Radon gas
Radon and radon gas are natural products of the decay of radioactive materials on earth. They are slowly released from soil, rocks, cement and sand, colorless and tasteless, and their specific gravity is 7.5 times that of air. They are the only natural radioactive gases in nature. Decay into solid particles.
* About 20% of indoor radon comes from building materials. 80% outdoor infiltration.
* The radiation damage caused by radon accounts for > 55% of all radiation damage in life,
The incubation period of lung cancer induced by radon is more than 15 years, and15 lung cancer in the world is related to radon. Radon is the second largest lung cancer factor after smoking, which is listed as one of the carcinogens of 19 by WHO. In the United States, 5000~20000 people suffer from lung cancer due to radon every year, accounting for 10~ 14% of the total lung cancer.
* Radon mixed with secondhand smoke is extremely harmful to health. In the same radon environment, smokers are more likely to develop lung cancer than non-smokers.
Radon has a high affinity for human fat, which affects the nervous system and makes people feel depressed and sleepy. Besides upper respiratory diseases and lung cancer, workers exposed to radon also have chronic nephritis, which is related to the transformation of radon into nephrotoxic radioactive uranium. Increase the probability of spontaneous abortion and deformed children in pregnant women.
Decay of uranium 238
* Radon will decay into other radioactive metal particles: polonium, lead 2 10 and bismuth, which are called daughters of daughter radon and are a series of daughter elements produced after radon decay.
* The decay time from radioactive radon to stable lead is about 25 years.
* Radon and its daughters can form radioactive gas gel in air at room temperature.
* Easy to be intercepted by the respiratory system and stay in the body. One cell in every 400 cells in the lung will mutate within one year due to the penetration of alpha particles, which is easy to cause genetic damage and form cancer. ?
* Natural stone has different radioactivity due to its origin, geological structure and generation age.
* Radioactive substances produced by decay, such as the content of degradable substances is too large, that is, the "specific activity" of radioactive substances is too high, which is harmful to human body.
* Igneous building materials (especially granite stones) contain radioactive elements, which are particularly easy to release radon.
* Radioactive radon may exist in Beitou Hot Spring Area, Guanggangyan Building Materials Building and Jinmen Granite Terrain in Taiwan Province Province.
* The building materials that release radon are brick sand, cement, stones, tiles and gypsum, and the typical radon in building materials is ~40Bq/kg.
Radiation dose unit
Radiation intensity of radioactive waste (radioactivity):
Curie: (Ci) is a unit of radioactivity. It is defined as the radioactivity released by one gram of radium. In memory of Julius and his wife. 1ci = 3.7×1010dps (transmutation/second), which is the radioactivity released by one gram of radium. Because its value is too large, it has been replaced by Bq.
* Baker: (Bq) international speCial activity unit, 1 Bq = 1 dps (metamorphosis/second), and replaced Curie (ci). 1975, ICRU, the International Committee of Radiation Units and Metrology, wrote to several journals, mentioning that ICRU's suggestion was adopted at the metrology conference: Baker is an international special activity unit.
* becquerel (1852- 1908) discovered radioactivity in 1896, and won the 1903 Nobel Prize in physics together with Julius and his wife * * *: the first Nobel Prize for studying radioactive substances.
Equivalent dose: it is the product of absorbed dose of human tissues and radiation factor, which already contains the significance of radiation damage to tissues and organs.
* 1 sievert = 100 rem. The annual dose of natural radiation received by each person in Taiwan Province Province is about 2 millisieverts, and the annual dose limit for professional workers is 50 millisieverts per year.
Radiation dose absorbed by the substance:
* 1 gregory ray (joule/kg) = 100 rad.
Radon gas
* Soil gas produced by soil and rock seeps into the room (radon in soil gas ~37 kBq/m3), and flows out from underground with wells and springs, or outdoor air seeps into the room (average atmospheric radon in the United States ~ 10 Bq/m3).
* If you live or work in poorly ventilated places such as the first floor, basement, tunnel and mine, radon will be higher than the ground atmosphere, especially in closed storerooms and storage cabinets. Room ... >>
Question 2: What are the common types of radioactive substances? What is the seventh radioactive substance?
CN № called UN №.
7 100 1 metallic thorium [pyrophoric]1886617
7 1002 metallic uranium [spontaneous combustion] 2979
7 1003 Thorium nitrate [solid] 2976
7 1004 uranyl nitrate [solid] 298 1
7 1005 uranyl nitrate hexahydrate solution 2980
71006 * * [fissionable, containing uranium -235 > 1.0%] 2977
7 1007 * *[ Special Fission or Non-Fission] 2978
7 1008 Radioactive Substances [Surface Contaminated Objects] 29 13
7 1009 Radioactive Material, Exception Package: 29 10
[instrument or clause]; 29 10
[* * * materials]; 29 10
[Natural uranium or depleted uranium or natural thorium products] 29 10
[Empty package] 29 10
710/0 radioactive substance [low specific activity, unnamed] low specific activity radioactive substance 29 12
7 10 1 1 radioactive material [fissionable, unnamed] 29 18
7 10 12 radioactive substance [special form, not listed]
Special forms of radioactive substances 2974
7 10 13 radioactive substance [unnamed] 2982
Question 3: What is the third-level radioactive material? Refers to substances with specific activity greater than 7.4× 104Bq/kg. According to its radioactivity, it can be divided into a class of radioactive substances, a class of radioactive substances and a class of radioactive substances. Such as metal uranium, * * *, metal thorium, etc.
Question 4: What are radioactive substances? Radioisotopes and irradiated metals and water
Question 5: What kind of solid material does radioactive material include? Liquid? Gas?
Gamma? Beta? Neutron?
Sealed? Open?
I don't know what you are asking.
Question 6: Definition of radioactive articles Generally speaking, radioactive articles refer to articles containing radionuclides, and the total radioactive content and unit mass radioactive content in the articles both exceed the inspection-free limit. At present, the exemption value stipulated by the state refers to the basic limit value of radionuclides in table 1 in the National Standard Provisions for Safe Transportation of Radioactive Materials (GB1kloc-0/806-2004).
Question 7: What are radioactive substances? Radioactive elements, nuclear medicine, nuclear power plant materials, uranium