Nuclear radiation, or commonly called radioactivity, exists in all substances, that is, the water you drink and the air I breathe. This is an objective fact that has existed for billions of years and is a normal phenomenon. So we are not discussing whether there is radioactivity, but discussing what substances in daily life, under certain conditions, have high or high radioactivity and are sufficient to cause harm to people.

Nuclear radiation mainly consists of three types of α, β, and γ:

Alpha rays are helium nuclei and β rays are electrons. Due to their small penetration force, these two rays have relatively close impacts. As long as the radiation source does not enter the body, the impact will not be too great.

The penetration power of γ rays is very strong, and it is an electromagnetic wave with a very short wavelength. Electromagnetic waves are very common radiation, and their impact on the human body is mainly determined by power (related to field strength) and frequency. Radio waves used for communication are electromagnetic waves with low frequency. If arranged in order according to the frequency from low to high (wavelength from long to short), electromagnetic waves can be divided into: long wave, medium wave, short wave, ultra-short wave, microwave, far infrared, infrared, visible light, ultraviolet, X-ray, and γ rays. Based on visible light, electromagnetic waves with a frequency lower than (wavelength longer than) visible light mainly produce thermal effects on the human body, and rays with a frequency higher than visible light mainly produce chemical effects on the human body.

Although indoor ornaments are small in size and weight, they are "pets" and are closely close to people. Their radioactivity can sometimes hurt people:

Gems include precious diamonds (diamonds), rubies, sapphires, emeralds and cat's eyes, as well as ordinary gem crystals, agate and garnets. After testing, no high radioactivity of this type of gem has been found. For example, crystals are quartz crystals, which have very low radioactivity and are not high in agate.

Jade, including jade and nephrite, as well as a variety of minerals and rocks used for arts and crafts carving, such as Xiuyan jade in Liaoning and Hetian jade in Xinjiang, "Guangpan" in Guangdong, "Qingtian jade carving" in Zhejiang, "Colored jade carving" in Tianjin and "Timble stone carving" in Hubei, etc. Among them, marble and similar marble, white marble, northeast red, northeast green, Qu pattern jade, peach red, moxa green, Quyang jade, etc., their products are all metamorphic from limestone, and their radioactivity is very low.

"Night Pearl" is reported to be processed by first, after partial barium in barite is replaced by radium and processed, it can emit light at night and has strong radioactivity; second, it is processed by fluorite, which can show fluorescence under heating or ultraviolet rays, and after irradiation by uranium, it can have varying degrees of radioactivity; third, it is processed by certain phosphorus-containing substances, generally radioactivity; fourth, it is processed by certain materials; fifth, it is made by irradiation. Whether the "Night Pearl" has an injuring radioactivity depends on the radioactivity safety certificate, and second, it must be measured by actual measurement and measured by international or national standards.

[Edit this section] 1. What is nuclear radiation?

Nuclear radiation is a flow of microscopic particles released by the atomic nucleus from a structure or energy state to another structure or energy state. Nuclear radiation can cause ionization or excitation of matter, so it is called ionizing radiation. Ionizing radiation is divided into direct ionizing radiation and indirect ionizing radiation. Direct ionizing radiation includes charged particles such as curtains, protons, etc. Indirect ionizing radiation includes photons (Minmengyaoyao rays), neutrons and other uncharged particles.

[Edit this section] 2. What are the commonly used radiation amounts and units?

Conversion relationship between old and new units of physical quantity

Activity Curie (Ci) Becole [Ler] (Bq) 1Ci = 3.7×1010Bq

Irradiation amount roentgen (R) Coulomb/kg (C/kg) 1R=2.58×10-4C/kg

Absorbent dose rad (rad)Gy (Gy)1Gy = 100rad

Dose equivalent rem (rem) ｎｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈｅｔｈ

[Edit this section] 3. How much does natural radioactivity contribute to public dosage?

There are three main sources of natural radiation: cosmic rays, terrestrial radiation sources and radioactive substances in the body. According to relevant data statistics, the average annual dosage value of the public caused by natural radiation is listed in the table below.

Annual effective dose of irradiation components (milli-sig)

Areas where the exposure volume increases in normal background areas

Cosmic rays 0.382.0

Yusheng Radionuclide 0.010.01

Land radiation: external radiation 0.464.3

Land radiation: internal radiation (except radon) 0.230.6

Land radiation: internal irradiation of radon and its decays

Inhalation 222Rn1.210

Inhalation 220Rn0.070.1

Ingestion 222Rn0.0050.1

total

2.4

[Edit this section] 4. How much does artificial radiation source contribute to public dosage?

Artificial radiation sources include radioactive diagnostic and radiotherapy radiation sources, radioactive drugs, radioactive waste, falling dust from nuclear weapons explosions, and irradiation from nuclear reactors and accelerators. According to relevant data records, the average annual dose value generated by artificial radiation sources to the public is listed in the table below.

Radiation source dose (milli-sig/year)

Radiation Diagnosis 0.22

Radiation therapy 0.03

Medical isotope 0.002

Radioactive waste 0.002

Nuclear explosion dropped 0.01

Occupational exposure 0.009

Other radiation sources 0.012

0.001~0.02 around the nuclear power plant

[Edit this section] 5. What is radiation protection?

Radiation protection is an applied discipline that studies the protection of humans (referring to all humans, some or individual members and their offspring) from or less affected by radiation. Sometimes it also refers to requirements, measures, means and methods used to protect humans from or as little as possible to avoid radiation hazards. Radiation includes ionizing radiation and non-ionizing radiation. In the nuclear field, radiation protection specifically refers to ionizing radiation protection.

[Edit this section] 6. What are the three principles of radiation protection?

The three principles of radiation protection refer to the legitimacy of practice, the optimization of protection level and the dosage limit for individuals receiving illumination.

Basic principles of radiation protection:

1. The legitimacy of practice;

2. Dosage limits and potential exposure risk limits;

3. Optimization of protection and safety;

4. Dosage constraints and potential exposure hazard constraints.

[Edit this section] 7. What are the main dose limits for international basic safety standards?

Dosage limit 5-year average (milli-sc/year) or one-year value (milli-sc/year)

Occupational Irradiation 2050

Public exposure 15

Note: The standards that my country will issue are equivalent to the international basic safety standards.

Occupational irradiation dose limit: The occupational irradiation level of any staff member should be controlled so that it must not exceed the following limits: 1) the annual average effective dose for 5 consecutive years determined by the regulatory authorities, 20mSv; 2) the effective dose in any year, 50mSv; 3) the annual equivalent dose of eye crystals, 150mSv; 4) the annual equivalent dose of limbs (hands and feet) or skin, 500mSv.

Public irradiation dose limit: Practice makes the average dose estimate received by members of the critical population in the public not exceed the following limits: 1) annual effective dose, 1mSv; 2) In special circumstances, if the annual average dose for 5 consecutive years does not exceed 1mSv/a, the effective dose for a single year can be increased to 5mSv; 3) annual equivalent dose of eye crystals, 15mSv; 4) annual equivalent dose of skin, 50mSv.

Potential irradiation: The purpose of setting dose limits is to limit the harm of real irradiation. However, the probability and level of potential irradiation are difficult to determine, and the optimization results should be used to determine its probability and level of occurrence.

[Edit this section]8. What is external irradiation? What are three methods of external irradiation protection?

The radiation source of external radiation on the human body is called external irradiation. The protection method of external irradiation is controlled by the irradiation time, increasing the distance with the radiation source and using three methods: shielding.

[Edit this section] 9. What is internal irradiation? The basic principles of controlling internal irradiation
Chapter completed!