Investigation of variations in cobalt and europium concentrations in concrete to prepare for accelerator decommissioning

Typically, the concentrations of cobalt and europium, which are trace elements in concrete, are difficult to determine by chemical analysis. While data sheets do not usually contain this information, it is important for the decommissioning of accelerators, especially for the decontamination of activated concrete. To understand the variations in trace element concentrations in concrete, we analyzed cobalt and europium concentrations in concrete samples from accelerator facilities in Japan by neutron activation analysis, which is suitable for trace element analysis on the order of parts per million (ppm).