Ukrainian Nuclear Power Plants Research Articles

Assessing the Role and Viability of Nuclear Power in Ukraine's Post-War Energy Strategy

Ukraine's nuclear power industry is partially under russian occupation, which poses a significant energy threat. This applies to both Ukraine and European countries. Nuclear power plants in Ukraine operate on imported uranium. The article analyses trends in the development of nuclear energy in the world and in Ukraine. The energy system of Ukraine depends on imported uranium. The article presents an assessment of the exhaustibility of uranium resource. Steps to improve the safety of nuclear energy are presented and the necessity of transition to green energy is substantiated. The problems of atomic energy of Ukraine in conditions of sustainable development are analysed. Keywords: energy, uranium, resource exhaustibility, energy strategy, nuclear power plants

Radiocaesium in mosses from the Kopački rit Nature Park in Croatia: searching for undeclared releases from nuclear facilities in war-torn Ukraine.

The invasion of Ukraine and military operations around Ukrainian nuclear power plants and other nuclear facilities have prompted us to search for radiocaesium in mosses from the Kopački Rit Nature Park in Croatia, since mosses are known bioindicators of airborne radioactive pollution, and Kopački Rit is a known low radiocaesium background area. Sampling was finished in August 2023, and our analysis found no elevated radiocaesium levels. Kopački Rit therefore remains a suitable place for future detection of anthropogenic radioactive pollutants.

IODINE FILTER CONTROL STAND (SKIF) FOR CERTIFICATION CARBON SORBENT VENTILATION SYSTEMS OF NPP

The article provides information on the creation of the first iodine filter control stand (SKIF) in Ukraine, designed to determine the coefficient of purification of gaseous radioactive emissions from iodine and methyl iodide by sorbents used in ventilation systems at Ukrainian nuclear power plants. The possibility of using a stable isotope of iodine to determine the adsorption capacity of carbon sorbents is substantiated. The development, installation, start-up and adjustment of the pumping module and the measuring module were carried out when using air mixtures with methyl iodide based on the stable isotope of iodine 127I. The developed software allows you to use the stand in automatic mode. The manual for the operation of the SKIF stand was created and the method of determining the coefficient of purification of ventilated air from methyl iodide by carbon sorbents was certified within the framework of the enterprise standard.

Magnetite-ferrocyanide-copper sorbents for recovery of cesium ions from low-activity liquid radioactive waters

The article is devoted to the development of nanoscale sorbents based on copper ferrocyanide and magnetites for the removal of cesium, strontium, and heavy metal ions in their simultaneous presence in a multicomponent two-phase low-level radioactive solution containing complexing agents and surfactants. It they noted that the highest values of cesium ion removal from low-level radioactive water - 99.96% and 99.62% - are obtained with sorbents based on 100% copper ferrocyanide and a mixture of copper ferrocyanide and industrial magnetite in a ratio of 2 to 1. The efficiency of the sorbents in terms of the distribution coefficient is 2394 and 1589.7 ml/g, which ensures the purification of radioactive water from trace concentrations of cesium ions to values of 2394 and 265.11. These sorbents provide water purification to values less than 2 Bq/cm3, which is typical for 1-4 classes of water quality in terms of radiation safety of groundwater and surface water as sources of centralised drinking water supply. It is noted that sorption of cesium ions on copper ferrocyanide and magnetite is carried out in the presence of water molecules and hydroxo groups. It is shown that artificial magnetite in its pure form exceeds the sorption capacity of industrial magnetite. This is due to the difference in the phase composition and particle size of the crystals. The results obtained will be use as components of the technological process in the Plasma-Sorb technology developed at the State Institution "The Institute of Environmental Geochemistry" of the National Academy of Sciences of Ukraine for the treatment of low- and intermediate-level radioactive water from Ukrainian nuclear power plants.

