Radiological Fundamentals

Tritium Primer

DOE-HDBK-1079-94

RADIOLOGICAL FUNDAMENTALS

RADIOLOGICAL FUNDAMENTALS

This section provides a review of radiological fundamentals. The reader is assumed to be

familiar with this information from radiological worker training. The section discusses hydrogen

and its isotopes and describes basic radiological concepts.

Hydrogen and Its Isotopes

Atomic nuclei of a particular element (such as hydrogen or oxygen) have the same number of

protons (positively charged), but may have a different number of neutrons (no net charge).

Those that have a different number of neutrons are isotopes of that element. Most elements exist

in nature in several isotopic forms. For example, hydrogen has one proton. The isotopes of

hydrogen either have no neutrons (normal hydrogen, called protium), one neutron (deuterium),

or two neutrons (tritium) (Figure 1). Although isotopes of an element have almost the same

chemical properties, the nuclear properties can be quite different.

1. Protium - 1H (1 proton, 1 electron)

-Stable (not radioactive)

-Comprises 99.985% of natural hydrogen.

2. Deuterium - 1H or D (1 proton, 1 neutron, 1 electron)

-Stable (not radioactive)

-Comprises 0.015% of natural hydrogen.

3. Tritium - 1 H or T (1 proton, 2 neutrons, 1 electron)

-Radioactive -18

-Comprises 10

parts of natural hydrogen.

Figure 1 Hydrogen isotopes

Rev. 0

Page 3

Tritium