1. Accidents at nuclear power plants. Medical and tactical characteristics of the zones of radioactive contamination

accident nuclear power plant radioactive

1.1 MTX of radioactive contamination zones

Nuclear power plants and other objects of the economy, in the event of accidents and destruction of which massive radiation damage to people, animals and plants can occur, are called radiation-hazardous objects (RHO). The release of radioactive substances outside the nuclear power reactor, as a result of which an increased radiation hazard can be created, which poses a threat to human life and health, is called a radiation accident.

Radiation-hazardous facilities, in case of accidents at which environmental pollution may occur, include: nuclear power plants, nuclear thermal power plants, ships with nuclear reactors, research reactors, laboratories and clinics that use radioactive substances in their work.

When forecasting the radiation situation, the scale of the accident, the type of reactor, the nature of its destruction and the nature of the release of radioactive substances from the core, as well as the weather conditions at the time of the release of radioactive substances, are taken into account.

Depending on the boundaries of the spread of radioactive substances and radiation consequences, the following are distinguished:

• local accidents (radiation consequences are limited to a building, structure with possible exposure of personnel);
• · local accidents (radiation consequences are limited to the territory of the nuclear power plant);
• · general accidents (radiation consequences extend beyond the territory of the nuclear power plant).

In the first hours and days after the accident, the effect on people of environmental pollution is determined by external exposure from the radioactive cloud (fission products of nuclear fuel mixed with air), radioactive fallout on the ground (fission products falling out of the radioactive cloud), internal exposure due to inhalation of radioactive substances from the cloud, as well as due to contamination of the surface of the human body with these substances. In the future, for many years, the accumulation of radiation dose will occur due to the consumption of contaminated food and water.

An important feature of the accidental release of radioactive substances is that they are fine particles that have the property of tightly adhering to the surfaces of objects, especially metal ones, as well as the ability to be sorbed by clothing and human skin, to penetrate into the ducts of the sweat and sebaceous glands. This reduces the effectiveness of decontamination (removal of radioactive substances) and sanitization (measures to eliminate contamination from the surface of the human body).

The size of the areas of contamination of the area depends on the category of atmospheric stability and the output of activity - the release of radioactive substances from the reactor core, depending on the scale of the accident.

According to the category of stability, the atmosphere is subdivided into a highly unstable conversion (A), neutral isotherm (D), and a very stable inversion (D). In the daytime, unstable, by evening, neutral stability of the atmosphere prevails. During the night and early morning hours, an inversion of a very stable state of the atmosphere prevails.

With a one-time release of radioactive substances from an emergency reactor and a stable wind, the movement of the radioactive cloud occurs in one direction. In this case, the trace of the radioactive cloud has the form of an ellipse.

The exposure dose to people in the early phase of the accident is formed due to gamma and beta radiation PB contained in the cloud, as well as due to inhalation of radioactive products contained in the cloud into the body. This phase continues from the start of the accident until the end of the release of nuclear fission products (NFP) into the atmosphere and the end of the formation of a radioactive trace on the ground.

In the middle phase, the source of external exposure is radioactive substances that have fallen out of the cloud and are on the soil, buildings, etc. They enter the body mainly with contaminated food and water. The middle phase lasts from the moment the formation of the radioactive trace is completed until all measures are taken to protect the population. The duration of this phase can be from several days to a year after the accident.

The late phase lasts until the termination of the implementation of protective measures and the abolition of all restrictions on the activities of the population in the contaminated area.

In this phase, the usual sanitary and dosimetric control of the radiation situation is carried out, and the sources of external and internal exposure are the same as in the middle phase.

In order to exclude massive radiation losses and overexposure of the population, workers and employees in excess of the established doses, their actions in conditions of radioactive contamination are strictly regulated and subject to the radiation protection regime.

Radiation protection regimes are the procedure for people to act, the use of means and methods of protection in zones of radioactive contamination, providing for the maximum reduction in possible radiation doses. Compliance with radiation protection regimes excludes radiation injuries and exposure of people in excess of the established radiation doses:

• for wartime;
• single irradiation during the first 4 days 50 rad;
• multiple irradiation for 30 days 100 rad"
• · repeated irradiation within 3 months 200 rad;
• repeated exposure during the year no more than 300 rad;
• · in peacetime 10 glad during the year.

The regime of radiation protection of the population includes three main stages:

• 1. Shelter of the population in an anti-radiation shelter (PRS).
• 2. Subsequent shelter of the population in houses and PRU.
• 3. Accommodation of the population in houses with limited stay in open areas for 1 - 2 hours a day. The same regime applies to hospital patients.

The radiation protection regime for workers and employees includes three main stages:

• 1. Duration of facility shutdown National economy(time of continuous stay of people in the PRU).
• 2. The duration of the operation of the facility with the use of protective structures for recreation.
• 3. Duration of operation of the facility with limited stay of workers and employees in open areas.

Radiation protection regimes are designed taking into account the duration of each shift 1 - 12 hours.

The decision to protect the public from radioactive exposure is made on the basis of the following criteria:

• · in the early phase of the accident, dose criteria (dose predicted for the first 10 days);
• · in the middle phase of the development of the accident dose criteria (dose predicted for the first year).

The modes of workers and employees at the facilities are put into effect by the decision of the NGOs of the facilities. On the territory of a settlement or an object of the national economy, the regime is selected:

• on the maximum level of radiation;
• · By the smallest value coefficient of attenuation of the protective structure.

The duration of compliance with the RRZ and the time of termination of its action are established by the head of the civil defense of the settlement (facility), taking into account the specific radiation situation.

Depending on the current radiation situation, the following measures are taken to protect the population:

• Limiting the stay of the population in open areas by temporary shelter in shelters and houses with sealing of residential and office premises for the time of dispersion of RS in the air4
• prevention of the accumulation of radioactive iodine in the thyroid gland - iodine prophylaxis (ingestion of stable iodine preparations: potassium iodide, 5% iodine tincture);
• · evacuation of the population at high radiation dose rates and impossibility to fulfill the appropriate radiation protection regime;
• exclusion or restriction of food intake;
• Sanitary treatment followed by dosimetric control;
• · the simplest processing of superficially contaminated food products (washing, removal of the surface layer);
• Respiratory protection with improvised means (towels, handkerchiefs, etc.), better moistened;
• · transfer of agricultural animals to uncontaminated pastures or fodder - decontamination of contaminated areas;
• Observance by the population of the rules of personal hygiene:
• § limit the time spent in open areas;
• § wash shoes and shake out clothes before entering the premises;
• § do not drink water from open water sources and do not swim in them;
• § do not eat or smoke;
• § do not pick fruits, berries, mushrooms in the contaminated area, etc.

Timely implementation of anti-radiation measures can minimize the number of exposed persons. In cases where protective measures are not carried out in full, population losses will be determined by:

• · the magnitude, duration and isotopic composition of the accidental release of nuclear weapons;
• · meteorological conditions (wind speed and direction, precipitation, etc.) at the time of the accident and during the formation of a radioactive trace on the ground, the distance from the emergency facility to the place of residence of the population;
• · population density in zones of radioactive contamination;
• The protective properties of buildings, structures, residential buildings and other places of shelter for people, etc.

Early effects of irradiation - acute radiation sickness, local radiation injuries (radiation burns of the skin and mucous membranes) are most likely in people who are near the emergency facility. The possibility of combined lesions of this group of the population, due to accompanying accidents of fires and explosions, is not excluded.

Acute radiation injuries among the population are possible from the outer boundary of the hazardous contamination zone (zone "B").

Acute or chronic exposure of the population in low doses (less than 0.5 Sv.) can lead to long-term effects of exposure. These include: cataracts, premature aging, malignant tumors, genetic defects. The probability of occurrence of oncological and genetic consequences exists at arbitrarily low doses of radiation. These effects are called stochastic (probable, random). The severity of stochastic effects does not depend on the dose, only the probability of their occurrence increases with increasing dose. Harmful effects for which there is a threshold dose and the severity increases with its increase are called non-stochastic (radiation cataract, impaired reproductive function, etc.).

A special position is occupied by the consequences of irradiation of the fetus - embryotoxic effects. The fetus is especially sensitive to radiation at 4-12 weeks of gestation.

