Development of recommendations for improving the radiation monitoring system of Ukraine

The effective functioning of the radiation monitoring network is an all-important task for all countries worldwide because the health of personnel working at radiation-hazardous facilities and the population living in the affected areas depend on it. A critical analysis of the functioning of radiation monitoring systems of various countries worldwide (Ukraine, United States of America, France, Sweden, Germany, South Korea, Switzerland, and China) was valid and showed their advantages and disadvantages. Criteria for displaying data on the electronic map about the state of radiation pollution and criteria for reports on the functioning of the radiation monitoring network have been determined. To improve the functioning of the radiation monitoring system of Ukraine, some recommendations for their improvement have been provided.


Introduction
Nowadays, many institutions and organizations worldwide use hazardous radiation technologies and sources of ionizing radiation in their activities (about 10 thousand enterprises in Ukraine, as of the end of 2021, were operating).Such objects include nuclear power plants (NPP), research reactors, specialized plants for processing and storing radioactive waste, enterprises extracting and processing uranium ores, and medical facilities using radioisotopes.Oil, gas, coal industry, and heat energy enterprises also participate in the radiation situation formation.During their operation, there is a noticeable redistribution of natural radionuclides (uranium, thorium, decay products, potassium, etc.) in the environment.In addition, fuel for nuclear power plants and spent fuel assemblies are transported through many territories.All these objects are objects of increased danger because emergencies related to their activities can lead to highly complex consequences for the present and future generations due to uncontrolled (accidents) or controlled (terrorist act) release of a significant number of radioactive substances into the environment.1254 (2023) 012109 IOP Publishing doi:10.1088/1755-1315/1254/1/012109 2 Therefore, one of the most critical components of the country's national security is the provision of nuclear and radiation safety.
In the territories where radiation-hazardous objects are in Ukraine, either non-automated sampling or stationary automated systems for monitoring the radiation situation are used for radiation monitoring.However, such approaches have some disadvantages: fieldwork is carried out, which poses a threat to humans in conditions of a significant level of radiation in the research territory; not equipment mobility of automatic systems doesn't allow assessment of radiation pollution levels across all studies territory.Furthermore, the non-automated sampling and stationary monitor posts don't allow to spend continuous environmental radiation monitoring in the part of a large square, resulting in information about the radiation situation in the research territory being released with a delay.
One of the main aspects of nuclear and radiation safety is radiation monitoring in the territories where hazardous radiation facilities are located, which various legal acts regulate.From that place, the effective functioning of radiation monitoring networks is an essential task for every country of the health of personnel working at hazardous radiation facilities and the population living in contaminated areas.
The legal acts regulate science publications, and information resources were analyzed in the research of the functionality of radiation monitoring networks.The result of analyzing showed that the problem outlined by us was considered and described in the following directions: • construction of environmental monitoring networks [1][2][3][4][5]; • development equipment for radiation monitoring networks [6-10]; • development software for analysis and visualization monitoring data [11][12][13][14]; • using monitoring data for solving management by the radioactively contaminated territory [15][16][17][18][19].
Therefore, issues of ensuring nuclear and radiation security are looked up worldwide.
The aim is to determine the main advantage and disadvantages of radiation monitoring networks and to provide recommendations for their improvement in Ukraine.

Results
Radiation monitoring is an information and technical system of observation, assessment, and forecast of the radiation state of the biosphere.Radiation monitoring is a system of long-term repeated monitoring to assess the state of the radiation situation.Environmental radiation monitoring is a system of regularly monitoring the radiation state of the environment, migration, and accumulation of radionuclides, potentially dangerous phenomena, etc.The primary purpose of monitoring is to provide information to decision-makers.
We will list the main tasks of radiation monitoring [20,21]: • observation and control of the state of the territory contaminated with radionuclides, its hazardous parts, and the development of ways to reduce the danger from contamination; • assessment of the state of objects in the environment according to the parameters that characterize the radioecological situation both in the zone of pollution and outside it; • identification of trends in changes in the state of radioactive contamination of the environment in connection with the operation of radiation-dangerous objects, as well as during the implementation of radiological protection measures carried out in pollution territories; • elucidation of possible trends to changes in the state of health of the population living in radionuclides-contaminated areas; • information provision of the forecast of the radioecological situation in the radionuclides pollution territories and the country in general.
Next, we will analyze the existing monitoring system in Ukraine and compare it with similar systems in other countries.This will allow us to identify shortcomings and determine directions for its improvement.

