Safety Design Research Articles

External Hazard Analysis for Water-Based Nuclear Power Plants

Based on recent studies, Water-Based Nuclear Power Plants (NPPs) include onshore and offshore floating NPPs, gravity-based structure NPPs, and underwater NPPs. These NPPs are increasingly considered for their benefits, such as the floating NPPs ability to distribute energy to remote areas, offshore sites, and construction activities. Regarding safety, external hazards must be considered during the design phase as stated in the Head of Nuclear Energy Regulatory Agency Regulation Number 3 Year 2011 and Specific Safety Requirements-2/1 (Rev 1). The external hazards of Water- Based NPPs should differ from those of land-based NPPs. Several studies have outlined the external hazards that water-based NPPs only address, such as onshore floating NPPs, and have yet to discuss the impact on water-based NPPs' safety. This study reviews the external hazards that must be considered and their effects on all types of Water-Based NPPs. The study is conducted by reviewing national regulations and international references to identify specific external hazards for Water-Based NPPs, followed by examining scientific works related to marine safety and Water-Based NPP design information to understand the impact of external hazards on the facilities. The review indicates that the external hazards that need to be considered for Water-Based NPPs include weather hazards, human- induced external hazards, earthquakes, and tsunamis. Keywords: NPP, Floating NPP, External Hazard, nuclear safety

Integration of Design for Manufacture and Assembly with Product Design in Product Design Improvement: A Systematic Literature Review

This paper aims to investigate and analyze some previous literature relevant to the Design for Manufacture and Assembly and Design for Safety methods in international journals. An extensive review and analysis of the body of literature was conducted to discuss the findings in a few chosen papers pertaining to the application of both methods, using a survey based on descriptive and qualitative surveys published in international journals with publication period limitations from 2011 to 2023 published in proceedings and electronic journals in English. So far, there has never been any research or literature review that discusses the Integration of Design for Manufacture and Assembly with Design for Safety.

Quality Matrix-Based Product Innovation in Birkinpet Pet Harness Apparel

This study employs the Quality Function Deployment (QFD) method to develop BirkinPet pet harness apparel, focusing on customer needs and competitive advantages. A House of Quality (HoQ) matrix was constructed using responses from 96 participants, evaluating the relationship between Customer Importance and Technical Importance to identify key technical priorities for immediate implementation in BirkinPet’s production process. The primary HoQ matrix results indicate that lightweight, comfort, and safety (481.5), design for various activities (416.1), and ergonomic and comfortable design (389.9) are the most important attributes to customers. The main technical priorities include ensuring the product is safe and strong (4.99) and providing a variety of sizes and options (4.86). The novelty lies in the comprehensive and structured application of QFD, emphasizing innovation in designing products that align with current market trends and customer preferences. By integrating comfort, safety, and flexible design, BirkinPet successfully creates a high-quality product that meets customer needs, enhancing customer satisfaction and loyalty while strengthening its competitive position in the pet accessories market.

Performance Analysis of Water Heat Pipe for Application of the Passive Cooling System in Nuclear Power Plants

Incorporating heat pipes into passive cooling systems in nuclear reactors offers the benefits of passive operation without external power, a simple design, and high thermal capacity. Accurate thermal performance prediction of the heat pipe is crucial for ensuring safe reactor design and operation. Prior studies on nuclear reactor systems utilizing heat pipes have focused on thermosyphons, which operate by gravity. However, to expand the range of heat pipe applications in reactor systems, experimental investigations of large-scale heat pipes driven by capillary pumping force are required. In this study, a water heat pipe with a 25.4-mm diameter and 4-m length was manufactured to provide thermal experimental results under extreme conditions, such as system rollover or loss-of-cooling accidents. A three-dimensional (3D) printing technique was used to fabricate the high-performance lattice capillary wick structure by combining cubic and diamond lattice structures. The 3D printed wick structure showed 21 to 165 times higher capillarity and enhanced surface properties compared to the screen mesh wick structure. Compared to wickless thermosyphons, the 3D printed wick heat pipe exhibited higher thermal conductivity, stable operation in both vertical and horizontal orientations, and faster startup under extreme conditions.

