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The survivability of the domestic nuclear power industry depends on the cost-competitiveness of safe and secure nuclear power generation. Advanced reactor design concepts aim to have increased safety margins over traditional large light water reactors (LWRs). With increased safety margins comes the potential for a corresponding decrease in off-site risk to the general public from a hypothetical release of radioactivity due to sabotage or theft. Without sacrificing safety or security, advanced reactor designers may be able to achieve operational cost improvements over current LWRs in part by designing less burdensome physical protection systems (PPSs) and by replacing on-site response forces with off-site response forces. To accommodate these developments, the U.S. Nuclear Regulatory Commission is drafting new rulemakings for physical security when licensing through the current frameworks in 10 CFR 50 or 10 CFR 52 along with drafting an entirely new licensing framework: 10 CFR 53. A novel technology-inclusive consequence-informed methodology for the selection of the optimal licensing path for the design of PPSs at advanced fixed-site commercial nuclear power facilities is presented herein. This methodology proposes integrating security considerations at the beginning of a reactor facility design effort to streamline the licensing process. Off-site total effective dose equivalents at the exclusion area and low population zone boundaries were identified as the key metrics when determining a design's most appropriate licensing path that in turn affects the design requirements placed upon the PPS. Given these metrics, source-term generation of potential adversary-induced physics-based sabotage actions utilizing severe accident modeling software and off-site plume dispersal modeling were identified as appropriate for determining siting constraints, potential target sets for hypothetical sabotage events, and their subsequent off-site dose consequences. The methodology proposes using the consequence results from the sabotage modeling, in combination with desired cost-saving PPS characteristics, to help inform the licensing path selection. Once a licensing path is chosen, the methodology utilizes the Design and Evaluation Process Outline to evaluate an effective PPS following the licensing requirements placed on the facility. This paper also presents examples of hypothetical commercial nuclear power facilities with varying consequence levels and demonstrations of how to select the optimal licensing pathways for each. [ABSTRACT FROM AUTHOR]

Local knowledge is recognised as a critical element of global energy transition and energy justice. This paper explores the roles local knowledge in the formation of a community organisation responsible for monitoring the nuclear facility operations, governance, and public risk communication. Our case study examines a local nuclear oversight organisation in the Kashiwazaki-Kariwa region in Japan, where suggestions have been made to consider nation-wide institutionalisation of organisations similar to French Commissions Locales d'Information (Local Information Commissions). Our findings reveal the critical roles of three forms of local knowledge, with a particular emphasis on the nuanced yet crucial impact of everyday-life knowledge (seikatsu-chi), a facet not extensively explored in existing studies, in facilitating the establishment of the local organisation. [ABSTRACT FROM AUTHOR]

As nuclear facilities are dismantled in decommissioning, various and large amounts of waste are generated. Even more inconveniently, they are radioactive waste due to neutron activation. Thus, the neutron capture cross-sections of nuclides targeted for decommissioning are required to evaluate the radioactivity produced. The present study selected 45Sc, 63Cu, 64Zn, 109Ag and 113In among targeted nuclides, and performed the measurements of thermal-neutron capture cross-sections by an activation method at the Kyoto University Research Reactor. The thermal-neutron capture cross-sections were derived on the basis of Westcott's convention. The present results were obtained as follows: 27.18 ± 0.28 barn for 45Sc(n,γ)46Sc, 4.34 ± 0.06 barn for 63Cu(n,γ)64Cu, 0.719 ± 0.011 barn for 64Zn(n,γ)65Zn, 4.05 ± 0.05 barn for 109Ag(n,γ)110mAg and 8.53 ± 0.27 barn for 113In(n,γ)114Inm1+m2 reactions. The results for 45Sc and 64Zn support evaluated cross-section data within the limits of uncertainties, while those for the other nuclides were slightly different from evaluated ones. The obtained results are useful not only for the evaluation of isotope production, but also for the consideration of those nuclides as flux monitors, as an alternative to Au and Co. [ABSTRACT FROM AUTHOR]

This work deals with smoke propagation through a multi-compartment assembly in case of a fire event in a nuclear installation. The scientific issues are the understanding of flows involving two modes of propagation (vent and doorway), together with the role of mechanical ventilation and oxygen backflows to the fire. The study is based on the analysis of two scenarios reproduced experimentally at large scale and simulated numerically. The main outcomes concern the comparison of the flow at a doorway and at a vent, the consequence of the smoke propagation for thermal stratification and the combined effect of the fire heat release rate and mechanical ventilation. The results highlight the performance of computational fluid dynamics simulations in predicting these complex scenarios. Low-velocity flow zones are identified, enabling the structure of these flows and their amplitudes to be quantified. This information provides new insights to improve fire risk assessment in nuclear facilities. [ABSTRACT FROM AUTHOR]

