Nuclear Safety Research Articles

Improvement of butt-fusion welding procedure and performance evaluation method for thick-walled bimodal polyethylene pipes

High-density polyethylene (HDPE) pipes have been continuously improved by the progress made by the resin industry and pipe manufacturers. Together with the advanced technology of welding equipment in terms of structure reliability and automations, HDPE pipes have been gradually applied to higher pressure level, bigger diameter, and thicker walls in operations which have become the preferred piping system for nuclear safety application in transporting cooling seawater. There are substantial differences in parameter settings when applying heat and force during different welding procedures, as well as the complicated evaluation methods for mechanical properties, which causes communication barriers between engineers and researchers. Thus, it is necessary to comprehensively study the welding procedures and evaluation methods to standardize the evaluation protocols in the industry. In this paper, based on the assumptions of temperature effect and molecular chain diffusion dynamics at the welding interface, the optimization of the welding procedure is proposed. Some well-established evaluation methods have been used for performance assessment and their feasibilities are discussed. The idea of creating crack along the weld interface is adopted as new method to evaluate the material ability of fracture resistance. Specimens with unilateral notch and weld interface crack are proposed and subjected for quasi-static axial tensile test. The fracture stress and fracture energy at the welding interface are used to differentiate the quality of the joint from different welding procedures. The fracture morphologies of the weld interface are analyzed. A complete picture is drawn for the mechanical fracture resistance of the weld interface. The method used in this paper can be corelated to the pipeline design conditions, therefore could be applied to the real-time engineering applications. Moreover, the evaluation method proposed in this paper is simple, reliable, and easy to implement.

Specific Grammatical Aspects of Translating the Iaea Regulatory Documents into the Russian Language

The article discusses some grammatical features of the IAEA safety requirements and guides in the English language and in their Russian translations. Considering that these documents make a foundation of the global nuclear safety system, and grammar is the backbone of the language and an essential constituent of the communication content, the paper is focused on the analysis of the ways of translating specific grammatical structures, which determines current importance of this study. The aim of the work is to compare typical grammatical constructions used in the texts of the Russian translations of the IAEA publications under consideration with the grammatical features of similar Rostechnadzor’s regulatory documentation. The main tasks of the authors are to compare the ways of translating English modal and passive constructions, English verbals and verbal structures into Russian and to verify the translator’s choice of a certain grammatical structure in the translations of the regulations and guidelines under consideration. Taking research tasks predetermined the choice of the following research methods: comparative analysis; linguistic and statistical analysis; contextual analysis; inductive and deductive analysis. To obtain linguistic and statistical analysis data, the authors applied such software tools as SDL Trados, Adobe Acrobat, Excel and MS Word. In order to ensure the correctness of the results, only the substantive part of the documents under consideration was analyzed.The analysis has brought to the following results: the need to comply with the regulatory requirements narrows the choice of Russian modal constructions in the translation of "should" statements used in IAEA documents. The issue of changing the regulatory requirement that prescribes to use the Russian verb "следует" has to be treated very carefully, considering the established practice of both translating the IAEA safety guides and their understanding by the target users; the translation of English passive constructions and verbals used in the IAEA safety guides gives clear preference to the use of Russian indefinite-personal structures with verbs in the active voice in the 3rd person plural; the grammatical structures used in the translation of the IAEA publications in question generally correspond to the grammatical structures used in the Rostechnadzor regulatory documents, which is predetermined by the information nature and ensures a fairly high similarity of their style.

Numerical Investigation of Process Parameter Effects on Flow Oscillations in a Natural Circulation Boiling Integral PWR-Type SMR Test Rig

Innovative reactor designs like small modular reactors (SMRs) have the potential to operate in a natural circulation (NC) boiling mode, but this mode introduces flow oscillations that pose a risk to nuclear safety. Therefore, it is essential to investigate the effects of various parameters on these oscillations. This study focuses on predicting the operational behavior of the Integral PWR-type SMR Test Rig (iPSTR) when operating in NC and subcooled boiling conditions. The iPSTR replicates an NC boiling loop with a vertical heater, vertical cooler configuration, high-temperature and high-pressure conditions, and nonuniform diameter structure. Using the RELAP5 model, thermal-hydraulic simulations were performed to anticipate how varying degrees of inlet subcooling affects parameters such as mass flow rate and void fraction, with experimental data used to validate the model’s accuracy. This investigation covers a range of process conditions, including system pressures from 5 to 20 bars, core input power varying from 8.5 to 14.5 kW, and degrees of inlet subcooling from 1 to 49 K. The results reveal that increasing input power leads to higher average mass flow rates, while at a constant system pressure, higher input power stabilizes flow rates at higher degrees of inlet subcooling. Moreover, reduced and more consistent oscillation amplitudes and frequencies at higher core power result at more elevated system pressure, enhancing the safety of the iPSTR facility.

