Applications and research opportunities for a neutron activation analysis (INAA/PGAA/DNAA) of radioactive wastes

Management of the various wastes from nuclear power plants, medicine, industrial activities, research and development, is a knotty problem unless they are properly managed. Waste component analysis is an important key for a proper waste management. By determining the amount of harmful elements in the wastes, and by determining the radioactive characteristics, we can make decisions on how to manage these wastes. Waste quantitative analysis has been carried out by utilizing various chemical analytical methods like ICP-OES, ICP-MS and ion chromatography etc. But these methods can not always be carried out because of a high cost and the sample pre-treatment and preparation problems. Most chemical analytical methods require a total dissolution of the sample and so it is difficult to avoid a contamination of the apparatus, whereas nuclear analytical methods like an instrumental neutron activation analysis (INAA) and a prompt gamma-ray neutron activation analysis (PGAA) are free from these problems and cost-effective. In Korea, the INAA system has been operated at a research reactor since 1962, and the HANARO reactor, a research reactor of the Korea Atomic Energy Research Institute (KAERI), has been utilized since 1995. Also, a PGAA system was installed at HANARO by the joint efforts of Seoul National University and KAERI in 2002. These systems have been applied to various fields like industrial materials, agricultural and marine products, archaeology and forensic samples, biological samples, environmental samples and geological samples but not yet actively applied to a radioactive waste analysis. Recently, a new delayed neutron activation analysis (DNAA) system is under development with funding from the Korea Institute of Nuclear Nonproliferation and Control (NNCA)