Modeling of the fracture behaviors of concrete using 3D discrete element method with softening effect

Understanding the fracture mechanism of concrete is very important for the safety design of concrete structures. We develop a 3D discrete element model with softening effect to study the fracture behaviors of quasi-brittle materials. The basic ideas of our model inspired from the flat-joint concept and the cohesive crack model are implemented in the framework of MUSEN, which is an open source discrete element software with CPU–GPU accelerating computation. The placement-package-compaction method is proposed together with laser scanning technology to construct the meso-scale geometric model of concrete. The meso-parameters of 3D discrete element model developed are calibrated by uniaxial compression and splitting tension tests of concrete. The validation of the present model is verified by the laboratory test of concrete. Compared with the results predicted by the flat-joint model, the F-CMOD curves and fracture parameters simulated by our model are in good agreement with that of the laboratory tests of concrete. Finally, it is concluded that the fracture strain of bond significantly affects the fracture behavior but the softening mode does not. It is found that the linear one is better choice among three softening modes in the present model.

Construction safety challenges and opportunities at design stage for building industry in Pakistan

The implementation of Design for Construction Safety (DfCS) at the early design phase can proactively identify and address potential hazards in construction projects. By integrating safety considerations into the design process, it becomes possible to eliminate or minimize risks before they become costly and dangerous issues can also be avoided during construction. To gain insights into the current practices and barriers faced by professionals in the construction industry of Pakistan regarding DfCS, a comprehensive study was conducted. This study utilized a combination of questionnaire-based surveys and interviews to gather data from various stakeholders involved in the design and construction processes. The research revealed that DfCS was absent in the standard design practice. The weaknesses identified for the implementation of DfCS were designers’ inevitable doubts about increasing cost, schedule problems, absence of contracts and regulations, designers’ lack of safety knowledge and skills. The largest influential factors were regulatory liability on the designer (29%) and increasing costs (27%). The study identified that less trained worker were rated 59% for site accidents. 87% of respondents suggested revision of contract and regulations. The study proposed a framework to check constructability with respect to safety standards. Alternative project delivery method i.e., Design Build (DB) was recommended to reduce health and safety accidents and barriers.

Study on the structure parameters and design method optimization of blade-type screw steel pipe pile

The rationality of structure parameters of the blade-type screw steel pipe pile is the major factor in determining the safety, applicability, and economy of a pile foundation, but the existing design methods have not defined the specific approaches to calculating structure parameters of blades and steel pipes. To address this issue, an analysis of the strength theory was performed on spatial helical blades, revealing the ratio of blade width to steel pipe radius as the core index to do the structure parameters design of blade-type screw steel pipe pile and established a mathematical calculation model between the vertical bearing capacity of single pile and a. The rational value of a is 2.0–3.0 using numerical calculation. The correlation between blade thickness and wall thickness of steel pipes was determined using the force analysis based on the synergy between blades and steel pipes. Then the structure parameters design method of blade-type screw steel pipe pile with coordinated parameters was proposed. The rationality and superiority of this design method were verified by comparing the existing test data and the finite element simulative analysis. Based on this design method and the current specifications, such as the Technical Code for Building Pile Foundations, a safe, applicable, and economical optimization design method and flow of blade-type screw steel pipe piles were further proposed for engineering design reference.

Crystalline Phase Regulates Microbial Methylation Potential of Mercury Bound to MoS2 Nanosheets: Implications for Safe Design of Mercury Removal Materials.

Transition-metal dichalcogenides (TMDs) have shown great promise as selective and high-capacity sorbents for Hg(II) removal from water. Yet, their design should consider safe disposal of spent materials, particularly the subsequent formation of methylmercury (MeHg), a highly potent and bioaccumulative neurotoxin. Here, we show that microbial methylation of mercury bound to MoS2 nanosheets (a representative TMD material) is significant under anoxic conditions commonly encountered in landfills. Notably, the methylation potential is highly dependent on the phase compositions of MoS2. MeHg production was higher for 1T MoS2, as mercury bound to this phase primarily exists as surface complexes that are available for ligand exchange. In comparison, mercury on 2H MoS2 occurs largely in the form of precipitates, particularly monovalent mercury minerals (e.g., Hg2MoO4 and Hg2SO4) that are minimally bioavailable. Thus, even though 1T MoS2 is more effective in Hg(II) removal from aqueous solution due to its higher adsorption affinity and reductive ability, it poses a higher risk of MeHg formation after landfill disposal. These findings highlight the critical role of nanoscale surfaces in enriching heavy metals and subsequently regulating their bioavailability and risks and shed light on the safe design of heavy metal sorbent materials through surface structural modulation.

