89Sr production in a reactor with solution fuel

Abstract

The experimental results for the validation of a technology for producing 89 Sr in a reactor with solution fuel are presented. The aggregate state of the fuel -a water solution of uranyl sulfate UO 2 SO 4 -opens up a unique possibility of acting not only on the target radionuclide but also on its genetic precursors, produced as a result of nuclear transformations of the fission products as a whole in the decay chain 89 Se→ 89 Br→ 89 Kr→ 89 Rb→ 89 Sr. The half-life of 89 Kr (T 1/2 = 190 sec) -a gaseous precursor of 89 Sr -is sufficient for it to leave the fuel solution and migrate into the gaseous medium. A series of experiments is performed on obtaining gas samples from the free volume of the solution of the 20 kW Argus minireactor. It is shown that the mechanism of delivery of 89 Sr into the sorption volume of the experimental loop of the Argus reactor system is based on transport along the 89 Kr loop. Measurements of the content of the radioactive impurities in a solution of 89 SrCl 2 showed that the purification of the gas flow by metal-ceramic filters and purification of the solution on DOWEX-50×8 or crown ehter Sr-Resin yields medical quality 89 Sr. The productivity of the new technology, which is many-fold greater than that of the modern industrial methods for producing 89 Sr, is assessed on the basis of experimental data. 89 Sr (T 1/2 = 50.5 days, E β = 1463 keV) is used in oncology for treating a painful syndrome accompanying bone metastases. As a rule, metastization in bones is of a multiplistic nature, which makes it impossible to perform surgery or remote-controlled radiation therapy. In such cases, the most effective method is using compounds which are tropic to metastic tissue and contain radionuclides with high-energy β radiation, which can act on the tumor tissue and nerve endings. The travel distance of 89 Sr β particles in bone tissue does not exceed 7 mm, which localizes the radiation effect in a small region of the skeleton, lowering the dose load on the bone marrow and neighboring sections of the soft tissue [1]. 89 Sr in a pharmaceutical form was first used in 1942 [2]. A radiopharmaceutical preparation Metastron, manufactured by the firm Nikomed Amersham (Great Britain), appeared on the market in the 1980s [3]. In 1999, the production of the preparation "solution of strontium-89 chloride, isotonic for injections" was organized in our country. The recommended single dose of 89 Sr is 150 MBq (4 mCi).Methods for Obtaining 89 Sr in a Nuclear Reactor. At the present time, 89 Sr is obtained for medical purposes using the reactions 88 Sr(n, γ) 89 Sr and 89 Y(n, p) 89 Sr, irradiating a target consisting of highly-enriched strontium ( 88 Sr > 99.9%) in

Radiochemistry

“…Improvements to the generator design 27 and to the purification 28 of strontium-82, made by [ 85 Rb(p,4n) 82 Sr], from rubidium have been described. A method for the preparation of strontium-89 from nuclear fission products, 29 via gaseous 89 Kr (t 1/2 , 190 s), has been outlined. A scheme for making yttrium-86 by irradiating natural germanium with a beam of oxygen ions 30 has been discussed, as has a new method 31 for the separation of yttrium-88 from a strontium chloride target.…”