Inherent Safety Aspects for Layout Design of a Floating LNG Facility

Author(s):  
Peiwei Xin ◽  
Salim Ahmed ◽  
Faisal Khan

This article outlines the aspects of inherent safety for the topside layout design of a floating liquefied natural gas (FLNG) facility. An FLNG plant requires a compact design; meanwhile, it needs the safest layout to tackle multi-dimensional safety issues. Thus, the layout of the facility is a paramount factor for ensuring its safety in a cost effective way. Three layouts are proposed and evaluated from the inherent safety perspective. The layout of the process area is mainly focused due to its higher risks. Integrated inherent safety index, cost index and domino hazard index are used to evaluate the three layouts in quantitative terms. An optimal layout is finally chosen based on both inherent safety and cost performance.

Author(s):  
H. Mimi

Pada peringkat awal reka bentuk loji kimia, keputusan paling penting dan kritikal yang perlu dibuat adalah ketika pemilihan proses kimia yang bakal digunakan untuk penghasilan produk yang dikehendaki. Sebelum ini, ekonomi merupakan faktor yang diberi keutamaan dalam pemilihan proses kimia yang terbaik. Sebaliknya kini, faktor kesihatan, keselamatan serta alam sekitar merupakan isu penting yang menjadi tumpuan dan amat dititikberatkan dalam pengoperasian sesebuah loji. Risiko ke atas kesihatan para pekerja di kawasan loji berikutan terdedah kepada bahan–bahan kimia di tempat kerja dapat dikurangkan melalui pemilihan proses kimia yang betul. Proses yang paling ‘sihat’ dapat dikenal pasti dengan menjumlahkan ancaman ke atas kesihatan manusia. Dalam projek ini, PRHI telah diperkenalkan untuk menjangka potensi ancaman proses kimia ke atas kesihatan pekerja. Proses alternatif yang wujud bagi menghasilkan produk yang sama akan disusun berdasarkan tahap kesihatan yang dihasilkan oleh setiap proses. Lebih tinggi nilai indeks yang diperolehi, maka lebih berbahayalah sesuatu proses itu. Nilai PRHI dikira berdasarkan pelepasan bahan kimia serta kuantiti bahan kimia yang dihidu oleh pekerja. Indeks yang telah dibangunkan dalam projek ini diaplikasikan ke atas enam proses kimia alternatif yang wujud bagi menghasilkan metil metakrilat (MMA). Keputusan bagi pengiraan PRHI ini kemudiannya dibandingkan dengan Inherent Safety Index (ISI), Environmental Hazard Index serta kos penghasilan produk bagi kesemua enam proses alternatif. Kata kunci: ISHE, teknik penilaian keselamatan loji Proper selection of chemical process route is one of the main design decisions during the preliminary stages of chemical plant design. Previously, the most important factor for selecting the best chemical process route was only the economics. But now, safety, environmental and health issues have become important factors to be considered. Health risks on workers could also be reduced by proper selection of chemical process route. However, the health hazards needed to be quantified in order to choose the ‘healthiest’ route. Process Route Healthiness Index (PRHI) has been developed to foresee the potential health hazards from chemical processes. PRHIP ranks process routes in terms of their occupational healthiness. The higher the index, the higher is the hazard. PRHI is influenced by the health impact due to chemical releases and the concentration of airborne chemicals inhaled by workers. In this article, PRHI has been applied on six alternative routes for Methyl Methacrylate (MMA). The results of the ranking was compared to the Inherent Safety Index, Environmental Hazard Index and production costs for the six alternative chemical process routes. Key words: Occupational health hazard, assessment method, ISHE, ranking index


Author(s):  
Jerry Rau ◽  
Mike Kirkwood

Pressure testing of pipelines has been around in some form or another since the 1950s1–14. In its earliest form, operators used inert gases such as Nitrogen or even air to test for pipeline integrity. However, with the significant increases in pipeline pressures and inherent safety issues with a pressurized gas, the switch to using water happened in the late 1960’s15–17. Hydrostatic tests (referred to as hydrotests) have been used since then to set and reset the Maximum Allowable Operating Pressure (MAOP) for pipelines but as other technologies develop and gain acceptance will hydrotesting still play a key role in pipeline integrity in the years ahead? Currently, hydrotesting is a topic for the impending US Pipeline and Hazardous Materials Safety Administration’s (PHMSA) Proposed New Rule Making (PNRM)18. Under the NPRM, hydrotesting is required to verify MAOP on pre-1970s US “grandfathered” pipelines, as well as on pipelines of any age with incomplete or missing testing record and include a high level test with a “spike” in pressure. But hydrotesting may not be the only method. Alternative methods and new technologies — used alone or used in combination with hydrotesting — may help provide a more comprehensive way for operators to identify and address potential problems before they become a significant threat. This paper explores both sides of the argument. Before In-Line Inspection (ILI) technology was even available, hydrotesting was the absolute means of the proof of integrity. However, hydrotesting is under scrutiny for many reasons that this paper explores. ILI was introduced in the 1960’s with the first commercially available Magnetic Flux Leakage (MFL) tools that presented the industry with an alternative. Currently there are a huge array of available technologies on an ILI tool and so is the role of the hydrotest over? The paper looks at the benefits of the hydrotest and these are presented and balanced against available ILI technology. Furthermore, as pipelines are being developed in even more harsh environments such as deepwater developments, the actual logistics of performing a hydrotest become more challenging. The paper will also look at both applications onshore and offshore where regulators have accepted waivers to a hydrotest using alternative methods of proving integrity. The paper concludes with the current use and needs for hydrotesting, the regulatory viewpoint, the alternatives and also what the future developments need to focus on and how technology may be improved to provide at least a supplement if not a replacement to this means of integrity assurance.


