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Safety Engineering
Safety engineering is an engineering Branches of science, discipline which assures that engineered systems provide acceptable levels of safety. It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering. Safety engineering assures that a life-critical system behaves as needed, even when components Failure, fail. Analysis techniques Analysis techniques can be split into two categories: Qualitative research, qualitative and Quantitative research, quantitative methods. Both approaches share the goal of finding causal dependencies between a hazard on system level and failures of individual components. Qualitative approaches focus on the question "What must go wrong, such that a system hazard may occur?", while quantitative methods aim at providing estimations about probabilities, rates and/or severity of consequences. The complexity of the technical systems such as Improvements of Design and Materials, Planned Inspections, Fool-pro ...
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ISS Impact Risk
The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United States), Roscosmos (Russia), European Space Agency, ESA (Europe), JAXA (Japan), and Canadian Space Agency, CSA (Canada). As the largest space station ever constructed, it primarily serves as a platform for conducting scientific experiments in microgravity and studying the space environment. The station is divided into two main sections: the Russian Orbital Segment (ROS), developed by Roscosmos, and the US Orbital Segment (USOS), built by NASA, ESA, JAXA, and CSA. A striking feature of the ISS is the Integrated Truss Structure, which connect the station’s vast system of solar panels and Spacecraft thermal control, radiators to its pressurized modules. These modules support diverse functions, including scientific research, crew habitation, ...
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WASH-1400
WASH-1400, 'The Reactor Safety Study (later known as NUREG-75/014) was a report produced in 1975 for the Nuclear Regulatory Commission by a committee of specialists under Professor Norman Rasmussen. It "generated a storm of criticism in the years following its release". In the years immediately after its release, WASH-1400 was followed by a number of reports that either peer reviewed its methodology or offered their own judgments about probabilities and consequences of various events at commercial reactors. In at least a few instances, some offered critiques of the study's assumptions, methodology, calculations, peer review procedures, and objectivity.John Byrne and Steven M. Hoffman (1996). ''Governing the Atom: The Politics of Risk'', Transaction Publishers, p. 147. A succession of reports, including NUREG-1150, the State-of-the-Art Reactor Consequence Analyses and others, have carried-on the tradition of PRA and its application to commercial power plants. Content WASH-1400 c ...
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Event Tree
An event tree is an inductive analytical diagram in which an event is analyzed using Boolean logic to examine a chronological series of subsequent events or consequences. For example, event tree analysis is a major component of nuclear reactor safety engineering.Wang, John '' et al.'' (2000). An event tree displays sequence progression, sequence end states and sequence-specific dependencies across time. Analytical tool Event tree analysis is a logical evaluative process which works by tracing forward in time or forwards through a causal chain to model risk. It does not require the premise of a known hazard. An event tree is an inductive investigatory process. In contrast, the Fault tree analysis (FTA) evaluates risk by tracing backwards in time or backwards through a cause chain. The analysis takes as a premise a given hazard. FTA is a deductive investigatory process. Applications An event tree may start from a specific initiator such as loss of critical supply, or component ...
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Idaho National Laboratory
Idaho National Laboratory (INL) is one of the national laboratories of the United States Department of Energy and is managed by the Battelle Energy Alliance. Historically, the lab has been involved with nuclear research, although the laboratory does other research as well. Much of current knowledge about how nuclear reactors behave and misbehave was discovered at what is now Idaho National Laboratory. John Grossenbacher, former INL director, said, "The history of nuclear energy for peaceful application has principally been written in Idaho". The present facility resulted from the 2005 merger of two neighboring laboratories, the National Engineering and Environmental Laboratory, and the Idaho site of the western branch of Argonne National Laboratory (Argonne-West). Various organizations have built more than 50 reactors at what is commonly called "the Site", including the ones that gave the world its first usable amount of electricity from nuclear power and the power plant fo ...
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SAPHIRE
{{primary sources, date=March 2015 SAPHIRE is a probabilistic risk and reliability assessment software tool. SAPHIRE stands for ''Systems Analysis Programs for Hands-on Integrated Reliability Evaluations''. The system was developed for the U.S. Nuclear Regulatory Commission (NRC) by the Idaho National Laboratory. Development began in the mid-1980s when the NRC began exploring two notions: 1) that Probabilistic Risk Assessment (PRA) information could be displayed and manipulated using the emerging microcomputer technology of the day and 2) the rapid advancement of PRA technology required a relatively inexpensive and readily available platform for teaching PRA concepts to students. The history of SAPHIRE 1987 Version 1 of the code called IRRAS (now known as SAPHIRE) introduced an innovative way to draw, edit, and analyze graphical fault trees. 1989 Version 2 is released incorporating the ability to draw, edit, and analyze graphical event trees. 1990 Analysis improvements to ...