Nuclear Aspects of the Russia-Ukraine War and its Implications for Nepal

Nearly two years old Russia-Ukraine war seems to go on for a long period. The United States and European Union are supporting Ukraine’s offensive to regain their lost land. The Russian threat to use nuclear bombs at the outset has taken the world by great surprise. The use of a megaton nuclear bomb could lead to unimagined catastrophe killing a billion people, and a nuclear winter could set in leading to a worldwide famine that could kill millions more. The nuclear watchdog of the United Nations - the International Atomic Energy Agency, is keeping track of Europe’s largest nuclear power plant in Ukraine. Nuclear-related international treaties are fast becoming ineffective and World War III could be possible. This war is, however, coming to a stalemate. Peace initiatives taken are ineffective so far. This war must end soon and nuclear weapons should remain as deterrence and should not and never be used to save mankind.

The people of Chernobyl: a community of loss in Svetlana Aleksievich’s Chernobyl Prayer

Svetlana Aleksievich conducted hundreds of interviews with those affected by the explosion at the Chernobyl Nuclear Power Plant in Ukraine and her native Belarus and assembled them in her 1997 novel Chernobyl Prayer. A Chronicle of the Future. Aleksievich, awarded the Nobel Prize in Literature in 2015, created a complex, polyphonic blend of oral history and literature and provided a fragmentated and diverse narrative of memory, trauma, and victimhood. The article examines Aleksievich’s rendition of the ways in which “the people of Chernobyl” convey their own understanding of this identity. The many voices of Aleksievich’s novel coalesce to speak for what Serguei Oushakine calls a community of loss. The article traces the articulation of their identity: from the frustrated search for appropriate discursive tools and points of reference, to the explicit sense of having formed a unique social entity, a community. This transition is also a progression, through the process of articulation and analysis, from a negative identity, defined by loss and a radical change in status, to one enhanced by philosophical and environmental awareness. This is also a shift from the mainstream Soviet worldview and identity to other more complex, albeit less comforting perspectives.

The Determination of the Efficiency of Cooling Systems of Nuclear Power Plants of Ukraine in the Conditions of Global Climate Changes

The Determination of the Efficiency of Cooling Systems of Nuclear Power Plants of Ukraine in the Conditions of Global Climate Changes

Automation of the procedure for determining the admissibility of erosion- corrosion wear in pipelines of nuclear power plants made of carbon steels

Many pipelines in Ukrainian nuclear power plants have been in operation for over 30 years, and the determination of the admissibility of erosion-corrosion wear (ECW) defects in the pipeline wall metal is currently one of the pressing issues in the nuclear energy sector of Ukraine. A comparative analysis of determining the admissibility of pipe wall thinning due to ECW was conducted using the adopted methodology “MT-T.0.03.224-18” by the State Enterprise “Energoatom” and the guidance based on the use of regulatory documents for designing pipeline elements. The use of the methodology demonstrated significant advantages in terms of reducing the conservatism of ECW assessment, especially for small-scale thinning and pipelines operating at pressures below 60-80 kgf/cm2, which allows for a substantial reduction in repair work. However, the implementation of the methodology in practice may encounter difficulties due to the complexity and labor-intensiveness of the calculation assessment procedure for nuclear power plant personnel. Therefore, to automate the ECW admissibility assessment in accordance with the methodology requirements, software (SW) was developed for use by nuclear power plant personnel, enabling the prompt generation of a protocol for the express assessment procedure of ECW admissibility for a straight section of the pipeline based on the measurement results of wall thinning parameters in the axial direction. The software allows for concluding whether the section can be put into operation, sent for repair, or requires further refined assessment. Additionally, software based on the finite element method (FEM) was developed, which, when necessary, allows for a refined assessment of a straight section, taking into account the depth and angle of thinning in the circumferential direction, and calculates the stress of the limit plastic state of the pipeline section with ECW from the perspective of viscous fracture. The devel- opment is applicable in the field of nuclear energy in Ukraine.