Acute radiation sickness

It is possible to develop several main clinical variants of acute radiation injuries in humans - acute radiation sickness (ARS), local radiation injuries (LRI) and combined radiation injuries (CRI).

The dependence of the severity of radiation injury on the dose of total exposure determines great importance dosimetric information as a diagnostic indicator. Information about the magnitude of the radiation dose can be obtained by:

• Dose measurements on the body surface (individual dosimetry);
• Dose measurement for a group of people who were in similar conditions (group dosimetry);
• · calculation based on data on the duration of people's stay in the area with certain levels of radiation (radiation dose rate), measured at the beginning of exposure, periodically during it and at the end of the period of radiation exposure, i.e. when leaving the contaminated area.

Acute radiation sickness is a nosological form that develops with external gamma and gamma neutron irradiation at a dose exceeding 1 gray (Gy) (1 Gy \u003d 100 rad), received at once or within a short period of time (from 3 to 10 days) , as well as upon ingestion of radionuclides that create an adequate absorbed dose.

ARS from uniform irradiation is a typical clinical variant of radiation injury under the action of gamma-neutron radiation from air nuclear explosion, as well as gamma irradiation while in the area contaminated with products of a nuclear explosion. For irradiation in the source of an explosion in an open area and at a relative distance from the source of radiation and in the territory of the trace of a radioactive cloud, a relatively uniform effect of ionizing radiation is characteristic, the dose difference at which for different parts of the body does not exceed 2.5 - 3 times.

Uneven exposure is created by increasing the proportion of neutrons in the total dose or by shielding individual parts of the body.

Clinical manifestations of ARS are the final stage in a complex chain of processes that begin with the interaction of ionizing radiation energy with cells, tissues and body fluids.

The primary effect of radiation is realized in physical, physicochemical and chemical processes with the formation of reactive free radicals (H+, OH-, water), which have high oxidizing and reducing properties. Subsequently, various peroxide compounds (hydrogen peroxide, etc.) are formed. Oxidizing radicals and peroxides inhibit the activity of some enzymes and increase others. As a result, secondary radiobiological effects occur at various levels of biological integration.

Violations of the physiological regeneration of cells and tissues, as well as changes in the function of regulatory systems, are of primary importance in the development of radiation injuries. Great sensitivity to the action of ionizing radiation of hematopoietic tissue, intestinal epithelium and skin, spermatogenic epithelium has been proven. Less radiosensitive muscle and bone tissue. High radiosensitivity in physiological terms, but relatively low radiosensitivity in anatomical terms, are characteristic of nervous system.

The discrepancy between the amount of the absorbed dose and the magnitude of the biological effect can be explained by taking into account violations of the regulatory functions of the central and autonomic nervous systems, and not only by the direct, direct effect of radiation on tissues and organs. Morphological changes in various systems and organs, most pronounced during the height of the disease, are mainly dystrophic and destructive.

Various clinical forms of ARS are characterized by certain leading pathogenetic mechanisms of the formation of the pathological process and their corresponding clinical syndromes.

In the dose range from 1 to 10 Gy, the bone marrow form of ARS develops with a predominant hematopoietic lesion of varying severity. With an extremely severe lesion (dose from 6 to 10 Gy), in the clinical picture, along with deep inhibition of hematopoiesis, characteristic intestinal lesions occur, in connection with which some researchers designate this pathology as a transitional from bone marrow to intestinal form.

Bone marrow form

The bone marrow syndrome in this form of ARS is the leading one, which largely determines the pathogenesis, clinic and outcome of the disease.

Infectious complications and hemorrhagic syndrome are mainly a characteristic consequence of agranulocytosis and thrombocytopenia.

Of particular importance in assessing the primary reaction belongs to the blood parameters in the first 3 days: relative and absolute lymphocytopenia is a reliable quantitative indicator for assessing the severity of radiation injury and predicting the course of the disease in subsequent periods.

The clinical manifestations of the primary reaction period are not only the result of direct damage to radiosensitive systems (lymphocytopenia, cell division delay, a decrease in the number or disappearance of young forms of hematopoietic cells), but also indicate early violations of the neuro-regulatory and humoral mechanisms (dyspeptic, general clinical, vascular disorders) .

latent period

After a period of initial reaction, there is a relative improvement in the condition. Vomiting, nausea stops, hyperemia of the skin and mucous membranes decreases, sleep and appetite normalize, general well-being improves. Objective clinical symptoms are expressed unsharply. The instability of the pulse and blood pressure, the lability of autonomic regulation, moderate general asthenia are revealed, although changes in hematopoiesis continue to progress. The duration of the latent period depends on the severity of ARS: 1 tbsp. - up to 3 days, 2 tbsp. -- 15 - 28 days, 3 tbsp. -- 8 - 15 days, 4 tbsp. - may not be or less than 6 - 8 days.

The greatest attention in the latent period should be given to the dynamics of hematological parameters - the timing and severity of cytopenia.

Cytopenia is caused by the disappearance of cells circulating in the blood at the time of irradiation with increasing damage to the growth elements of the hematopoietic organs and the cessation of the entry of maturing cells into the peripheral blood. The decisive prognostic value is the level of lymphocytes on the 3rd - 6th day and granulocytes on the 8th - 9th day. In extremely severe patients, the absolute number of lymphocytes in the first 3-6 days is 0.1 x 109 / l, granulocytes - less than 0.5 x 109 / l on the 8th day after irradiation, platelets - less than 50 x 109 / l l.

During this period, epilation occurs. The threshold absorbed radiation dose causing epilation is close to 2.5 - 3 Gy. The most radiosensitive hairy cover on the head, chin, to a lesser extent - on the chest, abdomen, pubis, limbs. Epilation of eyelashes and eyebrows is observed when irradiated with a dose of 6 Gy or more.

The peak period of the disease

Progressive damage to bone marrow hematopoiesis reaches significant and extreme degrees. Deep cytopenia to severe agranulocytosis (the number of granulocytes is less than 1 x 109/l) forms the basis of immunity disorders with a subsequent decrease in the protective properties of the body and the formation of infectious complications of exogenous and endogenous nature.

Trophic disorders of tissues and especially skin, mucous membranes of the intestine and oral cavity lead to an increase in the permeability of physiological barriers, the entry of toxic products and microbes into the blood, the development of toxemia, bacteremia, and sepsis. Anemia develops. Complications are of a mixed infectious-toxic nature. Thrombocytopenia and increased vascular permeability lead to the development of hemorrhagic syndrome.

The timing of the peak period and its duration depend on the severity of ARS:

• 1 tbsp. comes on the 30th day, lasts 10 days;
• 2 tbsp. comes on the 20th, lasts 15 days;
• 3 tbsp. comes on the 10th, lasts 30 days;
• 4 tbsp. occurs on the 4th - 8th day, on the 3rd - 6th week death occurs.

The clinical transition from latency to the peak period occurs abruptly (except for a mild degree). The state of health worsens, appetite decreases, weakness increases, the temperature rises. The pulse becomes more frequent, which is labile with a change in body position, slight physical exertion. BP goes down. Myocardial dystrophy is formed (muffled heart sounds, expansion of its size, changes in the ventricular complex on the ECG). Infectious-toxic complications acquire a vivid clinical picture: at 2 tbsp. there are changes in the nasal cavity, mouth, pharynx and larynx (stomatitis, laryngitis, pharyngitis, tonsillitis). At 3 - 4 tbsp. ulcerative-necrotic lesions of the mucous membranes of the digestive tract and upper respiratory tract are possible, which makes it possible to identify the corresponding syndromes: oral, oropharyngeal, intestinal. With deep agranulocytosis, severe pneumonia and the development of sepsis are possible. Hemorrhagic complications are manifested by hemorrhages, bleeding. Bone marrow at 4 tbsp. appears to be completely empty.

Recovery period

There is a phase of immediate (immediate) recovery, ending within 2 to 4 months from the moment of irradiation, respectively, with a mild, moderate and severe degree, and a recovery phase lasting from several months to 1 - 3 years. During these periods, the main functions are restored, and more serious defects acquire a certain resistance; the main reparative processes are practically completed and possible compensatory processes are being realized.