Ukraine
To date, non-automated sampling or stationary automated systems for monitoring the radiation situation are used for radiation monitoring in the territories where radiation-hazardous objects are in Ukraine.However, the disadvantage of such approaches and means is, firstly, the need for physical participation of a person in sampling, which creates a significant risk for his health in conditions with a substantial level of radiation in the research territory, and secondly, the lack of mobility of the equipment of automated systems, which does not allow to assess the level of radiation pollution in the entire studied area.They must provide an opportunity to quickly respond to complex radiation environment conditions of limited access to the research object (fire, destruction of the thing, rugged terrain, significant vegetation).Also, non-automated sampling and stationary posts do not allow for continuous environmental radiation monitoring of large areas, for example, such as the Chornobyl Exclusion Zone (CEZ).
Today, radiation monitoring in Ukraine is carried out by various entities -SE "NAEK "Enerhoatom", the State Agency of Ukraine on Exclusion Zone Management (SAUEZM), the State Space Agency, the National Academy of Sciences, and the UkrHydromet Center (UkrHMDs) under the State Service of Ukraine for Emergency Situations (SSUES).However, their systems provide only sectoral observations of the radiation environment.
All received information about radioactivity is open to the public through the Integrated Network of Radiation Monitoring of the Environment (figure 1).You can find out with the help of the map: the radiation level, the location of the measurement point, and who provided the information.[22].

Figure 1. Map of the radiation background in Ukraine
The Ukrainian Hydrometeorological Center of the SES of Ukraine (UkrHMC) monitors radioactive atmospheric pollution through daily measurements of gamma radiation exposure dose, deposition of radioactive particles from the atmosphere, and the content of radioactive aerosols in the air.
The UkrHMC measures radioactive contamination of surface water CS-137 and soil contamination and monitors gamma radiation exposure doses at ten automated points near NPPs.Furthermore, the UkrHMS monitors the concentration of radionuclides, radionuclides in atmospheric precipitation, and the concentration of 'hot' particles in the air within the 30kilometer zone around the Chornobyl NPP (exclusion zone).In addition, the International Radioecological Laboratory of the Chornobyl Center for Atomic Safety, Radioactive Waste, and Radioecology Slavutych monitors the impact of radiation on biota in the exclusion zone [1].
The SAUEZM implements the state policy in the exclusion zone management, the zone of unconditional (compulsory) resettlement, overcoming the consequences of the Chornobyl disaster.The SAUEZM provides work on determining the radiation status of the exclusion zone, including the industrial site of the Chornobyl NPP, and the area of unconditional (mandatory) resettlement, compliance with radiation safety standards, conducting radioecological monitoring and radiation control in the territories and objects located within them; carry out a general assessment of the radiation situation in the region of zones that have experienced radioactive contamination, environmental radiation monitoring in this territory.At all NPPs, research is conducted on the content of radioactive substances in ecological objects in the areas where the NPP is located in the water of surface reservoirs, the atmospheric air, and the soil of nearby settlements.

The USA
The nationwide RadNet system was generated to observe environmental radiation pollution levels.System RadNet has tracked radiation levels from testings nuclear weapons and nuclear reactor accidents at Chornobyl NPP (Ukraine) and Fukushima NPP (Japan).During a radiological incident, government officials use RadNet data to help make science-based decisions about protecting the population.Besides, scientists use the RadNet state of radioactive air pollution monitoring data to help estimate the potential radiation dose to humans.Also, use metrological data during the estimated quantity [23].
RadNet has 140 stationary air monitors that run 24 hours a day during the week and collect data near-real-time gamma radiation measurements.Figure 2 shows RadNet static air monitoring locations and precipitation and drinking water sampling locations that reported data in 2020.
Under standard conditions, air monitors RadNet operates continuously, and samples of air, precipitation, and drinking water are analyzed on a planned schedule (table 1) [24].In addition, during a radiological emergency, the United States Environmental Protection Agency (EPA) can deploy teams to conduct air monitoring and the environment.Table 1.Sampling frequency of the system RadNet.