As nuclear technology evolves in response to increased demand for diversification and decarbonization of the energy sector, new and innovative approaches are needed to effectively identify and deter the proliferation of nuclear arms, while ensuring safe development of global nuclear energy resources. Preventing the use of nuclear material and technology for unsanctioned development of nuclear weapons has been a long-standing challenge for the International Atomic Energy Agency and signatories of the Treaty on the Non-Proliferation of Nuclear Weapons. Environmental swipe sampling has proven to be an effective technique for characterizing clandestine proliferation activities within and around known locations of nuclear facilities and sites. However, limited tools and techniques exist for detecting nuclear proliferation in unknown locations beyond the boundaries of declared nuclear fuel cycle facilities, representing a critical gap in non-proliferation safeguards. Microbiomes, defined as "characteristic communities of microorganisms" found in specific habitats with distinct physical and chemical properties, can provide valuable information about the conditions and activities occurring in the surrounding environment. Microorganisms are known to inhabit radionuclide-contaminated sites, spent nuclear fuel storage pools, and cooling systems of water-cooled nuclear reactors, where they can cause radionuclide migration and corrosion of critical structures. Microbial transformation of radionuclides is a well-established process that has been documented in numerous field and laboratory studies. These studies helped to identify key bacterial taxa and microbially-mediated processes that directly and indirectly control the transformation, mobility, and fate of radionuclides in the environment. Expanding on this work, other studies have used microbial genomics integrated with machine learning models to successfully monitor and predict the occurrence of heavy metals, radionuclides, and other process wastes in the environment, indicating the potential role of nuclear activities in shaping microbial community structure and function. Results of this previous body of work suggest fundamental geochemical-microbial interactions occurring at nuclear fuel cycle facilities could give rise to microbiomes that are characteristic of nuclear activities. These microbiomes could provide valuable information for monitoring nuclear fuel cycle facilities, planning environmental sampling campaigns, and developing biosensor technology for the detection of undisclosed fuel cycle activities and proliferation concerns. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish an e-learning training system for radiation disaster management in order to effectively train and secure personnel for radiation disasters, independent of regional characteristics such as the presence or absence of nuclear facilities. An educational management tool was used to enable verification of the educational effects through on-demand videos and pre- and post-training tests based on standardized textbooks created by the government. This training was conducted for radiological technologists affiliated with the National Hospital Organization. The educational effects were analyzed based on the results of the pre- and post-training tests. The developed e-learning training system included on-demand videos, provision of PDF materials, implementation of pre- and post-tests, confirmation of attendance, and performance management. Of the 65 trainees, 59 completed all the lectures and tests. The correct answer rate of the pre-training test was 57.8 ± 19.0%, while that of the post-training test was 85.9 ± 12.5%. This study established the first-of-its-kind e-learning training system for radiation disaster management in Japan and participants received effective literacy education on radiation disaster management. The results showed that training can be conducted regardless of location, thereby facilitating effective training and securing of personnel. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The routine practice accompanying the operation of nuclear facilities involves the discharge of radioactive effluents from nuclear power plants (NPPs). Regulation of this discharge to the environment hinges on three criteria: radioactivity concentration, public dose, and radioactivity. Among these, radioactive carbon‐14 holds particular significance as it possesses an extensive half‐life of 5730 years, making it a primary source of radiation dose to communities residing around NPPs. In Korea, the monitoring of carbon‐14 discharges from pressurized water reactors (PWRs) in gaseous effluents has been ongoing since 2012, whereas before 2012, monitoring exclusively focused on carbon‐14 discharges from pressurized heavy water reactors (PHWRs). Analysis of carbon‐14 discharges from Korean PHWRs indicates that their emission constituted less than 1% of total radioactive effluents over the past two decades. In the context of Korean PWRs, carbon‐14 discharge monitoring was absent from 2002 to 2011, resulting in an absence of data regarding such discharges during that period. After introducing carbon‐14 discharge monitoring in gaseous effluents from Korean PWRs, emissions from 2012 to 2021 contributed 3% of the total gaseous effluents. These findings indicate that despite being the primary contributor to public dose, carbon‐14 discharges from NPPs constitute a minor portion of the radioactive effluent discharge. [ABSTRACT FROM AUTHOR]

This paper describes a measuring unit for synchronously collecting the air dose rate and measurement position for efficient dosimetry surveying and data logging. The developed prototype comprises a three-dimensional light detection and ranging-based mapping part and dosimetry part, which are integrated into a single measuring unit through an embedded computer that installs a ROS (robot operating system) framework. The unit can function as a standalone system with embedded batteries. Since it is portable, on-line data gathering in the workspace can be realized, thereby maintaining consistency between the air dose rate and measurement position. In this paper, we describe the functional requirements for the measuring unit, the prototype system configuration, and the experimental results obtained in the mockup environment and nuclear facility to discuss its performance. [ABSTRACT FROM AUTHOR]

During the decommissioning process of nuclear facilities, workers are exposed to radiation and face the risk of exceeding safe dose limits. Ensuring the safety of personnel requires not only enhancing radiation protection measures but also optimizing work paths to minimize exposure time and avoid high-radiation areas. This paper proposes a nested optimization algorithm that combines an ant colony optimization (ACO) with an improved A* algorithm for the decommissioning of a nonradiation source. The algorithm aims to minimize the total radiation dose and transforms the original path optimization problem into an equivalent traveling salesperson problem. The improved A* algorithm is employed in the inner layer to calculate the path with the lowest radiation dose for any given sales order. The ACO operates in the outer layer to determine a set of optimal working paths that traverse all target points. The provided solution example demonstrates that the proposed path optimization algorithm effectively integrates the radiation field and obstacles. It successfully identifies a sequence for dismantling with the lowest dose and corresponding optimal work path while ensuring the completion of the dismantling task. These findings are expected to offer valuable insights for optimizing personnel work paths during the subsequent decommissioning process of nuclear facilities. [ABSTRACT FROM AUTHOR]