The beginning of the immediate recovery phase occurs at the time of the patient's exit from agranulocytosis.

More severe forms of ARS (intestinal, toxemic, cerebral) in humans are not well understood.

intestinal form

The primary reaction develops in the first minutes, lasts 3-4 days. Multiple vomiting appears in the first 15 to 30 minutes. Characterized by abdominal pain, chills, fever, arterial hypotension. Often on the first day there is loose stools, later enteritis and dynamic intestinal obstruction are possible. In the first 4-7 days, the oropharyngeal syndrome is pronounced in the form of ulcerative stomatitis, necrosis of the oral mucosa and pharynx. From 5 to 8 days, the condition deteriorates sharply: high body temperature, severe enteritis, dehydration, general intoxication, infectious complications, bleeding. Lethal outcome on the 8th - 16th day.

Histological examination of the dead on the 10th - 16th day shows a complete loss of the intestinal epithelium, due to the cessation of physiological cell regeneration. The main cause of mortality is due to early radiation damage to the small intestine (intestinal syndrome).

Toxemic form

The primary reaction is noted from the first minutes, a short-term loss of consciousness and a violation of motor activity are possible. Severe hemodynamic disturbances develop with pronounced arterial hypotension and a collaptoid state. Intoxication is clearly manifested due to deep metabolic disorders and the breakdown of intestinal tissues, mucous membranes, and skin. Kidney function is impaired, which manifests itself in oliguria. Lethal outcome occurs on the 4th - 7th day.

cerebral form

According to the features of the clinical picture, it is designated as acute or lightning-fast radiation sickness. It is characterized by a half-lapse with loss of consciousness and a sharp drop in blood pressure. The clinical picture can be described as a shock-like reaction with severe hypotension, signs of cerebral edema, and anuria. Vomiting and diarrhea are debilitating. The following syndromes of this form are distinguished:

• Convulsive-paralytic;
• Amentative-hypokinetic;
• dyscirculatory with a violation of the central regulation of a number of functions due to damage to the nerve centers.

Lethal outcome occurs in the first 3 days, sometimes in the first hours.

Radiation exposure in doses of 250 - 300 Gy and more causes the death of experimental animals at the time of exposure. This form of radiation damage is referred to as "death under the beam."

Local radiation defeat

Along with long-term external gamma irradiation of people in the zone of fallout of nuclear explosion products, contact beta irradiation of predominantly open areas of the body is possible as a result of contact with the skin of radioactive explosion products. The ratio of doses as a result of external irradiation of the whole body and local (limited areas) can be such that the occurrence of skin lesions from beta radiation (a dose of more than 25 Gy) is real in the absence or weak severity of general clinical manifestations of radiation sickness from external gamma irradiation (dose less than 0 .5 Gy).

The development of local lesions from the effects of gamma and gamma neutron radiation during a nuclear explosion is possible only in rare cases. Significant protection of a large part of the body ensures survival even if unprotected areas are overexposed. Localization of damage is determined by the geometry of irradiation - the immediate proximity of any part of the body or limb to the source of radiation.

An eye burn is accompanied by complete, but usually short-term blindness. Rarely, inflammation of the superficial media of the eyes develops.

Scope of medical care for radiation injuries

First medical help

First medical aid (self-help and mutual aid) for radiation injuries provides for the elimination or weakening initial signs radiation sickness. For this purpose, the personnel of the Armed Forces, immediately after the explosion, to prevent the primary reaction, take from the first-aid kit an individual antiemetic - RSD or etaperazine (one tablet).

The population is instructed to take prophylactic antiemetics from the MSGO headquarters, the first aid unit.

If there is a danger of further exposure (in case of radioactive contamination of the area), a radioprotective agent is taken - cystamine - 6 tablets once.

After leaving the zone of radioactive contamination, partial sanitization is carried out.

Pre-hospital medical help

Pre-hospital medical care has as its task the elimination or weakening of the initial signs of radiation sickness and the adoption of measures to eliminate manifestations that threaten the life of the affected.

It provides:

• · with nausea and vomiting: repeatedly 1 - 2 tablets of dimetcarb or etaperazine;
• In case of cardiovascular insufficiency: 1 ml of cordiamine subcutaneously, 1 ml of 20% sodium caffeine benzoate s.c.;
• · with psychomotor agitation and reactions of fear: 1 - 2 tablets of fenozepam, oxylidine or phenibut;
• If necessary, further stay in the area with high level radiation (in the zone of infection): repeatedly (4 - 6 hours after the first dose) 4 - 6 tablets of cystamine;
• In case of infection of open areas of the skin and uniforms with products of a nuclear explosion: partial sanitization after leaving the zone of radioactive contamination.

First medical help

First aid is aimed at eliminating severe manifestations of radiation sickness and preparing the injured for further evacuation.

It provides:

• In case of infection of the skin and uniforms with products of a nuclear explosion (above the permissible level): partial sanitization, with nausea and vomiting: 1 - 2 tablets of dimetcarb or etaperazine; in case of persistent intractable vomiting 1 ml of 0.1% atropine sulfate s / c;
• With severe dehydration: intravenous isotonic sodium chloride solution, drink plenty of fluids;
• in case of cardiovascular insufficiency: 1 ml of cordiamine s / c, 1 ml of 20% sodium caffeine benzoate s / c or 1 ml of 1% mezaton in / m;
• · with convulsions: 1 ml of 3% phenazepam or 5% barbamil i/m;
• In case of upset stool, pain in the abdomen: 2 tablets of sulfadimethoxine, 1 - 2 tablets of besalol or fthalazole (1 - 2 g);
• · with severe manifestations of bleeding: inside 100 ml of 5% aminocaproic acid, vitamins C and P, 1 - 2 tablets of diphenhydramine.

Patients with ARS of the 1st degree after relief of the primary reaction are returned to the units; in the presence of manifestations of the height of the disease, they are sent to omedb (or omo) or specialized hospitals of the MSGO hospital base.

qualified medical help

Qualified medical care is aimed at eliminating severe, life-threatening manifestations of radiation sickness, combating its various complications and preparing the affected for further evacuation.

It provides:

• In case of infection of the skin and uniforms with products of a nuclear explosion (in excess of the permissible level): complete sanitization;
• With persistent vomiting: 1 ml of 2.5% chlorpromazine diluted in 5 ml of 0.5% novocaine, intramuscularly, or 1 ml of 0.1% atropine sulfate s / c; in case of severe dehydration - intravenous drip of isotonic sodium chloride solution (up to 3 l), hemodez (300 - 500 ml), reopoliglyukin (500 - 1000 ml);
• in acute vascular insufficiency: 1 ml of 1% mezaton / m or norepinephrine hydrotartrate (in / in drip, on glucose per 1 liter of 5% glucose 2 - 4 ml of 0.2% norepinephrine, 20 - 60 drops per minute, under the control of blood pressure);
• In case of heart failure: 1 ml of 0.06% corglicon in 20 ml of 20% glucose IV or 0.5 ml of 0.05% strophanthin in 10-20 ml of 20% glucose IV (inject slowly);
• When excited: phenazepam 0.5 - 1 mg 3 times a day, oxylidine 0.02 3 - 4 times a day or phenibut 0.5 3 times a day;
• with a decrease in the number of leukocytes to 1 x 109 / l: inside antibiotics (ampicillin or oxacillin 0.25 - 0.5 every 4 - 6 hours, rifampicin 0.3 2 times a day or tetracycline 0.2 3 - 5 times per day) or sulfanilamide preparations (sulfadimethoxine 1 g 4 times a day, sulfadimesin 1 g 4 times a day); if possible, carry out other preventive measures (isolation of patients, oral care, reduction of various infections);
• With the development of infectious complications: broad-spectrum antibiotics in high doses (ampicillin 6 g or more per day, rifampicin up to 1.2 g per day, tetracycline up to 2 g per day); in the absence of these drugs, penicillin is used (5-10 million units per day) with streptomycin sulfate (1 g per day);
• With bleeding: 5 - 10 ml of 1% amben IV, up to 100 ml of 5% aminocaproic acid IV, local hemostatic sponge, thrombin;
• With toxemia: 200 - 400 ml of 5% glucose intravenously once, up to 3 liters of isotonic sodium chloride solution intravenously, up to 3 liters of Ringer's solution - Locke intravenously, 300 - 500 ml of hemodez or 500 - 1000 ml reopoliglyukina in/in drip;
• With the threat and development of cerebral edema: intravenous infusion of 15% mannitol (at the rate of 0.5 - 1.5 g of dry matter per 1 kg of body weight), 10% sodium chloride (10 - 20 ml once) or 25% magnesium sulfate (10 - 20 ml, slowly!).

