3. For LLW containing two or more radionuclides, 10 CFR 61.55 requires the use of the sum of the fractions rule. Explain the rule, and use it to classify wastes containing the following radionuclides: (a) 50Ci/m3 of Sr90 and 22Ci/m3Cs137Ci/m3; (b) 0.01Ci/m3 of Sr90 and 0.55Ci/m3 of Cs137; (c) 0.01Ci/m3 of Sr90 and 0.75Ci/m3 of Cs- 137 ; (d) 0.01Ci/m3 of Sr90 and 0.65Ci/m3 of Cs137; (e) 68Ci/m3 of Sr90 and 41Ci/m3 of Cs137; (f) 3750Ci/m3 of Sr90 and 2240Ci/m3 of Cs137; (g) 3.5Ci/m3 of C14,12.6Ci/m3 of Ni59, and 4.7Ci/m3 of Ni63 in activated metal