The present study aims to investigate soil-to-plant transfer of natural radionuclides in some vegetables planted in arid region, and to evaluate the radiological hazards due to their intake. 40K was found to be the most bio-accessible radionuclides for the examined vegetables with soil-to-plant transfer factor (TF) of 1.57–5.56, followed by 226Ra and 232Th with TF factors ranging from 0.02 to 0.23. The radiological risk models revealed that the tested vegetables pose a negligible radiological hazard. The obtained results are very useful for understanding the behavior and transfer of radionuclides in the environment to ensure the safe and sustainable planning and operation of nuclear facilities. [ABSTRACT FROM AUTHOR]

The surface exhalation rates of thoron and the mass exhalation rate of radon were investigated in soil and sand samples from Surat District, Gujarat, Bharat (India). Samples were collected from diverse locations, including river beds, beaches, public gardens, highways, ports, colleges, and farm fields. Analysis was performed using a SMART RnDuo Radon monitor (MX400). Soil exhalation rates of thoron varied from 2.00 (Bq/m2/h2) at Sarsana (G6) to 127.55 (Bq/m2/h2) at Hazira (G15), with an average rate of 36.16 (Bq/m2/h2) for Surat District. Radon mass exhalation rates ranged from 3.26 to 81.22 (mBq/kg/h), with a mean of 27.98 (mBq/kg/h), below the global average. This data serves as crucial reference information for potential nuclear or other facility planning in the region. [ABSTRACT FROM AUTHOR]

The mission of Atomic Energy Regulatory Board (AERB) of India is to ensure that the use of ionising radiation and nuclear energy in India does not cause unacceptable impact on the workers, members of the public and to the environment. AERB has the mandate to carry out detailed safety review for the siting, construction, commissioning, operation and decommissioning of nuclear and radiation facilities established within the country. To deliver and maintain a strong, credible and technically sound regulation, AERB has established the Safety Research Institute (SRI) at Kalpakkam with a robust technical infrastructure and wide knowledge base. This paper highlights the independent safety research activities carried out at SRI and its role to support and facilitate the decision-making process by AERB at various stages of regulatory review for ensuring safety of the nuclear facilities in India. [ABSTRACT FROM AUTHOR]

To provide energy security and head off further increases in global temperatures, an aggressive transition from fossil fuels to other types of energy implies the need to possibly construct hundreds of nuclear power plants in the near future. However, the real and perceived risks of nuclear energy remain a significant impediment to that transition. This paper describes a comprehensive work process that combines the rigor of model‐based systems engineering (MBSE) with 1) the Idaho National Laboratory's (INL) decades of experience with small reactors and with 2) modern project delivery processes. The objective is to reduce the risks of building new facilities or converting existing facilities to nuclear power generation. [ABSTRACT FROM AUTHOR]

After the Second World War the technological progress in space systems has increased the relevance of the space domain, which has an essential strategic role in obtaining victory in all battlespace domains. Space capabilities perform a decisive role in all types of military operations, especially those involving the employment of nuclear weapons, in early warning, identification, location of nuclear facilities and launching sites, as well as in destroying them, in support or intermediary operations, collecting information in all warfighting domains, surveillance, reconnaissance, management and coordination of operating systems. Space-based capabilities are also relevant to the normal functioning of modern societies and can be used in activities characteristic to the entire political, economic, civil, information, cyber, infrastructure, and military spectrum. Thus, their interruption would lead to the suspension of the services on which a functional system, for example a state, its society, or departments depend. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This study used an analytical computational model to evaluate safe zones in contaminated areas that may result from a hypothetical significant off-site release from a nuclear power plant. The model, considering local atmospheric stability, wind direction, and location, calculates the expected total effective dose equivalent (TEDE) and potential safety zones. This research, focused on an area near a nuclear facility affected by an accidental release, used SCALE and HotSpot Health Physics codes to simulate the reactor's core inventory content and off-site release. This study's findings underscore that the risk of developing solid cancer (testing morbidity) is influenced by both local atmospheric stability and the composition of the potentially affected population (primarily age and sex). These findings, backed by an analytical approach, can significantly influence logistical and operational planning. The utilization of computer simulations can also aid in creating flexible response scenarios to real events. [ABSTRACT FROM AUTHOR]

This paper addresses the intricate challenge posed by remote handling (RH) operations in facilities with operational lifespans surpassing 30 years. The extended RH task horizon necessitates a forward-looking strategy to accommodate the continuous evolution of RH equipment. Confronted with diverse and evolving hardware interfaces, a critical requirement emerges for a flexible and adaptive software architecture based on changing situations and past experiences. The paper explores the inherent challenges associated with sustaining and upgrading RH equipment within an extended operational context. In response to this challenge, a groundbreaking, flexible, and maintainable human–machine interface (HMI) architecture named MAMIC is designed, guaranteeing seamless integration with a diverse range of RH equipment developed over the years. Embracing a modular and extensible design, the MAMIC architecture facilitates the effortless incorporation of new equipment without compromising system integrity. Moreover, by adopting this approach, nuclear facilities can proactively steer the evolution of RH equipment, guaranteeing sustained performance and compliance throughout the extended operational lifecycle. The proposed adaptive architecture provides a scalable and future-proof solution, addressing the dynamic landscape of remote handling technology for decades. [ABSTRACT FROM AUTHOR]

