Significance of physical state of starting precipitate in growth of uranium dioxide particles

Study on effect of process parameters and mixing on morphology of ammonium diuranate

“…It basically means shape morphology of individual particles and agglomerate [4]. Doi et al [10] and Manna et al [11] reported that an ADU particle basically consists of primary platelets and these primary platelets form primary agglomerates. Further, a number of primary agglomerates are connected with each other to form secondary agglomerates.…”

“…Doi et al [10] have studied the properties of ADU produced by reaction of 28 % NH 4 OH solution and uranyl nitrate solution containing two different uranium concentrations: 1 and 52 g/l. They observed that the formation of larger particles of more homogeneous secondary agglomeration was characteristic of ADU produced from uranyl nitrate solution having uranium concentration of 1 g/l as compared with 52 g/ l. Janov et al [12] investigated the effect of final pH of slurry on the properties of ADU.…”

Morphology of U3O8 materials following storage under controlled conditions of temperature and relative humidity

“…Process variables inherent in the synthesis of nuclear materials are known to influence the morphology of uranium oxide products [4,[6][7][8][9][10][11][12][13][14][15]. In particular, comparison of the morphology of precipitates with those of subsequent calcination products suggests that microstructures of the precursor precipitates are retained through heat treatment [6][7][8][13][14][15][16]. A number of studies have shown that U 3 O 8 , a common intermediate in the production of nuclear material, generates schoepite phases (UO 3 ÁxH 2 O) during storage under higher relative humidities presumably following oxidation and/or hydration [2,[17][18][19].…”

Study on the effect of free acidity and entrained TBP in UNPS on the quality of ADU powder

“…UO 2 powder is prepared either by the 'dry process' [3] or by the 'wet chemical process' [4,5]. There are different wet processes followed for the same, among these the ADU route is the most commonly followed and also well investigated [6][7][8][9][10][11][12][13].…”

“…Uranium dioxide (UO 2 ) is the commonly used fuel in present day nuclear power reactors [1][2][3][4][5][6]. In production process of UO 2 , intermediate process materials viz., Magnesium Di-Uranate (MDU) and Heat Treated Uranium Peroxide (HTUP) are produced by the processing of uranium ore concentrate.…”