Unsymmetrical diglycolamide for the safe management of nuclear waste

A new unsymmetrical diglycolamide, N,N-di-dodecyl-N′,N′-di-2-ethylhexyl-3-oxapentane-1,5-diamide trivially known as di-dodecyl-di-ethylhexyl diglycolamide (D3DEHDGA) has been synthesized, and characterized by 1H and 13C NMR, mass, and IR spectroscopic techniques. D3DEHDGA has been evaluated for the removal of long-term hazardous metal ions from high-level liquid waste (HLLW) originating from reprocessing of fast reactor spent nuclear fuel. The extraction behaviour of radiotoxic metal ions such as Am(III), U(VI), Eu(III), Ru(III), Sr(II), Ba(II), Sb(III), and Cs(I) was studied from nitric acid as well as from simulated HLLW in 0.1 M D3DEHDGA/n-dodecane. The stoichiometry of D3DEHDGA-Am(III) was determined by linear regression of extraction data. Third phase formation behaviour of D3DEHDGA/n-dodecane with nitric acid and trivalent metal ion, Nd(III), was investigated. Higher limiting organic concentration and critical aqueous concentration of trivalent metal ion, complete extraction of trivalent actinides, and negligible extraction of unwanted metal ions, make D3DEHDGA a promising candidate for partitioning of toxic trivalent actinides from HLLW.