Transmutation of long lived fission products. The possibilities of proton induced reactions

An option for management of nuclear spent fuel receiving more attention recently is transmutation of minor actinides and long lived fission products (LLFP's) into stable or shorter lived isotopes. Different authors state that if a solution for the transmutation of the MA was found the greatest overall remaining risk to health may come from LLFP's as ¹²⁶Sn, ⁷⁹Se, ⁹³Zr, ⁹⁹Tc, ¹²⁹I and ¹³⁵Cs. The few references to transmutation of LLFP's assume that (n, γ) reactions are used for incineration in dedicated ADS systems. We show that charged particle induced reactions on LLFP, especially the (p, n) reaction, also mostly result in formation of either short lived, either stable isotopes. As for both cases transmutation of isotopes, initially not relevant isotopes for waste management, could result in the production of new long lived products, elemental partitioning is necessary. We list and discuss the results for (n, γ) and (p, n), reactions in terms of transmutation products obtained on stable fission products and on the critical LLFP's mentioned above. Transmutation rates and obtainable loads, with comparisons and numerical values for some cases are presented. Realisation of charged particle irradiation, economics and public acceptance are discussed. (author)