Modern approaches to strength design substantiation for critical elements of WWER NPP reactor internals

This study presents the theoretical and applied results on the development and application of refined models and methods for solving actual problems of mechanics related to the substantiation of strength and forecasting the service life of elements of the primary circuit equipment of WWER nuclear power plants (NPPs). The scientific and applied developments take into account current trends in global practice and contain new conceptual approaches to solving nonlinear boundary value problems in the mechanics of deformed structures. Refined mathematical models have been proposed and theoretically substantiated to describe non-isothermal inelastic deformation processes, taking into account the deformation history of thermal and power loading, radiation effects of hardening, swelling and creep of irradiated metal, and accumulated damage of brittle-ductile fracture. The obtained scientific results are the basis for the methodology of refined design strength analysis and residual life assessment of critical elements of the equipment of the first circuit of WWER reactor units to solve urgent problems of ensuring the conditions for safe operation of Ukrainian NPPs and justifying the terms of their service life extension

THE IMPACT OF THE IMPLEMENTATION OF ELECTRIC TRANSPORTATION ON THE UKRAINE’S INTEGRATED POWER SYSTEM FUNCTIONING

The rapid development of electric transportation in the world is due to significant economic and ecological advantages. The Ukrainian government also is planning to develop a national strategy and plans for the implementation of electric transportation. But the additional load poses challenges for Ukraine’s Integrated Power System. The analysis of the influence of electric transportation introduction on Integrated Power System operation would facilitate its effective government implementation. The aim of this paper was to estimate the effect of implementation volumes of electric transportation on the Integrated Power System operation, fossil fuel consumption, greenhouse gases, and pollutant emissions. A set of calculations was carried out for electric transportation volumes from 30 to 420 thousand electric vehicles by step 30 thousand based on a program and information complex simulating the operation of Ukraine's Integrated Power System, which has been developed in the Institute of General Energy of the National Academy of Sciences of Ukraine for the past few years. The calculations show that the share of nuclear power plants in Ukraine’s Integrated Power System increases according to the growth of the electric vehicles fleet. Therefore, it is expected to decrease fuel consumption as well as greenhouse gases and pollutants emissions. Fuel intensity is reduced by approximately 5% for electric transportation volume of 150 thousand and approximately 8% for 300 thousand. Specific emissions decrease faster due to the ratio of coal and gas power plants. Fuel intensity considerably varies from 0.07 (Summer) to 0.15 (Winter) tce/kWh. In general, the additional load from the implementation of electric transportation positively affects the energy system of Ukraine, increasing the efficiency of its operation by reducing specific fuel consumption. It should be noted that such trends are observed exclusively for Ukraine due to the specific structure of Ukraine's Integrated Power System with the large share of nuclear energy. Keywords: electric transportation, Ukraine’s Integrated Power System, greenhouse gas emissions, pollutant emissions.

An Increase in the Energy Efficiency of a New Design of Pumps for Nuclear Power Plants

The reliability of pumping units at nuclear power plants (NPPs) is critical in terms of their energy efficiency and safety. Remarkably, WWER-1000 reactors at Ukrainian NPPs are equipped with outdated pumping units that have already served their full-service life. This fact leads to an urgent need to develop a new, more efficient pump. In the article, a promising pump, ACNA 600-35, was developed. It was designed to increase the energy efficiency of pumps TX 800/70/8-K-2E, applied at the holding pool and the industrial circuit of the nuclear reactor. Since these pumps should be imported from the monopoly suppliers, this affects both the energy efficiency of pumping equipment and the energy independence of Eastern Europe. The proposed pump ACNA 600-35 is characterized by an increased efficiency of up to 0.12–0.13 compared with the TX 800/70/8-K-2E pump. In general, the life cycle cost of the proposed pump is 15–20% lower than for the analog TX 800/70/8-K-2E. The design of the developed pump ACNA 600-35 and the related pumping unit based on its production at industrial facilities allows for further development of the industrial and fuel-energy complex, increasing the state’s energy independence and employment. According to expert estimates, the average economic effect from supplying the developed pump can reach 10 mln USD/year.

