A nuclear accident is a serious deviation from the operating conditions of a nuclear facility or activity. In such a situation, an unacceptable level of radioactive material may be released if the associated specialized safety facilities fail to function as designed.
2. How far is it safe to evacuate?
Under normal circumstances, the first priority is to limit the occurrence of radiation exposure. The effects of radioactive smoke cloud deposition are minimized primarily by evacuating or concealing the affected population. Depending on the amount of radioactive material released into the atmosphere and the prevailing meteorological conditions (e.g., wind direction, precipitation, etc.), and based on the extent of the center of the explosion, the State will determine the radius within which emergency sheltering measures should be taken.
3. How can I protect myself?
First of all, avoid panic, listen to the radio or watch television, and follow government instructions. Stay indoors in situations where radioactive contamination may be present. Take iodine tablets according to the government's instructions. Only the government can decide whether iodine tablets are needed after assessing the state of the accident. They should not be taken solely on the basis of personal subjectivity or out of fear.
4. What is the reason for feeling scared after a nuclear accident, even if I have not been exposed to radiation?
Any accident, whether or not there has been or has not been actual radiation exposure, is associated with mental fatigue and anxiety. This is attributed to people's self-perception of health risks, and it depends in part on whether people believe that the authorities are competent and trustworthy, and that prompt and effective action has been taken to control the radiation dose. At the same time medical practitioners should provide the necessary psychological counseling for their work to relieve the state of psychological panic.
5. How should the public control their emotions and maintain a good state of mind during and after an emergency?
Nuclear and radiation-related emergencies are prone to cause people's fear. The first step is to implement the principle of prevention. For the victims who have been psychologically shocked, some methods that have a calming effect on the heart can be used to relieve the mental tension. Some of the affected persons may exhibit certain undesirable behaviors, others may show inhibition, withdrawal, passivity and negative characteristics, and there may be others who show signs of disorientation. These situations require that the psychologist must adopt a psychotherapeutic approach that is tailored to the specific situation of the patient. The patient's family and those involved should promptly arrange psychotherapy for those with these manifestations.
6. Who should receive help in mental health?
After a disaster, mental health assistance should be provided to those who develop psychological difficulties. In general, survivors who have been directly involved in a large-scale disaster or who have suffered bereavement or property damage are potential disaster victims who need timely psychological assistance; individuals and families with whom they have close ties should also be considered; those who are engaged in rescue or search work, or those who are members of the reconstruction or rehabilitation efforts and volunteers should also be taken into account; and those who have a high level of vulnerability to disaster scenarios may also show signs of psychopathology and need help. help.
7. What does "hidden" mean?
It means that people stay in or go indoors with doors, windows, and ventilation systems closed to minimize inhalation and external exposure to radioactive material in the plume (fallout) and to minimize external exposure from radioactive deposits.
8. What does "evacuation" mean?
It refers to the emergency relocation of people from an affected area to avoid or minimize large-dose exposures from the plume or high levels of radioactive deposits. The measure is short-term and people are expected to be able to return to their original place of residence within a certain limited period of time.
9. How far can a smoke cloud float after a nuclear accident?
This is difficult to predict. It depends on wind speed and other meteorological conditions.
10.How much radiation dose will the released radioactive material cause and what are its adverse health effects?
Depending on the total amount of radioactive material released, the dose to the public may be in the range of low or even very low levels. The world background dose of natural radiation per capita is 2.4mSv/year, with regional differences resulting in values that can vary from one region to another, for example, up to 200mSv in some parts of Iran and India. Health effects such as acute radiation sickness only occur when the whole-body exposure dose is greater than 1Gy. However, for radioactive fallout released in nuclear power plant accidents, it is unlikely that such a high dose of irradiation would occur after a large cloud of radioactive smoke has been transported over long distances.
11. What are the early protective measures?
Early refers to the occurrence of nuclear and radiation emergencies within 1 to 2 days after the occurrence of the protective measures that can be used for personnel are: concealment, respiratory protection, taking stable iodine, evacuation, control of import and export access. Respiratory protection is the action of covering the nose with a dry or wet towel, which prevents or reduces inhalation of radionuclides. Taking stabilized iodine prevents or reduces the deposition of radioactive iodine in the smoke plume in the thyroid gland after it enters the body.
