A 'Tool Box' to Europe's looming irradiated-graphite waste challenge
As Europe gears up towards decommissioning its graphite-moderated nuclear reactors over the coming decades, disposing the i-graphite will present a major challenge. Of the 250 000 tonnes of the material worldwide, the bulk of it is in the EU. Currently, the small amount of i-graphite waste that has been retrieved from test reactors has been mostly stored in silos and vaults, awaiting a decision on its disposal. Even though i-graphite is classified as long-lived low- or intermediate-level waste, more robust and sustainable waste management options need to be devised to avert the radiation risks it poses. Financed by the EU's Euratom programme, the project 'Treatment and disposal of irradiated graphite and other carbonaceous waste' (CARBOWASTE) developed integrated guidelines for the retrieval, treatment and disposal of i-graphite. It targeted both legacy waste and waste to be produced by future generations of reactors. Among CARBOWASTE's achievements was the development of techniques for separating the coated particles from the moderator graphite of high-temperature reactor fuel. CARBOWASTE discovered that thermal, chemical or microbiological treatment can get rid of a significant proportion of the contamination. The project also investigated the possible reuse of this purified material. A sufficient understanding of irradiated graphite has been generated to conclude with confidence that irradiated graphite waste can be safely disposed in a wide range of disposal systems. As decommissioning looms ever closer, the CARBOWASTE toolbox promises to prove invaluable in the safe and effective disposal of i-graphite waste.
