ABSTRACT
There are more than 60 naturally-occurring radioactive elements (radionuclides), which can occur in air, water, soil and rocks. Radionuclides have been classified as primordial, cosmogenic or human-produced. Gamma radiation can be detected and counted by commercial gamma counters, commonly known as gamma well counters. If a gas is contained in a chamber in which there are two charged electrodes, a beta-particle can pass through this gas and can dislodge an orbital electron from one of the atoms. Before radioactive waste can be either stored or disposed of, it is usually analyzed, i.e., detecting the occurrence of radionuclides as well as their amounts and levels. During the process, a long-lived radioactive nucleus is changed into one with a shorter half-life. Next, radioactive nuclei are separated from non-radioactive nuclei. Then, the former are bombarded with high-speed subatomic particles generated by either accelerators or nuclear reaction.
