“Cyclotron” JSC, Obninsk, Kaluga Region, Russia

A. E. Gulyaev, Deputy Head of Radiochemical Laboratory, e-mail: cyclotron40@gmail.com
A. A. Razbash, Chief Executive Officer

Due to it’s nuclear characteristics, palladium-103 has been used for interstitial brachytherapy implants in various tumors, especially for the treatment of prostate cancer. One of the main effective methods of palladium-103 production is the proton irradiation of rhodium on cyclotron using ¹⁰³Rh(p,n)¹⁰³Pd reaction. This reaction is used at our enterprise. The target for the palladium-103 production represents the copper block with the diffusion welded plate from the metallic rhodium. It is necessary to dissolve the irradiated target for the separation and purification of palladium-103. This article is devoted to the development of the simple and effective method of the rhodium plates dissolving and to the development of the device for it’s realization. In this work the optimal parameters of an electrochemical dissolution of a compact rhodium with a rate up to 1 gram per hour were established. The decreasing of dissolution time and the completeness of rhodium plate dissolution were the aims of the optimization. The influence of the current density and the hydrochloric acid concentration on the dissolution rate were investigated. Based on these results the device for the dissolution of the irradiated rhodium plates (thickness 80–200 microns; weight 2.5–6 grams) using alternative current 50 Hz was developed and applied in production. Proposed method and concepts of the device constructions may be used for dissolution of other noble and rare metals and their based alloys. The significant advantage of the suggested method is unnecessary of a preliminary disaggregation of the rhodium plate. Because it is a complex operation, unable to be automated and may cause the contamination by an additional impurities. Also dissolution of an irradiated rhodium in hydrochloric acid simplifies the further process of the separation palladium-103 from target material and unacceptable impurities.

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