The structural, optical, electrical and radiation shielding properties of Co-doped ZnO thin films

Co:ZnO thin films are promising due to the similar ionic radii of cobalt and ZnO, and their potential for carrier spin injection, transfer, and detection. This study aims to investigate the structural, optical, electrical, and radiation shielding properties of Co-doped zinc oxide (Co:ZnO) thin films for potential applications in various fields such as semiconductors, solar cells, spintronics, and radiation shielding. The effect of commercially available Cobalt acetate tetrahydrate and Cobalt complex (Co with conjugated NN ligand) as cobalt additives on the synthesis of ZnO thin films is compared, aiming to discern their respective impacts. The dopants are incorporated in 2, 4, and 6 wt.%, employing the sol-gel spin coating method. Cobalt effectively served as a substitution dopant, preserving the wurtzite crystal structure, and the cobalt complex additive demonstrated a superior enhancement of the electronic band gap compared to the commercial cobalt additive. Applying cobalt complex additive as Co precursor resulted in ZnO:Co films with a superior enhancement of the electronic band gap of 2.84 - 3.00 eV compared to cobalt acetate precursor (2.67-2.84 eV). With the introduction of Cobalt, there is a notable change in the electrical conductivity, showcasing a decrease from 1.5x10-7 to 2.11x10-10 (S/cm). Also, radiation shielding parameters were experimentally measured in the energy range of 186.1-1764.5 keV within the scope of gamma ray spectral analysis. Exposure buildup factors (EBF) in the energy range of 15-15000 keV were calculated up to 1-40 mean free path (mfp). Mass stopping power (MSP) and projected range values (PR) for nuclear safety applications were calculated for protons and alpha particles using the SRIM code. Thin film thicknesses were determined by using Lambert-Beer law. It was observed that the thin film thicknesses obtained from gamma spectrometry (2.090-2.628 μm) and SEM (2.157-2.725 μm) were compatible with each other.

Basal and prismatic slip in hafnium

Metals with hexagonal crystal structure are found in many safety-critical applications, from titanium alloy fan blades in jet engines to magnesium alloys in the automotive industry. They also exist in nuclear reactors, such as hafnium alloy control rods whose structural integrity is critical to nuclear safety. However, mechanistic understanding of the micromechanical properties and deformation behaviour of Hf remains elusive. To aid in this understanding, we performed in situ scanning electron microscopy single crystal micropillar compression tests of a commercial Hf alloy, where the samples were aligned to activate <a> prismatic and <a> basal slip systems. We then employed transmission electron microscopy to examine the dislocation structure in the deformed pillars. These two slip systems exhibited distinctly different behaviour, where prismatic slip is planar and basal slip is wavy. Prismatic slip is the easiest deformation mode, while basal slip is at least twice as difficult. Generally, the characters of prismatic and basal slip in Hf show similarities to those in some other hexagonal metals such as Ti and Zr, except for the higher relative difficulty of basal slip. Our results provide fundamental knowledge and parameters that can be used for modelling degradation and predicting performance of Hf, and shed light on the general behaviour of basal and prismatic slip systems in low-c/a-ratio hexagonal metals.

Sulfur Vacancy-Rich Bismuth Sulfide Nanowire Derived from CAU-17 for Radioactive Iodine Capture in Complex Environments: Performance and Intrinsic Mechanisms

