Overview on the Brazilian scenario and the first efforts towards the development of a borehole repository

Abstract

The use of nuclear technologies has increased worldwide, leading to a continuous rise in radioactive waste generation. In Brazil, the National Nuclear Energy Commission (CNEN) faces growing challenges related to the safe management and disposal of radioactive waste from energy production, industrial, medical, security, and research activities. Because some waste remains hazardous for thousands of years, developing disposal solutions that protect both the environment and human health is essential. Current efforts focus on designing facilities suitable for disused sealed radioactive sources, which are not fully covered by the Brazilian near-surface repository project for low- and intermediate-level waste, Centro Tecnológico Nuclear e Ambiental (CENTENA). Although CENTENA does not include deep borehole disposal, this study examines this concept as a technically feasible complementary solution for the long-term isolation of disused sealed sources. To support container material selection for such disposal systems, a comparative electrochemical evaluation of stainless steels 316L, 2304, and 2205 was conducted in saline medium, assessing their corrosion resistance under conditions relevant to deep borehole environments. The results contribute to identifying suitable materials for long-term containment applications.