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 β^- 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 β^- (E_Mean ≈ 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.

Keywords: Molten salt reactor; Radiodiagnostics; Radiotherapy; Short life fission product radioisotopes.