RADON AS ONE OF THE MOST DANGEROUS FACTORS AFFECTING MINERS
Authors: Poliakova I. 
Published: October 2019

Introduction. Ukraine is among the leading mineral and raw material states. Nowadays in Ukraine prospected 20000 deposits and manifestations of 111 kinds of minerals (according to UNIAN - 200 minerals, 120 of which are used by mankind today). Of these 7807 deposits of 94 minerals with industrial value and accounted State balance of stocks. The greatest economic importance are coal, oil and gas, iron ore and manganese, native sulfur, rock and potassium salts, non-metallic building materials, mineral waters. These deposits are located in different geological regions of Ukraine.

During the extraction of natural resources are exposure of personnel of mines and population from naturally occurring radioactive materials (NORM - nature occurring radioactive materials). Adequate levels of radiation safety and radiation protection of the population and the personnel of any branch determined, above all, of the relevant public, industry and other regulations and systems monitoring their implementation. One of the significant components of the increase of radiation safety are methodical application of appropriate radiation monitoring devices and obtaining reliable data (results), which will allow processing to estimate actual radiation situation at the facility.

The natural and climatic conditions of the mines are specific. This fact is confirmed by the level of humidity, which can reach the value of 99%, but the temperature and atmospheric pressure are unchanged. In the process of work in the mine there is a harmful factor for the human body - dust in the air of the working zone and radioactivity. Alpha particles formed as a result of the decomposition of the daughter products of the decay of 224Ra, 223Ra and 226Ra, settling on aerosols and  enter the human body by inhalation, as well as actinon, radon and thoron lead to an increase in the dose of personnel.

Purpose. The purpose of the study is to determine the radiation situation at the sites for the extraction of minerals, taking into account the factors that affect the reliability of the results. Establishing reliable quantitative characteristics of harmful factors of the environment, which negatively affects the body of the personnel. Conducting an analysis of existing methods of measuring by direct methods and making suggestions for their improvement under the influence of factors that contribute to obtaining results with an error of more than 75%.

Methods. In the course of the research, direct measurement methods, calculations and analytical research were used to achieve the set goal and to solve the set tasks. During experimental and analytical work of physico-chemical and radiometric measurement methods were used, certified equipment and measuring control devices were used.

 Results. Measurements of equilibrium volume activity of radon and thoron using direct method is necessary task to assess the impact on personnel at the work time.

Quantitative assessment the air gases such as 222Rn, 220Rn, 219Rn depends on the amount of deposits of the uranium and thorium series in the earth's surface.

It should not be forgotten that after the radioactive decay of the aforementioned gases, a significant amount of α-radioactive daughter nuclides that enter the miners' body is formed. This causes an increase in the dose from the accumulation of α-radionuclides in the miners' organism, but this staff is not officially considered which works with NORM (with the exception of only uranium miners).

Comparing the results obtained by measuring 222Rn and 220Rn provided in Tables 1 and 2 using direct measurement methods using RHA-2006 «ICAR» and AlphaGuard PQ2000, show difference in the results, especially at higher humidity and with increasing of numbers of mineral dust in the air of mines.

Conclusions. The conclusions obtained by the author of the article on the state of experimental research and analysis of data:

Climatic conditions play an important role in data reliability. It is necessary to carefully select the devices of radiation control and measurement methods.

Conduct a quantitative analysis of radionuclides and set a dose for miners only from radon and thoron, which is possible with the use of a-spectrometry. In this study, an express control (real-time control) of α-emitting radionuclides in the air was carried out using detectors, whose activities are based on the use of an ionization chamber. But as a result of this study, we obtain the total activity of α-radionuclides in the air and α-aerosols identified with a significant systematic error. Since the measuring capabilities of these devices are determined by the humidity of no more than 85%.

The creation of new normative documents to determine the impact on employees and the population of the NORM should be a consequence and an integral part of scientific research in this field. The authenticity of experimental methods and the reliability of the results are the basis upon which radiation safety will be based on working with natural radionuclides.