Influence of the Crosstalk Effect on the Correct Determination of the Affected SG During Prise Accident in VVER-1000

The practical implementation of automated systems for management of primary-to-secondary leakage is a crucial issue for operational safety improvement at Ukrainian nuclear power plants. In this case, one of the main indicators of the primary-to-secondary leakage is the activity concentration increasing in the main steam lines of the affected steam generator. The detailed analysis of the geometrical features, arrangement of the main steam lines of the steam generator in VVER-1000 and radiation detectors allow identifying the crosstalk effect and its influence on the correct determination of the affected steam generator.
 The paper describes the main components of the developed models in the detection region in MCNP6.2 software. For the correctness of the comparative analysis, the distance between two adjacent main steam lines of the steam generators remains constant in all models. The radiation detectors have been modelled in the regular location and adjacent to the main steam lines of the steam generator. The registration efficiencies of ionizing radiation from 16N by the sensitive elements of the detectors such as BDMG-04-02, SGLM-201-1 and GIM-204 have been assessed. BDMG-04-02, SGLM-201-1 and GIM-204 responses, depending on the activity concentration of 16N in the detection area and considering the nonproportionality features of the devices, have been estimated. The presence of crosstalk effects has been confirmed. The significant influence of the paralyzing and non-paralyzing dead time on the reliable determination of the activity concentration and correct identification of the affected steam generator have been emphasized.
 The obtained results can be used as initial data for justification of system setpoints for launching the automated algorithm to manage the primary-to-secondary leakage accident without operator’ actions and fulfill its improvement.

CONCEPTUAL APPROACHES OF ORGANIZING PROCESSES OF VERIFICATION OF SOFTWARE PROJECTS OF CRITICAL INFORMATION-CONTROLLED SYSTEMS ON THE BASIS OF REQUIREMENTS FOR THEIR LIFE CYCLE

The implementation of an effective technology to ensure the required level of quality of software systems is one of the urgent and important tasks of software engineering. It is especially important to solve this problem for critical information management Ukrainian nuclear power plants. Ensuring the required quality of software systems requires an understanding of the process of organizing the verification of software projects. The purpose of this study is to review the main conceptual approaches to the organization of verification processes for software projects of critical information management systems based on the requirements for their life cycle. To achieve this goal, the authors considered the automation of Ukrainian nuclear power plants in the form of software and hardware complexes and the general principles for the implementation of critical information management systems based on programmable logic controllers, analyzed the processes of verifying the user's applied logic in these systems, reviewed the main procedures for verifying the applied logic of a special RadiCS platforms.

DETERMINATION OF THE TEMPERATURE FIELD DISTRIBUTION IN THE WINDING RODS OF THE STATOR OF TURBOGENERATORS OF TYPE TVV FOR PURPOSES OF CONTROL AND DIAGNOSTICS

Turbogenerators were and remain the most unreliable element at nuclear power plants in Ukraine. The most dangerous disturbances in the operation of turbogenerators of the TVV type is complete or partial blockage of the hollow conductors of the stator winding. The systems of operational control and technical diagnostics today, in a number of cases, cannot cope with the identification of these phenomena. The complex application of adequate mathematical models, indications of the standard thermal control system and new diagnostic features give the opportunity with sufficient accuracy for practical purposes to detect blockages in the hollow conductors of the stator windings of these turbogenerators. The aim of the work is to develop a program for calculating the three-dimensional temperature field in the rods of the stator winding of a turbogenerator of the TVV-1000-2U3 type, taking into account the temperature field of the stator core, to carry out a test calculation and to compare the experimental and to calculated data. The problem is solved with the help of the finite difference method using the integro-interpolation method.

DETERMINATION OF POTENTIAL AREAS OF INFLUENCE ON THE ROMANIAN TERRITORY OF UKRAINIAN NUCLEAR POWER PLANTS IN THE CONTEXT OF THE CRISIS GENERATED BY THE RUSSIAN-UKRAINIAN CONFLICT

In the context of the crisis generated by the Russian-Ukrainian conflict, radiological situation forecasts were made within the National Institute of Research and Development for Physics and Nuclear Engineering "Horia Hulubei" (IFIN-HH) for all nuclear power plants in Ukraine. Therefore, the resident decision support software systems for radiological and nuclear emergencies were used, with the main purpose of identifying potential areas of influence on the territory of Romania generated by Ukrainian power plants, as consequence of military actions. In the absence of pertinent and confirmed information, two hypothetical scenarios were considered by which the radioactive material could be dispersed into the atmosphere, for which appropriate accident source terms were built, using methods validated and approved by the international organizations in the field. The monitoring of the radiological situation of the Ukrainian nuclear power plants was carried out over a period of several months starting from the first day of the conflict outbreak. In the paper are presented comparative results obtained with two software systems for a representative case at the Zaporozhe Nuclear Power Plant, the largest nuclear power plant in Europe, situated in the center of several disputes.

