How did the development of atomic technology affect life in the United States?

I assume that you are asking about the time when atomic
technology was relatively new.  This was the time during the early parts of the Cold
War.  During this time, the main impact of atomic technology was to make life seem
precarious and to make Americans feel threatened with possible nuclear
war.

During the early parts of the Cold War, there was a
great deal of fear of nuclear war.  Americans were taught how to "duck and cover" in
school.  Many Americans had fallout shelters in their back yards.  There was a pervasive
sense that atomic technology might lead to destruction.  This made Americans feel that
their lives were less secure than they had been in the days before atomic technology had
been developed.