Short life fission products extracted from molten salt reactor fuel for radiopharmaceutical applications.

ABSTRACT

This work studies the potential of using short life fission product (AFp) radioisotopes e.g. 82Br, 86Rb, (90Sr) - 90mY, (99Mo) - 99mTc, 103Ru - 103mRh, 111Ag, 127Sb - 127(m)Te, 126I, 131I, 133Xe, 136Cs, 141Ce, 143Ce, 143Pr, 147Nd - 147Pm, 149Pm, 153Sm, 156Eu, 159Gd and 161Tb, extracted from a molten salt reactor and their separation using specific thermodynamic and radiochemical conditions. Their utilisation for coupled radiodiagnostics and radiotherapy is a key consideration. A molten salt reactor produces fission products during operation. These radioisotopes can be separated at line from the liquid fuel by evaporation/distillation, chemical reduction (using H2 doped gas), electro-deposition and/or chemical oxidation (using Cl2 doped gas). They can be refined and chemically treated for radiopharmaceutical use for imaging and radiodiagnostics utilising γ radioscopy or positron emission tomography, and potentially in radiotherapy to target specific cancers or viral diseases using ß- emitters. Some of the AFp isotopes are currently used for radiodiagnostics because they emit γ rays of energy 50-200 keV. However, some may also be used in parallel for radiotherapy utilising their ß- (EMean ≈ 100 keV) emission whose mean free pathway of c.a. 100 nm in biological tissue is much smaller than their penetration depth. Focus is given to 86Rb, 90Y, 99mTc, 131I and 133Xe as well as on the ALn isotopes (141Ce, 143Ce - 143Pr, 147Nd - 147Pm, 149Pm and 153Sm) because of their strong potential for complexation with bio-ligands (e.g. DOTA) or for their ability to form micro-nano-spheres, and because of their potential for dual radiodiagnostics and radiotherapy. It is shown that these radio-lanthanides could also replace 177Lu for the treatment of specific cancers.