Air filters Continuous (real-time) Continuous (real-time) Precipitation
As rainfall, snow or sleet occurs Monthly analysis of a composite sample Drinking water Quarterly Quarterly RadNet system data are available in databases and reports.In addition, EPA publishes analytical and monitoring results after checking to ensure they meet high-quality standards.
Envirofacts RadNet Database includes laboratory analysis results from air monitor filters, precipitation sampling, and drinking water.Also, this database is historical data about sampling milk.Finally, this database includes the current and historical data needed to estimate long-term environmental radiation trends [26].
As well United States Nuclear Regulatory Commission implements radiation pollution monitoring continuously in states in the USA, such as a sample of bioassay, alpha scans, a physical survey of the disposition of the materials and equipment, sampling or assessment levels to monitor air, surface water, and groundwater, soil, and sediment, equipment, and personnel [6].

France
On the national level, monitoring the dose equivalent rate is carried out on all territories of France (figure 4) laboratory in the Institut de radioprotection et de sûreté nucléaire (IRSN).The automated detectors represent proportional counters manufactured by BITT Technology (figure 5) [26].
The measurement of the monitors transmitted through a multiprotocol label switching virtual private network (MPLS VPN) or a direct contract between the IRSN and a telecommunications operator, or under the agreement between the IRSN and the Gendarmerie Nationale.The monitoring system ensures receiving of the measurement data in a Microsoft SQL Server database.Each measurement result is automatically compared to a sliding reference average of one week's data.In addition, the measurement automatically checks if it is within the acceptable variation range ±40 nSv/h of this average indicator.Nevertheless, in other cases, size has to be manually validated by the Téléray remote sensing system [26].
The monitoring system operates in real time.It includes redundancy, a recovery plan, and an agreed service commitment from the network operator.Monitoring of the public radiation dose (passive dosimetry) is carried out using about a hundred dosimeters.However, today monitoring is carried out more and more frequently using radio-photoluminescence (RPL) dosimeters (manufactured by the IRSN's dosimetry laboratory) [6].The dosimeters are exchanged every three months.
The facility from nuclear fuel processing Orano La Hague has mobile equipment for monitoring discharges and the environment, whether on a routine basis or in other emergencies.Four autonomous trailers are equipped with the following sampling and measurement equipment: • system for sampling aerosols with continuous alpha/beta measurement; • probe for continuous measurement of the ambient gamma dose rate; • mobile sampling equipment allowing samples pf bio-indicators (grass, soil, water).
The measurement data and report are sent in real-time to the correspondent department.Each trailer has an electrical generator and a lighting system.

Sweden
The Swedish Radiation Safety Authority (SSM) manages two telemetric networks for monitoring external gamma dose rates.A nationwide network consisting of 28 monitoring stations (figure 6) and a network comprised of 30 monitoring stations near nuclear power plants (figure 7) [27].
The monitoring stations operate autonomously and transmit data continuously to the network servers SSM.SSM manages the monitoring stations via special software and ensures supporting  The prim y purpose of the nationwide network is to alarm if there is a significant increase above the natural background gamma radiation level and provide an instant overall picture of the radiation situation in Sweden.In addition, the purpose of monitoring networks NPP is to give an early indication of gamma radiation levels and plume direction following a nuclear accident with the release of radioactivity to the environment.
Both networks monitor ambient dose equivalent rate using monitoring probes equipped with

Germany
The German nationwide monitoring network (ADER) includes ∼1800 stationary probes equally distributed over the German territory with a typical distance of 20 km between them (figure 8).Their density is increased in the 25 km emergency planning zone around NPP.These additional probes are installed and operated by complementary networks from federal states.Data are exchanged between das Bundesamt für Strahlenschutz (BfS) and the local government and are carried out on a bilateral agreement.In the emergency regimen, data from all stations can be accessed almost in real-time, enabling the population's information to be efficient and prompt [29].The monitoring network is a part of the German "Integrated Measuring and Information System for the Surveillance of Environmental Radioactivity" (IMIS) and German national response plan, which considered the consequences of large-scale radioactive pollution of the environment.Moreover, data was transmitted to the European radiological data exchange platform (EURDEP) to aggregate a complete picture of European persons who accept decisions [31].
Ideally, monitoring stations ADER should be located on extensive flat grassland on undisturbed natural ground.In practice, two rules are used for the selection of new places for the installation of detectors.Firstly, probes must be installed at a height of 1 m on the flat natural ground (grassland) without disturbing buildings at a distance of 20 m.Secondly, IOP Publishing doi:10.1088/1755-1315/1254/1/01210910 considering neighboring stations, necessarily choose aimed at an almost homogeneous coverage of the German territory [31].

