Magnox graphite core decommissioning and disposal issues

Graphite core dismantling and disposal will be a key issue for the decommissioning of the United Kingdom (UK) Magnox reactors. The irradiated graphite arisings from the UK gas cooled reactor programme represent a significant proportion of the radioactive wastes currently destined for the UK geological repository. Data on the graphite and radionuclide inventory of the Magnox reactor graphite cores are presented together with data on the core designs. Magnox reactor cores represent a significant fraction of the worldwide irradiated graphite inventory and the paper recognizes that there may be alternatives to geological disposal. Sources and arisings of carbon-14, which is one of the major long lived radionuclides of concern, are discussed along with wider aspects of the arisings and behaviour of carbon-14 in the environment. Indubitably, core graphite disposal and the technical challenges it poses is one of the major issues to address in achieving final site clearance in a cost effective manner and reducing the liability cost associated with disposal of graphite. (author)