Fundamental Safety Research Articles

Predictive modeling of hazard radius for refinery hydrogen releases using regression technique

Fundamental safety principle of hazardous area classification study is to avoid ignition of those releases that may occur during the operation of facilities handling flammable fluids. One of the methods for this study is the point source approach. Regarding this approach one can estimate hazard radius due to a release by having hole size and release pressure. However, till now no reference represents hazard radii for the wide range of possible hole sizes and release pressures. The aim of the present study is to propose a predictive model for estimation of hazard radii due to releases of typical refinery hydrogen gas based on hole size and release pressure. In this study, a complete database of hazard radii due to a broad range of hole sizes and release pressures is provided using available discharge and dispersion models. A regression-based model for estimation of hazard radii is developed based on the provided database. Performance investigation of the proposed model shows that the results are reliable with an acceptable standard error.

Fundamental safety strategy against severe accidents on prototype sodium-cooled fast reactor

ABSTRACTThe accident categories of severe accidents (SAs) for prototype sodium-cooled fast reactor (SFR) which need proper measures were investigated through the internal event probabilistic risk assessment (PRA) and event tree analysis for the external event and six accident categories, unprotected loss of flow (ULOF), unprotected transient over power (UTOP), unprotected loss of heat sink (ULOHS), loss of reactor sodium level (LORL), protected loss of heat sink (PLOHS) and station blackout (SBO), were identified. Fundamental safety strategy against these accidents is studied and clearly stated considering the characteristics and existing accident measures of prototype SFR, and concrete measures based on this safety strategy are investigated and organized. The sufficiency of these SA measures is confirmed by comparing the evaluated core damage frequency (CDF) and containment failure frequency (CFF) to the target value, 1×10−5 and 1×10−6 per plant operating year, respectively, which were selected based on the IAEA's safety target. However, the target value of CDF and CFF should be satisfied considering all the SAs caused by both internal and external events. External event PRA for prototype SFR is now under evaluation and we set out to satisfy the target value of CDF and CFF considering both internal and external events.

식품절단기 사용 사업장의 사고성 재해 특성에 따른 개선방안 연구

Abstract The past five years, industrial accidents due to food process ing machinery have been occurred 725 cases, injury by the food cutter occurred 390 cases in its. On this study, to prevent food cutter injury, an attempt is made to present the improved documentation of fun damental safety of the food cutter workplace through the injury analysis of food cutter injury and surveys on band saw machine business field. Analyzing the result of 390 cases on food cutter injury, amputation, cut, puncture occupied 75.1 percent (293 cases), compressed occupied 23.3% (91 cases), also it showed constant component without reference to gender, age, scale of work place, service period. In the survey, lack of concentration for workers have been pointed out as the biggest factor in the cause of band saw machine injury. Meanwhile, such as the EU and Japan, whereas pr esents safety standards about band saw machines that are tailored to each country, on the other ha nd, South Korea doesn't provide the standards. To prevent the food cutter injury, safety standards need to be established in consideration of amputation, cut, puncture, compressed injury and financial supp ort is required to procure protective equipment at each place of business.Keyword : food processing machine, band saw machine, industrial accident, safety standard

Journey Toward High Reliability: A Comprehensive Safety Program to Improve Quality of Care and Safety Culture in a Large, Multisite Radiation Oncology Department.

High-reliability organizations (HROs) focus on continuous identification and improvement of safety issues. We sought to advance a large, multisite radiation oncology department toward high reliability through the implementation of a comprehensive safety culture (SC) program at the University of Pennsylvania Department of Radiation Oncology. In 2011, with guidance from safety literature and experts in HROs, we designed an SC framework to reduce radiation errors. All state-reported medical events (SRMEs) from 2009 to 2016 were retrospectively reviewed and plotted on a control chart. Changes in SC grade were assessed using the Agency for Healthcare Research and Quality Hospital Survey. Outcomes measured included the number of radiation treatment fractions and days between SRMEs, as well as SC grade. Multifaceted safety initiatives were implemented at our main academic center and across all network sites. Postintervention results demonstrate increased staff fundamental safety knowledge, enhanced peer review with an electronic system, and special cause variation of SRMEs on control chart analysis. From 2009 to 2016, the number of days and fractions between SRMEs significantly increased, from a mean of 174 to 541 days (P < .0075) and 21,678 to 113,104 fractions (P < .0028) preintervention and postintervention, respectively. Agency for Healthcare Research and Quality results demonstrate a high patient SC grade over time. Our journey toward becoming an HRO has led to the development of a robust SC through a comprehensive safety framework. Our multifaceted initiatives, focusing on culture and system changes, can be successfully implemented in a large academic radiation oncology department to yield measurable improvements in SC and outcomes.

