The environmental biogeochemistry of chelating agents and recommendations for the disposal of chelated radioactive wastes

Radionuclide-Chelating Agent Complexes in Low-Level Radioactive Decontamination Waste; Stability, Adsorption and Transport Potential

“…Organic complexes of radionuclides have been implicated in several instances as enhancing the mobility of radionuclides such as 60Co, 23 8 Pu, 2iAm, and 9°Sr from shallow-land burial grounds at Oak Ridge, Tennessee (Means et al 1978;Means and Alexander 1981) and at Maxey Flats, Kentucky (Polzer et al 1982;O'Donnell 1983;Dayal et al 1986). Organic chelates, such as EDTA and picolinic acid, have also been shown to leach from solidified decontamination wastes from nuclear power stations (McIsaac and Mandler 1989).…”

Subsurface Behavior of Plutonium and Americium at Non-Hanford Sites and Relevance to Hanford

“…EDTA is a strong chelating agent that forms very stable complexes with many actinide elements and transition metals, resulting in increased solubility and reduced adsorption. It is believed that the EDTA complexed with Pu and other radionuclides, resulting in elevated concentrations of radionuclides in the leachates (Cleveland and Rees 1981;Means and Alexander 1981;Polzer et al 1982;Dayal et al 1986aDayal et al , 1986b. Dissolved concentrations of 238 Pu in the range of 600-16,100 pCi/L had been measured in trench leachates collected from the site (Cleveland and Rees 1981;Means and Alexander 1981).…”

Chelating Agents in the Environment

“…Elevated concentrations of chelating agents enhance the transport of metals (e.g. Zn, Cd, Ni, Cr, Cu, Pb, and Fe) in soils (101)(102)(103)(104)(105)(106)(107) and enhance the undesired transport of radioactive metals away from disposal sites (10,81,(108)(109)(110). Low concentrations of chelating agents may either stimulate planktic algae growth or decrease it while high concentrations inhibit activity (111)(112)(113).…”

“…Environmental concentrations, usage, biodégradation and toxicology of aminocarboxylates have been thoroughly reviewed (2,(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Much less is known about the fate and behavior of the corresponding phosphonates in the environment.…”