The time for ambitious action is now: Science-based recommendations for plastic chemicals to inform an effective global plastic treaty

The ubiquitous and global ecological footprint arising from the rapidly increasing rates of plastic production, use, and release into the environment is an important modern environmental issue. Of increasing concern are the risks associated with at least 16,000 chemicals present in plastics, some of which are known to be toxic, and which may leach out both during use and once exposed to environmental conditions, leading to environmental and human exposure. In response, the United Nations member states agreed to establish an international legally binding instrument on plastic pollution, the global plastics treaty. The resolution acknowledges that the treaty should prevent plastic pollution and its related impacts, that effective prevention requires consideration of the transboundary nature of plastic production, use and pollution, and that the full life cycle of plastics must be addressed. As a group of scientific experts and members of the Scientists' Coalition for an Effective Plastics Treaty, we concur that there are six essential “pillars” necessary to truly reduce plastic pollution and allow for chemical detoxification across the full life cycle of plastics. These include a plastic chemical reduction and simplification, safe and sustainable design of plastic chemicals, incentives for change, holistic approaches for alternatives, just transition and equitable interventions, and centering human rights. There is a critical need for scientifically informed and globally harmonized information, transparency, and traceability criteria to protect the environment and public health. The right to a clean, healthy, and sustainable environment must be upheld, and thus it is crucial that scientists, industry, and policy makers work in concert to create a future free from hazardous plastic contamination.

Thermal runaway front propagation characteristics, modeling and judging criteria for multi-jelly roll prismatic lithium-ion battery applications

Large-format prismatic Li-ion batteries (LIBs) are prominent energy storage devices in electric transportation applications. However, large-format LIB induces severe thermal runaway (TR) disasters. Battery failure commonly initiates from a local point of one jelly roll and then propagates to the whole cell, called thermal runaway front (TRF) propagation. This study investigates the TRF propagation mechanism of multi-jelly roll-based LIBs through experiments, modeling, and theoretical analysis for thermal runaway propagation (TRP) mitigation. Experiments prove that battery venting changes along the jelly roll-safety valve directions during the TRF boundary movement. Besides, TRF propagation speed is found to be accelerated inside each cell (from 3.6 to 10.6 mm/s) during TRP, driven by a significant temperature gradient, chemical reactions, and gas flow along the TRP direction. The in-cell TRF acceleration behavior is more noticeable for batteries with more jelly rolls. The TRF speed-jelly roll index equations are proposed to reveal the propagation acceleration principle mathematically. Furthermore, a thermal-physical model is developed to precisely simulate in-cell TRF propagation behavior, which is validated by experimental data. Moreover, the TRF boundary temperature equation and “No TRP” judging criteria are proposed through theoretical analysis. This study proposes promising strategies for potential TRP suppression, contributing to future safe battery system design.

Safety Design Criteria for the Emergency Discharge of Hazardous Substances in Small and Medium-Sized Polystyrene Polymerization Batch Reactor Processes: Case Study of the South Korean Chemical Industry

In small and medium-sized chemical plants, explosions constantly occur owing to runaway reactions because of equipment defects or human errors and so on. Accordingly, in this study, based on a case study of an explosion accident in a polystyrene reactor in South Korea, the dis-charge capacity of hazardous substances during a runaway reaction is reviewed and a method for safely disposing of hazardous substances is proposed. Using an acceleration rate calorimeter, the maximum temperature rise rate during the polystyrene reaction was determined, and it was determined that 355,643 kg/h can flow during a runaway reaction. A 30-inch header size was then selected to consider maximum flow rate, and two 81.4 m2 heat exchangers were selected to completely condense the hazardous substances. As a result, the facilities at the workplace were configured to condense all hazardous substances and discharge them into the atmosphere. If this method is used, it is believed that the lives of workers can be protected by preventing fires and explosions in small and medium-sized chemical plants in which runaway reactions may occur.

Evaluation of target area under the concentration-time curve of vancomycin in an initial dosing design: a retrospective cohort study.

