Regeneration ratio

An overall reclamation ratio of 92 %, as given above, is a normal value for mixed green sand -chemically bonded sand systems. Regeneration ratios of up to 98 % have been reported. The actual ratio depends on the volume and chemical composition of the used cores. For fiiran cold setting monosands, values around 78 % are reported. 

For a green sand monosystem, regeneration ratios of 98 % may be achieved. Systems with a high degree of incompatible cores, may achieve a regeneration ratio of 90 - 94 %. 

For fliran cold setting monosands regeneration ratios around 78 % are reported. 

Regeneration ratio, based on used sand throughput % 95 95 (99 95... 

The yield of regenerated sand for one cycle operation is reported to be 85 % of the initial weight (on the basis of Si02). In order to produce stable cores, and taking into account the further reduction of sand quality upon a second regeneration cycle, a maximum regeneration ratio of 62 % may be achieved (leaving 38 % new sand addition). 

Due to the high costs and relatively low regeneration ratio, depreciation of the installation in a reasonable time can only be guaranteed for plants with a capacity >2500 tonnes/yr. 

Regeneration ratio the ratio between the mass of regenerated sand and the total mass of sand used in mould and core-making, expressed as a percentage... 

Critical concentration, mass, inventory, and regeneration ratio. The data in Table 14-1 are more easily comprehended in the form of graphs, such as Fig. 14-1, which presents the critical concentration in these reactors as a function of core diameter and thorium concentration in the fuel salt. The data points represent calculated values, and the lines are reasonable interpolations. The maximum concentration calculated, about 35 X 10 ... 

Fig. 14-5, Maximum initial regeneration ratios in two-region, homogeneous, molten fluoride-salt reactors fueled with. U . Total power, 600 Mw (heat) external fuel volume, 339 ft .

Plotting the maximum regeneration ratio versus critical inventory generates the curve shown in Fig. 14-5. It may be seen that a small in-l estment in U- (200 kg) will give a regeneration ratio of 0.58, that 4(K) kg will gi e a ratio of 0.66, and that further increases in fuel inventory have little effect. 

Effect of substitution of sodium for Li. In the event that Li should prove not to be available in quantity, it would be possible to operate the reactor with mixtures of sodium and beryllium fluorides as the basic fuel salt. The penalty imposed by sodium in terms of critical inventory and regeneration ratio is shown in Fig. 14-8, where typical Na-Be systems are compared with the corresponding Li-Be systems. With no thorium in the core, the use of sodium increases the critical inventory by a factor of 1.5 (to about 300 kg) and lowers the regeneration ratio by a factor of 2. The regeneration penalty is less severe, percentagewise, with 1 mole % ThF4 in the fuel salt in an 8-ft-diameter core, the inventory rises from 800 kg to 1100 kg... 

The regeneration ratios and fuel inventories of reactors of various diameters containing 0.25 mole % thorium and fueled with or are compared in Fig. 14-11. The superiority of is obvious. 

Fig. 14r-ll. Comparison of regeneration ratios in molten-salt reactors containing 0.25 mole % ThF4 and or U -enriched fuel. 

Intermediate states. Calculations of the long-term performance of one reactor (Case 51, Table 14-5) with as the fuel are described below. The core diameter used was 8 ft and the thorium concentration was 0.75 mole %. The changes in inventory of and regeneration ratio are listed in Table 14 6. During the first year of operation, the inventory rises from 129 to 199 kg, and the regeneration ratio falls from 0.82 to 0.71. If the reprocessing required to hold the concentration of fission products... 

Initial states. Critical concentration, mass, inventory, and regeneration ratio. The results of calculations of a plutonium-fueled reactor having a core diameter of 8 ft and no thorium in the fuel salt are described below. The critical concentration was 0.013 mole % PuFs, which is an order of magnitude smaller than the solubility limits in the fluoride salts of interest. The critical mass was 13.7 kg and the critical inventory in a 600-Mw system (339 ft of external fuel volume) was only 31.2 kg. 

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