PLENTIFUL ENERGY

The first thing we wish to know is the state of saturation of the cadmium. In
these experiments the cathode contained 26 kg of cadmium. The number of moles
of cadmium were 26000/112.4 = 232 moles. Uranium saturates at a concentration
of 1.12%, 0.0112 x 232 = 2.60 moles U, or 2.6 x 238 = 618.8 grams U. Plutonium
saturates at a concentration of 1.81% = 0.0181 x 232 = 4.20 moles Pu, or 4.2 x 239
=1003.8 grams Pu. Thus the saturated amounts of the metals in the cadmium
cathode are 618.8 grams U and 1003.8 grams of Pu.
The anode in all three runs was EBR-II blanket material, substantially uranium,
only 1 percent or so was plutonium. The effect of this anode composition is to
increase the uranium content in the electrolyte as cadmium cathode electrorefining
proceeds. Uranium largely replaces plutonium in the electrolyte reduced at the
cathode. The measured results are given in Table A-5.
Table A-5. Results of Transuranic Recovery Experiments
Run 1 Run 2 Run 3
Heavy metal recovered, g 1365 1739 1313
Pu in casting furnace ingot, g 1024 1080 492
Np-237 in casting furnace ingot, g 4.5 1.2 0.6
U in salt at end of test, wt% 0.47 0.74 0.83
Pu in salt at end of test, wt% 2.67 2.46 2.38
Recovered metal theoretical, 10 6 coulomb 1.65 2.11 1.59
Integrated current, 10 6 coulomb 1.81 2.13 2.09
Transport efficiency, % 91.5 99.2 76.1
A.12.3 Equilibrium Constants Derived From the Measured Quantities
of Each Run
Our reaction is Pu + UCl 3 U + PuCl 3 .
Our calculated value for the equilibrium constant for the reaction is fixed at
1.2x10 6 , unchanged from run to run. We will compare this to the values derived
from the measured results of the three electrorefining runs. We want to see how
well calculations based on the assumptions we use, principally that of equilibrium,
are able to predict results.
The required input data is shown in Table A-6 below. We are indebted to Dee
Vaden of INL for explanation of the details of the experiments, published in
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