Grand Challenges in Transportation and Transit Systems

Transportation and transit systems draw upon broad spectra of research fields due to the diversity and interconnectivity of transport modes, including road, rail, aviation, pipeline, maritime, or even aerospace. These systems have evolved over centuries to be considerably more efficient and environment-friendly for a wide range of customers. The fundamental principle safety first is still the key priority in most research today. However, thanks to extensive interface with various customers; research and innovation in practices have shifted from optimizing functional purposes and targets through each stage of life cycle toward modernization, reliability, resilience, and better quality of life. These initiatives additionally coincide with the grand challenges for engineering proposed by the National Academy of Engineering and the United Nations' Millennium Development Goals (National Academy of Engineering, 2015). Language: en

Benchmarking minibus safety in Abu Dhabi, United Arab Emirates

The Department of Transport (DoT) in Abu Dhabi has recognised that while minibuses play a key role in transporting people within the United Arab Emirates, levels of fatal and serious injury among minibus occupants in crashes are high. As a first step toward addressing this problem, the DoT commissioned a benchmarking study to gain an understanding of the state of the minibus fleet, focusing on fundamental vehicle safety aspects, as well as fitment rates of safety features such as airbags and stability control systems. Furthermore, the in-service condition of vehicles was also assessed. Data was collected from 566 minibuses in Abu Dhabi and Dubai, comprising more than 80 separate data points characterising the presence, nature and condition of each vehicle. An innovative system was developed to combine these variables to yield a weighted safety score that allowed them to be grouped into categories for later input into a benefit cost analysis of a replacement program. A star rating system was used for the categorisation process because it allows for good discrimination between safety levels while remaining easy to comprehend. The results of the benchmarking study showed that despite the fleet being quite uniform by make and model, there was considerable variation among individual vehicles in terms of seat belt fitment rates and rear passenger compartment seat mounting integrity in particular. Many vehicles in current operation are deficient both in terms of primary and secondary safety, compounded by inconsistent fitment of passenger seat belts. This in-depth survey has provided significant additional information unavailable from registration data and provides a valuable insight into the state of minibus safety in the UAE. The data acquired will be used to conduct a benefit cost analysis targeted at determining the optimal means for implementing significant improvements to the minibus fleet.

Development of a PWR-W GOTHIC 3D model for containment accident analysis

The confinement of radioactive material in a nuclear power plant, including the discharge control and the release minimization, is a fundamental safety function to be ensured in a design basis accident (DBA).For plant licensing analysis, the containment is usually modeled with a lumped parameter approach. Inherent to the lumped parameter approach is the assumption that within each region the fluid is well mixed. However, the containment is a large building with a complex configuration and it is distributed in several compartments that avoid the well mixing of the fluid and could have three-dimensional effects that affect the thermal–hydraulic behavior. Therefore, the commonly used lumped parameter approach may not be enough to capture these effects.In order to study these assumptions, four generic PWR containment models have been developed for Mass and Energy (M&E) release analysis with GOTHIC 8.0 (QA) code, three of them being subdivided and the fourth one is a lumped parameter model. A Large Break LOCA is simulated in order to compare the thermal–hydraulic behavior of the different models. The results show a high dependence on the three-dimensional phenomena, especially the temperature and velocity distribution. In contrast, the pressure evolution is qualitatively similar in all models with small quantitative differences.

