Weegy: At present, the total number of long-term, commercial, below-ground nuclear waste depository sites in use in the United States is
zero. User: The average longevity of nuclear power plants has averaged about User: Radioisotopes form by 1 fusion and become stable by spontaneously ejecting subatomic particles.
2 fusion and become stable by absorbing high-energy radiation.
3 fission and become stable by spontaneously ejecting subatomic ... (More)