LILW-repositories

LILW-REPOSITORIES

The first three facility types listed by the IAEA (specific landfill disposal, near surface disposal and belowground facilities) have been implemented for decades in many countries. However, the degree of maturity of the implementations varies considerably and corresponds to the conceptual perspectives and the technical means of the time. The early landfills for commercial low-level waste in the United States, such as Maxey Flats or West Valley, New York, showed relatively quickly that radioactivity was discharged from the landfills. They were leaking, as later confirmed by monitoring programs at many other sites. In Maxey Flats it was already proven in the 1970s that LILWs deposited in large quantities were washed out and that plutonium complexes could also be found outside the landfill.197 At the Beatty landfill in Nevada, where both nuclear and chemotoxic waste was dumped in trenches, incidents accumulated from the start of operation until very recently, when disposed metallic natrium reacted and was partially ejected.198 Many other such landfills followed the same course, as can be seen from the US Environmental Protection Agency’s list of superfund sites. In summary, conventional landfills and trenches, the first of the plants named by the previously mentioned IAEA report, cannot be reliably sealed hydraulically. Therefore, these plants are to be regarded as more or less controlled permanent dilution ‘facilities’.

The second type of disposal facility consists of reinforcing the protective functions already achieved with the first type of landfill with the additional help of concreted components and structures. This type of construction contributes above all to the creation of a basic environment, which creates a geochemical barrier, especially for leachates containing heavy metals. This design is used for both LLW and LILW sites. One plant of this type is the one for LLW-waste opened 1971 in Barnley, South Carolina, which was designed as trenches, which has a clay seal and in which the waste is stored in prefabricated conditioned concrete cylinders.199 Other plants of this type include the two French Sites “Centre de Stockage de la Manche” (CSM), Digulleville, Normandy, operated between 1969 and 1994,200 and the successor landfill “Centre de Stockage de l’Aube” (CSA), Soulaines-Dyus, Aube.201 Here the pre-conditioned and packaged LILW were sunk into trenches in the early days before there were deposited into engineered concrete disposal vaults. The shallow landfills are covered using conventional sealing techniques. The sites are equipped with drainage systems and corresponding monitoring. The LLW deposit in Dessel, Campine Area, Belgium, is also constituted as monolithic blocks cast in concrete.202

Although these facilities are better protected against infiltration than the original trenches, rainwater penetrates into the concrete blocks over time and can wash out small amounts of soluble radioactive substances (especially tritium).203 Even these plants cannot do without dilution. The plants for LILW in

197 Shrader-Frechette, K. 1993, Burying Uncertainty, Risk and the Case Against Geological Disposal of Nuclear Waste, University of California Press, p.p 103-104; Cleveland, J. M., and Rees, T. F. 1981, Characterization of Plutonium in Maxey Flats Radioactive Trench Leachates, Science, 212(4502), pp.1506. 198 Alley and Alley 2013, pp. 139-148. 199 South Carolina Department of Health and Environment Control 2007, Commercial Low-Level Radioactive Waste Disposal in South Carolina, Bureau of Land and Waste Management, Division of Waste Management, Columbia, South Carolina, viewed 5 August 2019, https://www.scdhec.gov/sites/default/files/docs/HomeAndEnvironment/Docs/commercial_low_level.pdf 200 IAEA 2005, Upgrading of Near-Surface Repositories for Radioactive, Technical Report Series N° 433, pp. 63-70, viewed 5 August 2019, https://www-pub.iaea.org/MTCD/Publications/PDF/TRS433_web.pdf 201 Andra 2008, Rapport annuel (annual report), Centre de stockage de déchets radioactifs de faible et moyenne activité, viewed 5 August 2019, https://inis.iaea.org/collection/NCLCollectionStore/_Public/49/034/49034330.pdf 202 Wacquier, W. 2013, The safety case in support of the license application of the surface repository of low-level waste in Dessel, Belgium, NEA/OECD, NEA/NWR/R(2013)9 203 IAEA 2005, pp. 65.