Figure 6-1. Beta Radiation Readings at Surface of Uranium Metal vs. % Enrichment by Weight

DOE-STD-1136-2004

Guide of Good Practices for Occupational Radiation Protection in Uranium Facilities

of enrichment. Figure 2-2 (Chapter 2) shows the estimated activities of the uranium isotopes as a

function of enrichment as predicted by the reference equation.

Radiation fields from uranium are frequently dominated by contributions from daughter product or

impurity radionuclides. For example, nearly all of the beta radiation field from depleted uranium comes

from the daughter radionuclide 234mPa, and to a lesser extent from 234Th. During melting and casting

operations, these daughter elements may concentrate on the surface of the castings and equipment,

producing beta radiation fields up to 20 rad per hour.

Figure 6-1. Beta Radiation Readings at Surface of Uranium Metal vs. % Enrichment by Weight

6-5