Novovoronezh NPP Experience in Applying the Methodology for Measurement the Activity, Radionuclide Composition of Radioactive Waste in the NZK type Containers Using the «Satellite» Software

The article analyses the results of application of the radioactive waste activity measurement method based on measuring the energy distribution of gamma radiation near the container at the Novovoronezh NPP. The proposed method is applied to homogeneous radioactive waste and provides a reduction of the characterization costs. The results of an experimental study of the method and proposals for its improvement are presented.

Decontamination of Victims in the Event of a Radiation Accident at the Stages of Provision Medical Care

Purpose: To summarize and analyze the results of research and practical recommendations on the decontamination of victims in the event of radiation accidents, including taking into account the authors’ experience gained in the initial period of the Chernobyl accident (April – August 1986) and in other local radiation accidents (incidents), as well as during emergency exercises. Results: The indications for carrying out decontamination and the technique of its implementation were considered, a comparative assessment of the effectiveness of skin decontamination agents was presented. Recommendations were formulated for determining the priority (urgency) of carrying out decontamination, depending on the level of external radioactive contamination of the victims. Criteria, rules and methods for carrying out decontamination were proposed for use in relation to the practice of medical and hygienic measures at the stages of medical evacuation (accident site, enterprise health center, enterprise sanitary inspection department, triage site, hospital admission department). The features of decontamination of victims with combined radiation injuries and contaminated wounds (burns) were considered, issues of ensuring the radiation safety of medical personnel who provide assistance to victims are touched upon. Conclusion: Timely and correctly performed decontamination reduces the exposure of the skin, prevents the entry of radioactive substances into the body and the transfer (spread) of radioactive substances to the subsequent stages of medical evacuation. The main criteria for the urgency (priority) of carrying out decontamination are the levels of radioactive contamination of the skin, contamination nature (radionuclide composition, physicochemical form, etc.) and the presence of victim’s skin lesions (wounds, burns). Decontamination of victims with high levels of radioactive contamination should be considered as a part of the first and subsequent emergency health care and should be carried out as prescribed or with the direct participation of a healthcare professional. At the stages of medical evacuation, decontamination can be carried out if the victim’s condition is stabilized. In the case of a serious condition of the victim, the priority is evacuation to a hospital, while in the prehospital period, as a rule, only partial decontamination of skin areas with high levels of contamination can be carried out. The procedure and rules for decontamination, including the use of skin decontaminating agents, should be reflected in the action plans of the personnel of radiation hazardous enterprises and the plans for medical support of medical units of the FMBA of Russia.

Modelling of Pulse Height Spectra of Gamma Detectors for Simplified Models of a Radioactive Cloud

The paper considers the issues of determining the pulse height spectra of gamma detector from a radioactive cloud. This task is of interest from the point of view of possible improvement of existing systems for monitoring the radiation situation around nuclear power plants and nuclear industry enterprises due to the wider use of gamma-spectrometric equipment. Modeling of pulse height spectra will allow conducting research on the capabilities of monitoring system posts for detecting radionuclides in the radioactive cloud. A general approach to modeling pulse height spectra using division of the radioactive cloud into elementary gamma sources is developed. The pulse height spectra of scintillator NaI ∅63×63 mm are calculated for simplified models of the radioactive cloud in the form of a linear gamma source and a semi-infinite space. The obtained data can be used for rapid estimates of pulse height spectra, while the formulated approach to spectra modeling also allows for more time-consuming calculations for an arbitraryshaped radioactive cloud with an arbitrary radionuclide composition.

Radionuclide Composition of Airborne Discharges of European NPPS With WWER, Pressurized Water Reactor, and Boiling Water Reactor Facilities

The article presents the analysis of the data on radionuclide composition of airborne discharges of 52 European nuclear power plants (NPPs) with water–water energetic reactor facilities (WWER), pressurized water reactor facilities (PWR), and boiling water reactor facilities (BWR) under normal operation conditions. It contains lists of radionuclides, registered in discharges of researched NPPs, and gives estimation of contributions of radionuclides, forming the discharge, into total activity of discharge and into total effective dose, created by the discharge activity. It was determined that the maximal contribution into discharge activity of all researched NPPs make noble gases, tritium, and carbon-14, while the latter is the main dose-making radionuclide.

Factors affecting the minimum detected activity of the GAMMAVISION software report protocol

The article presents the results of a gamma- spectrometer study with a low- capacity scintillation (NaI(Tl)) detection unit, with software GammaVision v.8, adopted to solve certification problems, including for measuring activities close to zero. The list of factors influencing the presentation of the minimum detected activity (MDA) in the report protocol is analyzed software GammaVision v.8. To perform the measurements, the company´s ORTEC gamma-spectrometer with a low-capacity detection unit a type digiBASE-RH, in which a high-voltage power supply unit, amplifier, digital multi-channel analyzer with USB-connection to a computer with the installed driver are installed, was used. The peak search in the library was performed using a compressed version of the library, which contains two nuclides 137Cs and 40K. Methods of calculating MDA are based on the intensity of accounts. Nuclide activity is calculation for all peaks in the library, the energy of which is in the selected energy ranges for analysis. Measurements and calculations MDA under the given conditions of research for five methods depending on time of measurement and geometry of measurements are carried out. It is shown that the level of MDA can be reduced by choosing the optimal conditions, time of measurement and geometry of measurements. Recommendations are given for the use of capacity for counting sample, which will reduce the amount of substance required for analysis and optimize the time spent on measuring the counting sample. In a prospect it is expedient to undertake a study of dependence of MDA from the physical properties and radionuclide composition of the substance for the counting sample and the dependence from the uncertainty in the equation MDA.

Approaches to the Establishment and Justification of the Size of Emergency Planning Areas around NPPs

Emergency planning zones around facilities that use radiation and nuclear technologies are set up in order to prevent or minimize deterministic effects and reduce risks of stochastic effects of radiation exposure in case of nuclear or radiological emergency. In international practice, in order to enhance effectiveness of response to emergencies, it is common to set up emergency planning zones for nuclear facilities in accordance with their level of threat for the environment and public. As the establishment of such zones requires certain material resources, the size of the zones is to be justified. As of today, sanitary-protective zone and monitoring zone in Ukraine could be considered, to a certain extent, as analogues of such emergency planning zones. However, the main functional load of these zones are relevant more for routine operation of nuclear facilities than for the issues of emergency planning and do not have such a specific for the emergency planning zones functions as ensuring necessary infrastructure for conducting such urgent protective actions as evacuation, sheltering, notification, relocation and others in case of severe accidents at NPPs. Absence of transparent numerical criteria for determining the size of emergency planning areas, on one hand, and necessity to determine such areas as required by the key IAEA publication GSR Part 7, as well as due to understanding the importance of emergency planning areas in the state emergency response system, on the other hand, make the task on establishing approaches to the definition of the scope of emergency release, which is a framework for emergency zoning, crucial. The paper proposes to discuss two approaches to defining the scope of the boundary release, according to which the size of the emergency planning areas is to be defined. The paper presents results of assessing the size of the emergency planning areas around NPPs based on the scope and radionuclide composition of the boundary release.

On the Indicators of the Radioecological Situation at the Mid-Botuobin Oil and Gas Condensate Field with Underground Nuclear Explosions

The results of expeditionary and laboratory studies of the radiation situation of 2001–2002 and dosimetry measurements of 2017 are presented. there are small radioactive spots. The radionuclide composition in the soil-vegetation cover of the impact zones of the underground nuclear explosion has been studied. Data obtained prior to the industrial development of the field are reperator for further radioecological research and can be used by subsoil users in the development of the area.