Indústrias Nucleares do Brasil (INB) has resumed remediation of the Torta II packages at the Caldas Decommissioning Unit (UDC). Torta II is a radioactive residue, coming from the chemical treatment of monazite. It is considered a low radioactivity material and needs to be stored following safety regulations. Monazite was processed to produce rare earth compounds, used in ceramics, electronic materials composition, superconductors, permanent magnets and special metal alloys.

The activity, which should last more than a year, was approved and will be supervised by the National Nuclear Energy Commission (CNEN) and aims to process 16,100 metallic drums. The remediation consists of overpacking the oxidised drums of Torta II with new metallic drums and replacing the pallets with new ones, in order to guarantee the packaging of the material. The forecast to complete the work is 12 to 14 months. “As we overpacked 3,500 drums at the beginning of the year, we have a parameter of how the operation should take place and the estimated time of completion”, explained the Decommissioning Manager, João Viçozo da Silva Júnior.

The operation has its own and outsourced equipment and professionals. A hospital bed was also contracted in Poços de Caldas, intended for the decontamination of victims of a possible accident during work. The professionals involved in the operation underwent several training courses before the start of the activity. For the employees of the contracted hospital, training in radiological protection and radiological emergency care was given.

“This operation will also include weighing and taking samples for laboratory analysis, in order to improve the Torta II inventory”, the manager explained. The first stage of remediation of the packages took place at the unit between January and May 2022 and prioritised unstable piles. The remediation target was 1,500 packages and was exceeded in less than two months of operation, resulting in the over-packing and replacement of pallets of 3,500 metal drums, as well as the replacement of pallets of 400 plastic drums.

Image: Remediation of Torta II packages has resumed at the Caldas Decommissioning Unit (pictured) (courtesy of INB)