Specialized medical help

The task of specialized medical care is to treat the victims in full, to finally eliminate the main manifestations of radiation sickness and its complications, and to create conditions for the fastest recovery of combat capability and working capacity.

It provides:

• In case of infection of the skin and uniforms with products of a nuclear explosion above the permissible level: complete sanitization;
• · with clinical manifestations of the primary reaction: antiemetic inside;
• In case of indomitable vomiting: parenteral antiemetics, isotonic sodium chloride solution, gemodez, reopoliglyukin, glucose;
• in acute cardiovascular insufficiency: mezaton, norepinephrine, cardiac glycosides;
• in case of dehydration: reopoliglyukin, hemodez, glucose, isotonic sodium chloride solution (if necessary, in combination with diuretics);
• With anxiety, fear, painful phenomena: sedatives and painkillers;
• In the latent period of ARS: multivitamins, antihistamines, sedatives;
• in anticipation of agranulocytosis and possible infectious complications: sulfonamides and antibiotics, the creation of aseptic conditions for the maintenance of patients;
• With the development of infectious complications: broad-spectrum antibiotics at maximum therapeutic doses;
• · with symptoms of cystitis and pyelonephritis: nitrofuran preparations;
• With a decrease in immuno-biological reactivity: the introduction of a leukosuspension, freshly prepared blood, direct blood transfusions;
• in case of bleeding: fibrinolysin inhibitors, as well as replacement therapy;
• In case of severe anemia: transfusion of erythrocyte suspension, freshly prepared blood, direct transfusions;
• With toxemia: hemodez, reopoliglyukin, isotonic sodium chloride solution, glucose;
• With the threat and development of cerebral edema: osmodiuretics;
• With the appearance of gastrointestinal disorders: sulfonamides, besalol, electrolytes, in severe cases - parenteral nutrition.

For the treatment of initial radiation erythema, lotions or wet-drying dressings with anti-inflammatory drugs, corticosteroid ointments, novocaine blockades are applied topically.

In severe cases, bone marrow transplantation is possible.

The public should remember the following regarding radiation protection: radiation background due to introduced radioactive substances, which can spread mainly with dust, therefore, the following recommendations should be followed:

• · When working outdoors, be in outerwear and a hat, in case of strong dust-forming wind, use a cotton-gauze bandage.
• · Swimming in open water, staying on the beaches for some time is excluded.
• · It is undesirable to be in the rain and snow without an umbrella, to hide from the rain under a tree, to lie on the grass.
• Wells should be equipped with canopies and a blind area, tightly closed with lids so that dust does not get into them.
• Do not pick flowers, berries, mushrooms, etc.
• · When entering the premises, thoroughly wipe shoes on a richly dampened rug, thoroughly clean outer clothing with a vacuum cleaner, leave shoes and outerwear in the hallway, do not walk outside in slippers.
• · All premises must be cleaned daily with detergents.
• · It is better to ventilate the premises before going to bed, in calm weather, after rain or with subsequent wet cleaning of the premises.
• Before eating and drinking, rinse your mouth well with water, take water through your nose and blow your nose several times, wash your hands thoroughly.
• ・Meals must be nutritious.
• · Cooking: soak the meat in small pieces for 1 - 2.5 hours, then boil in water without salt until half cooked, drain the water and then cook until tender. It is advisable to exclude lettuce, sorrel and spinach. Rinse vegetables and fruits thoroughly under running water. Purchase food at a place where dosimetric testing is carried out.
• · Take pets for walks only on leashes, and upon returning from walks, wipe them thoroughly with a damp cloth and wash their paws.

Instructions for use of stabilized potassium iodide tablets

Potassium iodide tablets are effective in reducing the accumulation of radioactive iodine in the human thyroid gland. When drinking milk from cows and goats grazing on pastures contaminated with radioactive products, taking potassium iodide tablets reduces the thyroid dose by 50-60 times. The protective efficacy of a single dose of potassium iodide lasts one day. With the systematic consumption of foods contaminated with radioactive iodine, potassium-iodine tablets are used daily.

Way applications And doses

Starting from the moment of fallout of radioactive fission products, daily potassium iodide tablets are taken orally once a day on an empty stomach for 10 days in doses:

• adults and children over 5 years old - 0.25 gr.;
• children from 2 to 5 years old - 0.125 gr.;
• Children from 3 months to 2 years - 0.040 gr.;
• · for children who are breastfed, the amount of iodine that will come with the mother's milk, who has taken 0.25 g. potassium iodide.

However, before the first feeding of an infant of any age, he must be given 0.02 g. potassium iodide in the form of a solution (sweet boiled water).

To avoid irritation gastrointestinal tract the tablet must be taken with jelly, sweet tea, etc. For children, crush the tablet, dissolve in a small amount of jelly, tea. After taking it, be sure to give it to drink with jelly or sweet tea.

A variant of conclusions and suggestions from the assessment of the situation in the event of radioactive contamination is proposed.

Variant of conclusions and proposals from the assessment of the situation in the event of radioactive contamination

Due to the accident at ____________________ NPP as of ____ hour "___" __________ 199__.

The most difficult radioactive situation has developed in

___________________________________ ________________________,

where the dose of internal exposure to children exceeds _____rem,

adult population_______rem.

Radiation levels at _______ hour. after the fallout of RV are:

• - in _____________________________________________________ mr/h
• - in _____________________________________________________ mr/h

The population in these ______________________________________________________________

is __________ thousand. people, including children ___________ thousand. people

In this situation, I suggest:

1. Immediately inform the population that enters the infection zones and bring recommendations for its protection.

By _____ hour. "___" ____________ 199__ evacuate people,

caught in the zone ______________________________

from___________________________________________________________

to the districts _________________________________________________________

Residents of settlements ____________________________________

_____________________________________________________________

hide in ___________________________________________________________

with Kosl. =_______________,

population_____________________________________________________

in houses with Kosl. ______________.

2. From ______ hour. "____" _____________ 199__ start conducting radiation reconnaissance by the forces of ______________________________________

To identify the radiation situation

to ________________________________________________________________ attract __________________________________________________________

• 3. To establish the regimes of radiation protection of the population: in ________________________________________________________________N______ in ________________________________________________________________N______
• 4. From ______ hour. "____" ____________ 199__ by the forces of ____________________________________ _________________ to control the RH of food, milk, water, plants, weapons.
• 5. By ______ hour. "____" ____________ 199__ carry out dosimetric control of people, farm animals, equipment that have fallen into the contaminated zones to determine the amount of work on special treatment.
• 6. Sanitary treatment ______ thousand. people spend up to _____ hours. "___" ___________ 199__, why use SOPs _____________________________________________.

To decontaminate clothing, use COO _____________________________________________, and COTT technicians _______________________________________________________________

7. In order to reduce losses among the population, it is necessary until _____ hour "___" ____________ 199__. carry out urgent iodine prophylaxis, first of all __________________________________________________________

Children from settlements ________________________________________________________________________________________ who received internal doses of more than ____________ rem on the thyroid gland should be sent for inpatient examination to specialized medical institutions

7a. To carry out iodine prophylaxis, use the stocks of stable iodine available in pharmacies _____________________, in the central pharmacy warehouse, as well as _______________________________

Distribute the stocks of stable iodine _____________________________________________________________

7b. Head physicians ____________________________________________________________ to take strict control over the packaging and distribution of stable iodine preparations.

