1,720,975 research outputs found
Prediction of CoVid-19 infection, transmission and recovery rates: A new analysis and global societal comparisons
No full textWe analyze the process of infection rate growth and decline for the recent global pandemic, applying a new method to the available global data. We describe and utilize an original approach based on statistical physics to predict the societal transmission timescale and the universal recovery trajectory resulting from the countermeasures implemented in entire societies. We compare the whole-society infection growth rates for many countries and local regions, to illustrate the common physical and mathematical basis for the viral spread and infection rate reduction, and validate the theory and resulting correlations. We show that methods traditionally considered for the numerical analysis and the control of individual virus transmission (e.g. R0 scaling) represent one special case of the theory, and also compare our results to the available IHME computer model outcomes. We proceed to illustrate several interesting features of the different approaches to the mitigation of the pandemic, related to social isolation and “lockdown” tactics. Finally, we use presently available data from many countries to make actual predictions of the time needed for securing minimum infection rates in the future, highlighting the differences that emerge between isolated “islands” and mobile cities, and identifying the desired overall recovery trajectory
Predicting the rate of CoVid-19 infected cases by Learning Theory
Get PDFWe predict the evolution of the daily number of infected cases from CoVid-19 virus. We use the theory of learning from errors, adapted to the problem of virus containment by protective measures such as testing, isolation and social distancing. The theory is consistent with the findings of cognitive psychology on how humans address the solution of errors. Application of these measures leads to the infection rate declining, after reaching a peak. We use publicly available data to predict the recovery rate curve and the time still needed to reach minimum infection rates
Analysing Recovery from Pandemics by Learning Theory: The Case of CoVid-19
Get PDFWe present a method for predicting the recovery time from infectious diseases outbreaks such as the recent CoVid-19 virus. The approach is based on the theory of learning from errors, specifically adapted to the control of the virus spread by reducing infection rates using countermeasures such as medical treatment, isolation, social distancing etc. When these are effective, the infection rate, after reaching a peak, declines following what we call the Universal Recovery Curve. We use presently available data from many countries to make actual predictions of the recovery trend and time needed for securing minimum infection rates in the future. We claim that the trend of decline is direct evidence of learning about risk reduction, also in this case of the pandemic
COVID-19 pandemic trend modeling and analysis to support resilience decision-making
Get PDFPolicy decision-making for system resilience to a hazard requires the estimation and prediction of the trends of growth and decline of the impacts of the hazard. With focus on the recent worldwide spread of CoVid-19, we take the infection rate as the relevant metric whose trend of evolution to follow for verifying the effectiveness of the countermeasures applied. By comparison with the theories of growth and recovery in coupled socio-medical systems, we find that the data for many countries show infection rate trends that are exponential in form. In particular, the recovery trajectory is universal in trend and consistent with the learning theory, which allows for predictions useful in the assistance of decision-making of emergency recovery actions. The findings are validated by extensive data and comparison to medical pandemic models
Risk-Informing Nuclear Reactor Safety: The Prediction of the Probability of Core Damage Due to Loss of Power and Cooling
Get PDFThe modern idea of risk-informed decision-making (RIDM) is here critically examined for all existing, advanced and, generation-IV nuclear reactor systems. Motivated by the predictive difficulties of probabilistic risk assessment (PRA) in regard to occurred accidents, it is evident that the real (not hypothetical) consequences of nuclear core damage accidents that must be considered and quantified are the financial losses, infrastructure damages, societal disruptions, and adverse political policies, and not solely the traditional exceedance of regulated radiation release or public exposure limits. With this perspective, a new dynamic analysis is presented for estimating the probability of core damage due to extended loss of power and cooling in a modern nuclear reactor, giving results different from current standardized PRA/PSA analyses. Using existing data, we approach the multitude of different events in a new way: whatever the initial event in the finite event set fexternal flood, fire, hurricane, ice storm, typhoon, earthquake, cyber attack...g, the fundamental concerns are the consequent loss and nonrestoration of power, and the inadequate cooling of the core. The present proposed quantitative evaluation uses applicable and fully “exchangeable” severe event data for nuclear and nonnuclear systems, including active and passive emergency back-up systems for a wide range of power losses that lead to widespread damage and societal disruption. While not design-specific, this new independent “order-of-magnitude” estimate for the probability of core damage is some two to two hundred times larger than that shown or reported in recent modern and formal PSA/PRA for licensing submissions using generic failure rate data rather than actual severe event data. This new finding suggests greater uncertainties exist than presently assumed for risk-informed decision-making (RIDM), and points to the need for a major reconsideration and updating of risk assessment and regulatory risk-informed approaches for nuclear plant safety evaluation
Old Lessons of Risk Assessment and Management from the COVID-19 Pandemics and Individual Infections Dynamics
Get PDF“Certainty creates strength...Uncertainty creates weakness” (Barry, 2005) [1]. “The theory is this, that it would be appropriate to believe in a proposition until there is a founded reason to suppose its truth. If this view were to become commonly agreed upon, our social lives and our political system would turn out completely changed.” (Russell, 1928) [2]. “The best way to prevent becoming infected is to avoid being exposed to the virus” (Source: www.astho.org/COVID-19/Q-and-A/) [3]. The recent and ongoing COVID-19 pandemic is confirming that our society is vulnerable to global risk and that science and politics are challenged by the associated high uncertainties. This makes a number of old, foundational questions on risk and its management re-emerge. In this paper, specifically for the risk posed by the current pandemic and the infection spreading phenomena driving it, we observe from data and show from theory that there are four characteristic and very human-determined timescales for infection-spread rates. Then, we conclude on the need of putting the humans in the middle/focus of risk, as they are the ones that ultimately take decisions (almost rationally) and live their outcomes. So, we argue the obvious: that is, that for managing risk, it is necessary to realize and accept rationally that risk is not absolute- it is relative and in the uncertainty of the occurrence of different events, some just have more chance of occurring than others (i.e. high versus low chance). To evaluate and compare risks, as a society we should weigh, rank and decide the intertwined balances and resulting inequalities
The risk of the electrical power grid due to natural hazards and recovery challenge following disasters and record floods: What next?
