Is the Federal Reserve Learning? A New Simple Correlation of Inflation and Economic Stability Trends

Abstract The relatively recent (last few years) actions by the Federal Reserve and other economic factors have mitigated potential changes in unemployment rate. We examine the trends in economic inflation for the USA using the data and empirical models given in the recent paper by Yelle

Power Restoration Prediction Following Extreme Events and Disasters

Abstract This article examines electric power restoration following catastrophic damage in modern cities and regions due to extreme events and disasters. Recovery time and non-restoration probability are derived using new data from a comprehensive range of recent massive hurricanes, extensive wildfires, severe snowstorms, and damaging cyclones. Despite their totally disparate origins, over three orders of magnitude severe wildfires and hurricanes have the same non-restoration probability trends, which are of simple exponential form. The results fall into categories that are dependent on and grouped by the degree of damage and social disruption. The implications are discussed for emergency response planning. These new results demonstrate that the scientific laws of probability and human learning, which dominate risk in modern technologies and societies are also applicable to a wide range of disasters and extreme events

Risk-Informing Nuclear Reactor Safety: The Prediction of the Probability of Core Damage Due to Loss of Power and Cooling

International audienceThe 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 {external flood, fire, hurricane, ice storm, typhoon, earthquake, cyber attack and mldr;}, 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

Abstract: “Certainty creates strength…Uncertainty creates weakness” (John M Barry “The Great Influenza”, 2005, Penguin Books, p261.). “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.” (Bertrand Russell, Sceptical Essays, 1928). “The best way to prevent becoming infected is to avoid being exposed to the virus” (Source: www.astho.org/COVID-19/Q-and-A/). 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

ICONE10 -22433 THERMO-ECONOMIC ASSESSMENT OF ADVANCED, HIGH-TEMPERATURE CANDU REACTORS

ABSTRACT Research underway on the advanced CANDU examines new, innovative, reactor concepts with the aim of significant cost reduction and resource sustainability through improved thermodynamic efficiency and plant simplification

Two-phase flow instability and dryout in parallel channels in natural circulation

The unique feature of parallel channel flows is that the pressure drop or driving head for the flow is maintained constant across any given channel by the flow in all the others, or by having a large downcomer or bypass in a natural circulation loop. This boundary condition is common in all heat exchangers, reactor cores and boilers, it is well known that the two-phase flow in parallel channels can exhibit both so-called static and dynamic instability. This leads to the question of the separability of the flow and pressure drop boundary conditions in the study of stability and dryout. For the areas of practical interest, the flow can be considered as incompressible. The dynamic instability is characterized by density (kinematic) or continuity waves, and the static instability by inertial (pressure drop) or manometric escalations. The static has been considered to be the zero-frequency or lowest mode of the dynamic case. We briefly review the status of the existing literature on both parallel channel static and dynamic instability, and the latest developments in theory and experiment. The difference between the two derivations lies in the retention of the time-dependent terms in the conservation equations. The effects and impact of design options are also discussed. Since dryout in parallel systems follows instability, it has been traditional to determine the dryout power for a parallel channel by testing a single channel with a given (inlet) flow boundary condition without particular regard for the pressure drop. Thus all modern dryout correlations are based on constant or fixed flow tests, a so-called hard inlet, and subchannel and multiple bundle effects are corrected for separately. We review the thinking that lead to this approach, and suggest that for all multiple channel and natural circulation systems close attention should be paid to the actual (untested) pressure drop conditions. A conceptual formulation is suggested as a basis for discussion