Safety Assessment—A Method for Determining the Performance of Alarm and Shutdown Systems for Chemical Plants

1968 ◽  
Vol 1 (4) ◽  
pp. T72-T79 ◽  
Author(s):  
G. Hensley

Safeguards, for costly and hazardous chemical plants, are often provided by means of alarm or automatic shutdown systems. The adequacy of this protection—which is a measure of the capability of the newly installed system in shutting down the plant on the occurrence of a hazardous condition, and its effectiveness over the long term (its reliability)—may be judged by an independent safety assessment. Both qualitative and quantitative aspects of safety analysis are involved in an assessment, the quantitative approach being of particular use where there is a need to compare the anticipated reliability of the proposed system with a numerically specified, reliability requirement. Some of the techniques used in the assessment procedure are discussed in the paper and, by way of example, the performance of a typical shutdown system is assessed and its adequacy judged against a hypothetical plant fault condition.

2021 ◽  
Author(s):  
Zhiyuan Han ◽  
Guoshan Xie ◽  
Haiyi Jiang ◽  
Xiaowei Li

Abstract The safety and risk of the long term serviced pressure vessels, especially which serviced more than 20 years, has become one of the most concerned issues in refining and chemical industry and government safety supervision in China. According to the Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel”, if necessary, safety assessment should be performed for the pressure vessel which reaches the design service life or exceeds 20 years without a definite design life. However, the safety and risk conditions of most pressure vessels have little changes after long term serviced because their failure modes are time-independent. Thus the key problem is to identify the devices with the time-dependent failure modes and assess them based on the failure modes. This study provided a case study on 16 typical refining and chemical plants including 1870 pressure vessels serviced more than 20 years. The quantitative risk and damage mechanisms were calculated based on API 581, the time-dependent and time-independent failure modes were identified, and the typical pressure vessels were assessed based on API 579. Taking the high pressure hydrogenation plant as an example, this study gave the detailed assessment results and conclusions. The results and suggestions in this study are essential for the safety supervision and extending life of long term serviced pressure vessels in China.


Author(s):  
Shanshan Shao ◽  
Guodong Jia ◽  
Liang Sun ◽  
Hui Wang

The fitness-for-service assessment is widely used to demonstrate whether identified defects or in-service deterioration threaten the structure integrity of the pressure equipment. This article introduces the development of the Chinese national safety assessment standard. The assessment procedure and assessment techniques of current Chinese national safety assessment standard GB/T 19624-2004 are demonstrated, and the improvement is proposed. In order to maintain availability of aging equipment and enhance the long-term economic performance of in service pressure equipment, a new Chinese national safety assessment standard system is methodology proposed based on the analysis of some international structure integrity procedures or standards. A new national standard fitness-for-service which focuses on the evaluation of in-service damage and degeneration will be established while GB/T 19624 is applicable for general defects.


2000 ◽  
Vol 663 ◽  
Author(s):  
S. Keller

ABSTRACTScenarios were developed and analyzed as part of a long-term safety analysis of a permanent repository for radioactive wastes. A procedure is described by which features, events, and processes (FEP) at a specific site can be evaluated for the long-term safety assessment of a permanent repository for radioactive waste. These FEPs can be weighted according to selected criteria and combined to scenarios using a conceptual model of the site.


Author(s):  
B. Haverkamp ◽  
J. Krone ◽  
I. Shybetskyi

The Radioactive Waste Disposal Facility (RWDF) Buryakovka was constructed in 1986 as part of the intervention measures after the accident at Chernobyl NPP (ChNPP). Today, the surface repository for solid low and intermediate level waste (LILW) is still being operated but its maximum capacity is nearly reached. Long-existing plans for increasing the capacity of the facility shall be implemented in the framework of the European Commission INSC Programme (Instrument for Nuclear Safety Co-operation). Within the first phase of this project, DBE TECHNOLOGY GmbH prepared a safety analysis report of the facility in its current state (SAR) and a preliminary safety analysis report (PSAR) for a future extended facility based on the planned enlargement. In addition to a detailed mathematical model, also simplified models have been developed to verify results of the former one and enhance confidence in the results. Comparison of the results show that — depending on the boundary conditions — simplifications like modeling the multi trench repository as one generic trench might have very limited influence on the overall results compared to the general uncertainties associated with respective long-term calculations. In addition to their value in regard to verification of more complex models which is important to increase confidence in the overall results, such simplified models can also offer the possibility to carry out time consuming calculations like probabilistic calculations or detailed sensitivity analysis in an economic manner.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
ERCAN ÇATAK ◽  
Ali ATALAY

