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«The Danger of Radiation»
Municipal educational institution
«Secondary school № 100»
Leninsky district of the city of Saratov
Scientific and practical work
on this topic:
"Influence of radiation on people.
Causes of the accident at the Chernobyl Nuclear Power Plant in 1986."
Completed
by a student of the 10th “A” grade
MOU "School № 100"
Irina Prokazova
Head S. Aldaeva
Saratov
2019
Most of the discussion about radiation, how it works, and what its effects are boil down to the interaction of radiation with atoms (and molecules) that it comes into contact with. Atoms form the basic building blocks of all matter. They consist of a nucleus, made of positively-charged protons (and sometimes neutrally-charged neutrons), and an outer cloud of electrons, which have a negative charge. The positive charge of a single proton is equal to the negative charge of a single electron.
Since the discovery, radiation was considered not harmful but very healthy. The more radiation - the more useful. Radiation was added to creams, powders, perfumes, a well, made glowing paints ... Such a move sharply increased the cost of the product.
At the beginning of the 1950s, children's game of the «Do-It-Yourself Nuclear Power Plant» were sold in the USA, which, in addition to nuts, bolts and various rivets with punch cards, included a children's dosimeter, various varieties of uranium ore and four vials of isotopes.
As a result, people came to the conclusion that radiation is invisible, inaudible, has no taste, color and smell, and therefore is terrible. Causes paranoia, with direct use - radiation sickness. Sometimes fatal.
The Chernobyl accident.
The Chernobyl disaster was a nuclear accident that occurred on the 26 of April in 1986 at the No. 4 nuclear reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian SSR. It is considered the worst nuclear disaster in history. It`s one of only two nuclear energy disasters on the International Nuclear Event Scale, the second disaster was in 2011 in Fukushima in Japan.
On April 25, 1986, a shutdown of the fourth power unit was planned at the Chernobyl nuclear power plant for scheduled repairs and the experiment. Specialists of the Hydroproject Research Institute have proposed a method for emergency power supply to the station pumps. This would allow even when the power was turned off to maintain circulation of the coolant in the circuit until the backup power was turned on. According to the plan, the experiment was supposed to begin when the thermal power of the reactor dropped to 700 megawatts. The shutdown of the reactor was postponed for about nine hours upon request from Kiev. As soon as the power reduction resumed, it unexpectedly fell to almost zero due to erroneous actions of the NPP personnel and the accumulation of the isotope. To cope with a sudden problem, emergency rods were removed. Despite the unstable operation of the reactor, at 01:23:04 the experiment began. An attempt to introduce absorbent rods due to their unsuccessful design only aggravated the situation. Just 43 seconds after the start of the experiment, the reactor collapsed as a result of one or two powerful explosions.
A large amount of energy was suddenly released, vapourising superheated cooling water and rupturing the reactor core in a highly destructive steam explosion. This was immediately followed by an open-air reactor core fire that released considerable airborne radioactive contamination for about nine days that precipitated onto parts of the USSR and western Europe, before being finally contained on 4 May 1986. The reactor explosion killed two of the reactor operating staff. In the emergency response that followed, 134 firemen and station staff were hospitalized with acute radiation syndrome due to absorbing high doses of ionizing radiation. Of these 134 men, 28 died in the days to months afterward and approximately 14 suspected radiation-induced cancer deaths followed within the next 10 years.
The Chernobyl disaster is considered the worst nuclear power plant accident in history, both in terms of cost and casualties. The struggle to safeguard against hazards immediately after the accident, together with later decontamination efforts of the surroundings, ultimately involved more than 500,000 liquidators and cost an estimated 18 billion Soviet rubles—roughly US$68 billion in 2019, adjusted for inflation. The accident prompted safety upgrades on all remaining Soviet-designed RBMK reactors, of which 10 continue to be operational as of 2019.
Causes of the accident in 1986.
Swedish scientists came to the conclusion that during the accident at the Chernobyl nuclear power plant there was a weak nuclear explosion. Experts analyzed the most likely course of nuclear reactions in the reactor and simulated the meteorological conditions for the propagation of decay products. There are various versions of the causes of the disaster. Most often they indicate incorrect actions of Chernobyl personnel, which entailed the ignition of hydrogen and the destruction of the reactor. However, some scientists believe that there was a real nuclear explosion. There are several versions of the causes of the Chernobyl accident:
Violation of the operating rules of the fourth power unit by maintenance personnel and plant managers.
A mistake in the design of the reactor, which engineers had no idea about. The reactor was extremely unstable.
In both explanations, the emphasis is on gross violations of the operating rules of nuclear power plants:
the experiment at any cost, despite the change in the state of the reactor;
Reactor protection systems did not provide its jamming in a dangerous situation regardless of personnel actions. This is the main omission of designers. Attendants may make mistakes, neglect their work, or even have malicious intent, but in all cases an explosion should be impossible. And the reactor exploded.
shutting down serviceable defenses that would simply stop the reactor preventing an explosion;
silence on the scale of the accident in the early days of the Chernobyl leadership.
