Too Long; Didn't Read
Worlds Within Worlds: The Story of Nuclear Energy, Volume 1 (of 3), by Isaac Asimov. Volume I, ENERGY: The Energy of Radioactivity. The energy of radioactivity is millions of times as intense as the energy released by chemical reactions. It took 4.5 billion years (!) for that rate to decrease to half what it was to begin with. The rate of radioactive changes, however, could not apparently be altered. The breakdown of uranium-238 could not be hastened by heat, pressure, changes in chemical combination.