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        Step 3.--If n (2) (i) - nc (i) I > 1 for any i,

Step 2 is repeated r times until nc(r) (i) - nc (r-) (i) I< 1 for all i. When this condition is satisfied, the plasma composition is determined consistent with the ionization potential lowering and cut-off quantum numbers. Results of Uranium Plasma Composition Calculations

        The UPLAZ-2 program was used to calculate the uranium plasma composition for pressures from 1 atm to 1000 atm and temperatures from 50001K to 120,0001K. Typical results are shown in Figures 8, 9, and 10, for pressures of 100, 500, and 1000 atmospheres. The electron density and the densities of individual uranium species are given in per cent of total particle density. Additional calculated uranium plasma compositions for pressures from 100 atm to 1000 atm are shown in Figures 25 through 34, Appendix A.

        The fact that the fuel region of the "gaseous"

core reactor is a plasma, rather than a ordinary gas, is clearly demonstrated in Figures 8, 9, and 10. At a temperature of 20,0000K, the total number of particles in the fuel region consists of about 50% uranium and 50% electrons. Above 40,0000K, the fuel region contains approximately 80% electrons and only 20% uranium. In