Dounreay Nuclear Power Development Establishment (NPDE) was built in the far north-east of Scotland due to the possible 'misbehaviour' of the technology and the dangerous nature of the materials involved. From 1960 to the eve of decommissioning in 2007, despite numerous health and safety issues across the Dounreay nuclear facility, a visitor centre operated there. Initially, its purpose was to satisfy public curiosity and provide information about the atomic work being undertaken. From the 1970s, however, the objective of the Dounreay visitor centre shifted, to focus on overcoming public objections to nuclear power. Archive material made available by the Nuclear Decommissioning Authority (NDA) was analysed according to themes addressed in the literature review. Findings reveal an ideological narrative curated by the UK Atomic Energy Authority (UKAEA) and presented to the public via exhibitions, brochures, hands-on displays and outreach activities. At the visitor centre, Dounreay and its associated technologies were simplified, 'banalized', via a narrative that sought to frame an inhospitable destination (Dounreay) as a safe, welcoming and hospitable place to visit. [ABSTRACT FROM AUTHOR]

Everything in the world is about risk, from individual decisions to global manipulations, which is of fundamental importance in a nuclear power plant environment. The question is whether, in a given situation, this risk is acceptable or no longer acceptable. In some respects, the risk analysis applied to construction projects differs from the risk analysis applied to nuclear installations. For nuclear installations, the risk as such is primarily nuclear risk. In view of this, for investments involving a nuclear installation, the risk analysis to be carried out must be carried out at two separate levels. The first level is the traditional construction risk analysis, and then as a second level, each risk item should be classified from a nuclear risk point of view. In this study, the nuclear exposure of construction risks will be presented. [ABSTRACT FROM AUTHOR]

Copyright of Uranium Mining & Metallurgy is the property of Uranium Mining & Metallurgy Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is of meaningful importance to evaluate the performance of all the nuclear facilities, and particularly those part of such buildings where spent nuclear fuel (SNF) is stored to assess what kinds of consequences are anomalous/abnormal or to determine what types of accident events may occur. In this preliminary study, the strategies adopted for the management of SNF, and the risk related to them are discussed. The aim of this study is to evaluate the total radioactivity inventory characterising Ukrainian nuclear facilities, including storage facilities. The dataset used to calculate the total activity associated with nuclear fuel is provided and discussed. For the evaluation, it is considered that a SNF pool in VVER-1000 is designed to store 687 fuel assemblies, and 670 are in VVER-440. When it is half full, which is the case for 15 Ukrainian units, it will store about 2200 tU containing up to 1·1019 Bq of 137Cs, 7·1018 Bq of 90Sr, and 1·1019 Bq of TUE. This study focuses particularly on the total activity of the SNF stored at the Zaporozhye plant, the biggest nuclear plant in Europe, and the risk posed by the potential loss that cooling the plant could incur because of pond water level variation. The results of the analysis of the Zaporozhye NPP behaviour suggest that the water flow rate which keeps the SNF pool temperature constant is about 200,000 m3·day−1. Therefore, the water level in the pond should not be lower than 1.5–2 m; otherwise, the plant will need an additional source of water of more than 200,000 m3 per day to guarantee safe storage of SNF. [ABSTRACT FROM AUTHOR]

Currently, over 100 nuclear power units globally have been in operation for more than 40 years. Hindered by the limitations of computer technology at the time, these nuclear facilities lack detailed electronic drawings. Activities such as equipment replacement and process circuit system modifications during operation result in discrepancies between paper drawings and actual conditions. Given the complexity and irreversibility of nuclear facility decommissioning activities, virtual simulation technology is often employed before the decommissioning process begins to assist in designing and validating decommissioning plans. Consequently, the creation of high-precision 3D models is crucial for subsequent decommissioning designs. Through innovatively utilizing laser-scanning 3D model reconstruction technology in the reconstruction of the model of China's first heavy water research reactor undergoing decommissioning, this paper provides an overview of the process of laser-scanning 3D model reconstruction and its application in reconstructing the heavy water research reactor model. Using a 3D laser scanner, four decommissioning areas of the heavy water research reactor, including the reactor building, secondary water pump room, ventilation center, and low-level radioactive wastewater storage tank area, were subjected to 3D laser scanning. The acquired point cloud data from 572 scanning stations were processed using point cloud processing software for denoising, stitching, and triangulation. The triangulated model was then imported into modeling software for 3D reconstruction, ultimately establishing a digitalized model of the heavy water research reactor suitable for subsequent decommissioning simulation and design. [ABSTRACT FROM AUTHOR]