A MANAGEMENT DECISION-MAKING ALGORITHM FOR PLANNING ACTIVITIES TO REDUCE THE PRODUCTION RISK LEVEL

It is important to minimize the negative consequences of exposure to hazardous and harmful production factors that constitute a danger to the health of workers, through the introduction of effective technical and organizational measures and personal protective equipment. The aim of the article is to develop a sequence of implementation of safety measures to reduce the risk of occupational diseases among employees of nuclear power plants in Ukraine. The research methodology is based on the analysis of the peculiarities of working conditions, the determination of dangerous and harmful production factors and the choice of an optimization model of support systems in decision making. Statistical data and research findings have confirmed that the poor health and safety of workers is due to inefficiency of available occupational safety management methods, limited implementation of the latest technical and economic arrangements, imperfect methods of limiting the impact of hazardous and harmful production factors, and insufficient funding for such activities. In the general case, the implementation of management methods that provide the safety of life and health of workers and ensure risks are kept at a reasonably low level is to choose the optimal set of technical and organizational arrangements, determine the sequence of their introduction, to control their implementation and evaluation of their results. The article proposes a method of discrete step-by-step optimization of the sequence of implementation of security arrangements. The method involves setting of the most important criterion and a number of limitations. The method modified to the requirements of the set tasks is aimed at choosing the optimal within the framework of the general annual financing of technical and organizational arrangements and means of individual protection of employees and reducing the levels of risk in individual workplaces.

"Human factor" in emergency situations development at Nuclear Power Plants in the conditions of war

Since the beginning of Ukraine's full-scale war with the russian federation, the personnel of two Ukrainian Nuclear Power Plants (NPP) (Chornobyl and Zaporizhzhya) have been held hostage by the russian occupiers and subjected to intimidation and abuse. An additional strong stress factor can significantly affect the decision-making of NPP control panel operators, increases the probability of erroneous actions in the event of emergency situations, and can even become their cause. The purpose of our study was to determine the possible influence of the "human factor" on the development of emergency situations, as well as additional parameters for monitoring the health and psychological state of NPP operators working as hostages. Fourteen expert psychologists with at least 10 years of experience in the field of extreme psychology were involved in the study. After the introductory seminar, they were offered a questionnaire to determine the range of professionally important qualities that have the greatest impact on the effectiveness of professional activity. The results of the expert evaluation became a hypothesis for the next stage of research on the possible influence of the temperament of operators on resistance to the stress of captivity. The technique of professiograms and psychograms separation, methods of scaling and balancing, methods of mathematical statistics and system analysis were used for the research. One hundred and twenty-four anonymous psychological examination cards and occupational profiles of NPP control panel operators who received a license for professional activity in Ukraine or improved their qualifications within the period of 2017‒2020 were analyzed. The predominant types of psychological reactions according to subjective-objective indicators in response to significant stressful situations were studied, and the types of temperaments were determined. The ability to perform professional functions at high and medium levels was recorded in 79 sanguine operators (63.2% of the total number of examined), in 16 choleric operators (12.8%), and was not recorded in melancholic operators. Also, high and medium levels of neuropsychological stability of operators were recorded in 74 sanguine operators (59.2% of the total number of examined), in 6 choleric operators (4.8%), and was not recorded in melancholic operators. To assess the psychological state of NPP control panel operators, it is proposed to use a retrospective analysis of interrelated parameters necessary for the performance of professional functions and indicators of neuropsychological stability. The study of additional parameters of the psychological state will allow to reduce the influence of the "human factor" on the risks of creating or untimely correction of emergency situations. Keywords: professionally important qualities, nuclear terrorism, hostages, performance of professional functions, neuropsychological stability, NPP control panel operators.

