Among the many fission products that may be extracted chemically from the spent fuel of a nuclear

Question:

Among the many fission products that may be extracted chemically from the spent fuel of a nuclear reactor is 90Sr (T1/2 = 29 y).This isotope is produced in typical large reactors at the rate of about 18 kg/y. By its radioactivity, the isotope generates thermal energy at the rate of 0.93 W/g.