The level of chromosomal abnormalities in the somatic cells of adult individuals is characterized by significant interindividual variability, which may be partly affected by the genetic and epigenetic background. The epigenetic landscape in cells is largely determined by genome methylation. This study aimed to analyze the relationships between global genome methylation and the frequencies of chromosome abnormalities in lymphocytes of plutonium workers. The frequencies of chromosome aberrations, micronuclei, aneuploidy of chromosomes 2, 7, 8, 12, X, and Y and sister chromatid exchanges were analyzed in the lymphocytes of 40 male workers from a nuclear chemical facility (Seversk, Russia) with incorporated plutonium-239 and 49 healthy male volunteers who had no occupational exposure to ionizing radiation. The long interspersed nuclear elements-1 (LINE-1) methylation index was assessed as a well-known marker of global genome methylation. The frequencies of centromere-negative micronuclei (4.74 ± 2.26 vs. 3.02 ± 1.69‰), chromosome-type aberrations (0.81 ± 0.79 vs. 0.44 ± 0.69%), and total chromosome non-disjunction (0.93 ± 0.43 vs. 0.50 ± 0.25%) were significantly higher in the group of workers than in controls (p < 0.05). The LINE-1 methylation index did not differ significantly between the worker and control groups (74.93 ± 3.63 vs. 73.92 ± 4.62%). Correlations between LINE-1 methylation and the frequency of micronuclei (R = –0.35, p = 0.031) were observed in the control group, whereas correlations of LINE-1 methylation with chromatid-type aberrations (R = –0.42, p = 0.012) (but not chromosome-type aberrations) and with sister chromatid exchanges (R = –0.53, p = 0.004) were observed only in the group of plutonium workers. Thus, LINE-1 hypomethylation after plutonium exposure is associated mainly with chromatid breaks, either repaired or misrepaired. [ABSTRACT FROM AUTHOR]

Production processes become more and more complex in terms of engineering implementation. During the operation of equipment for nuclear power plants or research reactor facilities, it is advisable to consider big data volumes, their change dynamics and deviations from the normal state. The IRT-T reactor facility at the School of Nuclear Science and Technology in National Research Tomsk Polytechnic University, is used for machine learning. [ABSTRACT FROM AUTHOR]

With the construction and development of nuclear facilities, many nuclear production sites need to monitor artificial radioactive aerosol. However, radon and its daughters are ubiquitous in the environment, and their concentration levels are considerably higher than those of artificial radioactive aerosols. Therefore, artificial radioactive aerosol monitors can reliably measure environmental artificial radioactive aerosol only by testing the effectiveness of radon daughter compensation. By studying the mechanism of radon progeny aerosol and establishing a radon progeny aerosol control device that meets the measurement standards, the concentration of radon progeny aerosol in a radioactive aerosol monitor in certain places can be corrected. Thus, the interference to the measurement of specific radioactive aerosol can be reduced in the high radon environment of such places. In this study, we established a radon progeny aerosol control device that can be used to compensate the radon daughter aerosol for the radioactive aerosol monitoring equipment and help to eliminate or reduce the radon progeny aerosol interference of the radon daughter aerosol correction radioactive aerosol monitoring equipment. [ABSTRACT FROM AUTHOR]

The exploration and inspection of narrow spaces in nuclear facilities require the use of long-reach manipulators. Coupled tendon-driven manipulators can realize lightweight and slender arms by positioning actuators, such as motors, at the base. Currently, we are developing a coupled tendon-driven super long-reach articulated arm, which we name "Super Dragon." Super Dragon is a robot arm with a total length of 10 m, a maximum arm diameter of 0.2 m, and 10 joints. In this paper, we focused on the elasticity and elongation of ropes. The joint actuation of Super Dragon utilizes synthetic fiber ropes characterized by their high strength and flexible bending. However, when these ropes are used over long lengths, wire elongation occurs, thus causing the joint angles to exhibit unintended and unstable behavior. Therefore, we focused on a specific posture and employ a double pulley as a mechanical solution to suppress unstable behavior. We introduced stability criteria and performed parametric searches to obtain the appropriate double pulley radii. Subsequently, we identified the position and radius of the introduced double pulley that can be analytically stabilized. By installing a double pulley in the actual machine and conducting experiments, we successfully suppressed the unstable behavior. [ABSTRACT FROM AUTHOR]

Nuclear power plants (NPPs) have been affected by various failures through corrosion which causes economic losses, increased chance of the radiation exposure and environmental risk. One of the major durability issues in reinforced concrete is the corrosion of reinforcement which significantly reduces the life of reinforced concrete. Considering the increasing demand for longer service lives of NPPs, and the high cost involved in building and maintaining it, adequate preventive measures should be followed to minimize the corrosion. This review majorly discusses about the mechanism of corrosion of steel in NPP structures with emphasis on the mechanisms relevant to NPPs, possible reasons for the concrete corrosion as well as potential failure happening in NPPs. The majors reason for the concrete corrosion in nuclear power plants are mainly corrosive external and internal environment, thermal and mechanical stress, moisture content, microorganisms and stray electrical currents. The corrosion of NPPs may result in loss of structural integrity and leakage of radioactive material. The review also discusses about various corrosion prevention and protection techniques against concrete corrosion and concludes with an overview of present methods and possible future perspectives used to enhance the efficiency of concrete corrosion mitigation methods with focus of NPPs. [ABSTRACT FROM AUTHOR]