No full textThe electrical power grid is one of the most critical infrastructures (CIs) in many developed and developing countries and must be planned, operated, maintained, and managed to ensure reliable, secure, and resilient service supply. Being coupled to the transport network, water distribution, Internet, food, etc., all are highly mutually dependent, including through information and communication technologies (the so-called cyber-based systems). We examine the threats to the electrical CIs of natural and man-made disasters that cause loss of power systems for several weeks over vast urban or statewide areas, affect many millions, and result in intersystems cascading failures. Key future questions include: how high and reliable to build flooding defenses; how to enhance backup power systems for all CI fail-safe interconnections; and establishing increased investment. What next must and can only be better systems, improved reliability, more effective emergency management, through decision-making guided by quantified risk and resilience of coupled CI. What we have learned from past real events discussed in this chapter has national as well as systems engineering implications
Innovation needs in nuclear reactor safety and risk
No full textAfter three quarters of a century using nuclear fission to produce energy, Nuclear Reactor Safety and Risk constitutes an established technological sector. A key feature is continuous updating following new discoveries and progress in knowledge, resulting in extensive and elaborate safety methodologies, which are still not internationally accepted, generally applicable or technically consistent. Each country developed its own methods, guides, traditions and requirements to deal with evolving design, safety, siting and licensing issues. There is a clear parallel in societal risk perception between nuclear radiation exposure in accidents and viral infection in pandemics and the fear of the “unknown”. Unfortunately, over the last 20–30 years the declining introduction of electricity by nuclear fission in the countries that contributed most to its earliest development also has broken the bond between new scientific advancements and improvements of existing safety methodologies. By looking at the origins and fundaments of nuclear technology, we consider the following topics of both deterministic and probabilistic interest: a) Loss of Coolant analysis; b) nuclear fuel accident performance weaknesses; c) role of containment and ultimate heat sinks; d) residual risk and emergency system deployment, and e) independent and risk informed decision making assessment. As a key outcome, we propose modifying the traditional licensing methodology, and the use of active and/or passive systems by being subsumed into a broader Engineered Safety Features Management process. Furthermore, we emphasize the need of connecting the As Low As Reasonably Achievable principle with the analyses to demonstrate the safety of nuclear installations minimizing the need for excessive “paper” safety analyses and licensing efforts
The Present and the Future of Nuclear Power Technology: An Opinion On Energy Policy, Competitive Concepts, Societal Safety And Acceptable Risk
No full textThe future of nuclear technology is driven by communication rather than by rationality, which
motivates the present paper. Globally there is need for nuclear reactors that produce cheap, safe,
reliable, resilient and low-emissions electricity to power modern societies. The purpose of the
present paper is to inform debate and provide opinions about challenges and solutions for the
development of nuclear fission technology. We review the socio-political and techno-economic
status of nuclear power technology that, as almost always during its history, is on an edge from
which it may jump to success, or fall into the abyss of forgetfulness. In addition to cost, safety,
social acceptance and political will, climate change with the need to prevent further pollution of the
environment, constitutes a challenge for nuclear technology. To avoid the associated scramble for
and hoarding of financial resources, and competing concepts we try to provide a framework for
discussion and resolution. We look at the history of nuclear technology where high capital cost has
slowed its development what has killed certain concepts is the high operation and maintenance cost.
At the interrelated policy, fiscal level and international levels feasible actions are required with
aggressive timelines and specific goals for nuclear power systems. The aim is to reduce both capital
price and financial risk to achieve the overall goal of enhanced orders and deployment. We strongly
recommend the deployment of nuclear fission for energy production everywhere in the world. The
large reactors, whenever possible, should contribute to energy security, financial stability and
technology development. The small reactors may contribute in areas directly impacting the
reduction of pollution like naval transportation, hydrogen production and remote areas energy
powering
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