Extraction generator of 188Re

The results of development of 188Re extraction generator for medical purposes are presented. The main advantage of such generator is the possibility to use as starting material the tungsten oxide of natural isotope composition irradiated in reactor with mean neutron flux (1.0-1.4-1014 n/cm2 s). The parent (188W) and daughter radionuclides were separated on centrifugal semi counter-current extractor elaborated at Institute of Physical Chemistry and Electrochemistry RAS. In the course of experiments with simulated solutions the optimal operating conditions were established for 188Re production process. For this purpose, it is proposed to recover 188Re by methylethylketone from alkaline solution (2.5 M KOH + 2.5 M K2CO3) containing up to 200 g/l W. Then methylethylketone is evaporated to dryness and residue is dissolved in isotonic solution of NaCl. A model of the extraction generator in hot box was created and the elaborated process was tested on radioactive solutions. The testing has shown that the yield is 89 % in the average and the radiochemical purity of 188Re solution is ∼ 97 %. The activity of 188W was less than 1x10-3 relative to that of 188Re. Activity of other radionuclides was below 1x10-4. The content of inorganic impurities in 188Re solution is determined only by the purity of aqueous solutions used for 188Re dissolution. The generator model may be recommended as a basis for creation of commercial prototype of 188Re extraction generator