CONTENT OF ACTINIDES IN GRAPHITE FROM THE DECOMMISSIONED PLUTONIUM-PRODUCTION REACTORS OF THE SIBERIAN GROUPS OF CHEMICAL ENTERPRISES

摘要

The residual actinide concentrations and distributions in graphite from two (EI-2 and I-1) decommissioned plutonium-production reactors have been investigated. Emphasis has been placed on measuring 241{sup left}Am, 243{sup left}Am, 244{sup left}Cm and (239-241){sup left}Pu. It was established that, currently, the major contributor to activity of actinides is 244{sup left}Cm. For the first time the samples taken from the whole transverse section of the graphite blocks have been assayed. Content of actinides in the block volume is several hundred times smaller than that in superficial layer. Radionuclides weakly migrate from the surface into the depth of the graphite block. The penetration through the graphite cracks was observed only in single cases. Superficial character of the blocks contamination gives a possibility to remove actinides during future dismantling of the stack.