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Electric Power Research Institute
EPRI, is an American independent, nonprofit organization that conducts research and development related to the generation, delivery, and use of electricity to help address challenges in the energy industry, including reliability, efficiency, affordability, health, safety, and the environment. EPRI's principal offices and laboratories are located in Palo Alto, California; Charlotte, North Carolina; Knoxville, Tennessee; Washington, DC; and Lenox, Massachusetts. History In November 1965, the Great Northeastern Blackout left 30 million people in the United States without electricity. Historic in scale and impact, it demonstrated the nation's growing dependence upon electricity and its vulnerability to power loss. The event marked a watershed moment for the U.S. electricity sector and triggered the creation of the Electric Power Research Institute. Following the blackout, leaders in Congress held hearings in the early 1970s about the lack of research supporting the power industry ...
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Reliability Block Diagram
A reliability block diagram (RBD) is a diagrammatic method for showing how component reliability contributes to the success or failure of a redundant system. RBD is also known as a dependence diagram (DD). An RBD is drawn as a series of blocks connected in parallel or series configuration. Parallel blocks indicate redundant subsystems or components that contribute to a lower failure rate. Each block represents a component of the system with a failure rate. RBDs will indicate the type of redundancy in the parallel path. For example, a group of parallel blocks could require two out of three components to succeed for the system to succeed. By contrast, any failure along a series path causes the entire series path to fail. An RBD may be drawn using switches in place of blocks, where a closed switch represents a working component and an open switch represents a failed component. If a path may be found through the network of switches from beginning to end, the system still works. ...
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De Morgan's Laws
In propositional calculus, propositional logic and Boolean algebra, De Morgan's laws, also known as De Morgan's theorem, are a pair of transformation rules that are both Validity (logic), valid rule of inference, rules of inference. They are named after Augustus De Morgan, a 19th-century British mathematician. The rules allow the expression of Logical conjunction, conjunctions and Logical disjunction, disjunctions purely in terms of each other via logical negation, negation. The rules can be expressed in English as: * The negation of "A and B" is the same as "not A or not B". * The negation of "A or B" is the same as "not A and not B". or * The Complement (set theory), complement of the union of two sets is the same as the intersection of their complements * The complement of the intersection of two sets is the same as the union of their complements or * not (A or B) = (not A) and (not B) * not (A and B) = (not A) or (not B) where "A or B" is an "inclusive or" meaning ''at least' ...
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Fault Tree
Fault tree analysis (FTA) is a type of failure analysis in which an undesired state of a system is examined. This analysis method is mainly used in safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk and to determine (or get a feeling for) event rates of a safety accident or a particular system level (functional) failure. FTA is used in the aerospace, nuclear power, Process manufacturing, chemical and process, Pharmaceutical drug, pharmaceutical, petrochemical and other high-hazard industries; but is also used in fields as diverse as risk factor identification relating to social services, social service system failure. FTA is also used in software engineering for debugging purposes and is closely related to cause-elimination technique used to detect bugs. In aerospace, the more general term "system failure condition" is used for the "undesired state" / top event of the fault tree. These conditions are classifie ...
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Boolean Logic
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denoted by 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra uses logical operators such as Logical conjunction, conjunction (''and'') denoted as , disjunction (''or'') denoted as , and negation (''not'') denoted as . Elementary algebra, on the other hand, uses arithmetic operators such as addition, multiplication, subtraction, and division. Boolean algebra is therefore a formal way of describing logical operations in the same way that elementary algebra describes numerical operations. Boolean algebra was introduced by George Boole in his first book ''The Mathematical Analysis of Logic'' (1847), and set forth more fully in his ''An Investigation of the Laws of Thought'' (1854). According to ...
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Deductive Reasoning
Deductive reasoning is the process of drawing valid inferences. An inference is valid if its conclusion follows logically from its premises, meaning that it is impossible for the premises to be true and the conclusion to be false. For example, the inference from the premises "all men are mortal" and " Socrates is a man" to the conclusion "Socrates is mortal" is deductively valid. An argument is ''sound'' if it is valid ''and'' all its premises are true. One approach defines deduction in terms of the intentions of the author: they have to intend for the premises to offer deductive support to the conclusion. With the help of this modification, it is possible to distinguish valid from invalid deductive reasoning: it is invalid if the author's belief about the deductive support is false, but even invalid deductive reasoning is a form of deductive reasoning. Deductive logic studies under what conditions an argument is valid. According to the semantic approach, an argument is valid ...
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Failure Mode, Effects, And Criticality Analysis
Failure mode effects and criticality analysis (FMECA) is an extension of failure mode and effects analysis (FMEA). FMEA is a bottom-up, inductive analytical method which may be performed at either the functional or piece-part level. FMECA extends FMEA by including a ''criticality analysis'', which is used to chart the probability of failure modes against the severity of their consequences. The result highlights failure modes with relatively high probability and severity of consequences, allowing remedial effort to be directed where it will produce the greatest value. FMECA tends to be preferred over FMEA in space and NATO military applications, while various forms of FMEA predominate in other industries. History FMECA was originally developed in the 1940s by the U.S military, which published MIL–P–1629 in 1949. By the early 1960s, contractors for the U.S. National Aeronautics and Space Administration (NASA) were using variations of FMECA under a variety of names. I ...
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