Here is a map showing Russia's ten closed nuclear cities where three
quarters of a million people still live. These cities were built between the
late 1940s and early 1960s in remote areas behind barbed wire; their only
purpose was to make nuclear weapons and their essential ingredients.
This 1998 article on the nuclear cities summarizes how Russia's
economic crisis has caused loss of jobs and nonpayment of wages for hundreds
of thousands in these cities and outlines efforts underway to help these
cities shift to new industries and enterprises.
Finally, here's a closed nuclear city with its own web site (warning: this site can be slow at times). Snezhinsk (formerly known as Chelyabinsk-70) offers an "excursion along the
town," a history of the city and information on culture, sports and the region.