Radiological characterisation of graphite components in Advanced Gas-cooled Reactor cores

As the Advanced Gas-cooled Reactors approach the end of generation, research and characterisation are required to support the decommissioning strategy. Radiological data for AGR graphite are negligible and the radiological inventory of the AGR core and other graphite components rely on activation modelling. This is the first study of C-14 activity and its release behaviour in AGR core graphite and its associated carbonaceous deposits and provides valuable information that can support decommissioning activities. In combination with corresponding studies on Magnox core graphite, significant understanding is attained on the main C-14 precursors in the graphite and the deposits. In addition, this study reports C-14, H-3 and gamma spectrometry data on AGR graphite fuel sleeves. This is a waste stream that is currently stored in heavily engineered stores at a significant cost. The data indicate that alternative storage and disposal options with a lower environmental and financial impact are worth considering.