Packaging should be carried out by employees of pharmacies, as well as sanitary teams

• 8. By the forces of the PLO service by ______ hour. "____" ______________ 199__ block roads and restrict access to contaminated areas
• 9. To decontaminate streets and roads __________________________________________________________________________________________ use __________________________

Carry out work in shifts, while _______________________________________________________________

On March 11, 2011, Japan was hit by an earthquake measuring 9.0 on the Richter scale, resulting in a devastating tsunami. In one of the most affected regions was the Fukushima Daiichi nuclear power plant, where, 2 days after the earthquake, an explosion occurred. This accident was called the largest since the explosion on Chernobyl nuclear power plant in 1986.

In this issue, we take a look back at 11 of the biggest nuclear accidents and disasters in recent history.

(Total 11 photos)

1. Chernobyl, Ukraine (1986)

On April 26, 1986, the reactor at the Chernobyl nuclear power plant in Ukraine exploded, resulting in the worst radiation pollution in history. A radiation cloud hit the atmosphere 400 times more than during the bombing of Hiroshima. The cloud passed over the western part Soviet Union, and also affected Eastern, Northern and Western Europe.
Fifty people died in the reactor explosion, but the number of people who got in the way of the radioactive cloud remains unknown. The report of the World Atomic Association (http://world-nuclear.org/info/chernobyl/inf07.html) mentions more than a million people who may have been exposed to radiation. However, it is unlikely that it will ever be possible to establish the full scale of the catastrophe.
Photo: Laski Diffusion | Getty Images

2. Tokaimura, Japan (1999)

Until March 2011, the most serious incident in Japanese history was the Tokaimura uranium accident on September 30, 1999. Three workers tried to mix nitric acid and uranium to obtain to obtain uranyl nitrate. However, unknowingly, the workers took seven times the allowed amount of uranium, and the reactor did not keep the solution from reaching critical mass.
Three workers received strong gamma and neutron radiation, from which, subsequently, two of them died. 70 other workers also received high doses of radiation. After investigating the incident, the IAEA reported that "human error and a serious disregard for safety principles" were the cause of the incident.
Photo: AP

3. Accident at the nuclear power plant Three Mile Island, Pennsylvania

On March 28, 1979, the largest accident in US history occurred at the Three Mile Island nuclear power plant in Pennsylvania. The cooling system did not work, which caused a partial meltdown of the nuclear fuel elements of the reactor, however, a complete meltdown was avoided, and the disaster did not occur. However, despite the favorable outcome and the fact that more than three decades have passed, the incident still remains in the memory of those who were present.

The consequences of this incident for the American nuclear industry were colossal. The accident caused many Americans to reconsider their views on the use of atomic energy, and the construction of new reactors, which has been constantly increasing since the 1960s, has slowed significantly. In just 4 years, more than 50 plans for the construction of nuclear power plants were canceled, and from 1980 to 1998, many ongoing projects were canceled.

4. Goiania, Brazil (1987)

One of the worst cases of radiation contamination of the area happened in the city of Goiania in Brazil. The Institute of Radiotherapy moved, leaving the radiotherapy unit in the old building, which still contained cesium chloride.

On September 13, 1987, two looters found the unit, removed it from the hospital grounds, and sold it to a landfill. The landfill owner invited relatives and friends to look at the glowing blue substance. All of them then dispersed around the city and began to infect their friends and relatives with radiation.

The total number of infected people was 245, and four of them died. According to Eliana Amaral from the IAEA, this tragedy had a positive consequence: “Before the incident in 1987, no one knew that radiation sources had to be monitored from the moment they were created and then until they were disposed of, and also to prevent any contact with the civilian population. This case contributed to the emergence of such considerations.

5. K-19, Atlantic Ocean (1961)

On July 4, 1961, the Soviet submarine K-19 was in the North Atlantic Ocean when a reactor leak was noticed on it. There was no reactor cooling system and, having no other options, the team members entered the reactor compartment and repaired the leak with their own hands, exposing themselves to doses of radiation incompatible with life. All eight crew members who fixed the reactor leak died within 3 weeks of the accident.

The rest of the crew, the boat itself and ballistic missiles on it were also subjected to radiation contamination. When K-19 rendezvoused with the boat that received their distress call, it was towed back to base. Then, during the repair, which lasted 2 years, the surrounding area was contaminated, and the workers of the dock were also exposed to radiation. In the next few years, another 20 crew members died from radiation sickness.

6. Kyshtym, Russia (1957)

Tanks for radioactive waste were stored at the Mayak chemical plant near the city of Kyshtym, and as a result of a malfunction in the cooling system, an explosion occurred, due to which about 500 km of the surrounding area were exposed to radiation contamination.

Initially, the Soviet government did not disclose the details of the incident, but a week later they were left with no choice. 10,000 people were evacuated from areas where symptoms of radiation sickness had already begun to appear. Although the USSR refused to divulge details, the journal Radiation and Environmental Biophysics estimates that at least 200 people died from radiation. The Soviet government finally declassified all information about the accident in 1990.

7. Windscale, England (1957)

On October 10, 1957, Windscale became the site of the worst nuclear accident in British history and the worst in the world until the Three Mile Island accident 22 years later. The Windscale complex was built to produce plutonium, but when the US built the tritium atomic bomb, the complex was converted to produce tritium for Britain. However, this required the reactor to operate at higher temperatures than those for which it was originally designed. The result was a fire.

At first, the operators were reluctant to extinguish the reactor with water because of the threat of an explosion, but eventually gave up and flooded it. The fire was extinguished, but a huge amount of water contaminated with radiation fell into environment. Studies in 2007 showed that this release led to more than 200 cases of cancer in the surrounding area.

Photo: George Freston | Hulton Archive | Getty Images

8. SL-1, Idaho (1961)

Stationary Low Power Reactor Number 1, or SL-1, was located in the desert 65 km from the town of Idaho Falls, Idaho. On January 3, 1961, the reactor exploded, killing 3 workers and causing the fuel elements to melt. The reason was an incorrectly removed reactor power control rod, but even 2 years of investigation did not give an idea about the actions of the personnel before the accident.

Although the reactor released radioactive materials into the atmosphere, they were few and its remote location minimized the damage to the population. Yet, this incident is notable for being the only fatal nuclear reactor accident in US history. Also, the incident led to an improvement in the design of nuclear reactors, and now one rod for regulating the power of the reactor will not be able to cause such damage.
Photo: United States Department of Energy

9. North Star Bay, Greenland (1968)

On January 21, 1968, a US Air Force B-52 bomber flew as part of Operation Chrome Dome, a Cold War-era operation in which US nuclear-capable bombers were in the air all the time, ready to strike targets in the Soviet Union. Combat bomber with four hydrogen bombs caught fire. The next emergency landing could have been made at Thule Air Base in Greenland, but there was no time to land, and the team left the burning plane.

When the bomber fell, the nuclear warheads detonated, which caused the contamination of the area. In the March issue Time magazine in 2009 it was said to be one of the worst nuclear disasters of all time. The incident prompted the immediate shutdown of the Chrome Dome program and the development of more stable explosives.
Photo: U.S. air force

10 Jaslovske Bohunice, Czechoslovakia (1977)

The nuclear power plant in Bohunice was the very first in Czechoslovakia. The reactor was an experimental design to run on uranium mined in Czechoslovakia. Despite this, the first of its kind complex had many accidents, and it had to close more than 30 times.

Two workers died in 1976, but the worst accident occurred on February 22, 1977, when one of the workers, during a routine fuel change, incorrectly removed the reactor power control rod. This simple mistake caused a massive reactor leak and, as a result, the incident earned a level 4 on the International Nuclear Event Scale from 1 to 7.

The Soviet government covered up the incident, so no casualties are known. However, in 1979 the government of socialist Czechoslovakia decommissioned the station. It is expected to be dismantled by 2033.
Photo: www.chv-praha.cz

11. Yucca Flat, Nevada (1970)

Yucca Flat is an hour from Las Vegas and is one of Nevada's nuclear test sites. December 18, 1970 at the detonation of 10 kilotons atomic bomb, buried at a depth of 275 meters underground, the plate holding the explosion from the surface cracked, and a column of radioactive fallout rose into the air, as a result of which 86 people who took part in the tests were irradiated.

