(1) Protection against external exposure:

Three methods of time, distance, and shielding.

<1>Time protection-shorten the exposure time: shortening the exposure time is a simple and effective protection measure. For this reason, all unnecessary stays in the radiation field should be avoided. Even if the work requires, the stay time in the radiation field should be shortened as much as possible.

<2> Distance protection-increase the distance from the radiation source: the dose rate of the human body is close to and inversely proportional to the square of the distance. In other words, if the distance is doubled, the dose rate is reduced to 1/4 of the original. It is very necessary that there is sufficient distance between the operator and the radiation source. To

<3> Shielding protection-setting up a protective barrier between the person and the source: In radiation protection, it is impossible to shorten the exposure time and increase the distance from the source without limitation. Then the use of barrier protection is a practical and effective protection measure. Use lead plates, steel plates or cement walls to shield to ensure safety.

(2) Protection of body exposure:

The ways that radioactive substances enter the body are: diet, respiration, skin absorption, and wound invasion. Therefore, the protection methods for internal exposure are to avoid ingestion, reduce inhalation, increase excretion, and avoid staying in contaminated areas. In addition, it is necessary to strengthen the site decontamination work to reduce the chance of personnel contamination.