Calculation of the Absorbed Dose by a Borosilicate Glass Matrix and its Simulated Irradiation

The state of liquid radioactive wastes (LRW) management at Ukrainian Nuclear Power Plants (NPPs) is characterized by the lack of a completed technological cycle from processing to obtaining the final product suitable for further long-term storage or disposal. As a result, the storage tanks for bottoms residue (BR) are 65-75% full (Zaporozhye and South-Ukrainian NPPs), and the resource for placing molten salt at Zaporizhzhya NPP (92.7%) is close to exhaustion [1]. Therefore, the development of technologies and materials for NPP LRW solidification is an urgent need and aims to ensure the processing of LRW to a solid state that will meet the acceptance criteria for disposal in centralized storage facilities. One of the effective methods of LRW solidification is their vitrification. The main advantage of vitrification is that during the vitrification process the volume of waste is reduced by several times and this saves expensive storage space [2, 3]. The purpose of this work is to calculate the absorbed dose that borosilicate glass matrices with included bottoms residue will accumulate over 300 years of storage, and to study the effect of simulated X-ray irradiation on their physical and mechanical properties.

LOW CARBON ENERGY 2. Hydrogen energy: problems, achievements, possible risks (review)

Ways to reduce the carbon capacity of Ukraine's economy through the active use of energy efficiency measures in energy, extensive use of renewable energy sources, in particular hydrogen, with possible problems and risks of transition to low-carbon energy. The aim of the work is to assess the contribution of hydrogen use in the perspective of achieving decarbonized energy of Ukraine, taking into account the advantages, available achievements and obstacles to the movement of the economy on this path. To this end, estimates of energy efficiency of primary energy resources according to the EROEI indicator, in particular, renewable energy sources; indicators of environmental friendliness of basic energy resources according to specific (per unit of energy) greenhouse gas emissions are given; IEA data on the volume of global investments in energy efficiency are presented.
 The main scientific and technical results of recent times in the field of research on the processes of production, transportation and end use of hydrogen, obtained by teams from a number of institutes of the National Academy of Sciences of Ukraine. The problems of hydrogen energy are in the focus of close attention of scientists in the country. The use of Ukrainian nuclear power plants for hydrogen production is considered.
 Particular attention is paid to the materials of the draft Hydrogen Strategy of Ukraine until 2050, according to which the volume of hydrogen production in the final period of implementation will be up to 330 billion nm3 annually.
 The risks of formation and development of energy at RES are assessed, the optimal scenarios of the country's economic development are considered.

Expert express assessment of the impact of heat and mass transfer processes on the residual life of the WWER-1000 reactor vessel due to metal embrittlement

The WWER-1000 reactor is operated at 13 of the 15 operating power units of Ukraine's nuclear power plants (NPPs). Ensuring long-term and safe operation of such reactors is the basis for reliable operation of all 13 Ukrainian nuclear power plants units and the guarantor of Ukraine's energy security. The determining and leading factor influencing the safety and proper residual life of the WWER-1000 reactor vessel is the radiation embrittlement of the reactor steel. The consequences of radiation embrittlement of reactor steel are negatively manifested in emergencies with cooling of the core. This process itself – radiation embrittlement – accumulates constantly and gradually. Therefore, it is important to monitor it by periodically performing ongoing rapid assessments of the brittle strength of the WWER-1000 reactor vessel (along with other factors, including cyclic damage, as discussed in a previous publication). Therefore, it is important to use the calculated express methods of periodic assessment of the brittle strength of the WWER-1000 reactor vessel with guaranteed accuracy. The effectiveness of the approach is supported by low cost of resources – engineering staff, fast and relatively simplified use of computers and software. As an example and confirmation of the applicability of the proposed approach, an expert rapid assessment of the fragile strength and residual life of the reactor vessel of Unit № 1 of the South-Ukrainian Nuclear Power Plant was performed. This takes into account the actual, passport characteristics of its metal. The negative impact of the rigid regime with cooling of the WWER-1000 reactor of Unit № 1, not taken into account by the operating organization (South-Ukrainian Nuclear Power Plant) when extending its designated resource / service life, is shown. timely to clarify complex factors, technical aspects and parameters, as well as – their possible negative effects on the safe operation of systems and elements of nuclear power plants.