Effective capture and immobilization of volatile radioiodine from the off-gas of post-treatment plants is crucial for nuclear safety and public health, considering its long half-life, high toxicity, and environmental mobility. Herein, sulfur vacancy-rich Vs-Bi2S3@C nanocomposites were systematically synthesized via a one-step solvothermal vulcanization of CAU-17 precursor. Batch adsorption experiments demonstrated that the as-synthesized materials exhibited superior iodine adsorption capacity (1505.8mgg-1 at 200 °C), fast equilibrium time (60min), and high chemisorption ratio (91.7%), which might benefit from the nanowire structure and abundant sulfur vacancies of Bi2S3. Furthermore, Vs-Bi2S3@C composites exhibited excellent iodine capture performance in complex environments (high temperatures, high humidity and radiation exposure). Mechanistic investigations revealed that the I2 capture by fabricated materials primarily involved the chemical adsorption between Bi2S3 and I2 to form BiI3, and the interaction of I2 with electrons provided by sulfur vacancies to form polyiodide anions (I3-). The post-adsorbed iodine samples were successfully immobilized into commercial glass fractions in a stable form (BixOyI), exhibiting a normalized iodine leaching rate of 3.81×10-5gm-2 d-1. Overall, our work offers a novel strategy for the design of adsorbent materials tailed for efficient capture and immobilization of volatile radioiodine. Environmental ImplicationDue to the biological toxicity, ionizing radiation and environmental mobility, volatile radioiodine will affect the ecological environment and human health. Bi-based adsorbents have become potential candidates for their low-cost and high adsorption properties. This work proposed a solvent thermal vulcanization method to obtain Vs-Bi2S3@C nanocomposites with abundant sulfur vacancies. Importantly, the prepared materials exhibited excellent iodine capture performance at high temperatures, high humidity and irradiation environments. In addition, the iodine-captured Vs-Bi2S3@C could be immobilized into commercial glass compositions. This work demonstrated a viable strategy for constructing adsorbent materials for efficient capture and immobilization of radioiodine through surface defect engineering.

US nuclear agency struggles with production and costs

US nuclear agency struggles with production and costs

Timing bombs and the temporal dynamics of Iranian nuclear security

Abstract For more than two decades, Iran’s nuclear programme has concerned policymakers and scholars alike. Whether speeding up uranium enrichment, slowing down international negotiations, or disrupting the timing of key initiatives, actions around Iran’s nuclear programme bear a clear time signature. Yet systematic accounts of the importance of time in shaping foreign and security policymaking have been largely neglected. Through foreign policy timing theory’s (FP4D) reconceptualisation of time we show how actors both constructed and then used time to pursue their strategic interests, creating, altering, and sabotaging the timing mechanism linking Iranian nuclear technology and international sanctions. These manipulations of time by both domestic and international actors resulted in prolonged international negotiations and fluctuating periods of crisis and produced a temporally flawed agreement frozen in time. We consider time’s impact on the current challenges and future direction of nuclear diplomacy with Iran as well as its importance for broader nuclear security issues.

Keep your enemies safer: technical cooperation and transferring nuclear safety and security technologies

Even during the Cold War, the United States and the Soviet Union cooperated on nuclear safety and security. Since accidental or unauthorized nuclear detonations anywhere threaten peace everywhere, it seems straightforward that states more experienced in developing nuclear safety and security technologies would transfer such methods to other states. Yet, the historical record is mixed. Why? While existing explanations focus on the political costs and proliferation risks faced by the transferring state, this article argues that specific technological features condition the feasibility of assistance. For more complex nuclear safety and security technologies, robust technical cooperation is crucial to build the necessary trust for scientists to transfer tacit knowledge without divulging sensitive information. Leveraging elite interviews and archival evidence, my theory is supported by four case studies: US sharing of basic nuclear safety and security technologies with the Soviet Union (1961–1963); US withholding of complex nuclear safety and security technologies from China (1990–1999) and Pakistan (1998–2003); and US sharing of complex nuclear safety and security technologies with Russia (1994–2007). My findings suggest the need to examine not only the motivations behind nuclear assistance but also the process by which it occurs and the features of the technologies involved, with implications for how states cooperate to manage the global risks of emerging technologies.

Experimental Study on Two-Phase Countercurrent Flow Limitation in Horizontal Circular Pipes

The two-phase countercurrent flow limitation (CCFL) in horizontal channels is important in relation to nuclear reactor safety. In this study, we aim to investigate the CCFL characteristics and the flow behaviors in horizontal circular pipes with small diameters. The effects of pipe diameter and the water head in the upper plenum on CCFL characteristics are experimentally studied. An image-processing technique and statistical treatments are implemented to analyze the horizontal countercurrent flow. The results show that the CCFL characteristics for the horizontal circular pipes with small diameters can be well correlated using the dimensionless parameters, which are based on adding fluid viscosity to the Wallis parameters. The CCFL characteristics are significantly affected by the pipe diameter and are slightly affected by the water head above the horizontal pipe. The gas–liquid interface fluctuates with certain periods, and flow pattern transitions happen in the horizontal air–water countercurrent flow. As the air flow rate increases, the occurrence location of the liquid slug appears to shift towards the water entrance. In addition, the further away from the water entrance, the lower the average of liquid holdup.