Evolutionary Optimization of a Motorcycle Traction Control System Based on Fuzzy Logic

Braking and traction control systems are fundamental vehicle safety equipments. The first ones prevent the wheels from locking, maintaining, when possible, the handling of the vehicle under emergency braking. While the second ones control wheel slip when excessive torque is applied on driving wheels. The aim of this study is to develop and implement a new control model of a traction control system to be installed on a motorcycle, regulating the slip in traction and improving dynamic behavior of two-wheeled vehicles. This paper presents a novel traction control algorithm, which makes use of a fuzzy logic control block. Two strategies to create the control block have been carried out. In the first one, the parameters that define the fuzzy logic controller have been tuned according to experience. In the second one, the parameters have been obtained by means of an evolutionary algorithm (EA) in order to design an augmented traction controller. It has been proved that the use of EA can improve the fuzzy-logic-based control algorithm, obtaining better results than those produced with the control tuned only by experience.

Mevsimlik (Gezici/Geçici) tarım işçilerinin iki yerleşim birimindeki yaşam koşulları ve sağlık durumlarına niteliksel bakış

Objective : In this research we aimed to determine the status of seasonal agricultural workers located in two housing units in terms of living, working and health conditions. Methods: This is a descriptive study using qualitative methods: in-depth interviews and in situ observations. It took place in provinces of Adana and Mersin located in the Cukurova region and the Sanliurfa province. A common feature of these provinces is their high density of seasonal agricultural workers. Our field work was performed by going to places where seasonal agricultural workers live and work. The research was conducted during the dates of March 2014 and August 2014. Snowball sampling methods was used in this research. Data were collected by interviews with 26 seasonal agricultural workers who were older than 15. Results: Seasonal agricultural workers were working without social insurance, safe transportation facilities, or guarantee of employment and without any worker’s health and safety precautions being taken by the employees. Accommodation units lacked fundamental structural and safety features. Seasonal agricultural workers were faced with social alienation and could not access the basic health services such as vaccination, antenatal follow-up, reproductive health or outpatient services. Also, their diet was unbalanced and insufficient. Children could not take the benefit sufficiently from education and were employed in agricultural work. In addition to their agricultural work, women also were exploited in their domestic life. Conclusion: Seasonal agricultural workers were in an aggrieved position concerning topics such as transportation, accommodation, wages and social insurance. To eliminate these conditions, the opinion of agricultural middlemen, seasonal agricultural workers and employees should be taken into account with the financial support of local authorities under the scope of the law.

Fundamental Use of Surgical Energy (FUSE): Closing a Gap in Medical Education.

Traditional medical education curricula for students, residents and trainees do not address the rapidly growing number of technological devices that are fundamentally changing health care delivery today. This is most relevant in those medical specialties that rely heavily on the use of advanced technologies and devices, for example minimally invasive surgery, interventional radiology, gastroenterology, cardiology and anesthesia. Health care professionals in these domains are increasingly sharing procedures that use energy devices of many different designs and functionality without training in their fundamental use and safety. This exposes both operators and patients to increasing risk for injury. The definitive gap in adequate education and training in new technologies prompted the development of The Fundamental Use of Surgical Energy (FUSE) program by a multidisciplinary team of clinicians, nurses, educators and engineers under the leadership of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). The sweeping changes in the surgical and interventional professions due to technological innovation call for the development of additional curricula to close the educational gap on other medically important technologies. The FUSE program and future educational curricula on medical technologies are fundamental to patient care and represent a necessary paradigm shift in traditional medical education.

From behavioral psychology to acceleration modeling: Calibration, validation, and exploration of drivers’ cognitive and safety parameters in a risk-taking environment

