Bioapatite, found in vertebrate bones and teeth, is highly reactive and may incorporate high concentrations of some radionuclides, including U, Pu, and Sr. Therefore, bioapatite may be useful in backfill or overpack materials in nuclear waste repositories. The dissolution rate for bioapatite is constant at pH > 4 and is about 5 times faster than fluorapatite. In terrestrial environments, bioapatite recrystallizes over periods of up to ca. 40 ka.