2021 ◽  
Vol 7 ◽  
Author(s):  
Qijie Wu ◽  
Kewei Shu ◽  
Lili Sun ◽  
Haihua Wang

High-performance electrolyte is still a roadblock for the development of rechargeable magnesium (Mg) batteries. Grignard-type electrolytes were once the only choice in the early stage of rechargeable Mg batteries research. However, due to their nucleophilic nature and high reactivity, Grignard-type electrolytes have inherent safety issues and low oxidation stability, which restrict the development of rechargeable Mg batteries in terms of practical application. Recently, emerging novel Mg battery systems such as Mg-S, Mg-O2/air batteries also require non‐nucleophilic electrolytes with high oxidation stability. This short review summarizes recent advances in non‐nucleophilic Mg electrolytes and aims to provide insights into electrochemical properties and active Mg ion structure of such electrolytes.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Peng Chen ◽  
Weiliang Zeng ◽  
Guizhen Yu ◽  
Yunpeng Wang

Conflict analysis using surrogate safety measures (SSMs) has become an efficient approach to investigate safety issues. The state-of-the-art studies largely resort to video images taken from high buildings. However, it suffers from heavy labor work, high cost of maintenance, and even security restrictions. Data collection and processing remains a common challenge to traffic conflict analysis. Unmanned Aerial Systems (UASs) or Unmanned Aerial Vehicles (UAVs), known for easy maneuvering, outstanding flexibility, and low costs, are considered to be a novel aerial sensor. By taking full advantage of the bird’s eye view offered by UAV, this study, as a pioneer work, applied UAV videos for surrogate safety analysis of pedestrian-vehicle conflicts at one urban intersection in Beijing, China. Aerial video sequences for a period of one hour were analyzed. The detection and tracking systems for vehicle and pedestrian trajectory data extraction were developed, respectively. Two SSMs, that is, Postencroachment Time (PET) and Relative Time to Collision (RTTC), were employed to represent how spatially and temporally close the pedestrian-vehicle conflict is to a collision. The results of analysis showed a high exposure of pedestrians to traffic conflict both inside and outside the crosswalk and relatively risking behavior of right-turn vehicles around the corner. The findings demonstrate that UAV can support intersection safety analysis in an accurate and cost-effective way.


Author(s):  
Jack W. Foster ◽  
John V. Kauffman

The United States Nuclear Regulatory Commission (NRC) has a Generic Issues Program (GIP) to address Generic Issues (GI). A GI is defined as “a regulatory matter involving the design, construction, operation, or decommissioning of several, or a class of, NRC licensees or certificate holders that is not sufficiently addressed by existing rules, guidance, or programs.” This rather legalistic definition has several practical corollaries: First, a GI must involve safety. Second, the issue must involve at least two plants, or it would be a plant-specific issue rather than a GI. Third, the potential safety question must not be covered by existing regulations and guidance (compliance). Thus, the effect of a GI is to potentially change the body of regulations and associated guidance (e.g., regulatory guides). The GIP was started in 1976, thus it is a relatively mature program. There have been approximately 850 issues processed by the program to date. More importantly, even after 30 years, new GIs continue to be proposed. The entire set of Generic Issues (GIs) is updated annually in NUREG-0933, “A Prioritization of Generic Safety Issues.” GIs tend to involve complex questions of safety and regulation. The efficient and effective means of addressing these issues is very important for regulatory effectiveness. If an issue proves to pose a genuine, significant safety question, then swift, effective, enforceable, and cost-effective action needs to be taken. Conversely, if an issue is of little safety significance, the issue should be dismissed in an expeditious manner, avoiding unnecessary expenditure of resources and regulatory burden or uncertainty. This paper provides an overview of the 5-stage program, from identification through the regulatory assessment stage. The paper also includes a discussion of the program’s seven criteria, sources of proposed GIs, recent improvements, publicly available information, historical performance, and status of current GIs.


2018 ◽  
Vol 198 ◽  
pp. 04009 ◽  
Author(s):  
Shi Jun

In the field of integrated circuits, ESD (Electro Static Discharge) has always been a rather serious problem of reliability. Enhanced ESD tolerance of IC chips became a focus of research on IC failure protection design. The thesis is better to solve the multi-fingered non-uniform conduction of ESD devices under electrostatic pulse. Layout parameters DCGS (Drain-Contact to Gate Spacing), SCGS (Source-Contact to Gate Spacing) and BS (Substrate-source spacing) size in the paper can be used as reference for ESD GGNMOS (Gated Ground NMOS) layout design. Also this paper provides setting the DRC (Design Rule Check) command to check the distance between the N+ diffusion regions of different potentials so that ESD failure is prevented effectively. TLP (Transmission Line Pulse) current pulse signal is adopted to measure characteristics of the GGNMOS. The thesis descripts a ESD Optimal layout design from five aspects of introduction, Key elements of ESD circuits layout design, ESD layout optimization, a ESD GGNMOS layout instance and conclusion.


Sign in / Sign up

Export Citation Format

Share Document