Test program for design of a radon barrier

Spain's radioactive waste management agency (ENRESA) is in charge of the decommissioning and remedial action for an inactive uranium mill on the outshirts of Adujar town in the southern province of Jaen. Decommissioning to be done at the site consists of: dismantling all the facility's equipment, demolition the structures, dumping all the equipment, and covering the tailings with a multilayer system of radon and infiltration barrier (clay), filter media (sand) and erosion barrier (rock and gravel). Calculations with the RAECOM code showed that 50 cm of clay barrier was sufficient to reduce the radon flux from 400 pCi/m2/sg to 20 pCi/m2/sg, as specified in the general design criteria. To protect the radon barrier from erosion a cover was designed, consisting of the following layers: Radon barrier of clay; Filter layer of sand; Erosion barier of local soils. The monitoring program, in operation since February 1988, will provide data for radon barrier characterization and RAECOM calibration. The results will be used in the first design of the Andujar tailings pile cover. 1 fig., 2 tabs