We investigate a utility-based approach for driver car-following behavioral modeling while analyzing different aspects of the model characteristics especially in terms of capturing different fundamental diagram regions and safety proxy indices. The adopted model came from an elementary thought where drivers associate subjective utilities for accelerations (i.e. gain in travel times) and subjective dis-utilities for decelerations (i.e. loss in travel time) with a perceived probability of being involved in rear-end collision crashes. Following the testing of the model general structure, the authors translate the corresponding behavioral psychology theory – prospect theory – into an efficient microscopic traffic modeling with more elaborate stochastic characteristics considered in a risk-taking environment.After model formulation, we explore different model disaggregate and aggregate characteristics making sure that fidelity is kept in terms of equilibrium properties. Significant effort is then dedicated to calibrating and validating the model using microscopic trajectory data. A modified genetic algorithm is adopted for this purpose while focusing on capturing inter-driver heterogeneity for each of the parameters. Using the calibration exercise as a starting point, simulation sensitivity analysis is performed to reproduce different fundamental diagram regions and to explore rear-end collisions related properties. In terms of fundamental diagram regions, the model in hand is able to capture traffic breakdowns and different instabilities in the congested region represented by flow-density data points scattering. In terms of incident related measures, the effect of heterogeneity in both psychological factors and execution/perception errors on the accidents number and their distribution is studied. Through sensitivity analysis, correlations between the crash-penalty, the negative coefficient associated with losses in speed, the positive coefficient associated with gains in speed, the driver’s uncertainty, the anticipation time and the reaction time are retrieved. The formulated model offers a better understanding of driving behavior, particularly under extreme/incident conditions.

Hardhat-Wearing Detection for Enhancing On-Site Safety of Construction Workers

AbstractConstruction is one of the most dangerous job sectors, which annually reports tens of thousands of time-loss injuries and deaths. These injuries and deaths do not only bring suffering to the workers and their families, but also incur delays and costs to the projects. Therefore, safety is an important issue that a general contractor must monitor and control. One of the fundamental safety regulations is wearing a hardhat, which should not be violated anytime on the sites. In this paper, a novel vision-based method is proposed to automate the monitoring of whether people are wearing hardhats on the construction sites. Under the method, human bodies and hardhats are first detected in the video frames captured by on-site construction cameras. Then, the matching between the detected human bodies and hardhats is performed using their geometric and spatial relationship. This way, the people who are not wearing hardhats could be automatically identified and safety alerts could be issued correspondingly. Th...

Applicability of 100 TBq cesium 137 release into environment as a safety criterion for consequence assessment at reactor design approval stage

The International Atomic Energy Agency (IAEA) fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. Therefore, a severe accident consequence assessment has to be able to include all quantifiable consequences on people and the environment. Our previous studies on estimation of cost per severe accident succeeded in quantifying aforementioned consequences. However, the estimation requires enormous quantity of data, time and human resources, thus it may be inappropriate at the reactor design approval stage. Finnish government uses “100 TBq cesium 137 release into environment”, which was proved to generate limited health effects, as one of the reactor design criteria for accident consequences. In this study, we perform an evaluation of annual dose from the 100 TBq cesium 137 release and confirm limited health effects. We form the environmental impact index based on insights from our previous studies and used it to assess consequences to the environment. The estimated environmental impact index is very small, which confirms the limitedness of the environmental impacts of the release. These findings ensure the applicability of 100 TBq cesium 137 release into environment as a safety criterion for consequence assessment at reactor design approval stage.

Aviation Cabin Safety Situated Learning Education Design-An Empirical Study for Elementary Students

Responsibility and obligation of aviation safety are undertaken not only by the crew but also by the passengers in a flight. Therefore, the importance of aviation safety should be recognized by both parties. Current fundamental traffic safety educations in Taiwan are more inclined to road safety and most of the way education is taught in the classroom, this study presents a Cabin mockup-based situated learning education program design with immersive education means to enhance children's understanding of the relevant cabin safety. Due to plasticity of elementary school students are better, this method can not only improve aviation education but also be better achieved popularity aviation knowledge in the long run. A pretest-posttest control group design was used to evaluate the effect of a cabin mockup-based situated learning education program designed to enhance the safety concepts in elementary school students, the results showed that after a different education method, students learning outcomes in the two groups on cabin safety concept presenting significant differences. Significantly better than the control group students (traditional instruction) in the experimental group students (situational experience), and the control group students in the context of strengthening the implementation using cabin mockup simulated leaning education, this can significantly improve the effectiveness of learning into. For airline cabin safety promotion, it is recommended to change the pattern from visiting to cabin experience camp that is because the airlines can use their own cabin mockup to promote the site as a situation education classroom.