Very sensitive loads require the safe operation of electrical distribution networks, including hospitals, nuclear and radiation installations, industries used by divers, etc. To address this issue, the provided paper suggests an innovative method for evaluating the appropriate allocation of Distribution STATic COMpensator (DSTATCOM) to alleviate total power losses, relieve voltage deviation, and lessen capital annual price in power distribution grids (PDGs). An innovative approach, known as the modified capuchin search algorithm (mCapSA), has been introduced for the first time, which is capable of addressing several issues regarding optimal DSTATCOM allocation. Furthermore, the analytic hierarchy process method approach is suggested to generate the most suitable weighting factors for the objective function. In order to verify the feasibility of the proposed mCapSA methodology and the performance of DSTATCOM, it has been tested on two standard buses, the 33-bus PDG and the 118-bus PDG, with a load modeling case study based on real measurements and analysis of the middle Egyptian power distribution grid. The proposed mCapSA technique's accuracy is evaluated by comparing it to other 7 recent optimization algorithms including the original CapSA. Furthermore, the Wilcoxon sign rank test is used to assess the significance of the results. Based on the simulation results, it has been demonstrated that optimal DSTATCOM allocation contributes greatly to the reduction of power loss, augmentation of the voltage profile, and reduction of total annual costs. As a result of optimized DSTATCOM allocation in PDGs, distribution-level uncertainties can also be reduced. [ABSTRACT FROM AUTHOR]

Emergency drills and drills against terrorism have been held at nuclear facilities. Shortcomings of these drills are that the numbers of emergency scenarios and roles are limited because many workers must participate in them simultaneously. The times during which all employees can participate simultaneously are limited. As a means of solving these problems, augmented reality (AR) training has been increasingly adopted in recent years, but difficulties of creating contents and the inadequate degrees of freedom in the created contents are becoming problematic. For this study, we developed an AR training environment construction system for users to create scenarios easily by simply assembling and placing blocks representing scenario components in a real-world environment. To realize the construction system, we also developed the "Program Block," which enables users to create scenarios in a puzzle-like style. The system can create and simulate various scenarios involving interaction between trainees and a real-world environment. To evaluate the ease of system usage and flexibility for scenario creation, a subjective experiment was conducted at a nuclear facility. Results indicate that users can construct an AR training environment easily. [ABSTRACT FROM AUTHOR]

Pushover analysis is a common nonlinear static procedure, performed to evaluate seismic response of civil structures. This approach allows considering the structural nonlinear behavior under earthquake loading in a simplified yet effective way; however, in its classic formulation, it is limited by restrictive and unrealistic assumptions. Thus, the basic method is inadequate for the accurate analysis of buildings without a vertical plane of symmetry and/or for multi-component earthquakes, where torsion effects cannot be neglected. Furthermore, standard pushover analysis only comprises one dominant mode of vibration; higher modes, and therefore their effects, are not accounted for. For all these reasons, the standard technique is generally not considered suitable for the assessment of buildings at high risk of natural-technological (NaTech) events, such as nuclear facilities in areas of high seismic activity. To overcome these limitations, a multi-modal pushover analysis procedure is here tested and validated on the data from a non-symmetric structure (the SMART case study) under multi-component earthquakes. In detail, the procedure applies a linear combination of modal load patterns, defined according to the well-established Direct Vectorial Addition (DVA) method. With respect to other existing multi-modal pushover analysis techniques, elliptical response envelopes are employed to calculate the corresponding combination factors. Innovatively, the identification of the dominant modes for the load pattern is not limited to the classic maximization of the forces at the basis of a structure but rather generalized to shear and displacement maximization at different heights and locations throughout the whole structural frame. [ABSTRACT FROM AUTHOR]

Nuclear power plants require cooling water. When numerous nuclear plants were built in the 1970s, they were thus placed at major rivers. This caused cross-border problems, since in Europe, many rivers crossed or constituted borders. As awareness for thermal and radioactive pollution grew, border areas became hotbeds of European anti-nuclear protest. Advocates of European integration suggested that the European Communities (EC) were best positioned to resolve this issue. This article analyses the EC rulemaking attempts regarding the siting of nuclear power plants and explains why they failed. It argues that while the cross-border nature of the problem of nuclear installations at borders justified EC-level legal solutions, the geography of nuclear plants militated against supranational solutions -- at a time of national vetoes and when energy security was considered a national sovereignty concern. The article is based on the analysis of primary sources from European Union and national archives. By taking the physical and political geography of nuclear energy into account, this article offers new perspectives on the role of borders and border studies, on the history of nuclear energy and society, and on the history of European integration. [ABSTRACT FROM AUTHOR]

In decommissioning projects of nuclear facilities, radiological characterisation aims to estimate the quantity and spatial distribution of different radionuclides. To carry out the estimation, measurements are performed on site to obtain preliminary information. The usual industrial practice consists of applying spatial interpolation tools (as the ordinary kriging method) on these data to predict the value of interest for the contamination (radionuclide concentration, radioactivity, etc.) at unobserved positions. This paper questions the ordinary kriging tool on the well-known problem of the overoptimistic prediction variances due to not taking into account uncertainties on the estimation of the kriging parameters (variance and range). To overcome this issue, the practical use of the Bayesian kriging method, where the model parameters are considered as random variables, is deepened. The usefulness of Bayesian kriging, whilst comparing its performance to that of ordinary kriging, is demonstrated in the small data context (which is often the case in decommissioning projects). This result is obtained via several numerical tests on different toy models and using complementary validation criteria: the predictivity coefficient ( Q 2 ), the predictive variance adequacy, the α confidence interval plot (and its associated mean squared error α ), and the predictive interval adequacy. The latter is a new criterion adapted to Bayesian kriging results. Finally, the same comparison is performed on a real data set coming from the decommissioning project of the CEA Marcoule G3 reactor. It illustrates the practical interest of Bayesian kriging in industrial radiological characterisation. [ABSTRACT FROM AUTHOR]

