The First Nuclear Era is Alvin Weinberg's autobiography, the memoirs of a most influential American nuclear engineer/physicist. These reminiscences date from the dawning of the nuclear age in the early 1940s to the present. It is the story of one notable scientist's life and times and a look back at one of humankind's most ambitious endeavors: the attempt to harness and safely distribute nuclear power.

Weinberg has witnessed and played a major part in many of the defining scientific moments of his era. Here he describes his academic career at the University of Chicago, under the tutelage of Nicolas Rashevsky and Carl Eckart. He recalls his wartime days at the Manhattan Project's Chicago Metallurgical Laboratory where he helped Nobelist Eugene Wigner design the Hanford plutonium producing reactors.

He then focuses on what would become the abiding legacy of his professional life: his development of and involvement with nuclear reactors. In discussing both great commercial successes (such as the Light-Water Reactor) and unsuccessful experiments, Weinberg offers an objective critique of the technical and political shortcomings that have haunted the nuclear age. He also demonstrates how the lessons learned from unsuccessful reactors paved the way for later triumphs.