The Department of Radiation Safety and Regime (hereinafter - ORBiR) is an independent structural subdivision of the Polesie State Radiation and Environmental Reserve, whose activities are aimed at carrying out the entire range of radiation control measures during work in zones of radioactive contamination. The purpose of radiation control on the territory of the institution is to ensure safe working conditions for personnel working in the territory contaminated with radionuclides, as well as to take measures to prevent the spread of radionuclides outside the territory of the reserve.
The Department of Radiation Safety and Regime consists of a sector for individual dosimetric control and a group for radiation monitoring of environmental objects.
The Department of Radiation Safety and Regime is headed by the head of the department and has 13 employees, of whom 8 work in the Khoiniki region, 3 in Bragin and 2 in Narovlya.
The main tasks of the department of radiation safety and regime:
- measurement of radiation factors affecting external and internal dose loads, namely: control of the dose rate of gamma radiation, flux density of alpha and beta particles, measurement of the content of gamma-emitting radionuclides in the human body;
- control of the content of radionuclides in the air of the working area;
- dosimetric support of work performed by employees of the Polesie State Radiation and Environmental Reserve in the territory with a dose rate exceeding 11.7 μSv/h;
- organization and implementation of contamination control of vehicles and goods exported from the zone of radioactive contamination at checkpoints along the perimeter of the Polesie State Radiation and Environmental Reserve;
- quality control of decontamination of special equipment, overalls and vehicles at decontamination stations Babchin, Savichi, Konotop;
- systematic monitoring of the radiation situation at workplaces, in premises, on the adjacent territory of facilities located in the zone of radioactive contamination, as well as over the disposal of radioactive waste.
- annual examination of knowledge on radiation safety by heads of departments and personnel.
- conducting security measures related to taking into account visits to the zone by employees of third-party organizations, coordinating transport routes for persons who have arrived on a business trip, checking the availability of passes for employees of third-party organizations arriving to work in the evacuation (alienation) zone, monitoring the mode of operation of the reserve, etc.
External exposure of personnel
On the territory of the institution, the main radionuclides that form the external dose are Cs-137, the dose-forming contribution of which is about 90%, and Sr-90.
The determination of individual doses of external exposure of the reserve workers is carried out on a quarterly basis using thermoluminescent dosimeters (TLD). In 2019, 615 people are under individual dosimetry control in the reserve: 350 people in the Khoiniki area, 116 in Narovlyansky and 149 in Bragin.
Internal exposure of personnel
A direct source of obtaining reliable information on the content of radionuclides and the levels of internal exposure of people is the lifetime measurement of the content of γ-emitting radionuclides in the body using a human radiation spectrometer. This information is necessary for making decisions on conducting and evaluating the effectiveness of measures to protect personnel from exposure to ionizing radiation..
The main goals of in vivo measurements of incorporated activity in the human body are as follows:
- identification of cases of accumulation of radioactive substances above average age values in the body of individual citizens to search for sources of increased accumulation of radionuclides and take specific measures to reduce the level of exposure;
- study and prediction of the medical consequences of internal irradiation of workers and employees working on the territory of the reserve;
- ensuring the rights of workers and employees of the reserve to receive reliable and timely information on the levels of internal exposure;
- forecasting the levels of internal exposure of the reserve personnel.
In the scope of work carried out by the Department of Radiation Safety and Regime, dosimetric control includes:
- accounting of the actual working time of personnel in the territory contaminated with radionuclides;
- control of the terrain and objects in the work areas with the measurement of the dose rate of gamma radiation and the flux density of alpha and beta particles;
- control of contamination with alpha- and beta-emitting radionuclides of special clothing and footwear of personnel working in the zone of radioactive contamination;
- control of contamination by alpha- and beta-emitting radionuclides of administrative, production and storage facilities located on the territory of the zone of radioactive contamination, measuring the dose rate of gamma radiation at facilities;
- control of pollution by alpha- and beta-emitting radionuclides of vehicles and transported goods from the zone of radioactive contamination;
- control of the efficiency of decontamination of the machine and tractor fleet and overalls at decontamination stations (SD "Babchin", SD "Konotop" and SD "Savichi").
Radiation monitoring at reference sites
In order to assess changes in the radiation situation on the territory of the reserve in 1997, 8 reference sites were laid, which are located near the former settlements or in settlements bordering the territory of the reserve. The breakdown of reference sites was carried out in such a way as to cover territories with different values of pollution density.
Benchmarks based on the measured values of gamma radiation power at a height of 1 m can be divided into three groups: the first - up to 1 µSv/h (Babchin, Novoselki, Savichi); the second - 1 - 5 μSv/h ("Pogonnoe", "Masany", "Orevichi", "Kulazhin"); the third - more than 5 μSv/h ("Hooks").
The highest values of the power of gamma radiation (up to 9.5 μSv/h) are observed in Kryuki.