In addition to the fact that the radiation fallout fell in the district, they were also carried to the north of Nevada, to the states of Idaho and California, as well as to the eastern parts of the states of Oregon and Washington. It also seems that the precipitation was carried to the Atlantic Ocean, Canada and Gulf of Mexico. In 1974, two specialists who were present at the explosion died of leukemia.

Photo: National Nuclear Security Administration / Nevada Site Office

The very first major radiation accidents in history occurred during the development of nuclear materials for the first atomic bombs.

September 1, 1944 In the United States, Tennessee, at the Oak Ridge National Laboratory, while trying to clean a pipe in a laboratory uranium enrichment device, an explosion of uranium hexafluoride occurred, which led to the formation of a dangerous substance - hydrofluoric acid. Five people who were at that time in the laboratory suffered from acid burns and inhalation of a mixture of radioactive and acid fumes. Two of them died and the rest were seriously injured.

In the USSR, the first severe radiation accident occurred June 19, 1948, the very next day after the release of the nuclear reactor for the production of weapons-grade plutonium (object "A" of the Mayak plant in Chelyabinsk region) to design capacity. As a result of insufficient cooling of several uranium blocks, they locally fused with the surrounding graphite, the so-called "goat". For nine days, the “goaty” canal was cleared by manual reaming. During the liquidation of the accident, all the male personnel of the reactor, as well as the soldiers of the construction battalions involved in the liquidation of the accident, were exposed to radiation.

March 3, 1949 in the Chelyabinsk region, as a result of the mass discharge of high-level liquid radioactive waste by the Mayak plant into the Techa River, about 124 thousand people were exposed to radiation in 41 settlements. The highest radiation dose was received by 28,100 people living in coastal settlements along the Techa River (average individual dose - 210 mSv). Some of them had cases of chronic radiation sickness.

December 12, 1952 In Canada, the world's first serious accident occurred at a nuclear power plant. A technical error by the personnel of the Chalk River NPP (Ontario) led to overheating and partial melting of the core. Thousands of curies of fission products fell into external environment, and about 3800 cubic meters radioactive contaminated water was dumped directly on the ground, in shallow trenches near the Ottawa River.

November 29, 1955"human factor" led to the accident of the American experimental reactor EBR-1 (Idaho, USA). During the experiment with plutonium, as a result of incorrect actions of the operator, the reactor self-destructed, 40% of its core burned out.

September 29, 1957 there was an accident, called "Kyshtym". A container containing 20 million curies of radioactivity exploded in the Mayak radioactive waste storage facility in the Chelyabinsk region. Experts estimated the power of the explosion at 70-100 tons of TNT. The radioactive cloud from the explosion passed over the Chelyabinsk, Sverdlovsk and Tyumen regions, forming the so-called East Ural radioactive trace with an area of ​​over 20 thousand square meters. km. According to experts, in the first hours after the explosion, before evacuation from the industrial site of the plant, more than five thousand people were subjected to single exposure to 100 roentgens. Between 1957 and 1959, from 25,000 to 30,000 servicemen took part in the elimination of the consequences of the accident. IN Soviet time the crash was covered up.

October 10, 1957 in the UK at Windscale there was a major accident at one of the two reactors for the production of weapons-grade plutonium. Due to an error made during operation, the temperature of the fuel in the reactor rose sharply, and a fire broke out in the core, which lasted for 4 days. 150 technological channels were damaged, which resulted in the release of radionuclides. In total, about 11 tons of uranium burned down. Fallout has contaminated large areas of England and Ireland; the radioactive cloud reached Belgium, Denmark, Germany, Norway.

April 1967 there was another radiation incident in the Mayak Production Association. Lake Karachay, which Mayak used to dump liquid radioactive waste, became very shallow; at the same time, 2-3 hectares of the coastal strip and 2-3 hectares of the lake bottom were exposed. As a result of wind uplift bottom sediments radioactive dust of about 600 Ku of activity was carried out from the exposed areas of the bottom of the reservoir. The territory of 1,800 square kilometers, where about 40,000 people lived, was polluted.

In 1969 an accident occurred at an underground nuclear reactor in Luzens (Switzerland). The cave where the reactor was located, contaminated with radioactive emissions, had to be permanently walled up. In the same year, an accident occurred in France: a running reactor with a capacity of 500 MW exploded at the St. Lawrence nuclear power plant. It turned out that during the night shift, the operator inadvertently loaded the fuel channel incorrectly. As a result, some of the elements overheated and melted, and about 50 kg of liquid nuclear fuel leaked out.

January 18, 1970 a radiation disaster occurred at the Krasnoye Sormovo plant ( Nizhny Novgorod). During the construction of the nuclear submarine K 320, an unauthorized launch of the reactor occurred, which worked at exorbitant power for about 15 seconds. At the same time, radioactive contamination of the zone of the workshop in which the ship was built took place. There were about 1000 workers in the shop. Radioactive contamination of the area was avoided due to the closeness of the shop. On that day, many went home without receiving the necessary decontamination treatment and medical care. Six victims were taken to a Moscow hospital, three of them died a week later with a diagnosis of acute radiation sickness, and the rest were ordered not to disclose what had happened for 25 years. The main work to eliminate the accident continued until April 24, 1970. More than a thousand people took part in them. By January 2005, 380 of them were still alive.

seven o'clock fire March 22, 1975 at the Browns Ferry nuclear power plant in the United States (Alabama) cost $10 million. It all happened after a worker with a lit candle in his hand climbed to close up an air leak in a concrete wall. The fire was picked up by a draft and spread through a cable duct. The nuclear power plant was put out of action for a year.

The most serious incident in the US nuclear industry was the accident at the Tree Mile Island nuclear power plant in Pennsylvania, which occurred March 28, 1979. As a result of a series of failures in the operation of equipment and gross errors of operators at the second power unit of the nuclear power plant, 53% of the reactor core melted. Inert radioactive gases - xenon and iodine - were released into the atmosphere. In addition, 185 cubic meters of weakly radioactive water were dumped into the Sukuahana River. 200 thousand people were evacuated from the area exposed to radiation.

On the night of 25 to 26 April 1986 at the fourth block of the Chernobyl nuclear power plant (Ukraine), the largest nuclear accident in the world occurred, with partial destruction of the reactor core and the release of fission fragments outside the zone. According to experts, the accident occurred due to an attempt to make an experiment to remove additional energy during the operation of the main nuclear reactor. 190 tons of radioactive substances were released into the atmosphere. 8 out of 140 tons of radioactive fuel from the reactor ended up in the air. Other dangerous substances continued to leave the reactor as a result of the fire, which lasted almost two weeks. People in Chernobyl were exposed to 90 times more radiation than when the bomb fell on Hiroshima. As a result of the accident, radioactive contamination occurred within a radius of 30 km. An area of ​​160,000 square kilometers has been polluted. The northern part of Ukraine, Belarus and the west of Russia were affected. 19 Russian regions with a territory of almost 60,000 square kilometers and a population of 2.6 million people were subjected to radiation contamination.

September 30, 1999 the largest accident in the history of Japan's nuclear power industry. At the plant for the manufacture of fuel for nuclear power plants in the scientific city of Tokaimura (Ibaraki Prefecture), due to a mistake by the personnel, an uncontrolled chain reaction began, which lasted for 17 hours. 439 people were exposed to radiation, 119 of them received a dose exceeding the annual allowable level. Three workers received critical radiation doses. Two of them have died.

August 9, 2004 an accident occurred at the Mihama nuclear power plant, located 320 kilometers west of Tokyo on the island of Honshu. In the turbine of the third reactor, there was a powerful release of steam at a temperature of about 200 degrees Celsius. Nearby employees of the nuclear power plant received serious burns. At the time of the accident, there were about 200 people in the building where the third reactor is located. No leaks of radioactive materials were found as a result of the accident. Four people died and 18 were seriously injured. The accident became the most serious in terms of the number of victims at a nuclear power plant in Japan.