By obtaining changes on gene sequences of living things with the applied biotechnological methods; The idea of "Genetically Modified Organisms (GMO)", which aims to bring the living creature in question the original gene combinations with the desired characteristics, came to life in the late twentieth century. Despite the high probability that hunger problems may increase with the increasing world population; It is thought that plant breeding with classical farming methods will be insufficient in solving these problems. With various GMO applications developed all over the world, it aims to produce solutions to these problems. With the presence of GMO, it was possible to increase the shelf life of qualitative and quantitative values of the existing foods. In addition, decreases in agricultural use of pesticides used in agricultural struggle and threatening human health with GMO production are noteworthy. However, some concerns about anomalies that may occur in living things fed GMO products remain on the agenda. Because, in the long term, there is no clear and precise information that GMO will not have negative effects on living things; There are many recorded incidents showing their negative effects.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 559-559
Author(s):  
Sara Freed ◽  
Briana Sprague ◽  
Lesley Ross

Abstract Interventions using exercise video games, or exergames, have shown short-term cognitive and physical benefits to older adults, though long-term effects are less promising. Enjoyment of exergames may promote exergame use after the intervention period, though little work has examined older adults’ views of exergames before and after gameplay experience. We invited 20 older adults between 65 and 84 years of age (M=73.30, SD=5.95) to play two Xbox Kinect games, Just Dance and Kinect Sports Rivals, for twenty minutes. In our presentation, we will present qualitative and quantitative findings of this pilot study, including findings that older adults reported that they were not likely to play similar exergames in the future and that they did not find the exergames to be more fun compared to other ways of exercising. We will discuss implications for game design and research relevant to game developers, manufacturers, and researchers. Part of a symposium sponsored by Technology and Aging Interest Group.


2016 ◽  
Vol 61 (2) ◽  
pp. 761-766 ◽  
Author(s):  
A. Zieliński ◽  
M. Sroka ◽  
A. Hernas ◽  
M. Kremzer

Abstract The HR3C is a new steel for pressure components used in the construction of boilers with supercritical working parameters. In the HR3C steel, due to adding Nb and N, the compounds such as MX, CrNbN and M23C6 precipitate during service at elevated temperature, resulting in changes in mechanical properties. This paper presents the results of microstructure investigations after ageing at 650, 700 and 750 °C for 5,000 h. The microstructure investigations were carried out using scanning and transmission electron microscopy. The qualitative and quantitative identification of the existing precipitates was carried out using X-ray analysis of phase composition. The effect elevated temperature on microstructure and mechanical properties of the examined steel was described.


1985 ◽  
Vol 4 (3) ◽  
pp. 1-22 ◽  

Isostearyl Neopentanoate, the ester of Isostearyl Alcohol and Neopentanoic Acid, is used in cosmetic products as an emollient at concentrations up to 50 percent. The undiluted ingredient at doses up to 4 ml/kg was shown to be relatively non-toxic in short-and long-term feeding studies. Test data from animal and clinical studies indicate the undiluted ingredient is neither an irritant nor a sensitizer. A cosmetic formulation containing 16 percent Isostearyl Neopentanoate produced no phototoxicity and no photoallergenicity. Mutagenicity, carcinogenicity, and teratogenicity data were not available. Isostearyl Neopentanoate was not considered to be a significant comedogenic agent. On the basis of available data, it is concluded that this ingredient is safe as a cosmetic ingredient in its present practices of use.


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