12. What are the interim protective measures?
In the mid-incident phase, a significant amount of radioactive material has been deposited on the ground. At this point, early protective measures can be continued for individuals, except that discontinuation of respiratory protection may be considered. In order to avoid excessive cumulative doses from prolonged stays, the competent authorities may take the form of controlled and planned relocation of the population from the contaminated area to the outside. Restrictions on the sale and consumption of locally produced or stored food and drinking water should also be considered. According to the characteristics of the exposure pathway for personnel in this period, protective measures can also be taken: the use of stored feed in animal husbandry, decontamination of the body surface of personnel, and treatment of the sick and wounded.
13. What are the protective measures for tattooing?
The question at the late stage of an accident (recovery) is whether and when society can return to normal life or whether further protective measures are needed. In the late phase of an incident, the main exposure pathways are internal exposure due to ingestion of contaminated food and inhalation of resuspended material. Therefore, protective measures that can be taken include control of import and export access routes, avoidance of relocation, control of food and water, use of stored feed and decontamination of areas.
14. What should the public do in the event of a nuclear and radiation emergency?
In the event of a nuclear and radiological emergency, the first thing the public must do is to obtain as much credible information as possible about the emergency, and to be aware of decisions and notifications made by governmental authorities. Information communication with local governments should be maintained through various means, and it is important not to believe rumors or gossipy information. The second thing to do is to quickly take the necessary protective measures to protect yourself. For example, you can choose the nearest building for concealment, you should close the doors and windows and turn off the ventilation equipment. Evacuate in an organized and orderly manner according to the arrangements of the local government. When a radioactive dispersal event is judged to have occurred, it is important not to face the wind or run with the wind, but to try to hide to the side of the wind and quickly enter a building to take cover. Take respiratory protection, including covering the mouth and nose with a wet towel or piece of cloth to filter out radioactive particles. If radioactive contamination of body surfaces is suspected, use bathing and changing clothes to minimize radioactive contamination. Prevent ingestion of contaminated food or water.
In the event of a nuclear and radiological terrorist incident, the public should take special care to keep their minds calm and never panic.
15. What are the circumstances for taking sheltering measures? What should the public be aware of?
Concealment is one of the main protective measures in the early and middle stages of an emergency in which a relatively large amount of radioactive material is released into the atmosphere. Most buildings can reduce the inhalation dose to people inside the building by about half.
After a period of sheltering and the passage of the plume, the concentration of radionuclides in the air within the shelter rises, and ventilation is necessary to reduce the airborne concentration of radioactivity to a level equivalent to that of a cleaner outdoor area. Consequently, sheltering is less effective protection against a sustained release. The duration of concealment is generally considered to be no more than 2 days.
16. When are personal protective measures required? What should the public be aware of?
Some personal protective measures are needed when the air is contaminated with radioactive material. Covering the mouth and nose with handkerchiefs, towels, cloths, etc. can reduce the dose due to inhalation of radioactive material by about 90%. Body surface protection can be provided by a variety of everyday clothing, including hats, bandanas, raincoats, gloves and boots.
Decontaminating personnel who have been or are suspected of having been contaminated by radioactivity on their body surfaces is as simple as telling the personnel concerned to shower with water and to remove and store contaminated clothing, shoes, hats, etc., until there is time to monitor or treat them at a later date. It is important to prevent the spread of radioactive contamination to uncontaminated areas.
17. What does the term "iodine protection" mean?
When an accident has caused or is likely to cause the release of radioactive isotopes of iodine, compounds containing non-radioactive iodine are distributed to residents as a protective medicine to reduce the dose to the thyroid gland. 18. Under what circumstances is stabilized iodine taken?
After a nuclear and radiation emergency, it is possible for a person to ingest radioactive iodine and concentrate it in the thyroid gland, exposing this organ to a larger dose of irradiation; at this time, taking stabilized iodine can reduce the absorption of radioactive iodine by the thyroid gland. If stable iodine is taken at the same time as radioactive iodine inhalation, 90% of the radioactive iodine deposition in the thyroid can be blocked. Taking stabilized iodine within a few hours of inhaling radioactive iodine still reduces the amount of radioactive iodine absorbed by the thyroid by about half. The recommended dosage for adults is 100 milligrams of iodine, for pregnant women and children 3 to 12 years of age, 50 milligrams, and for children under 3 years of age, 25 milligrams.
