PACKAGING EXPERIENCE OF60 Co SOURCES FROM RESEARCH IRRADIATORS

After Latvia has used the opportunity to get back its independence the investigations for the former military industrial complex of the big soviet empire have been stopped. These and following economic problems in the newly re-established as independent country have brought to the situation where high activity 60Co irradiation devices for research purposes have been left without necessary operator supervision and maintenance. The situation was aggravated by the fact that Russia, the supplier of 60Co sources had refused to accept back spent sources with expired warranty time. According to official information there were in Latvia at the beginning of 1995 three high activity research irradiation devices with totally 150 sources. Only 48 from them were well suitable (due to warranty time and natural decay) for further use. By the assistance from IAEA and Sweden Latvia received 2 concrete containers with 5 technological channels in each (Studsvik RadWaste AB design). Because such type of containers was not intended for high activity sources improving of them by adding lead shielding between stainless steel receptacle for sources and external hull in each of the channels was planned and realised by Latvian company \"Radons\". For the transportation of cobalt sources from devices to storage place the standard soviet design container KT-26-12 belonging to Russian company \"Radij\" was used. The unloading the sources from transport container to storage container were made by the personnel of \"Radij\" and \"Radons\" together. For this purpose a special reloading platform was designed by \"Radons\" and accepted by state authority. Each of the channels after the loading with twelve sources was planned to close by lead plug. All the reloading operations have been planned in details, accenting radiation safety during transportation and reloading. However, by starting the operation additional 42 not registered old, no more suitable sources were found in one of irradiators. That have create the problem what to do, because there was place only for 120 spent sources, but suddenly there was 144. There was no financial means and no time left to receive additional concrete containers from Sweden. The situation was rescued by the same Latvian company \"Radons\" that designed a special concrete drum for 12 sources, with additional lead shielding . The state authority - Radiation and Nuclear Control division of the Environmental State Inspectorate - worked together with the company in the design phase and accepted the design without delay. All the unloading, transportation and reloading operations went successfully. The received doses to the staff were insignificant.