Наукові новини - Chornobyl disaster

Chornobyl disaster - 33 years after

May 30, 2019

Oleksii Berezovskiy

Senior Researcher of the Chromatographic Research Sector, Department for Monitoring the Quality and Safety of Agricultural Products, Laboratory of Quality and Safety of Agricultural Products of Ukraine, 08162, smt. Chabany, Kyiv-Svyatoshin district, Kyiv region, Ukraine

From the editor: Chornobyl nuclear power plant was named after V.I. Lenin...

Could this disaster and its consequences be a real "monument" to Ulyanov-Lenin?

D. Demydenko

(USSR, Ministry of Nuclear Energy, Chornobyl Nuclear Power Plant named after V. I. Lenin ) Taken from [1]

Although on April 26, 2019 passed a 33d year of the Chornobyl tragedy [2] which became the largest technogenic disaster in the world, yet its effects continue to be felt and remain a problem for Ukraine [3]. Detailed assessment of the contaminated ecosystems, study of changes in the ecosystems, and an assessment of the impact on the health of the population affected by radioactive contamination is important for overcoming consequences of this disaster.

For reminder, the explosion destroyed the reactor core and the roof of the nuclear reactor No. 4. After the explosion and the subsequent two-week fire, the radioactive substances spread into the environment. The disaster caused pollution of more than 145 thousand sq.km of territory of Ukraine, the Republic of Belarus and the Russian Federation, with the density of pollution of this territory by radioactive cesium-137 exceeding 37 kBq/sq.m [4], which is a level that allows these territories to be considered radioactively contaminated by the legislation of the mentioned countries. Although the most dangerous short-term radioactive isotope that got into the air was iodine-131 (half-life - eight days) because of its danger to the thyroid gland, which is the main consumer of iodine in the human body and uses it for the synthesis of hormones of thyroxine and triiodothyronine, which regulate growth, development and some functions of all organs of the human body. More than 2.6 million people were affected by Chornobyl disaster in Ukraine, and 2293 settlements were located in contaminated areas in Ukraine [4].

Direct economic losses due to the Chornobyl disaster for Ukraine can be attributed to such losses as material and property complexes and separate objects of the economy in the Exclusion zone on the territory of Ukraine, loss of the capable to labor population. Indirect economic losses can be attributed to non-use of agricultural, water and forest resources, the cost of shortfall in electricity production, damages from the moratorium on the building new reactors at nuclear power plants and long-term consequences for people's health. Although in quantitative terms, these losses are difficult to assess and they are a subject of speculations.

The consequences of the Chornobyl disaster on human health are varied and associated with direct exposure to ionizing radiation and with other negative factors, such as the movement of large number of people from the contaminated areas and psycho-emotional (mental) overload [3].

Children who have experienced prolonged exposure to radiation during mother’s pregnancy and after the birth, had an increase in the frequency of genetic material changes, which included changes in chromosomes 1, 4, 5, 9, 17, 22 [5].

Info: all humans have 23 pairs of chromosomes which contain hereditary material called DNA, the total length of which in the chromosomes is about 3 billion nucleo bases.

Children born to mothers who were evacuated from the 30-km Exclusion zone long time after disaster period had increased frequency of structural changes in the chromosomes with dominance of stable damages preferential localization in chromosomes 1, 2, 3, 5, 7, 11, 13, 17 [5].

It was established that exposure to small doses of radiation causes an increase in the level of anxiety, aggressiveness, affects the mental development of the children [6].

The number of victims of the Chornobyl disaster is constantly decreasing. From 2007 to 2015, the total number of victims fell by 501 075 people. In the period since the 25th year passed after Chornobyl disaster, the number of cases of thyroid gland cancer continues to increse in people irradiated in childhood and adolescence, and in people irradiated in adulthood - in the participants of the liquidation of the consequences of the disaster and evacuated from the 30-kilometer Exclusion zone [3].

The maximum radiation exposure to objects of wildlife fell on the first 10-20 days from the moment of the disaster. The next phase included the summer and early fall of 1986, during which the dose rate on the surface of the soil decreased to 20-25% of the initial values [7]. It has been established that in the Chornobyl Exclusion zone there were significant, previously not observed in nature, damages to ecosystems, although in relatively small areas [7]. The death of pine forest was recorded on the territory of about 500 hectares ("ore forest") in the immediate vicinity of ChNPP (Chornobyl Nuclear Power Plant). In the same area, practically complete destruction of soil invertebrates was noted, later in these areas marked signs of change in population characteristics in mouse-like rodents was detected[7].

Conducting large-scale radioecological investigations in areas that have been exposed to radioactive contamination as a result of this largest nuclear disaster in history allows us to obtain information on the reactions of wildlife to it at different levels of biological organization - from molecular and cellular levels to the level of ecosystem - under conditions of large-scale radioactive contamination of large areas. A generalization and comprehensive analysis of this information will make it possible to assess the need for the development of norms limiting the radiation impact on biota and to formulate the principles on which they should be based.

