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What is nuclear radiation?
Nuclear radiation, also known as radiation, exists in all substances. Nuclear radiation is mainly caused by α、β、γ Three types of radiation composition. α Radiation is a helium nucleus, and its ability to penetrate through external radiation is weak. It can be blocked with just a piece of paper, but inhaling it into the body can cause greater harm. β Radiation is an electron flow that causes significant burns on the skin after irradiation. These two types of rays have relatively small penetration power and have a relatively close impact distance, γ Radiation has a strong penetrating power and is a type of electromagnetic wave with a very short wavelength.
Nuclear radiation exists in all substances, which has been an objective fact for billions of years and is a normal phenomenon. Many human activities are inseparable from open radiation, such as the radiation dose of air, food, and water that people consume, which is about 0.25mSv/year. Wearing a luminous watch produces 0.02mSv per year; Traveling 2000 kilometers by plane, approximately 0.01mSv; Smoking 20 cigarettes a day, with an annual intake of 0.5-1mSv; One X-ray examination at 0.1mSv, etc.
Safety standards for human nuclear radiation levels
The safety standards for human nuclear radiation levels are divided into dose limits for radiation workers and individual dose limits for the public. In clinical practice, there are clear regulations on the annual dose limits for radiation workers and the public, which must be strictly followed by any organization or individual. Nuclear radiation, X-ray radiation, and γ Like X-rays, they all belong to ionizing radiation.
1. Dose limits for radiation workers: The annual equivalent dose for radiation workers refers to the sum of the dose equivalent of external exposure received during one year of work and the cumulative equivalent produced by the intake of radioactive isotopes within that year, but does not include natural background exposure and medical exposure. The effective dose in any year should be 50mSv, the annual equivalent dose for the eye lens should be 150mSv, and the annual equivalent dose for the limbs (hands or feet) or skin should be 500mSv, The average effective dose for 5 consecutive years should be 20mSv/year;
2. Individual dose limits for the public: The annual effective dose for individual individuals should be 1mSv. In special circumstances, when the average annual dose for five consecutive years does not exceed 1mSv, the annual effective dose can be 5mSv, the annual equivalent dose for intraocular lenses should be 15mSv, and the annual equivalent dose for skin should be 50mSv.
Recently, the international community has been increasingly concerned about the discharge of nuclear contaminated water and various topics related to nuclear safety. Although nuclear contaminated water has been treated, its discharge still contains radioactive isotopes such as tritium, strontium-90, cesium-137, cobalt-60, and carbon-14.
Nuclear radiation is difficult to perceive through conventional methods, so professional detection equipment is needed to confirm the presence of radiation.
The hazards of nuclear radiation?
The harm of nuclear radiation to humans and organisms is related to the dose of nuclear radiation, the time people are exposed to nuclear radiation, and the half-life of nuclear substances. Mild exposure to radiation can cause physical discomfort such as dizziness, fatigue, and decreased appetite. As the radiation dose increases, it can lead to damage to the patient's hematopoietic function and gastrointestinal diseases. If severe nuclear radiation occurs, it can lead to lung cancer, thyroid cancer Malignant tumors such as breast cancer and bone cancer can cause immediate death in serious cases.
Nuclear radiation detector
The nuclear wastewater incident in Japan has recently attracted public attention, and at the same time, a large number of detection instruments claiming to be able to accurately detect nuclear radiation have emerged on the market, with a wide variety of categories and low prices, leading to a surge in sales on major platforms. But in reality, most of these instruments use Geiger tubes. Although they are simple to use and responsive, they can only detect the presence or absence of radiation, but cannot detect the type, intensity, and dosage of radiation. Many detection devices even have huge detection errors, causing panic among consumers who have recently purchased a large number of detection devices, claiming to have paid intelligence taxes.
In response to the recent hot issues that have attracted widespread attention, the registered and safety engineers of Shanghai Proton Heavy Ion Hospital have provided professional suggestions:
"Different types of radiation can be measured, but accurately reflecting dose levels is questionable. Each device has different detection effects for different types of radiation, and the detection methods for different objects are also different. Therefore, using a single radiation detector to measure different types of radiation is not scientific and rigorous enough. Self testing at home is generally not accurate enough, and it requires sampling to the laboratory for professional testing according to national standards."
In addition, for many nuclear facility environmental protection departments, as well as areas with high radiation risks such as nuclear industry radiation protection, public security border defense, and industrial and mining enterprises, there is an urgent need to equip precision radiation monitoring instruments. It is required that the measurement range, energy response, dose response linearity, response time, and units of instrument readings of nuclear radiation detectors can meet strict requirements.
Nuclear Radiation Detector:
Pioneer in Radiation Measurement Technology, Real time Monitoring Concerns Safety at Every Second
SIGAS provides the German GRAETZ radiation detector, which adopts international advanced detection technology and uses a multifunctional microprocessor, significantly improving the sensitivity and accuracy of monitoring radioactivity, and meeting the strict requirements of radiation detection in various hazardous scenarios. Since its establishment in 1949, GRAETZ has been committed to designing and manufacturing portable, battery powered dose rate measurement and alarm devices for measurement and detection α,β and γ Radiation personal radiation protection dosimeters and alarm devices, as well as fixed indoor monitoring equipment.
Product scope: German GRAETZ radiation dose rate instrument, GRAETZ personal dose alarm instrument, GRAETZ dosimeter, GRAETZ surface contamination instrument, GRAETZ probe
Main models: ED150, GPD150G, ABG170, X5C plus, X5CEx, CoMo 170, CoMo 170 F, GTw S+ABG
Selection of nuclear radiation detectors
Performance which affects nuclear radiation detectors
1. Measurement range, which is one of the important indicators affecting the detection device. Different devices have their own range, such as 0.01-1500 μ Sv/h, 0.01~100mSv/h, 50 nSv/h~10Sv/h.
2. Energy response: The smaller the lower limit of energy response and the wider the range of energy response of radiation protection detection device, the better, and the wider the range suitable for detecting radiation.
3. Dose response linearity, this parameter is one of the important indicators to measure the quality of the device. Within its measurement range, the better the linear relationship between the measured dose values from small to large, the more reliable the data measured by the device.
4. Stability,In some radiation sites, due to the randomness of radioactive material decay, the device's indication exhibits statistical fluctuations within a certain range. To ensure the accuracy and traceability of the test results, the testing device should be regularly verified or calibrated by the metrological verification department. In daily use, relevant quality control procedures should be established, and periodic verification work should be carried out
5. There are differences in the units of instrument readings for different radiation dose detection instruments, such as exposure "Roentgen (R)", air specific release energy "Gy", and surrounding dose equivalent "Sv". These unit quantities are relatively large, and measuring devices usually use smaller units“ μ R“ μ Gy“ μ Sv displays the measured value.
6. Response time, the shorter the response time, the better. If the exposure time or beam exit time of the radiation field exceeds the response time, it can reflect relatively accurate data. If the response time of the instrument cannot be reached, the detection results should be corrected for time readings.
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