The specific activity limits for shallow land ("Class C") waste disposal of all long-lived radionuclides with atomic number less than 88 have been calculated using the 10 CFR 61 methodology. These specific activity limits were used to determine the concentration limits of nearly all naturally-occurring elements in fusion reactor blanket materials. Of the elements that could be constituents of or impurities in blanket materials, aluminum, silicon, nickel, zirconium, tantalum, and tungsten were found to be limited to concentrations of 0.1 to 10%, and niobium, molybdenum, silver, gadolinium, terbium, and holmium were found to be restricted to 0.1 to 10 parts per million.
School Authors: Jaganath Sankaran , Steve Fetter