The consequences of disposal of low-level radioactive waste from the Fernald Environmental Management Project: Report of the DOE/Nevada Independent Panel

The Department of Energy (DOE) convened a panel of independent scientists to assess the performance impact of shallow burial of low-level radioactive waste from the Fernald Environmental Management Project, in light of a transportation incident in December 1997 involving this waste stream. The Fernald waste has been transported to the Nevada Test Site and disposed in the Area 5 Radioactive Waste Management Site (RWMS) since 1993. A separate DOE investigation of the incident established that the waste has been buried in stress-fractured metal boxes, and some of the waste contained excess moisture (high-volumetric water contents). The Independent Panel was charged with determining whether disposition of this waste in the Area 5 RWMS has impacted the conclusions of a previously completed performance assessment in which the site was judged to meet required performance objectives. To assess the performance impact on Area 5, the panel members developed a series of questions. The three areas addressed in these questions were (1) reduced container integrity, (2) the impact of reduced container integrity on subsidence of waste in the disposal pits and (3) excess moisture in the waste. The panel has concluded that there is no performance impact from reduced container integrity--no performance is allocated to the container in the conservative assumptions used in performance assessment. Similarly, the process controlling post-closure subsidence results primarily from void space within and between containers, and the container is assumed to degrade and collapse within 100 years.