Simulated safety analysis of a total loss of feedwater accident in the steam generator of CPR1000 nuclear power plant

As M310 series units, CPR1000 Nuclear Power Plant in China is also the first batch of demonstration nuclear power plants in China to try out SOP(the state-oriented procedure) accident procedures. The establishment of SOP accident regulations is an important work to mitigate the consequences of radioactive accidents in the design of nuclear power plants, and it is also the embodiment of the defense-in-depth requirements in the implementation of nuclear safety regulations. It can handle superimposed accidents, human errors in program implementation and events not considered in the primary cause sequence. In order to study the efficiency of its upgraded SOP procedure and its ability to deal with severe accidents, the typical primary cause event of severe accidents in nuclear power plants–such as the total loss of feedwater accident of steam generators has been adopted for research. The initial state of the simulation is the full power operation of the nuclear power plant, the simulation process is from the loss of all the water supply accidents to the whole accident processing. A total of 30 simulation experiments were carried out. The temperature and pressure of the key parameters obtained are the average values of 30 simulation experiments. The stability and efficiency of the updated SOP are evaluated by the treatment time of the water supply loss accident and the changes of reactor temperature and pressure after the accident. The results show that the upgraded SOP procedure is more stable and efficient. The upgraded SOP procedure, when dealing with other types of accidents, has improved the treatment of residual heat conduction in the core, increased the efficiency of accident treatment, and enhanced the safety of the reactor. At the same time, based on the weaknesses of the upgraded SOP procedure, constructive suggestions on changing the setting value of the steam generator bypass valve have also been put forward accordingly. Furthermore, it can be concluded from many simulated accidents that this change will win about 5% more of the disposal time for nuclear power plants under accidents, which provides references for the subsequent upgrading of M310 series power plant procedures.

Radiation-hygienic situation in the area of sublimate production waste storage of JSC “AECC”

In accordance with the fundamentals of state policy in the field of ensuring nuclear and radiation safety, State Corporation «Rosatom» carries out the remediation of JSC “AECC” nuclear legacy sites. The article presents the results of environmental impact assessment carried out in 2021-2023 in the vicinity of sublimation waste storage facilities that are being decommissioned. Health physics studies involved ambient dose rate measurements, sampling (soil, groundwater) and analysis of radiological and non radiological environmental pollutants. The external gamma dose rate, as well as content of natural and artificial radionuclides in soil, don’t exceed background levels. While uranium presence in groundwater is found to be 10 times and higher then background level. The data obtained indicate that the accumulated wastes of sludge sumps (bottom sediments, pulp) сome into contact with natural water. Flooded storage facilities form a plume of contamination spreading out in the direction of groundwater flow. Given the current situation optimization of the existing environmental monitoring programs in the JSC “AECC” health protection zone is recommended and reference levels of uranium proposed.

Experimental study on pressure fluctuation in header of nuclear power plant SEC system after long-term pump shutdown

The Essential Service Water System (SEC) is a nuclear safety level system in nuclear power plants. It’s responsible for transporting the heat load collected by the equipment cooling water system (RRI) to the final heat sink – seawater. When the SEC system equipment is damaged, it can lead to ineffective heat transfer in RRI system, ultimately resulting in a major accident. Therefore, this article focuses on the SEC system of nuclear power plants and a technical solution combining model similarity experiments and theoretical analysis was adopted to restore the pressure fluctuation phenomenon that occurred after long-term pump shutdown of the SEC system, and the mechanism of pressure fluctuation phenomenon after long-term pump shutdown of the SEC system was analyzed. The results indicate that: the mechanism of pressure fluctuations in header of the nuclear power plant after long-term pump shutdown is the combined effect of an increase in the volume of the air chamber in the system and leakage in the check valve. In the design process of the unit, it is possible to consider reducing the high point position reasonably to improve the negative pressure situation of the SEC system, and it is recommended to replace the butterfly check valve with a two-stage slow closing check valve. This will provide certain experience and technical support for the further development of the SEC system.

