Analytical electron microscopy characterization of uranium-contaminated soils from the Fernald Site, FY1993 report

Thermodynamic properties of the uranyl carbonate minerals roubaultite, fontanite, widenmannite, grimselite, čejkaite and bayleyite

“…The uranyl carbonate [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] minerals are extraordinarily important in actinide environmental chemistry [1][2][3][13][14][15][21][22][23][24][25][26][27][28][29][30] because their dissolution/precipitation processes control the aqueous mobility of uranium 1-10,13-17,19.23-30 in circumneutral to alkaline conditions 2,8,10 and, therefore, their knowledge is essential in the research of migration of uranium from contaminated sites [31][32][33][34][35][36][37][38][39] and nuclear waste repositories (NWR). 1,…”

Analytical electron microscopy characterization of Fernald soils. Annual report, October 1993--September 1994

“…Other non-uranium-bearing phases found in the soil samples included rutile, ilmenite, maghemite, apatite, cerium phosphate, yttrium phosphate, and zircon. The identification of these phases was confirmed by AEM and was discussed in our FY 1993 annual report [8]. The distribution of non-uranium-bearing phases will affect the efficiency of the treatment methods.…”

“…The large number of uranium phases present at Fernald was described in the FY 1993 annual report [8]. In this section, the types of" uranium phases commonly found are discussed with reference to new samples, and data are given on some new uranium phases, which may have been produced by the action of chemical remediation agents.…”

“…These results indicated that characterization by electron microscopy would be representative, as all the contamination was in particulate form. Buck et al [2,7,8], using electron microscopy techniques, also confirmed that most uranium in incinerator and SP2 soils was in the form of discrete particles but were unable to locate many uranium-bearing particles in SP4 soil samples.…”

The crystal structures and mechanical properties of the uranyl carbonate minerals roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite

“…1-7,12-16,18.22-29 Carbonate and bicarbonate ions, present in significant concentrations in many natural groundwaters, are extraordinarily strong complexing agents for actinides and, therefore, the carbonate complexes of uranium [1][2]4,7,[12][13][14][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] play an important role in the migration from nuclear waste repositories 1,5,8,[12][13][14][15][16]19,[47][48][49][50][51][52] or in the accidental site contaminations. [53][54][55][56][57][58][59][60][61] Aqueous uranyl carbonate complexes are the most prominent uranium species in circumneutral to alkaline natural waters in which carbonate or bicarbonate ions are present or contain significant amounts of dissolv...…”