Reduction in the Toxicity of Fission Product Wastes Through Transmutation with Deuterium-Tritium Fusion Neutrons

A waste management concept that employs irradiation of fission products in fusion reactor blankets is evaluated. The purpose of the irradiation is to reduce the toxicity of the material to be committed to geologic disposal Target isotopes included ⁹⁰Sr, ¹³⁷Cs, ¹²⁹I, ⁹⁹Tc, ¹³⁵Cs, and ⁹³Zr. The (n,γ), (n,2n), (n,3n), (n,p), (n,α), (n,d), (n,t), and (n,n'α) reactions were all considered to contribute to the transmutation process. Extensive chains were employed in the depletion calculations performed to quantify the toxicity of the products. A sharp reduction in the shortterm toxicity of the fission wastes could not.be accomplished due to the small capture cross sections of ⁹⁰Sr and ¹³⁷Cs and limitations on the neutron flux. Reduction in the long-term toxicity by a factor of 100 or more appears achievable, but should not be pursued unless the toxicity of the actinide wastes can also be substantially reduced.