In order to coordinate efforts to more effectively combat the consequences of the disaster an International Chornobyl Portal was created [1] by the International Chornobyl Research and Information Network (ICRIN) UN project. This online resource that provides information on radiological and related aspects of safety to the population living in areas affected by the Chornobyl disaster. The portal was created with the support of UN agencies (World Health Organization, United Nations Children's Fund, International Nuclear Energy Agency and United Nations Development Program) and in cooperation with relevant international organizations, ministries and organizations of the Republic of Belarus, the Russian Federation and Ukraine.

In March 2004, the European Bank for Reconstruction and Development announced a tender for the design, construction and commissioning of a new sarcophagus for 4^th nuclear reactor of ChNPP. Consortium NOVARKA [8], joint venture of the French company Vinci Construction Grands Projets and BOUYGUES, was announced as the winner of the tender in August 2007.

The new arch-shaped sarcophagus, which is the world's largest mobile metal structure, is made of 25 050 tons of steel structures. Its dimensions : 108 meters in height of 162 meters in length and 257 meters in width, the non-standard arch is large enough to cover the Stade de France stadium, the Statue of Liberty or the foot of the Eiffel Tower. During the assembly, the arch stood on two concrete supports and was located west of the destroyed reactor covered by first sarcopagus. Now it covers the existing first shelter, built in 1986 (right after the disaster). Approximately 10 000 people from almost 30 countries worked on this project [9].

Taken from [10]

The main purpose of this arch is to ensure the retention of covered radioactive materials, also during the process of deconstuction of the first sarcophagus for 4^th nuclear reactor of ChNPP unit in order to remove used nuclear fuel and transport it to the storage facility. The deconstruction and nuclear fuel removal under the arch is suppoused to be carried out by remotely controlled equipment installed inside. The arch is designed for operation over the next 100 years.

At the time of the 33rd anniversary of the Chornobyl disaster, the project is ready for 99% and should be completed in May-June 2019 [11].

More than 40 countries have provided about 2 billion euros for the construction of the arch [9].

It should also be noted that by the Decree of the President of Ukraine on April 26, 2016 [12] was created Chornobyl radiation-ecological biosphere reserve [13]

List of references

1. International Chornobyl Portal of International Chornobyl Research and Information Network (ICRIN) UN project, (http://chernobyl.info/en-US/Home.aspx)

2. Chornobyl disaster, Wikipedia (https://en.wikipedia.org/wiki/Chernobyl_disaster )

3. Thirty years after Chornobyl disaster: radiological and medical consequences. National report of Ukraine. National Research Center for Radiation Medicine, National Academy of Medical Sciences of Ukraine, Kyiv, 2016, 177 p. (http://www.rv.gov.ua/sitenew/data/upload/photo/table1.pdf)

Radiological state of the territories classified as radioactive contamination zones (in the section of districts). Edited by VI Kholoshi, The State Emergency Service of Ukraine, Kyiv 2008 (http://www.rv.gov.ua/sitenew/data/upload/photo/table1.pdf)

5. Misharina Zh. A. Somatic and genetic effects in children in remote terms after intrauterine irradiation as a result of the Chornobyl disaster. Author's abstract. dis Cand. biol. Sciences: 03.00.15. - K., 2006. - 12 p.

6. Bakumenko V. D. et al. Modern approaches to solving the problems of the Chornobyl exclusion zone and unconditional (mandatory) resettlement: Monograph. -K: UADU, 2000. -С. 151

7. What are the consequences of the Chornobyl disaster?, Chornobyl Center, (http://bit.ly/2EJ8vdZ).

8. NOVARKA (http://www.novarka.com)

9. Chornobyl New Safe Confinement: a one-of-a-kind project. November 29, 2016, press materials Chornobyl, Ukraine (http://www.novarka.com/wp-content/uploads/2016/11/VINCI-RV_Dossier-de-presse_Tchernobyl_GB_v31_HD2.pdf).

10. Chornobyl unit 4: Novarka and EBRD have got it covered, Modern Power Systems, January 26, 2017 (https://www.modernpowersystems.com/features/featurechernobyl-unit-4-novarka-and-ebrd-have-got-it-covered-5725961/).

11. With deep gratitude, we thank the liquidators of the Chornobyl NPP disaster, who have courageously fulfilled their duty, - Head of Government during the visit to the Exclusion zone, Government Portal, April 26, 2019 (https://www.kmu.gov.ua/ua/news/z-glibokoyu-shanoyu-dyakuyemo-likvidatoram-avariyi-na-chaes-yaki-muzhno-vikonali-svij-obovyazok-glava-uryadu-pid-chas-vidvidannya-zoni-vidchuzhennya )

12. On creation of the Chornobyl radiation-ecological biosphere reserve, Decree of the President of Ukraine №174/2016 (https://www.president.gov.ua/documents/1742016-19957)

13. Chornobyl Radiation and Ecological Biosphere Reserve (https://zapovidnyk.org.ua/index.php)

/next article

naukovinovyny.com