Innovative Approach for the Decommissioning and Dismantlement of the 'Old Cave' Project

摘要

Located in the Semi-Works (SW) Building of the DOE’s Mound Plant, the Old Cave is the entombedrnremains of a hot cell used to process radium (Ra-226) and actinium (Ac-227) from 1951 to 1955. Thernprocess was terminated in 1955 and the area was later entombed in 1959. The size of the entombed area isrnapproximately 30 feet by 50 feet. The exact radiological inventories and physical items that may be buriedrnwithin the entombment are unknown. A conservative estimate indicates that a maximum of 5 curies (Ci) ofrnAc-227 and 12 Ci of Ra-226 could still be present. The radiological hazards and the potential hazardsrnassociated with the separation process make the D&D of this area a great challenge from the perspectivesrnof worker and environmental protection. The project plan was designed to ensure maximum protection tornthe workers. The plan includes a totally remote waste removal and excavation operation, in-process wasterncharacterization, a specially designed waste processing and loading station and remote radiation andrnvideo monitoring systems. The entire project is expected to be completed in eighteen (18) months with arnminimum production rate of 100 - cubic feet of excavated material per day (or one and one half wasterncontainers), and a four day work week using one 10 hour shift.