Silence of the catastrophe led to the fact that the population behaved completely wrong, because it was not informed. On the spot, the children almost ran to see the fire, although this categorically could not be done. This also led to the loss of the image of the Soviet government both domestically and abroad.
Consequences of the 1986 accident.
One of the expeditions conducted by scientists took place in 2007: the researchers visited the so-called Red Forest - 10 km² of trees adjacent to the Chernobyl nuclear power plant and that took on the largest share of the release of radioactive dust during the reactor explosion in 1986. Scientists have noticed that, despite the fact that the trees finally died about 10-15 years ago, their trunks and branches are perfectly preserved. According to all laws of nature, they would have to rot and turn into dust, but this did not happen. The researchers decided to measure the speed with which materials of plant origin decompose in infected areas. To do this, they scattered 572 mesh bags filled with leaves from various trees that were brought from areas not affected by radiation in June 2008 through the territory of the Red Forest. Nine months later, scientists measured the weight of these bags, and it turned out that it had not changed much. In particular, this affected those places that were most affected by radiation pollution.
Studies have identified threats from Chernobyl:
The size of populations and the number of species of birds, mammals, insects and spiders, in other words, biodiversity in parts of Chernobyl, especially those affected by radioactive contamination, is much lower than in other areas.
47 500 inhabitants of Pripyat were evacuated. Now 140 people live in the exclusion zone - the so-called self-settlers.
Many birds and small mammals breed worse in such areas, and their life expectancy is much lower than that of their relatives.
In Fukushima, only birds, butterflies, and cicadas showed some abnormalities, while the remaining animals showed no signs of abnormalities during the first summer after the disaster.
There is a big difference in the sensitivity of different species to radionuclides.
A powerful radiation leak "painted" the forest near the Chernobyl nuclear power plant in a bright red color. Since then, it has been called the "Red Forest.
Representatives of many species have been found to have genetic damage. We were able to trace how the mutations that appeared as a result of radiation pollution appeared in several generations of living organisms in Chernobyl.
It was found that those species of birds, whose number decreased due to radiation pollution, throughout their existence underwent a large number of mutations.
The vital activity of microbes, as well as the growth of trees in these areas are significantly slowed down.
The Exclusion zone.
The Chernobyl Nuclear Power Plant Zone of Alienation is an officially designated exclusion zone around the site of the Chernobyl nuclear reactor disaster. It is also commonly known as the Chernobyl Exclusion Zone, the 30 Kilometre Zone, or simply The Zone.
Established by the Soviet Armed Forces soon after the 1986 disaster, it initially existed as an area of 30 km (19 mi) radius from the Chernobyl Nuclear Power Plant designated for evacuation and placed under military control. Its borders have since been altered to cover a larger area of Ukraine. The Chernobyl Exclusion Zone borders a separately administered area, the Polesie State Radioecological Reserve, to the north in Belarus. The Chernobyl Exclusion Zone is managed by an agency of the State Emergency Service of Ukraine, while the power plant and its sarcophagus (and replacement) are administered separately.
The Exclusion Zone covers an area of approximately 2,600 km2 (1,000 sq mi) in Ukraine immediately surrounding the Chernobyl Nuclear Power Plant where radioactive contamination from nuclear fallout is highest and public access and inhabitation are restricted. Other areas of compulsory resettlement and voluntary relocation not part of the restricted exclusion zone exist in the surrounding areas and throughout Ukraine. In February 2019 it was revealed that talks have been underway to redraw the boundaries of the Exclusion Zone to reflect the declining radioactivity of the Zone's outer areas.
Historically and geographically, the zone is the heartland of the Polesia region. This predominantly rural woodland and marshland area was once home to 120,000 people living in the cities of Chernobyl and Pripyat as well as 187 smaller communities, but is now mostly uninhabited. All settlements remain designated on geographic maps but marked as "uninhabited". The woodland in the area around Pripyat was a focal point of partisan resistance during the Second World War, experience of which allowed evacuated residents to evade guards and return. In the woodland near the Chernobyl Nuclear Power Plant stood the 'Partisan's Tree' or 'Cross Tree', which was used to hang captured partisans. The tree fell down due to age in 1996 and a memorial now stands at its location.
VI.I Population.
The 30 km zone is estimated to be home to 197 samosely living in 11 villages as well as the town of Chernobyl. This number is in decline, down from previous estimates of 314 in 2007 and 1,200 in 1986. These residents are senior citizens, with an average age of 63. After recurrent attempts at expulsion, the authorities became reconciled to their presence and have allowed them with limited supporting services. Residents are now informally permitted to stay by the Ukrainian government.
Approximately 3,000 people work in the Zone of Alienation on various tasks, such as the construction of the New Safe Confinement, the ongoing decommissioning of the reactors, and assessment and monitoring of the conditions in the zone. Employees do not live inside the zone, but work shifts there. Some of the workers work "4-3" shifts (four days on, three off), while others work 15 days on, 15 off. Other workers commute into the zone daily from Slavutych. The duration of shifts is counted strictly for reasons involving pension and healthcare. Everyone employed in the Zone is monitored for internal bioaccumulation of radioactive elements.