Policy makers around the world have been advocating for an expansion of nuclear energy as a way to mitigate climate change, putting in place financial and political incentives for building new reactors and associated facilities. At the same time, policy makers have also been emphasizing the importance of incorporating justice considerations while decarbonizing. The two are not compatible because of the environmental injustices inflicted by the chain of processes required to generate electricity at nuclear power plants. These injustices are a result of the radioactive nature of the waste materials produced at each step of the nuclear fuel chain. Some of these materials remain hazardous for tens of thousands of years. In addition, nuclear facilities face the ever present risk of catastrophic accidents which can contaminate large tracts of land, rendering them uninhabitable for decades if not centuries. These consequences disproportionately fall on Indigenous Peoples and other disempowered communities, as well as non‐human entities. Such impacts are overlooked in our current socio‐political system committed to growth and a techno‐economic approach to dealing with any challenges to its continued existence. This article is categorized under:Human and Social Dimensions > Energy and Climate JusticeEnergy and Power Systems > Energy Infrastructure [ABSTRACT FROM AUTHOR]

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The article describes the model for calculating external doses from surface and clouds as well as internal doses due to inhalation and food chains, which is incorporated in the RC code used to calculate doses to the public from accidental short-term releases and continuous releases during normal operation of nuclear facilities (NFs). The article describes the features of the code, such as the consideration of aerodynamic shadow and linear source model. The results of verification of the code using experimental data on aerosol transport and the results of calculations using the certified NOSTRADAMUS code are presented. The results of calculations and measurements of doses after the Chernobyl accident and as a result of continuous releases from RIAR reactors are also compared. [ABSTRACT FROM AUTHOR]

The paper describes a continuous numerical model of polluted groundwater plumes near the LRW storage reservoirs Lake Karachay and Staroye Boloto of Mayak Production Association. This model, developed by Gidrospetsgeologiya, is based on the long-term monitoring of data obtained by Facility-Focused Monitoring System (FFMS). The model is regularly updated as the FFMS database is augmented, new data of engineering-geological and hydrogeological surveys are obtained, and new tasks are set to assess the hydrogeological safety of nuclear facilities at the industrial site of Mayak Production Association. [ABSTRACT FROM AUTHOR]

The paper is focused on the problem of groundwater flow and transport modeling applied to safety assessment of nuclear facilities and development of relevant computational codes. The classification of typical tasks of the nuclear industry is provided, and specific features typical of different classes of simulated objects are analyzed, including their near and far fields. The most radioecologically relevant radionuclides are identified for each class. GeRa computational code is used as an example to analyze current trends of the development of hydrogeological modeling software. [ABSTRACT FROM AUTHOR]

Conditioning of radioactive waste generated from the operation of medical institutions, nuclear cycle facilities, and nuclear facilities is important for the safety of the environment. One of the most hazardous radionuclides is radioactive cesium. There is a need for more effective solutions to contain radionuclides, especially cesium (Cs+). Geopolymers are promising inorganic materials that can provide a large active surface area with adjustable porosity and binding capacity. The existence of nanosized zeolite-like structures in aluminosilicate gels was shown earlier. These structures are candidates for immobilizing radioactive cesium (Cs+). However, the mechanisms of their interactions with the aluminosilicate framework related to radionuclide immobilization have not been well studied. In this work, the influence of alkaline cations (Na+ or K+) and the aluminosilicate framework structure on the binding capacity and mechanism of interaction of geopolymers with Cs+ is explored in the example of a sodalite framework. The local structure of the water molecules and alkaline ions in the equilibrium state and its behavior when the Si/Al ratio was changed were studied by DFT. [ABSTRACT FROM AUTHOR]

Radioactive wastes, such as concrete and soil, generated during the decommissioning of nuclear facilities contain radionuclides with varying levels of activity. Beta-emitting radionuclides can be identified after thoroughly decomposition and separation from the sample matrix. Among these radionuclides, Fe–55 and Ni–63 play vital roles in the management of radioactive waste from nuclear facilities owing to their pronounced incidence and high mobility in the environment. This study documents the results of the extraction efficiencies of Fe and Ni with a rapid pretreatment method within 2 h by wet digestion methods using hydrochloric acid and nitric acid (3:1, v/v). The average Fe and Ni extraction efficiencies for certified reference materials in soil and sediment matrix were evaluated to be 84–94% and 90–96% with analytical precision within 5%, respectively. [ABSTRACT FROM AUTHOR]

Nuclear safety-related structures are crucial for ensuring the safety of nuclear facilities and preventing the leakage of radioactive materials, with the primary structural component being low-rise reinforced concrete (LRC) walls. These walls are required to carry combined in-plane axial and horizontal loads, making the accurate prediction of their lateral load-carrying capacity particularly important. In this study, six LRC walls with aspect ratios between 0.33 and 1 were tested and a model for the prediction of the lateral load-carrying capacity of LRC walls was established based on the observed failure mode and plastic limit theory. The parameter in the model was calibrated using the obtained results in this test along with a database containing 131 walls in the literature. Compared to the equations in the American standard ACI 349 and the French standard RCC-CW, the proposed equation is most suitable for assessing the lateral load-carrying capacity of LRC walls in nuclear safety-related structures. The calculated values of the proposed equation exhibit a ratio closest to 1 when compared to experimental values and possess the minimum degree of variation. The computational results reveal that the proposed equations in this study exhibit superior precision and stability. [ABSTRACT FROM AUTHOR]

