ChemInform Abstract: Assessment of the Radium—Barium Co‐precipitation and Its Potential Influence on the Solubility of Ra in the Near‐Field

Abstract

Review: 103 refs.

Radium removal in a large scale evaporitic system

“…226 Ra is also a critical radionuclide with respect to the long-term safety of radioactive waste disposal (half-life of 1600 years). Hence, the fate of radium in deep bedrock repositories has been deserved special attention in safety case studies for potential high level waste repositories in Sweden and Switzerland (e.g., Berner, 1992;Berner and Curti, 2002;Grandia et al, 2008;SKB, 2008). In safety assessments for a repository in Sweden, interactions of radioactive waste with chloride-rich formation water are considered, because intrusions of sea-water derived solutions into the repository may occur in the long run.…”

Co-precipitation of radium in high ionic strength systems: 1. Thermodynamic properties of the Na–Ra–Cl–SO4–H2O system – Estimating Pitzer parameters for RaCl2

“…226 Ra is a critical radionuclide with respect to the longterm safety of radioactive waste disposal (half life of 1600 years). Hence, the fate of radium in deep bedrock repositories has been deserved special attention in safety case studies for potential high level waste repositories in Sweden and Switzerland (e.g., Berner, 1992;Berner and Curti, 2002;Grandia et al, 2008;SKB, 2008). In safety assessments for a repository in Sweden, interactions of radioactive waste with chloride-rich formation water are considered, because intrusions of sea-water derived solutions into the repository may occur in the long run.…”

Extraction and transport of sulfate using macrocyclic squaramide receptors

“…[5][6][7] Precipitation of BaSO 4 is frequently used to remove sulfate from solution, but this approach is problematic in removing sulfate from nuclear waste as a result of the co-precipitation of radioactive 228 Ra/ 226 Ra and 90 Sr ions forming Ba(Ra)SO 4 and Ra(Sr)SO 4 . [8][9][10] Therefore, it has been proposed that the selective extraction of sulfate from nitrate rich solutions by liquid-liquid extraction (LLE) using synthetic receptors could have signicant benets for nuclear waste remediation. 11 Despite the need to selectively extract sulfate from aqueous media, several key challenges have hindered the development of selective sulfate extraction agents.…”