Radioactive source refers to a substance or entity made of radioactive substances that can produce radiation exposure. Radioactive sources can be divided into sealed sources and unsealed sources according to their sealing conditions.
Sealed sources are radioactive substances sealed in cladding or tight covering, and all sealed sources are used for level meters and flaw detectors applied in industrial and agricultural production, such as cobalt -60, cesium-137, iridium-192, etc.
Unsealed sources refer to radioactive substances without cladding, and radioactive tracers used in hospitals belong to unsealed sources, such as iodine-13 1, iodine-125, technetium -99m, etc.
The radiation emitted by radioactive sources has certain energy, which can destroy cell tissue and cause harm to human body. When people are exposed to a lot of radiation, they may have dizziness, fatigue, loss of appetite, nausea, vomiting and other symptoms. In severe cases, it may lead to physical injury or even death; However, when people receive only a small amount of radiation, there is generally no discomfort and no harm to the body.
In order to prevent or reduce the harm of radiation emitted by radioactive sources to human body, Su summarized the following three main protection methods: (1) distance protection: the farther away from radioactive sources, the less radiation you contact and the less damage you suffer. 2) Shielding protection: Select appropriate shielding materials (such as concrete, iron or lead) to make shielding bodies to block the radiation emitted by radioactive sources. (3) Time protection: minimize the contact time with radioactive sources. In practical work, the above three protective measures are usually used in combination.