South Korea
The country operates 25 nuclear power reactors, a nuclear research reactor, nuclear fuel fabrication facilities, and radioactive waste disposal facility.Korean Institute of Nuclear Safety (KINS) is the only atomic safety regulatory expert organization that protects the public and the environment from the harmful effects of radiation.KINS, on behalf of the Korean government, conducted radiation monitoring around nuclear facilities and analyzed the relevant samples.Furthermore, local government around nuclear facilities have operated their radiation monitoring system [32].
The received information about radioactivity is open to the public via the Integrated Network of radiation monitoring of the environment (IERNet) (figure 9) [33].

Discussion
To analyze and compare the nationwide monitoring systems of different countries, the criteria for displaying data on the electronic map about the state of radiation pollution were determined.The authors of the publication attributed to such measures (table 2): 1. Interface in national and English languages.2. Meteorological data (direction, wind speed, humidity, air temperature, and atmospheric pressure).3. The speed of updating the display of radiation monitoring data on the map.4. Number of radiation monitoring networks posts. 5. Coverage density of the radiation monitoring network, m 2 .6. Availability of mobile radiation monitoring stations.7. Coordinates of locations of stationary posts.8. Coordinates of locations of radiation-hazardous facilities: NPP, research reactor, specialized plants for the processing and storage of radioactive waste, uranium ore mining and processing enterprises, medical facilities that use radioisotopes.9. Availability and coordinates of radioactive monitoring stations of water bodies.10.Availability of these stationary monitoring stations for atmospheric air pollution by chemical substances and dust of various fractions.11.Ability to export monitoring data for a certain period to a separate file for an independent analysis.---------Each monitoring network is specific to a particular country, considering all its factors.Each country has information on the coordinates of the locations of stationary posts, and data on radiation pollution is updated daily.Unfortunately, the China map needs an interface in English, which complicates the data analysis process.We want to note that the highest coverage density of the radiation monitoring networks is in Germany; however, in some countries, information on the number of stationary posts was unavailable.As shown in table 2, all the studied countries have mobile radiation monitoring posts, but their number still needs to be determined, except for France.The availability of meteorological data and stationary monitoring stations for atmospheric air pollution by chemical substances and dust of various fractions was available in Sweden, Ukraine, and China.Also, exporting monitoring data for a certain period cannot be exported into a separate file for an independent analysis.
We also analyzed the availability of various reports on the functioning of the radiation monitoring networks of the countries mentioned above, which were found in public access.Accordingly, criteria were developed for the following reports (table 3): 1. Availability of materials in English.2. Frequency of updating the report on the functioning of the radiation monitoring networks in the country.3. The year of publication of the last general report on the functioning of the radiation monitoring networks in the country 4. Availability of information about radiation pollution from radiation-hazardous objects.
We want to note that over half of the countries have publicly available outdated reports (from 3-5 years).Notices provided by the International Atomic Energy Agency were public in English, while other pieces were available only in the national language and on other sites.In connection with the military actions in the territory of Ukraine, information about the actual state of operation of the radiation monitoring network is not displayed in open sources on the Internet, including at the NPP.--------

Author contributions
This section describes the contributions of each author to the research presented in this publication.
• Andrii V. Iatsyshyn: Idea, justification, and article outline; analysis of literature sources on environmental monitoring networks; analysis of Ukraine's existing monitoring system and identification of monitoring subjects; development of criteria for displaying radiation pollution data on the electronic map; recommendations for increasing the efficiency and information usefulness of Ukraine's radiation monitoring system.• Taras G. Ivaschenko: Analysis of literature sources on using monitoring data to solve environmental safety management problems in radiation-contaminated territories; analysis of the work of the National Emergency Operations Center (NEOC) and weather stations MeteoSwiss (Switzerland) in the field of radiation safety; development of criteria for displaying radiation pollution data on the electronic map; recommendations for increasing the efficiency and information usefulness of Ukraine's radiation monitoring system.

