The Brazilian repository is being planned to be a near-surface one. In Brazil, the low and intermediate level radioactive wastes are immobilized using cement and bitumen for nuclear plant Angra 1 and Angra 2, respecti...The Brazilian repository is being planned to be a near-surface one. In Brazil, the low and intermediate level radioactive wastes are immobilized using cement and bitumen for nuclear plant Angra 1 and Angra 2, respectively. The major problems due to the disposal of bituminized wastes in repositories are swelling of the waste products and their degrad^ttion in the long term. To accommodate the swelling of the bituminized wastes, the drums are filled up to 70-90% of their volume, which reduces the structural the repository stability and the disposal availability. Countries, which use bitumen in the solidification of NPP＇s radioactive waste and have near-surface repositories, need to immobilize this bituminized waste within other drums containing cement pastes or mortars to disposal them. This study aims to evaluate the properties of bitumen, cement pastes and mortars to be used in the encapsulation of bituminized wastes. The formulations of two pastes and two mortars were selected for the pilot scale tests. The laboratory and pilot scales results were very similar, indicating that any of these formulations could be used. However, the better formulation will be chosen after the leaching test results, because it is an essential parameter in the long-term repository performance.展开更多
文摘The Brazilian repository is being planned to be a near-surface one. In Brazil, the low and intermediate level radioactive wastes are immobilized using cement and bitumen for nuclear plant Angra 1 and Angra 2, respectively. The major problems due to the disposal of bituminized wastes in repositories are swelling of the waste products and their degrad^ttion in the long term. To accommodate the swelling of the bituminized wastes, the drums are filled up to 70-90% of their volume, which reduces the structural the repository stability and the disposal availability. Countries, which use bitumen in the solidification of NPP＇s radioactive waste and have near-surface repositories, need to immobilize this bituminized waste within other drums containing cement pastes or mortars to disposal them. This study aims to evaluate the properties of bitumen, cement pastes and mortars to be used in the encapsulation of bituminized wastes. The formulations of two pastes and two mortars were selected for the pilot scale tests. The laboratory and pilot scales results were very similar, indicating that any of these formulations could be used. However, the better formulation will be chosen after the leaching test results, because it is an essential parameter in the long-term repository performance.