Towards an international regulatory framework for AI safety: lessons from the IAEA’s nuclear safety regulations

This study explores the necessity and direction of safety regulations for Artificial Intelligence (AI), drawing parallels from the regulatory practices of the International Atomic Energy Agency (IAEA) for nuclear safety. The rapid advancement and global proliferation of AI technologies necessitate the establishment of standardized safety norms to minimize discrepancies between national regulations and enhance the consistency and effectiveness of these rules. The study emphasizes the importance of international collaboration and the engagement of various stakeholders to strengthen the appropriateness of regulations and ensure their continuous updating in response to the evolving risks associated with technological advancements. The paper highlights the critical role of subgoal setting mechanisms in AI’s decision-making processes, underscoring their significance in ensuring the technology’s stability and social acceptability. Improperly tuned subgoal setting mechanisms may lead to outcomes that conflict with human intentions, posing risks to users and society at large. The study draws attention to the hidden risks often embedded within AI’s core decision-making mechanisms and advocates for regulatory approaches to guarantee safe and predictable AI operations. Furthermore, the study acknowledges the limitations of directly applying IAEA’s nuclear safety cases to AI due to the distinct characteristics and risks of the two fields. The paper calls for future research to delve deeper into the need for an independent regulatory framework tailored to AI’s unique features. Additionally, the study emphasizes the importance of accelerating international consensus, developing flexible regulatory models that reflect the situation in each country, exploring harmonization with existing regulations, and researching timely regulatory responses to the fast-paced development of AI technology.

Gamma noise to non-invasively monitor nuclear research reactors

Autonomous nuclear reactor monitoring is a key aspect of the International Atomic Energy Agency’s strategy to ensure nonproliferation treaty compliance. From the rise of small modular reactor technology, decentralized nuclear reactor fleets may strain the capacities of such monitoring and requires new approaches. We demonstrate the superior capabilities of a gamma detection system to monitor the criticality of a zero power nuclear reactor from beyond typical vessel boundaries, offering a powerful alternative to neutron-based systems by providing direct information on fission chain propagation. Using the case example of the research reactor CROCUS, we demonstrate how two bismuth germanate scintillators placed outside the reactor vessel can precisely observe reactor criticality using so called noise methods and provide core status information in seconds. Our results indicate a wide range of applications due to the newly gained geometric flexibility that could find use in fields beyond nuclear safety.

Demonstrating a Quantitative and Systematic Approach to Reducing Excess Conservativism in Nuclear Criticality Safety Analyses

Although reducing conservatism would alleviate unnecessary constraints in processing, storage, transportation, and disposal of nuclear materials, excessively conservative approaches are still utilized in many safety analyses. Criticality safety limits are put in place to reduce the likelihood of having a nuclear criticality accident to a value that is deemed incredible but often utilize parameters that are conservative to the point of becoming incredible themselves. The analyses that determine criticality limits are supposed to be based on credible instead of incredible events and circumstance, highlighting the need to be able to distinguish between what is in the realm of possibility and what is not. This paper provides a quantitative approach for reducing unrealistically conservative parameters by recalculating limiting factors in a state that deviates from the worst-case scenario and assigning probability distributions to these systematic deviations. This provides a technical basis for replacing excessively conservative values with something that is both objective and reasonably bounding, which may be systematically utilized in any criticality safety analyses. The assumption of “perfect sphericity” in the TRUPACT-II package’s fissile contents model was used as an example case to demonstrate the proposed approach for replacing qualitative reductions to conservatism with quantitative reductions. Through a series of Monte Carlo calculations and statistical analyses, it was shown that conservative deviations from sphericity will provide lower keff values, where the magnitude and impact of this deviation is system specific. The statistical significance from applying probabilistic conservatism will be dependent on the chosen κ value and integration limit for the exponential distribution, as it varies the degree of conservatism applied to any parameter of interest. This approach is not limited to geometric assumptions and may be applied to a variety of conservative parameters. In an effort to move toward a standard method for reducing conservatism, this objective approach may be used in lieu of or in conjunction with subjective methods for relaxing constraints.

Characteristics of 3D Printed Functionally Graded Material for Replacement of Dissimilar Metal Weld in Nuclear Reactor

The dissimilar metal welds in the most of the reactors are connections between low alloy steel parts and stainless steel piping. There is a high possibility of primary water stress corrosion cracking (PWSCC) damage attributed to residual stress caused by the difference in material properties in the dissimilar metal weld joints. A number of accidents such as leakage of radioactive coolant due to PWSCC have been reported around the world, posing a great threat to nuclear safety. The objective of this study is to develop a technology that can fundamentally remove dissimilar metal welds by replacing the existing dissimilar metal parts with the functionally graded material (FGM) manufactured by metal 3D printing consisting of low alloy steel and austenitic stainless steel. A powder production, mixing ratio calculation, and metal 3D printing were performed to fabricate the low alloy steel-stainless steel FGM, and microstructure analysis, mechanical properties, and coefficient of thermal expansion (CTE) measurement of the FGM were performed. As a result, it is observed that CTE tended to increase as the austenite content increased in FGM. The gradual change of coefficient of thermal expansion in a FGM showed that the additive manufacturing using 3D printing was effective for preventing an abrupt change in thermal expansion properties throughout their layers.

