The electrochemical conversion of solid oxide preforms to metal by molten salt electrolysis is influenced by many parameters like duration of electrolysis, temperature, applied voltage, open porosity of the preform and mode of electrolysis. The effect of these parameters on the electro-reduction of UO 2 pellets in CaCl 2 -48 mol% NaCl melt was studied in the temperature range 923-1173 K with graphite rod as the counter electrode. U metal formation started at the surface of the dense UO 2 pellets (95% TD) and it extended towards the bulk with time. Enhanced electrochemical activity was observed during the initial phase of electrolysis with porous UO 2 pellets (52% TD). The rate of deoxidation increased with increase in the electrolysis temperature from 923 K to 1023 K, but decreased on further increase to 1173 K, due to sintering of U particles on the surface of the pellet. The thickness of U metal layer increased with increase in the applied voltage from 3.1 to 3.3 V whereas no reduction of the oxide occurred at 2.8 V. The behavior of the graphite anode, in relation to the electro-reduction of the UO 2 pellets under different experimental conditions, was studied by determining the mass loss of the electrode and discussed.Direct electrochemical reduction of solid metal oxides to metals is a novel method of metal production, named as FFC (Fray-FarthingChen) Cambridge process, reported recently by Chen et al and this created a flurry of research and developmental studies in the field of electro-pyrometallurgy. 1-3 Presently the Direct Oxide Electrochemical Reduction (DOER) method is being studied with different oxides right from TiO 2 available on earth 1 to that of the monolith samples from lunar surface. 4 Many groups all over the world have reduced different individual metal oxides as well as their mixtures. 1,[5][6][7][8][9][10][11][12][13][14][15] The electro-deoxidation process is known to be influenced by various experimental parameters such as the duration of electrolysis, temperature, applied voltage, open porosity of the solid preforms, mode of electrolysis etc. and the oxides with different chemical and electrical properties were found to follow different electro-reduction mechanisms. 2,6,16,17 Yan and Fray discussed the effect of some of the parameters such as the particle size of the precursor, porosity of the pellets etc. on the electrochemical reduction of Nb 2 O 5 in molten CaCl 2 -NaCl eutectic. 18 Mohandas and Fray discussed the various issues influencing the electro-reduction of ZrO 2 and TiO 2 in molten CaCl 2 . 9 Peng et al. 19 reported the electrolytic synthesis of consolidated Zr and Zr-2.5 Nb tubes, wherein it was claimed that the reduction improved with increase in the magnitude of cell voltage, temperature and duration of electrolysis. However, this lowered the current efficiency and increased the energy consumption of the reduction process. Bixia et al 20 observed that the TiO 2 pellets sintered in the temperature range of 1273-1373 K for a duration of 4 h were found to undergo better redu...

In the absence of fuel pin failure, major radiation burden in primary heat transport system of a sodium cooled fast reactor is due to long-lived and high gamma active corrosion products 54 Mn, 60 Co and 58 Co. For minimizing the radiation burden to operation and maintenance personnel, radionuclide traps are essential to concentrate and contain these radionuclides in a particular location of primary system. To remove activated corrosion products from primary sodium, use of nickel foam as radionuclide trap material has been proposed as a candidate trap material for fast reactors as against the use of nickel in form of rolled sheet and pall rings. This paper describes about the effectiveness of nickel foam for trapping manganese and cobalt from liquid sodium.