 100 highly educated people and enough others, who provide for them) in a post-apocalyptic world, which have a way of life comparable to ours (at the very least - they know, how to read and write and believe in reason more than in any deity).
- the US drop all the nukes they have on Russia,
- the Swiss learn early enough about that to put as many of their citizens into bomb shelters (allegedly, Switzerland is the only country, which has bomb shelters for 100 % of the population),
- Russian guaranteed retaliation system nukes the US automatically (automatically because most people are dead from the first strike) and
- the Chinese also nuke the US after the attack because they had a secret pact with the Russians (that's part of the story).
Let's assume that Switzerland wasn't nuked neither by the Americans, nor by the Russians, nor by the Chinese (but its environment may still suffer from global effects of the nuclear war).
How many Swiss without damaged DNA are likely to survive 100 years after the nuclear war, provided that
- they adopt strict mating protocols,
- 100 % of their population was in the bomb shelters at the time when the first bomb exploded,
- they manage to establish connection to other people in the bunkers and
- the environment isn't completely screwed up (e. g. the climate in Switzerland doesn't get significantly colder due to a nuclear winter)
Extra credit: Does the fact that Switzerland is a country with lots of mountains make it easier for a post-nuclear society to survive, or harder than in a "flat", low-altitude land?