Careful Planning in a Pediatric Expected Difficult Airway in a Specialized Tertiary Hospital: What can Go Wrong? A Case Report

The expected difficult airway in children is a rare but challenging entity. Publications about pediatric airway management present global recommendations and strategies in order to improve safety and outcome. However, even when a careful plan is implemented according to these fundamental aspects, safety and efficacy may be compromised. The objective of this case report is to alert for the importance of a careful airway planning along with an exhaustive attention to details. A 6 month-year-old child with a complex polymalformative syndrome was scheduled for anti-reflux surgery due to recurrent respiratory infections. A careful plan for airway management was designed, based on airway examination and description of a previous approach with a video laryngoscope. It was decided to schedule two anesthesiologists, one of them experienced in the difficult airway approach. Airway management was planned in order to maintain spontaneous ventilation under inhalational anesthesia with sevoflurane and 100% inspired oxygen fraction. Approaches and sequential steps after failed intubation attempts are described as well as technical difficulties related to material and devices. Given the risk of losing the airway and ventilation it was decided to proceed with the final step of our plan and a surgical tracheostomy was performed. This is an example of how meticulous should be our preparation when planning the airway management in pediatric anesthesia. The presence of another anesthesiologist with expertise in pediatric difficult airway approach, exhaustive description of previous airway approaches and the meticulous revision of the available material including that for invasive procedures should always be kept in mind.

Explosion risk on offshore and onshore facilities—is there an explosion risk problem or an explosion modelling problem?

Management of the risk related to the loss of containment of flammable fluid is paramount to ensure safe operations at facilities processing or storing flammable fluids. According to best industry practice, an extensive set of safety functions—including measures that reduce the frequency of initiating events (e.g. leaks) and measures that mitigate consequences in case of ignition—are implemented in design to control the risk. Adopting the risk-based design principles that are commonly enforced in the oil and gas industry, the performance of implemented safety barriers are assessed both qualitatively and quantitatively using different methodologies such as hazard and operability analysis (HAZOP), failure mode and effects analysis (FMEA), and quantitative risk analysis (QRA). The ultimate outcome from the QRA methodology is used to assess the overall risk level as well as to assess dimensioning accidental loads (DALs) for equipment and structures that will ensure a design that is within the tolerable risk level set for the facility. An accurate assessment of DALs resulting from fires and explosion is crucial to manage both the risk and corresponding cost driving factors. The most critical safety barrier in this regard is to minimise leaks and thereafter to prevent ignition of the dispersed flammable fluid. A fundamental safety design principle is to find ways to avoid the occurrence of incidents rather than implement measures that mitigate consequences. This peer-reviewed paper demonstrates the significance of modelling the safety functions that are in place to ensure that the initial leak does not ignite by presenting a case example for different layouts of a conventional jacket installation with gas turbines. It is concluded that the difference between various available ignition models can be more prominent than the uncertainty related to any other model element in the QRA. To uncover potential hazards not reflected by the model and identify optimal control measures, the effect of the ignition model applied should be investigated in detail for installations where the QRA displays a prominent fire and explosion frequency.

Safety Performance of the Full Harness in Various Falling Postures of Wearer

Fundamental safety measure for falling is to prepare flat and effective wide workplace with guardrails. However, their countermeasures may be difficult to apply for short-duration works and disaster relief works. In such cases, the fall arrest system has been applied to the height workplaces. This study focuses on fundamental characteristics of full body harness in various postures of wearer during falling. Three kinds of situation, such as (1) leg first fall, (2) head first fall, and (3) stop falling when the wearer body in parallel to the ground, were considered to recognize the performance. Experiments were carried out using 735N of human dummy, called HybridIII pedestrian 50%tile model in the automobile industry. The shock-absorber of the Lanyards used in this study were designed about 4kN. Impact force acting on hook, head accelerations, and a chest displacement were measured during falling. From the results, not only the vertical acceleration of the human dummy but also horizontal were measured. Due to the horizontal acceleration, a huge bending moment acting on the dummy's neck observed in several situations. It indicates that the wearer may have risks of whiplash or more serious injuries such as dislocation of cervical vertebrae or spinal injuries. Chest deformations measured in this study were not also small for aged workers. It indicates that there are some risks of rid fractures or related chest injuries. The back of the head crashed aggressively to the D-ring of the full harness when the dummy rebounded due to stop falling by lanyard. Therefore, special helmet to resist the impact force due to D-ring, and the design force of shock-absorber should be reconsidered.