19. What should I be aware of when taking stabilized iodine?
For newborns within the first month of life, the amount of stabilized iodine taken should be kept to the lowest effective level. Stabilized iodine should be used with caution or not used in some people, such as those with nodules in the thyroid gland, those who have been cured of goiter, those who have received radioactive iodine therapy, those with chronic inflammatory diseases of the thyroid gland, those who have had unilateral removal of the thyroid gland, those who have subclinical hypothyroidism, those who are allergic to iodine, and those who have certain skin diseases (acne, eczema, and psoriasis).
20. Can iodine tablets (KI) protect against radiation? How does it protect against radiation? How much should I take?
Physiologically, the main source of iodine in the human body is the uptake by the thyroid gland, which relies on iodine for the production of thyroid hormones. ki is a stable iodine, which saturates the iodine in the thyroid gland and thus prevents the intake of radioactive iodine.
The Chernobyl experience has shown that radioactive iodine was a major factor in the impact of the Chernobyl accident, which resulted in over 5,000 cases of thyroid cancer in children, with all of the irradiated population being between the ages of 0 and 18. Therefore, the primary targets for potassium iodide distribution are young children and pregnant women.
Iodine tablets do not protect against radioactivity from outside the body and radioactivity absorbed by the body other than iodine. This is why iodine thyroid blockade will be used in combination with other protective measures (e.g., staying concealed indoors, closing doors and windows, etc.) in most settings.
Exposure to radioactive iodine can lead to a significant increase in thyroid cancer, especially in young children. Inhaled and ingested radioactive iodine accumulates in the thyroid gland. Prophylactic administration of potassium iodide prior to exposure prevents uptake of radioactive iodine by the thyroid and reduces the long-term risk of thyroid cancer.
To take full advantage of the iodine-blocking effect of stable iodine on the iodine thyroid, stabilized iodine tablets need to be taken before or as soon as possible after exposure. Even a few hours after the accident, the uptake of 50% iodine by the thyroid gland can still be blocked by taking them. To prevent inhalation of radioiodine isotopes, a single tablet dose of stabilized iodine is usually sufficient, which provides continuous protection for 24 hours and adequate protection of the thyroid gland in the event of an incoming smoke cloud containing radioiodine isotopes. However, in a prolonged sustained-release situation, there is a risk of repeated exposure.
Once again, potassium iodide provides the best protection only if taken before exposure to radioactive iodine.
21. When should food and water be controlled?
When the concentration of radionuclides in food and drinking water exceeds the levels specified by national standards the consumption or drinking of such contaminated food and drinking water should be prohibited or restricted. The national standard divides foods into two categories, those for general consumption and those for milk, baby food and drinking water; the concentration levels at which intervention is required are specified for each of the different nuclides.
22. What is radioactivity?
Radioactivity has been discovered for more than a hundred years. The earliest discovery of radioactivity was made by the French scientist Becquerel, who in 1896, while studying the fluorescence of uranium ore, discovered that uranium salts emitted penetrating radiation similar to X-rays. Two years later, the French physicist Madame Curie discovered polonium, another new element capable of emitting rays, from uranium ore, and four years later she discovered radium. Madame Curie suggested that the property of a substance to be able to emit rays spontaneously be called radioactivity. Nuclides that are radioactive are called radionuclides. Radionuclides that emit radiation will turn into new isotopes, which may be radioactive or stable, and the process is called radioactive decay.
23. Under normal circumstances, people are generally exposed to what kind of radiation?
The global average annual effective dose of individuals from natural radiation is about 2.4mSv, of which 0.4mSv is from cosmic rays, 0.5mSv is from terrestrial γ-rays, 1.2mSv is produced by inhalation (mainly indoor radon), and 0.3mSv by ingestion. it can be seen that radon is the most important source of irradiation.
24. What are some of the activities of the people that are also radioactive? Many activities of human beings are inseparable from radioactivity. For example, the radiation exposure dose from air, food and water ingested by people is about 0.25mSv/year. Wearing a luminous watch is 0.02mSv per year; traveling 2000km by plane is about 0.01mSv; smoking 20 cigarettes a day is 0.5-1mSv per year; an X-ray examination is 0.1mSv, and so on. People in the long-term practice and application found that a small amount of radiation exposure will not jeopardize human health, excessive exposure to radioactive rays on the human body will produce harm, make people sick, death. The larger the dose, the greater the harm.