March 11, 2011 Japan was hit by the most powerful earthquake in the history of the country. As a result, a turbine was destroyed at the Onagawa nuclear power plant, a fire broke out, which was quickly eliminated. At the Fukushima-1 nuclear power plant, the situation is very serious - as a result of the shutdown of the cooling system, nuclear fuel melted in the reactor of block No. 1, a radiation leak was recorded outside the block, and evacuation was carried out in a 10-kilometer zone around the nuclear power plant. In the following days, hydrogen explosions occurred at power units 1, 3, 2 and 4, which was released during the steam-zirconium reaction in overheated reactors and was vented to the outside of the reactor containment to reduce pressure.

Characteristics of accidents at nuclear power plants

Radiation accident - loss of control of a source of ionizing radiation caused by a malfunction, damage to equipment, improper actions of employees (personnel), natural phenomena or other reasons that could lead or have led to exposure of people or radioactive contamination of the environment in excess of the established norms.

The main sources of environmental pollution with radioactive substances are manufacturing enterprises mining and processing raw materials containing radioactive substances, nuclear facilities (NW), radiochemical plants, research institutes and other facilities.

The most dangerous sources of ionizing radiation and radioactive contamination of the environment are accidents at nuclear facilities. Radiation accidents at nuclear facilities are understood as a violation of their safe operation, in which radioactive products and (or) ionizing radiation escaped beyond the boundaries provided for by the project for normal operation in quantities exceeding the established values. Radiation accidents are characterized by the initiating event, the nature of the course and radiation consequences.

In 1988, the International Atomic Energy Agency (IAEA) developed the International Nuclear Event Scale (INES, abbr. International Nuclear Event Scale). Already since 1990, this scale has been used for the purpose of uniform assessment of emergency cases related to the civil nuclear industry.

The scale is applicable to any event related to the transport, storage and use of radioactive materials and radiation sources and covers a wide range of practices, including radiography, the use of radiation sources in hospitals, in any civil nuclear installations, etc. It also includes the loss and theft of radiation sources and the discovery of orphan sources.

According to the INES scale, nuclear and radiological accidents and incidents are classified into 8 levels (Appendix 1):

Level 7. Major accident

Level 6

Level 5. Accident with wide consequences

Level 4. Accident with local consequences

Level 3. Serious incident

Level 2 Incident

Level 1. Abnormal situation

Level 0. Event below the scale.

Chronology of accidents and disasters at nuclear power plants

A complete chronology of events is described in an environmental blog post dated April 17, 2011. The world's first serious accident occurred on December 12, 1952 in Canada, Ontario, at the Chalk River nuclear power plant "NRX". A technical error of the personnel led to overheating and partial melting of the core. Thousands of curies of fission products were released into the environment, and about 3,800 cubic meters of radioactively contaminated water were dumped directly onto the ground, into shallow trenches near the Ottawa River.

Almost 14 years later, on October 5, 1966 in the United States at the Enrico Fermi nuclear power plant, an accident occurred in the cooling system of an experimental nuclear reactor, which caused a partial meltdown of the core. The staff managed to manually stop it. It took a year and a half to restart the reactor at full capacity.

Three years later, in France, on October 17, 1969, at the Saint Laurent nuclear power plant, when reloading fuel at an operating reactor, the operator mistakenly loaded into the fuel channel not a fuel assembly, but a device for controlling the flow of gases. As a result of the melting of five fuel elements, about 50 kilograms of molten fuel fell into the reactor vessel. There was a release of radioactive products into the environment. The reactor was shut down for one year.

On March 20, 1975, a fire broke out at the Brown Ferry nuclear power plant in the United States, which lasted 7 hours and caused direct material damage of 10 million dollars. Two reactor blocks were disabled for more than a year, which caused an additional $10 million in losses. The cause of the fire was non-compliance with safety measures during the work on sealing the cable glands that passed through the wall of the reactor hall. The verification of this work was carried out in the most primitive way; by the deflection of the flame of a burning stearin candle. As a result, the insulation materials of the cable holes ignited, and then the fire penetrated into the reactor room. It took a lot of effort to bring the reactor to a trouble-free mode and put out the fire.

On January 5, 1976, an refueling accident occurred at the Bohunice nuclear power plant in Czechoslovakia. With an extensive leak of "hot" radioactive gas, two station workers died. The emergency exit through which they could leave the scene of the emergency was blocked (to "prevent frequent cases of theft"). The population was not warned about the accidental release of radioactivity.

The largest accident in the history of US nuclear power occurred on March 28, 1979 at the Three Mile Island Nuclear Power Plant. As a result of a series of equipment failures and operator errors, 53 percent of the reactor core melted at the second power unit of the nuclear power plant. What happened was like a domino effect. First, the water pump failed. Then, due to the interrupted supply of cooling water, the uranium fuel melted and went beyond the shells of the fuel assemblies. The resulting radioactive mass destroyed most of the core and almost burned through the reactor vessel. If this happened, the consequences would be catastrophic. However, the station staff managed to restore the water supply and reduce the temperature. During the accident, about 70 percent of the radioactive fission products accumulated in the core passed into the primary coolant. The exposure dose rate inside the vessel, in which the reactor and the primary circuit system were enclosed, reached 80 R/h. There was a release into the atmosphere of an inert radioactive gas - xenon, as well as iodine. In addition, 185 cubic meters of weakly radioactive water were dumped into the Saskugana River. 200 thousand people were evacuated from the area exposed to radiation. The residents of Dauphin County, who lived near the nuclear power plant, suffered the most. Serious negative consequences had a two-day delay in the decision to evacuate children and pregnant women from the 10-kilometer zone around the nuclear power plant. Work on cleaning up the second power unit, which was almost completely destroyed as a result of the accident, took 12 years and cost $ 1 billion, which actually bankrupted the owner company.

On March 8, 1981, about 4,000 gallons of highly radioactive water leaked at the Tsugura Nuclear Power Plant in Japan through a crack in the bottom of the building where spent fuel assemblies were stored. 56 workers were subjected to radioactive exposure. A total of four such leaks occurred between January 10 and March 8, 1981. 278 NPP workers received increased exposure during emergency recovery operations.

On December 9, 1986, as a result of a break in the secondary pipeline at the Surry nuclear power plant in the United States, 120 cubic meters of superheated radioactive water and steam were released. Eight nuclear power plant workers fell under a boiling stream. Four of them died from their burns. The cause of the accident was the corrosion wear of the pipeline, which led to a decrease in the thickness of the pipe walls (from 12 to 1.6 mm).

The largest accident in the history of the Spanish nuclear industry (an event of the third level on the INES scale) occurred at the Vandellos nuclear power plant on October 19, 1989. Fire at the first power unit of the nuclear power plant. Due to the sudden stop of one of the turbines, overheating and decomposition of the lubricating oil occurred. The resulting hydrogen exploded, which caused the turbine to ignite. Since the automatic fire extinguishing system did not work at the station, the fire departments of neighboring cities were called, including those located at a distance of up to 100 kilometers from the nuclear power plant. The fight with the fire lasted more than 4 hours. During this time, the turbine power supply and reactor cooling systems were seriously damaged. The firemen who worked at the station risked their lives. They did not know the location and functions of its facilities, they were not familiar with the emergency plan at the nuclear power plant. Used to extinguish electrical systems with water instead of foam, which could lead to damage to them electric shock. In addition, people were not warned about the risk of working in areas with increased level radiation. So, three years after Chernobyl, firefighters, already in another country, became hostages of a dangerous situation at a nuclear power plant. Luckily, none of them were badly hurt this time.

In Japan, on February 9, 1991, an accident occurred at the Mihama nuclear power plant, 320 kilometers northwest of Tokyo. Due to a pipe rupture, 55 tons of radioactive water leaked from the cooling system of the reactor of the second power unit. There was no radioactive contamination of personnel and the area, but the incident was considered at that time the most serious accident at Japanese nuclear power plants.

An accident of the third level according to the INES scale was recorded at the Khmelnitsky NPP in Ukraine on July 25, 1996. There was a release of radioactive products into the premises of the station. One person died.

During scheduled maintenance work on April 10, 2003, at the second power unit of the Paks NPP (Hungary), inert radioactive gases and radioactive iodine were released into the atmosphere. The reason is damage to the fuel assemblies during chemical cleaning their surfaces in a special container. An accident of the third level according to the INES scale.