Navigation with ECDIS: Choosing the Proper Secondary Positioning Source

The completion of ECDIS mandatory implementation period on-board SOLAS vessels requires certain operational, functional and educational gaping holes to be solved. It especially refers to positioning and its redundancy, which represents fundamental safety factor on-board navigating vessels. The proposed paper deals with primary and secondary positioning used in ECDIS system. Standard positioning methods are described, discussing possibilities of obtained positions' automatic and manual implementation in ECDIS, beside default methods. With the aim of emphasizing the need and importance of using secondary positioning source in ECDIS, positioning issue from the standpoint of end-users was elaborated, representing a practical feedback of elaborated topic. The survey was conducted in the form of international questionnaire placed among OOWs, ranging from apprentice officers to captains. The result answers and discussion regarding (non)usage of secondary positioning sources in ECDIS were analysed and presented. Answers and statements were elaborated focusing not only in usage of the secondary positioning system in ECDIS, but in navigation in general. The study revealed potential risks arising from the lack of knowledge and even negligence. The paper concludes with summary of findings related to discrepancies between theoretical background, good seamanship practice and real actions taken by OOWs. Further research activities are pointed out, together with planned practical actions in raising awareness regarding navigation with ECDIS.

Manual of Good Practices for Food or Feed Recalls

Product recall is a fundamental food safety risk management tool. The key to successful implementation of a recall is recognizing the importance of shared responsibility between government/competent authority and industry. Within the recall process, the main objective for the competent authority is to protect public health by ensuring the rapid removal of unsafe foods or feeds from the market. To address the impact of a globalized food supply on the facilitation of recalls, competent authorities around the world have adopted regulations addressing product tracing through the food supply chain, clarifying responsibilities within the recall process, mandatory recall authority for food safety agencies, and disposal of contaminated products. During the recall process, the key areas in which the competent authority plays a vital role include: Communication; Coordination, Initiation and Completion of the Recall Process; Evaluation of Effectiveness of the Recall Process; Data collection, and Providing Guidance and Training to Industry and other Stakeholders.

OBSERVABILITY-IN-DEPTH: AN ESSENTIAL COMPLEMENT TO THE DEFENSE-IN-DEPTH SAFETY STRATEGY IN THE NUCLEAR INDUSTRY1

Defense-in-depth is a fundamental safety principle for the design and operation of nuclear power plants. Despite its general appeal, defense-in-depth is not without its drawbacks, which include its potential for concealing the occurrence of hazardous states in a system, and more generally rendering the latter more opaque for its operators and managers, thus resulting in safety blind spots. This in turn translates into a shrinking of the time window available for operators to identify an unfolding hazardous condition or situation and intervene to abate it. To prevent this drawback from materializing, we propose in this work a novel safety principle termed “observability-in-depth”. We characterize it as the set of provisions technical, operational, and organizational designed to enable the monitoring and identification of emerging hazardous conditions and accident pathogens in real-time and over different time-scales. Observability-in-depth also requires the monitoring of conditions of all safety barriers that implement defense-in-depth; and in so doing it supports sensemaking of identified hazardous conditions, and the understanding of potential accident sequences that might follow (how they can propagate). Observability-in-depth is thus an information-centric principle, and its importance in accident prevention is in the value of the information it provides and actions or safety interventions it spurs. We examine several “event reports” from the U.S. Nuclear Regulatory Commission database, which illustrate specific instances of violation of the observability-in-depth safety principle and the consequences that followed (e.g., unmonitored releases and loss of containments). We also revisit the Three Mile Island accident in light of the proposed principle, and identify causes and consequences of the lack of observability-in-depth related to this accident sequence. We illustrate both the benefits of adopting the observability-in-depth safety principle and the adverse consequences when this principle is violated or not implemented. This work constitutes a first step in the development of the observability-in-depth safety principle, and we hope this effort invites other researchers and safety professionals to further explore and develop this principle and its implementation.