The Challenge

Decommissioning of graphite-moderated reactors will bring new challenges for the nuclear community. Although a number of such reactors have been decommissioned in various EU Member States, the quantity of irradiated graphite (i-graphite) involved and size of those reactors were small (experimental or material test reactors) in comparison to the future amounts associated with commercial reactors, which are scheduled for decommissioning in the next decades. It is estimated that the total quantity of i-graphite involved worldwide is of the order 250,000 tons, with the majority residing in EU reactors. Currently, there are no fully optimised waste management options for this material. Some Member States classify i-graphite as Intermediate Level Waste (ILW) whilst others regarded it as Low-Level Waste (LLW). I-graphite that has been removed from reactors is currently stored in silos, vaults and other buildings, awaiting a final management solution. Irrespective of its classification, the challenges for the ultimate management options are complex reflecting the nature of the material itself, its retrieval from the core, and e.g. the associated inventory of long-lived radio-isotopes like radiocarbon (14C), chlorine (36Cl), iodine (129I), technetium (99Tc), selenium (79Se), caesium (135Cs) etc. that results from activation processes, or from the transformations of the graphite matrix due to neutron irradiation.

Dismantling of the GLEEP Facility in UK

last change: 06.12.2012 | | Print