Area under the concentration-time curve (AUC)-guided dosing of vancomycin was introduced in a clinical setting; however, the target range of non-steady-state AUCs, such as Day 1 AUC and Day 2 AUC, remains controversial. Therefore, we sought to determine pharmacokinetic parameter thresholds and identify independent risk factors associated with acute kidney injury (AKI) to establish a safe initial dosing design for vancomycin administration. A single-centre, retrospective, cohort study of hospitalized patients treated with vancomycin was conducted to determine the threshold of both non-steady-state AUCs (Day 1 and 2 AUCs) and trough levels at the first blood sampling point (therapeutic drug monitoring, TDM). In addition, independent risk factors associated with AKI were evaluated using univariate and multivariate logistic regression analyses. The thresholds for predicting AKI were estimated as 456.6 mg·h/L for AUC0-24h, 554.8 mg·h/L for AUC24-48h, 1080.8 mg·h/L for AUC0-48h and 14.0 μg/mL for measured trough levels, respectively. In a multivariate analysis, Day 2 AUC ≥ 554.8 mg·h/L [adjusted odds ratio (OR), 57.16; 95% confidence interval (CI), 11.95-504.05], piperacillin/tazobactam (adjusted OR, 15.84; 95% CI, 2.73-127.70) and diuretics (adjusted OR, 4.72; 95% CI, 1.13-21.01) were identified as risk factors for AKI. We identified thresholds for both AUCs in the non-steady-state and trough levels at the first TDM. Our results highlight the importance of monitoring not only the AUC but also trough levels during vancomycin treatment to reduce the likelihood of AKI.

Bicycle Lanes Design for Road User Safety

Bicycle Lanes Design for Road User Safety

Numerical simulation study on explosion characteristics of large vault tanks with different height-to-diameter ratios

ABSTRACT This study employs Large Eddy Simulation (LES) to investigate the effects of the Height-to-Diameter (H/D) ratio on the explosion characteristics of gasoline-air mixtures in storage tanks, and the flow field, flame propagation velocity, and explosion overpressure were analyzed. The research shows that the dynamic change of the vortex in the tank is the key to the explosion oscillation, its generation accelerates the flame propagation, and its weakening inhibits the explosion. As the H/D ratio increases, the peak speed of flame propagation decreases, and when the H/D ratio increases from 0.5 to 0.9, the peak speed decreases by 200%. The study also reveals that with the decrease of H/D, both peak explosion overpressure and flame velocity increase. The maximum overpressure appears near the tank top, and when H/D is 0.5, the maximum overpressure of the tank top is 3.75 MPa. The simulation result shows that internal explosion pressures exceed the tanks’ design limits across all H/D ratios, which indicates that it is necessary to take reasonable pressure relief measures to prevent and control the explosion disaster of the vaulted tanks. The research results provide important theoretical and practical guidance for the safe design of storage tanks and the prevention of explosion accidents.

Acoustic design considerations for mental and behavioral healthcare facilities

The acoustic environment in healthcare settings can impact patient comfort and clinical outcomes. Design of mental and behavioral healthcare facilities have the unique challenge of balancing acoustic needs with the considerations of patient safety, maintenance requirements, and cost-effective design. The acoustic quality of these patient care spaces is often overlooked or considered impractical to achieve due to other design constraints. This evaluation reviews the applicable acoustic guidelines and unique design considerations related to mental and behavioral healthcare facilities, current design practices, and developer feedback for recently constructed facilities.

The reduced order model for creep using dynamic mode decomposition

Given the computational challenges associated with finite element methods in analyzing creep behavior in high-temperature components, this work presents an advanced method for modeling thermal creep in complex structures through a reduced order model (ROM) developed via dynamic mode decomposition (DMD). The results indicate that the ROM using DMD can predict long-term structural responses related to creep based on short-term data with high accuracy, enhancing significantly computational efficiency. The application of ROM allows for the rapid estimation of creep effects in complex structures, like monoliths in the MegaPower reactor, thereby improving the design efficiency. The eigenvalues of the creep related ROM all fall in the unit circle on the complex plane, indicating that creep is a stable development process. The DMD with improved time mode coefficient can reconstruct strain-rate related plastic deformation and cyclic visco-plastic deformation process. Additionally, we derive the necessary stress updating algorithm and consistent tangent operator matrix for the 316H unified visco-plastic constitutive equation in 2023 edition ASME code, ensuring accurate modeling of material creep behavior under high temperatures in this paper. This work provides a valuable tool for the safe design and operation of critical components in nuclear engineering and other high-temperature applications.

