Research program to investigate the fundamental chemistry of technetium

Behavior of technetium in nuclear waste vitrification processes

“…Electrochemical measurements made in borosilicate glass melts have shown that technetium is more easily reduced than is rhenium [ 3 ], as also is the case in aqueous solutions. Similarities as well as important differences in the behavior of technetium and rhenium during vitrification of LAW simulants and subsequent vapor phase hydration testing of the resulting LAW glasses have also been reported [ 4 – 6 ]. In aggregate, however, for these and many other reasons, rhenium, while imperfect, remains the best known chemical surrogate for technetium [ 1 ].…”

“…It is important to note that incorporation of technetium into the glass melt is limited by volatility and not solubility. Homogeneous LAW glasses with over 1,500 ppm Tc have been made and characterized [ 4 – 6 ] and the solubility has been estimated at around 2,500 ppm [ 10 ], whereas the average concentration in the WTP LAW glass is expected to be about 3 ppm. Studies using X-ray absorption [ 4 , 5 , 10 ] and Raman spectroscopy [ 6 , 11 ] have shown that technetium is present in these glasses as both Tc(VII) and Tc(IV), with the former dominating under the redox conditions expected for LAW vitrification.…”

Monitoring and Management of Anions in Polluted Aqua Systems: Case Studies on Nitrate, Chromate, Pertechnetate and Diclofenac

“…Moreover, it is also important to consider the management of the radioactive waste after separation. In the most recent work, the separative system developed is also intended to be transformed into a containment matrix [88,197,198]. In addition, it should be noted that the constraints linked to the handling of a radioelement such as Tc often lead to the use of stable chemical analogues such as ReO4and ClO4or the 99m Tc isotope in the ultra-trace state, which is easy to detect thanks to its gamma emission.…”