Chernobyl town, located outside of the 10 km Exclusion Zone, was evacuated following the accident, but now serves as a base to support the workers within the Exclusion Zone. Its amenities include administrative buildings, general stores, a canteen, a hotel, and a bus station. Unlike other areas within the Exclusion Zone, Chernobyl town is actively maintained by workers, such as lawn areas being mowed and autumn leaves being collected.
VI.II Access and tourism.
There have been growing numbers of visitors to the Exclusion Zone each year, and there are now daily trips from Kiev offered by multiple companies. In addition, multiple day excursions can be easily arranged with Ukrainian tour operators. Most overnight tourists stay in a hotel within the town of Chernobyl, which is located within the Exclusion Zone. According to an exclusion area tour guide, as of 2017, there are approximately 50 licensed exclusion area tour guides in total working for approximately nine companies. Visitors must present their passports when entering the Exclusion Zone, and are screened for radiation when exiting both at the 10 km checkpoint and at the 30 km checkpoint. The Exclusion Zone can also be entered if an application is made directly to the zone administration department.
Some evacuated residents of Pripyat have established a remembrance tradition, which includes annual visits to former homes and schools. In the Chernobyl zone, there is one operating Eastern Orthodox Christian church, St. Elijah Church. According to Chernobyl disaster liquidators, the radiation levels here are "well below the level across the zone", a fact that president of the Ukrainian Chernobyl Union, Yury Andreyev, considers miraculous.
The Chernobyl Exclusion Zone has been accessible to interested parties such as scientists and journalists since the zone was created. An early example was Elena Filatova's online account of her alleged solo bike ride through the zone. This gained her Internet fame, but was later alleged to be fictional, as a guide claimed Filatova was part of an official tour group. Regardless, her story drew the attention of millions to the nuclear catastrophe. After Filatova's visit in 2004, a number of papers such as The Guardian and The New York Times began to produce reports on tours to the zone.
Tourism to the area became more common after Pripyat was featured in popular video games: S.T.A.L.K.E.R.: Shadow of Chernobyl and Call Of Duty 4: Modern Warfare. Fans of the S.T.A.L.K.E.R. franchise, who refer to themselves as "stalkers", often gain access to the Zone. (Both the name "the Zone" and the term "stalker" derive from Arkady and Boris Strugatsky's book Roadside Picnic, which predates the Chernobyl disaster but describes a similar setting.) Prosecution of trespassers became more severe after a significant increase in trespassing in the Exclusion Zone. An article in the penal code of Ukraine was specially introduced, and horse patrols were added to protect the zone's perimeter.
In 2012, journalist Andrew Blackwell published Visit Sunny Chernobyl: And Other Adventures in the World's Most Polluted Places. Blackwell recounts his visit to the Exclusion Zone, when a guide and driver took him through the zone and to the reactor site.
On 14 April 2013, the 32nd episode of the wildlife documentary TV program River Monsters (Atomic Assassin, Season 5, Episode 2) was broadcast featuring the host Jeremy Wade catching a wels catfish in the cooling pools of the Chernobyl power plant, at the heart of the Exclusion Zone.
On 16 February 2014, an episode of the British motoring TV programme Top Gear was broadcast featuring two of the presenters, Jeremy Clarkson and James May, driving into the Exclusion Zone.
A portion of the finale of the Netflix documentary Our Planet, released in 2019, was filmed in the Exclusion Zone. The area was used as the primary example of how quickly an ecosystem can recover and thrive in the absence of human interference.
Resume.
In the process of working on this topic, I came to the conclusion that nuclear accidents worse than all wars in the world. First of all, we must remember that there is a Balakovo Nuclear Power Plant which is not far from us. This is not an ordinary enterprise, it`s a nuclear power plant, which stores many abilities that haven`t been studied by scientists yet. We should remember about what negligence and miscalculations of power plant personnel can lead to.
Some brief information about Balakovo Nuclear Power Plant:
Balakovo nuclear power station is located in the city of Balakovo, Saratov Oblast, Russia, about 900 kilometres (560 mi) south-east of Moscow. It consists of four operational reactors; a fifth unit is still under construction. Owner and operator of the nuclear power station is Rosenergoatom.
Balakovo NPP participates in a twinning program between nuclear power stations in Europe and Russia; since 1990 it has been in partnership with Biblis Nuclear Power Plant.
On 27 June 1985 during startup of the first reactor unit, a human error (later attributed to inexperience and haste) unexpectedly opened a pressurizer relief valve, and 300 °C (572 °F) steam entered the staff work area. Fourteen people were killed. This event is cited as one of the predecessors of the Chernobyl disaster.
Over the entire existence of nuclear power plants around the world, 99 accidents occurred. 57 of them occurred after the Chernobyl disaster, while 57% (56 of 99) of all accidents at nuclear power plants occurred in the United States. The most serious accidents at nuclear power plants include the accident at the Fukushima-1 nuclear power plant (2011), the Chernobyl disaster (1986), the accident at Three Mile Island (1979), and some others.