Modified Evaporation Model for ATHLET System Code in a Passive Containment Cooling System for Nuclear Safety

The presented work deals with the improvement of the evaporation model of the ATHLET (Analysis of Thermal and Hydraulics of Leaks and Transients) system code to be applied to a passive containment cooling system of a nuclear power plant. For the model validation, INTRAVIT (Investigation of Passive Heat Transfer in a Variably Inclined Tube) test facility setup at the University of Luxembourg was used. The first part of the paper presents a review of the existing literature on evaporation models that revealed that those models significantly simplify the physical processes that occur. Next, a modified evaporation model is proposed that offers a realistic description of various evaporation processes and the start of bubble formation using a nucleation model, and a surface density calculation model is introduced that is necessary for evaporation simulation. The final part of this work explored five different system configurations to test the evaporation model: three condenser tube inclinations (5 deg, 60 deg, and 90 deg), two riser lengths (1 m and 2.5 m), and different thermal loads. They made it possible to simulate several experiments for stable and unstable natural circulation and to verify the proposed model.

PCMI Uncertainty and Sensitivity Analysis of Es-Salam Reactor Fuel Rods During Steady-State Operations

Nuclear safety relies heavily on the quality of the results of numerical simulation codes. Among the various components of the simulation of the installation are the pellet-cladding mechanical interaction (PCMI), and the peak cladding temperature (PCT). Although the correlations describing the physical, mechanical, chemical, and thermal phenomena that occur in nuclear installations have reached a high level of quality, there remain uncertainties on the final results due to uncertainties in the input parameters which cannot be eliminated. A realistic estimate of these uncertainties is necessary to evaluate the reliability of the simulation results. When the best-estimate approach plus uncertainty (BEPU) is employed in the design of a nuclear installation, design-basis accidents are studied more realistically. This method must be used even in the design of research reactors because they are at the origin of any development of nuclear technology. We propose through this study an uncertainty and sensitivity analysis of PCMI and PCT of a heavy water nuclear research reactor fuel rod. To determine the input parameters that influence PCMI and PCT, we utilize the FEMAXI-6 code. The thermodynamic table of the FEMAXI-6 code is adapted to the case of heavy water. Two system codes are used for uncertainty and sensitivity analysis: RELAP5 and PARET. The study confirmed that in the event of a shortage of heavy water, light water can be injected in its place to remove decay heat from the core and shut down the reactor safely. The safety margin between the PCT and the saturation temperature is reduced from about 10°C in the conservative approach to less than 1°C by the BEPU approach.

Позиции России и США по вопросам ядерной безопасности и перспективы новых договоренностей

In the modern complex system of international relations, in a situation of escalating confrontation between Russia and the United States, increasing tension in relations between Western countries and the "Global South", arms control, primarily nuclear, as well as non-proliferation of nuclear weapons, continues to be one of the most important areas of Russian foreign and defense policy. The Russian Federation pays priority attention to strengthening and developing the system of international treaties in the fields of strategic security and arms control. Therefore, the purpose of this article is to consider the prospects for one of the key aspects of the Russian-American agreements - nuclear arms control and the achievement of sustainable strategic stability. This led to the active use of such methods as analysis and synthesis of data on the current state of nuclear strategic security, a historical approach that identifies the previous context of agreements, as well as a comparative analysis focused on comparing the basic approaches, interests, goals and priorities of the Russian and American sides. Based on foreign policy imperatives, including consolidating Russia's role as a guarantor of international stability and arms control, the authors propose a non-standard scenario for restoring the viability of the key START Treaty of 2010. The article suggests the outlines of possible concrete solutions and potential elements of agreements that can become the basic topic for the resumption of bilateral consultations on strategic stability and an integral part of the new agreement. The authors conclude that reaching mutually acceptable agreements on this topical issue will have a positive impact on reducing the military threat and reducing the risks of unleashing a nuclear conflict, which meets the strategic interests of Russian national security and global stability.