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Defense In Depth (nuclear Engineering)
U.S. non-military nuclear material is regulated by the U.S. Nuclear Regulatory Commission, which uses the concept of defense in depth when protecting the health and safety of the public from the hazards associated with nuclear materials. The NRC defines defense in depth as creating multiple independent and redundant layers of protection and response to failures, accidents, or fires in power plants. For example, defense in depth means that if one fire suppression system fails, there will be another to back it up. The idea is that no single layer, no matter how robust, is exclusively relied upon; access controls, physical barriers, redundant and diverse key safety functions, and emergency response measures are used. Defense in depth is designed to compensate for potential human and mechanical failures, which are assumed to be unavoidable. Any complex, close-coupled system, no matter how well-engineered, cannot be said to be failure-proof. That is especially true if people operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defence In Depth (non-military)
A defence in depth uses multi-layered protections, similar to Redundancy (engineering), redundant protections, to create a reliable system despite any one layer's unreliability. Examples The term defence in depth is now used in many non-military contexts. Fire prevention A defence in depth strategy to fire prevention does not focus all the resources only on the prevention of a fire; instead, it also requires the deployment of fire alarms, extinguishers, evacuation plans, mobile rescue and fire-fighting equipment and even nationwide plans for deploying massive resources to a major blaze. Defense-in-depth is incorporated into fire protection regulations for nuclear power plants. It requires preventing fires, detecting and extinguishing fires that do occur, and ensuring the capability to safely shutdown. Engineering Defence in depth may mean engineering which emphasizes redundancy (engineering), redundancy – a system that keeps working when a component fails – over attempts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Point Energy Center
Indian Point Energy Center (I.P.E.C.) is a three-unit nuclear power plant station located in Buchanan, just south of Peekskill, in Westchester County, New York. It sits on the east bank of the Hudson River, about north of Midtown Manhattan. The facility has permanently ceased power operations as of April 30, 2021. Before its closure, the station's two operating reactors generated about 2,000 megawatts ( MWe) of electrical power, about 25% of New York City's usage. The station is owned by Holtec International, and consists of three permanently deactivated reactors, Indian Point Units 1, 2, and 3. Units 2 and 3 were Westinghouse pressurized water reactors. Entergy purchased Unit 3 from the New York Power Authority in 2000 and Units 1 and 2 from Consolidated Edison in 2001. The original 40-year operating licenses for Units 2 and 3 expired in September 2013 and December 2015, respectively. Entergy had applied for license extensions and the Nuclear Regulatory Commission (NRC) was m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probabilistic Risk Assessment
Probabilistic risk assessment (PRA) is a systematic and comprehensive methodology to evaluate risks associated with a complex engineered technological entity (such as an airliner or a nuclear power plant) or the effects of stressors on the environment (probabilistic environmental risk assessment, or PERA). Risk in a PRA is defined as a feasible detrimental outcome of an activity or action. In a PRA, risk is characterized by two quantities: #the magnitude (severity) of the possible adverse consequence(s), and #the likelihood (probability) of occurrence of each consequence. Consequences are expressed numerically (e.g., the number of people potentially hurt or killed) and their likelihoods of occurrence are expressed as probabilities or frequencies (i.e., the number of occurrences or the probability of occurrence per unit time). The total risk is the expected loss: the sum of the products of the consequences multiplied by their probabilities. The spectrum of risks across classe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defence In Depth
Defence in depth (also known as deep defence or elastic defence) is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space. Rather than defeating an attacker with a single, strong defensive line, defence in depth relies on the tendency of an attack to lose momentum over time or as it covers a larger area. A defender can thus yield lightly defended territory in an effort to stress an attacker's logistics or spread out a numerically superior attacking force. Once an attacker has lost momentum or is forced to spread out to pacify a large area, defensive counter-attacks can be mounted on the attacker's weak points, with the goal being to cause attrition or drive the attacker back to its original starting position. Strategy A conventional defence strategy would concentrate all military resources at a front line, which, if breached by an attacker, would leave the remaining defenders in d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defence-in-depth (Roman Military)
Defence-in-depth is the term used by American political analyst Edward Luttwak (born 1942) to describe his theory of the defensive strategy employed by the Late Roman army in the third and fourth centuries AD. Luttwak's ''Grand Strategy of the Roman Empire'' (1976) launched the thesis that in the third and early fourth centuries, the Imperial Roman army's defence strategy mutated from "forward defence" (or "preclusive defence") during the Principate era (30 BC-AD 284) to "defence-in-depth" in the fourth century. "Forward-" or "preclusive" defence aimed to neutralise external threats before they breached the Roman borders: the barbarian regions neighbouring the borders were envisaged as the theatres of operations. In contrast, "defence-in-depth" would not attempt to prevent incursions into Roman territory, but aimed to neutralise them on Roman soil - in effect turning border provinces into combat zones. Scholarly opinion generally accepts "forward-defence" as a valid descripti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
