Module 104 Internal Dose Control
detect gamma and X r ays emitted fro m radioactive
material inside the body. For example, the 235U and
uranium-234 (234U) isotopes of uranium present in
enriched uranium emit X rays that can be detected.
Alpha and beta radiation emitted by material inside
the body is shielded by body tissue and cannot be
Direct measurement is useful for detecting uranium
that is not easily eliminated by the body. This
method may also be used to estimate an internal
dose. Because of the very low energy and intensity
of gamma rad iation emitted f rom deple ted uran ium,
direct measurements are not effective in detecting
depleted ur anium in the bod y.
Internal Dose Reduction and Control Techniques
The hierarchy for minimization of internal dose is given in
the RCM, Article 316. Engineering controls should be the
primary method of minimizing airborne contamination and
internal exposure to workers, where practicable.
Administrative controls, including access controls and
specific work practices, should be used as the secondary
method to minimize internal exposure. If the potential for
airborne radioactivity still exists after engineering and
administrative controls have been applied, respiratory
protection should be considered. Other specific controls,
such as stay ti mes, worker safe ty, comfort, and efficiency,
are also discussed in Article 316.