On July 4, 2003, an explosion occurred at the radioactive waste processing plant of the Fugen nuclear complex, 350 kilometers west of the city of Tokyo, which caused a fire. The 165 MW experimental nuclear reactor, shut down in March 2003, was not affected by this incident.

Accident at the Mihama nuclear power plant on August 9, 2004. From the burst pipe of the second circuit of the cooling system of the third power unit, a jet of steam with a temperature of 270 ° escaped and scalded the workers who were in the turbine hall. Four people died and 18 were seriously injured.

On August 25, 2004, a large leak of radioactive water occurred from the cooling system of the reactor of the second power unit of the Vandellos NPP (Spain). According to the Spanish Council for Radiation Safety, this is the most serious accident at this nuclear power plant since a fire in 1989.

On March 11, 2011, Japan was hit by the most powerful earthquake in the history of the country. As a result, a turbine was destroyed at the Onagawa NPP, a fire broke out, which was quickly extinguished. At the Fukushima-1 nuclear power plant, the situation is very serious - as a result of the shutdown of the cooling system, nuclear fuel melted in the reactor of block No. 1, a radiation leak was recorded outside the block, and evacuation was carried out in a 10-kilometer zone around the nuclear power plant. The next day, March 12, the media reported an explosion at a nuclear power plant.

On March 19, 2012, Canadian authorities reported a radioactive water leak into Lake Ontario from a nuclear power plant owned by Ontario Power. According to MIGnews, the nuclear power plant is located in the city of Pickering, 35 km from Toronto. The company said in a statement that 73,000 liters of radioactive water entered the lake. This fact was confirmed by representatives of the Canadian Commission on Nuclear Safety.

On 26 October 2012, the Flamanville nuclear power plant in France, located in the northwestern department of the Manche, experienced a radiation leak, causing the first reactor to go into a cold shutdown. Behind Last year this is not the first case of accidents at French nuclear power plants, which makes opponents of this type of energy increasingly demand the abandonment of nuclear energy.

At the very end of the 18th century, radioactive radiation was discovered, after which an active study of this phenomenon began. Already in 1901, radiation was first used for medical purposes. After 30 years, they began to think about the development of nuclear weapons. The first plutonium production plants started operating in 1944. Waste material was initially simply dumped into the environment, like ordinary garbage. The surrounding area suffered significant damage. This is how the statistics of radiation accidents in the world was born. The era of radioactive contamination of the environment by man has begun.

Peaceful "atom"

From the middle of the 20th century, the development of the engine began, for its use in the transport industry. With the development of this direction, they tried to develop an atomolet, an atomic carrier, an atomic ship. The most successful idea was to create nuclear-powered ships. In the civilian sphere, these are nuclear icebreakers,.

In medicine, radiation began to serve the good almost immediately after the discovery. Today, radioactive radiation is effectively used in the field of neurology, oncology, cardiology, as well as complex diagnostics.

Statistics of radiation accidents in the world in the field of the national economy:

years	Release type, conditional* quantity
	Unorganized dumping of nuclear waste	Industrial accidents and other leaks	Civil incidents
1944–1949	2	4	–
1950–1959	1	15	–
1960–1969	1	11	–
1970–1979	1	10	–
1980–1989	1	28	1
1990–1999	2	31	15
2000–2009	2	10	9

* - the table shows conditional quantitative values. So, for example, only at the Mayak enterprise (Chelyabinsk region, Russia), about 32 incidents of varying severity are known for the entire time of operation, and only 15 of them were included in the summary statistics.

From the table, you can see that since the 90s, incidents began to occur among citizens. Cases of theft of nuclear materials and attempts to sell them have become more frequent (the culprits in most cases soon after the radiation received). In particular, the theft of medical radioactive sources was observed, which were dismantled and sold as scrap metal. In general, various materials “contaminated” with radiation more than once got to the enterprises for the remelting of scrap metal.

Nuclear disasters

After the discovery of a chain reaction of decay in 1941, they thought about using a nuclear resource to generate electricity. In 1954, the world's first nuclear power plant was completed (Obninsk, USSR). Nowadays, there are about 200 power plants on the planet. However, it is difficult to ensure trouble-free operation of such facilities.

To assess the degree of danger of the statistics of radiation accidents in the world in 1990, INES (INES) was developed - an international classification of nuclear events in the civil sphere. According to this scale, events rated above 4 points are considered major radiation accidents in the world. In the entire history of nuclear energy, there are about 20 such cases.

INES 4. Events leading to the release into the environment of insignificant doses of radiation equivalent to 10–100 TBq 131 I. In such accidents, isolated deaths from radiation are recorded. In the incident area, only food control is required. Examples of accidents:

1. Fleurus, Belgium (2006).
2. Tokaimura, Japan (1999).
3. Seversk, Russia (1993).
4. Saint Laurent, France (1980 and 1969).
5. Bohunice, Czechoslovakia (1977).

INES 5. Incidents resulting in a release of radiation equivalent to 100–1000 TBq 131 I and causing several deaths. In such areas, local evacuation may be required. Examples:

1. Goiania, Brazil (1987). A certain orphan object was found, which turned out to be destroyed by a highly radioactive source of Cesium-137. Strong doses of radiation received 10 people, 4 of them died.
2. Chazhma Bay, USSR (1985).
3. Three Mile Island, USA (1979).
4. Idaho, USA (1961).
5. Santa Susana, USA (1959).
6. Windscale Pyle, UK (1957).
7. Chalk River, Canada (1952).

INES 6. Accidents in which the release of radioactive material into the environment is equivalent to 1000–10000 TBq 131 I. The evacuation of the population or its shelter in shelters is required. One example is known. This is the very first radiation accident in the world of this magnitude - Kyshtymskaya, USSR (1957).

Mayak is an enterprise for the storage and processing of nuclear fuel in the Chelyabinsk Region. In 1957, there was an explosion of a tank containing 70-80 tons of nuclear waste. A radioactive cloud formed, which spread dangerous substances over a territory of more than 23 thousand km 2 onto the heads of 272 thousand people. For the first time in 10 days, about 200 people died from exposure.

INES 7. This score is assigned to the largest radiation accidents and catastrophes in the world. They are characterized by extensive radiation impact on people and the environment, equivalent to a release of 10,000 TBq 131 I or more. They have enormous consequences for human health and the state of nature. Planned and lengthy countermeasures designed for such cases are urgently required. This rating is assigned to the two largest radiation accidents in the world:

1. Fukushima (2011). A series of tragic events befell Japan that year. The Fukushima-1 nuclear power plant could not resist them either. and the subsequent one left 3 reactors without power supply, and therefore without a cooling system. The explosion was inevitable. Vast territories were contaminated with radiation, the waters of the ocean suffered the most in the accident. The 30-kilometer territory around the nuclear power plant became the exclusion zone. Approximately 1,000 people died from radiation sickness in the first year.
2. Chernobyl (1986). The disaster at the Chernobyl nuclear power plant occurred on April 26. In the fourth power unit, where there were about 190 tons of nuclear fuel, an explosion occurred. The accident, which began due to erroneous actions of the personnel, acquired an inadequate scale due (as it turned out later) to violations committed during the construction of the reactor.

As a result, about 50 thousand km 2 of agricultural land became unsuitable for cultivation. The city of Pripyat, whose population at that time was 50 thousand people, fell into the 30-kilometer exclusion zone. As well as other towns.

The statistics of radiation accidents show that in the next twenty years, about 4 thousand people died from exposure.

Military "atom"

The development of nuclear weapons began to be thought about since 1938. In 1945, the United States for the first time in the world tested a nuclear bomb on its territory, and then two more were dropped on the cities of Japan: Hiroshima and Nagasaki. More than 210 thousand people were killed,.

According to Wikipedia, the city of Hiroshima was completely rebuilt in 1960. For the period from 1945 to 2009, 62 nuclear weapons tests and 33 accidents of military equipment using nuclear power plants as an engine or with nuclear weapons on board are known.

years	Ejection type, number of pieces.
	Weapon Test	accidents military equipment
1945–1949	2	–
1950–1959	13	1
1960–1969	28	9
1970–1979	12	3
1980–1989	7	7
1990–1999	–	2
2000–2009	–	11