Radiation Shielding Requirements
The basic shielding requirements for radiation protection depend on several factors. The type of radiation encountered, length of exposure, and distance from the source of radiation are all important in determining the correct shielding requirements.
Type of Radiation
Different types of radiation are emitted with different levels of energy behind them. The greater the energy of the radiation, the greater the level of shielding required to safely shield against it.
Alpha radiation (α) is very weak and requires little shielding-the outermost layer of human skin is actually enough to protect against it. Beta radiation (β) requires more protection, such as heavy clothing. Certain beta radiation particles can penetrate and burn the skin. Gamma radiation (γ) and x-ray radiation are considerably stronger and require thick, dense shielding, such as lead.
Obviously, the longer the time spent near a source of radiation, the greater the level of exposure. Even the briefest direct exposure to gamma and x-ray radiation can be extremely hazardous, and unprotected exposure to any sort of radiation for any length of time should be avoided. Extended indirect exposure to radiation (e.g. an x-ray technician who is in a separate, but nearby, room from the x-ray source for several hours a day) also requires shielding to keep personnel safe.
The longer one must be exposed-directly or indirectly-to radiation, the greater the level of shielding required. For medical and dental patients, for example, the length of direct exposure to x-rays is very brief, therefore a lead vest is sufficient for safe shielding. However, because an x-ray technician is indirectly exposed to radiation for extended periods, stronger, more substantial shielding is necessary.
Distance from Source
The greater the distance from a source of radiation, the lower the level of exposure. Doubling the distance from the source reduces the level of exposure by a factor of four (i.e. at ten feet from the source, radiation exposure will be 1/4 the level present at five feet). Therefore, the closer to the source of radiation one must be, the more protection is required.
Minimum safe distances are affected by the type of radiation encountered-alpha and beta particles lack the energy to travel far, while gamma radiation is powerful enough to travel long distances.
Contact RPP for all your radiation shielding requirements.