Conclusions
One of the main aspects of nuclear and radiation safety is radiation monitoring in the territories where hazardous radiation facilities are located, which various legal acts regulate.Therefore, the effective functioning of radiation monitoring networks is an essential task for every country of the health of personnel working at hazardous radiation facilities and the population living in contaminated areas.
A critical analysis of the functioning of nationwide monitoring systems of various countries of the world showed that these systems have differences in their organization (density of coverage, technological and scientific support, transmission, processing, and display of data).
The criteria for displaying data on the electronic map about the state of radiation pollution and for reporting on the functioning of nationwide radiation monitoring networks, which showed the advantages and disadvantages of such systems, were defined.
Several recommendations are given for improving Ukraine's radiation monitoring systems for monitoring entities, which will increase their efficiency for information usefulness.
To improve the radiation monitoring systems of Ukraine, the authors suggest the following: • to improve and optimize the notification system for receiving daily information; • increase the coverage area of monitoring network posts to obtain more accurate information about radiation pollution; • increase the number of mobile surveillance posts; • on the electronic map, which displays the state of radiation pollution, indicate the coordinates of the locations of radiation-hazardous objects (NPP, research reactors, specialized plants for processing and storing radioactive waste, enterprises extracting and processing uranium ores, and medical facilities using radioisotopes); • make it possible to export monitoring data for a certain period into a separate file for independent analysis; • implement an interface of maps and reports in English to provide information to the broader masses; • to update quarterly publicly available reports on the radiation status of the territory of Ukraine, including on the websites of relevant international organizations; • to prove information on radiation pollution from radiation-hazardous objects.

Figure 6 .
Figure 6.Location of the nationwide network of monitoring stations [27].

Figure 9 .
Figure 9. Integrated Network of radiation monitoring of the environment [33].

2. 7
. Switzerland National Emergency Operations Centre (NEOC) has its radioactivity monitoring network -NADAM.It consists of 76 stations, placed on the metrological stations MeteoSwiss in all territory of Switzerland (figure 10), that transmitted the measured values at ten-minute intervals to the NEOC [34].

2. 8
. China Mainland China is building and exploiting 56 nuclear power units as of 31 March 2022; 38 are operating units.All data about NPP and environmental radiation monitoring can receive at the website http://spi.mee.gov.cn:8080/spi(figure11)..

Figure 11 .
Figure 11.Information about the Chinese NPP location.

Table 2 .
Criteria for a report on the functioning of the radiation monitoring networks.

Table 3 .
Criteria for a report on the functioning of the radiation monitoring networks.

•
Iryna V. Matvieieva: Analysis of literature sources on the development of software for analysis and visualization of monitoring data; features of operation, construction, and transmission of measured data of the French radiation monitoring system network; features of the process and construction of environmental radiation monitoring networks in China and Hong Kong; development of criteria for displaying radiation pollution data on the electronic map.•Julia V. Zakharchenko: Functions and role of the Swedish Radiation Safety Authority; principles of operation of Sweden's monitoring stations using special software; principle of operation of the German nationwide monitoring network, network density and its construction, transmission of monitoring data; analysis of the availability of various reports on the functioning of radiation monitoring networks of the countries considered in the publication, which were found in public access, and development of criteria for such statements.• Anastasiia M. Lahoiko: Substantiation of the relevance of the research; analysis of literature sources on the development of equipment for radiation monitoring networks; analysis of the national monitoring system RadNet (United States of America), features of its construction and operation of the corresponding equipment; role of the Korea Institute of Nuclear Safety (KINS) in implementing state-level radiation monitoring, the functions and analysis of the Integrated Environmental Radiation Monitoring Network (IERNet); analysis of the availability of various reports on the functioning of radiation monitoring networks of the countries considered in the publication, which were found in public access, and development of criteria for such messages; recommendations for increasing the efficiency and information usefulness of the functioning of Ukraine's radiation monitoring system.1254 (2023) 012109