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  • 1 Bhabha Atomic Research Centre (F) Kalpakkam Reprocessing Plant Kalpakkam 603102 India Kalpakkam 603102 India
  • 2 Indira Gandhi Centre for Atomic Research Materials Science Division Kalpakkam 603102 India Kalpakkam 603102 India
  • 3 C-MARS, Regional Research Laboratory Thiruvananthapuram 695019 India Thiruvananthapuram 695019 India
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Abstract  

Ammonium uranates are important intermediates in the preparation of nuclear fuel UO2. These can generally be prepared through two different routes: heterogeneous (conventional) and homogeneous methods of precipitation. In the conventional method, ammonium hydroxide, gaseous ammonia and ammonium carbonate are the precipitating agents. In the homogeneous method, urea hydrolysis is used to generate in situ ammonia needed for precipitation. For the present studies, ammonium hydroxide is used for the conventional and urea for the homogeneous methods of precipitation. The uranates, thusprepared, are characterized by thermogravimetry (TG), differential thermogravimetry (DTG)and differential thermal analysis (DTA). Thermally the numbers of decomposition steps are identical for both uranates but the temperatures of the decomposition and mass losses vary. The intermediate and final oxides are identified by X-ray diffractometry (XRD).