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being removed by the hydrogen coolant. For the hydrogen distribution, the mass flow is proportional to the constant NH(r H), bH describes the dispersion of hydrogen from the annular injection region, and NH (0) describes the amount of coolant penetration into the central fuel region.

        The simulated hydrogen-uranium mixing is calculated by the NORM program, which computes the radially dependent and region averaged values of the hydrogen and uranium distributions and the mixing ratio as a function of the mixing parameters Nu(O), bU, Nu(R), NH(rH), bH, and NH(O). The resulting hydrogen and uranium distributions are then used to investigate the relations connecting nuclear criticality and radiant energy transfer in an inhomogeneous fissioning plasma, as will be described in Chapter VIII.