Nuclear energy has become a complicated and controversial issue. The public perception of controversial issues in general has an influential role in this policy debate. With representative data (N = 1,933) from Taiwan, China, this study explores the factors that influence public acceptance of nuclear waste facilities and suggests a moderating mediation model of their acceptance. This study finds that public acceptance of nuclear waste facilities is typically a psychological perception issue, rather than a political one which is quite different from public acceptance of nuclear energy. In addition, this study finds that perceived environmental justice is a significant variable in the relationship between risk perception of nuclear waste and public acceptance of nuclear waste facilities. Further, this study also summarizes a moderated mediation model of the public's acceptance of nuclear waste facilities and reveals the risk perception of nuclear energy weakens, while the benefit perception of nuclear energy strengthens the relationship between the risk perception of nuclear waste facilities and public acceptance of nuclear waste facilities. Furthermore, a substitutional relationship between the risk perception of nuclear energy and the risk perception of nuclear waste facilities was identified. Policy implications based on the empirical results are also discussed. [ABSTRACT FROM AUTHOR]

In this manuscript, production of 201TlCl, one of the radiopharmaceuticals used in the field of nuclear medicine for diagnostic purposes in heart, muscle, thyroid gland imaging, and cancer diagnosis, at Turkish Energy Nuclear and Mineral Research Agency is described. The production process starts with a cyclotron type proton accelerator operated in energy range of 15–30 MeV with beam intensities up to 1200 μA currently available at the facility. The production is detailed along with the main lines in the other steps. In addition to the radiopharmaceutical productions carried out according to international standards at the facility, new projects are planned in the short and long terms. [ABSTRACT FROM AUTHOR]

Precariously balanced rocks (PBRs) are a type of naturally occurring freestanding structure that provides valuable information to constrain seismic hazard at return periods which are important for critical facilities such as nuclear power plants and nuclear repositories. Exposure ages have been established to be in excess of 10,000–30,000 years, which is why precarious rocks are one of the only available means to validate seismic hazard associated with long return periods. One critical component for constraining seismic hazard in this way is the overturning estimate of a given precarious rock as a function of earthquake intensity. However, current state‐of‐the‐art methods for modeling the seismic response of precarious rocks involve significant sources of uncertainty. One of the main sources of uncertainty stems from the interface of the rock, which is usually occluded during surveying and assumed during modeling. Through extensive shake table testing, this study analyzes the uncertainty in the overturning response of a granite precarious rock specimen incorporating various degrees of interface contact. The results indicate that a small variation in the contact geometry could result in a substantial increase in the stability of the specimen, which is significant given the difficulty of surveying the interface of PBRs in the field. Repeatability tests indicate that the overturning demand can vary up to nearly ±50%. The probabilistic overturning responses are compared across the interface changes to bound uncertainty; and, the effect of modeling parameters, namely the contact normal stiffness, is evaluated through a parametric study and comparison with experimental results. [ABSTRACT FROM AUTHOR]

An ion chromatography method was developed for the simultaneous determination of fluoride, iodate and iodide in a caustic scrubber solution used for trapping off-gases released during the dissolution of nuclear fuels. A separation between iodate and fluoride could be realized with 0.6 mM hydroxide, which is too weak to elute other anions including iodide in reasonable time. Studies were carried out at different column temperature, and with the help of Van't Hoff plots the thermodynamic parameters associated with the column equilibrium were estimated, which helped in understanding the co-elution of iodate and fluoride at higher concentration of eluent. An arrangement of conductivity detector and UV-VIS detector in sequence after the ion exchange column (with 15 mM NaOH as eluent) was used for recording chromatograms for conductivity signal and UV-VIS signal simultaneously. The information from the two chromatograms was utilized to quantify iodate, fluoride and iodide in a single run. The limit of detection for fluoride, iodate and iodide is 7 ppb, 10 ppb and 12 ppb, respectively. The precision of the method is better than 2% (RSD) at 0.5 mg/L. The method was used successfully for the real sample analysis. [ABSTRACT FROM AUTHOR]

To achieve permanent disposal of radioactive waste drums, the radionuclides analysis process is essential. A variety of waste types are generated through the operation of nuclear facilities, with dry active waste being the most abundant. To perform radionuclides analysis, sample pre-treatment technology is required to transform solid samples into solutions. In this study, we developed a dry ashing-microwave digestion method and secured the reliability of the analysis results through a validity evaluation. Additionally, we conducted a comparative analysis of the radioactivity of 94Nb nuclides with and without the chemical separation process, which reduced the minimum detectable activity level by more than 65-fold for a certain sample. [ABSTRACT FROM AUTHOR]

The environmental effects of severe nuclear accidents pose a great threat to the environment and to living organisms. Unfortunately, there have been several examples of this over time. In our work, we present development solutions and opportunities which a nuclear power plant or other nuclear facility can implement nuclear environmental monitoring even under extreme conditions. We will discuss systems and tools that can be used to increase the efficiency of the radiation situation assessment, helping decision-makers to make quick and optimal decisions, thus helping to minimise the environmental impact. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)