Short-term extreme response estimation methodology for marine umbilical cables with two configuration types

This study investigates the critical engineering problem of the short-term extreme responses of marine umbilical cables, which are essential components in offshore oil and gas operations. Umbilical cables play a pivotal role in connecting subsea systems to surface platforms, necessitating a safe design to withstand external loads. This study focused on two primary umbilical cable configuration types: deep-water catenary and shallow-water lazy wave. For each configuration type, 100 3-h dynamic numerical simulations were performed, with maximum values fitted by using the Gumbel distribution, and the most probable maximum (MPM) values were set as benchmark values. The average conditional exceedance rate (ACER) method and uncertainty-incorporated ACER method were applied to study the short-term extreme values of umbilical cable responses based on limited sample data. The predicted results have been compared with the MPM values, and the accuracy and uncertainty of different efficient extreme-value analysis methods are discussed. This study provides a comprehensive methodological framework for the reliability analysis and safety design of umbilical cables in marine engineering.

A study of mechanism of wellbore instability by means of strain energy density

The paper presents a new analytical method based on the strain energy density to investigate the mechanism of wellbore instability. To establish the method, pre- and post-drilling states of strain energy densities were first formulated, and then have been applied to the wellbore wall using the strain energy balance. This innovative approach differentiates the instability prone zones into two distinct parts; the compressive, and the tensile zones that also known as borehole breakout and drilling-induced fracture, respectively. These two types of instabilities are related to the restored strain energy density (RESED) and the released strain energy density (RLSED), accordingly. Among the two types of instabilities, the geometrical characteristics of the compressive instable prone zone, that is, width, 2 θ b , and length, L b , were further formulated, examined and proposed. The results of the presently developed method have been compared with those that obtained by using the existing borehole breakout’s geometry. In each case, good agreement was found between the results of this study and the conventional methods. This method has further been compared and verified by using the experimental data. Finally, it has been demonstrated that how this method helps to determine the optimal mud pressure for a safe wellbore design.

Analysis of sensitive clay landslide mechanism and impact pipeline bearing characteristics considering spatial variability

Landslides caused by the progressive failure of sensitive clay slopes may cause substantial economic losses and environmental pollution to pipelines. This study utilizes the Karhunen-Loève (K-L) expansion method, the coupled Eulerian-Lagrangian (CEL) method, and the Monte Carlo method to model the large deformation behaviour of slopes with spatial variability. The proposed RCEL-MC framework for joint analysis of extensive deformation-probability statistics of landslide impact on pipelines confirms that the spatial variability clay slope instability failure mechanism, considering the soil softening effect under earthquake action, aligns more closely with real-world scenarios. Furthermore, based on the statistical failure probability of pipelines impacted by landslides, a sensitive clay slope pipeline safety design method is suggested. The research highlights that the random field parameters significantly influence the load-bearing characteristics of pipelines affected by spatially variable slope progressive failure landslides. The uncertainty surrounding the maximum impact force on pipelines notably increases with the rise of the horizontal correlation length and variability coefficient. When accounting for spatial variability, the maximum impact force on landslide pipelines surpasses the deterministic model analysis results by 28-69 %. It is emphasized that the deterministic model analysis, which neglects the spatial variability of soil and the soil softening effect, may seriously underestimate landslide risk. Based on the criteria for pipeline buckling failure and yield failure, it is advised that the safe design parameters for pipelines in practical projects should fall within the intersection of the secure regions defined by the two failure criteria.

Study on the Design Parameters of Landscape Elements of Urban Tunnel Body Segments in China Based on Biomass Perception

To provide a comprehensive analysis of how an intricate landscape environment comprising various landscape elements influences driving safety and comfort. Beginning with the individual design of the tunnel body section, which includes the roof, sidewalls, road surface, and sidewalk facade markings, this paper references the driver’s biomass index to identify design alterations that satisfy basic safety requirements through simulated driving experiments. Subsequently, employing orthogonal experimental design and semi-supervised clustering algorithms, we ascertain the optimal combination of the four main landscape elements of the tunnel body section that align with both safety and comfort objectives. The experimental findings demonstrate that a safe and comfortable landscape design for urban tunnel sections does not entail a single optimal design; rather, any landscape design conforming to the criterion of “patterned landscapes are set on the side walls and roofs of the tunnel instead of the surface of the road” is the optimal design.