Preliminary Evaluation of the Flooding Effects on an Existing PWR

2013 ◽  
Author(s):  
Vincenzo Baudanza ◽  
Rosa Lo Frano ◽  
Giuseppe Forasassi
Keyword(s):  
Water Waves ◽  
Safety Margin ◽  
Breaking Waves ◽  
Preliminary Evaluation ◽  
Structural Effects ◽  
Fukushima Accident ◽  
Concrete Material ◽  
Impact Forces ◽  
The Impact ◽  
Severe Flooding

The aim of the study is the evaluation of the structural effects induced by a severe flooding or tsunami (which is one of the external events to be considered for the safety margin reassessment purpose according to the International requirements, after the Fukushima accident) in an outer containment walls of a typical PWR. The hydrodynamic forces exerted by the breaking waves, characterizing the inundation phase of tsunami/flooding phenomenon, are calculated in agreement with ASME rules. Therefore to evaluate the consequences and damages, if any, induced by the breaking water waves which have arisen on an existing PWR containment building, non linear analyses (by using an adequate FEM code) were performed simulating the impact forces of the water waves in terms of pressure. Moreover a FSI analysis was carried out in order to verify the adequacy (and consistency) of the methodology adopted in the evaluation of the pressure forces mentioned above. To analyze the performances of the containment building suitable reinforced concrete material properties and damage phenomena features were considered. The results obtained highlighted that the tsunami effects are strongly dependent on the wave height, flow velocity, hydrodynamic phenomena and on the geometry and material behaviour of the analyzed structures. Finally they showed that the containment building considered seemed capable to withstand the flooding/tsunami effects without loss of the integrity of PWR containment structure.

scholarly journals IMPACT WAVE FORCES ON VERTICAL AND HORIZONTAL PLATE

1978 ◽  
Vol 1 (16) ◽  
pp. 141
Author(s):  
S.R. Massel ◽  
M. Oleszkiewicz ◽  
W. Trapp
Keyword(s):  
Water Waves ◽  
Difficult Problem ◽  
Wave Forces ◽  
Horizontal Plate ◽  
Hydrodynamic Impact ◽  
Impact Forces ◽  
Wave Parameters ◽  
The Subject ◽  
The Impact ◽  
Impact Problem

The hydrodynamic impact problem is a very difficult problem because the physics of what actually happens during the instant of impact are not understood. Despite of fact that a large number of references exist on the subject, many questions are left unanswered. The object of this research is to investigate the problems of hydrodynamic impact associated with the water waves impacting on the vertical and horizontal plates..Of particular interest are the impact forces, their relation to the incident wave parameters and scale effect problems.

Experimental Investigations of Breaking Wave Impact Forces on a Monopile Substructure for Offshore Wind Turbines Under Regular Breaking Waves

2017 ◽  
Author(s):  
Vipin Chakkurunni Palliyalil ◽  
Panneer Selvam Rajamanickam ◽  
Mayilvahanan Alagan Chella ◽  
Vijaya Kumar Govindasamy
Keyword(s):  
Circular Cylinder ◽  
Wind Turbines ◽  
Breaking Waves ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Breaking Wave ◽  
Wave Impact ◽  
Offshore Wind Turbines ◽  
Impact Forces ◽  
The Impact

The main objective of the paper is to investigate wave impact forces from breaking waves on a monopile substructure for offshore wind turbine in shallow waters. This study examines the load assessment parameters relevant for breaking wave forces on a vertical circular cylinder subjected to breaking waves. Experiments are conducted in a shallow water flume and the wave generation is based on piston type wave maker. The experiments are performed with a vertical circular cylinder with diameter, D = 0.20m which represents a monopile substructure for offshore wind turbines with regular waves of frequencies around 0.8Hz. The experimental setup consists of a 1/10 slope followed by a horizontal bed portion with a water depth of 0.8m. Plunging breaking waves are generated and free surface elevations are measured at different locations along the wave tank from wave paddle to the cylinder in order to find the breaking characteristics. Wave impact pressures are measured on the cylinder at eight different vertical positions along the height of the cylinder under breaking waves for different environmental conditions. The wave impact pressures and wave surface elevations in the vicinity of the cylinder during the impact for three different wave conditions are presented and discussed.

scholarly journals RESPONSE OF SEADYKES DUE TO WAVE IMPACTS

1976 ◽  
Vol 1 (15) ◽  
pp. 149 ◽  
Author(s):  
A. Fuhrboter ◽  
H.H. Dette ◽  
J. Grune
Keyword(s):  
Laboratory Data ◽  
Breaking Waves ◽  
Scale Model ◽  
Small Scale ◽  
Air Entrapment ◽  
Small Areas ◽  
Impact Forces ◽  
The Stability ◽  
Short Time ◽  
The Impact

Damages on seadykes and revetments are mainly caused by wave impacts due to breaking waves. These impact forces act on small areas for a very short time and cause crater-like formations, when the forces are transmitted instantaneously to the side-walls of cracks in the cover of dykes or through joints into and below revetments. In this paper the results of investigations on impact forces are presented. A comparison of field data and laboratory data proves considerable differences, which must be explained mainly by the different air entrapment for prototype and small-scale conditions in the breaking waves. Both the data from field and small-scale model emphasize, that the slope of the dyke or revetment is responsible at first for frequency and magnitude of the impact forces. Furthermore the effect of impact forces is demonstrated by the results of investigations on the stability of stone revetments with joints.

scholarly journals An Evaluation Methodology for Interactive Reinforcement Learning with Simulated Users

Biomimetics ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Adam Bignold ◽  
Francisco Cruz ◽  
Richard Dazeley ◽  
Peter Vamplew ◽  
Cameron Foale
Keyword(s):  
Reinforcement Learning ◽  
Information Source ◽  
Human Interaction ◽  
Evaluation Methodology ◽  
External Information ◽  
Preliminary Evaluation ◽  
Learning Agents ◽  
Learning Agent ◽  
Knowledge Bias ◽  
The Impact

Interactive reinforcement learning methods utilise an external information source to evaluate decisions and accelerate learning. Previous work has shown that human advice could significantly improve learning agents’ performance. When evaluating reinforcement learning algorithms, it is common to repeat experiments as parameters are altered or to gain a sufficient sample size. In this regard, to require human interaction every time an experiment is restarted is undesirable, particularly when the expense in doing so can be considerable. Additionally, reusing the same people for the experiment introduces bias, as they will learn the behaviour of the agent and the dynamics of the environment. This paper presents a methodology for evaluating interactive reinforcement learning agents by employing simulated users. Simulated users allow human knowledge, bias, and interaction to be simulated. The use of simulated users allows the development and testing of reinforcement learning agents, and can provide indicative results of agent performance under defined human constraints. While simulated users are no replacement for actual humans, they do offer an affordable and fast alternative for evaluative assisted agents. We introduce a method for performing a preliminary evaluation utilising simulated users to show how performance changes depending on the type of user assisting the agent. Moreover, we describe how human interaction may be simulated, and present an experiment illustrating the applicability of simulating users in evaluating agent performance when assisted by different types of trainers. Experimental results show that the use of this methodology allows for greater insight into the performance of interactive reinforcement learning agents when advised by different users. The use of simulated users with varying characteristics allows for evaluation of the impact of those characteristics on the behaviour of the learning agent.

scholarly journals A Whole Virion Vaccine for COVID-19 Produced via a Novel Inactivation Method and Preliminary Demonstration of Efficacy in an Animal Challenge Model

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 340
Author(s):  
Izabela K Ragan ◽  
Lindsay M Hartson ◽  
Taru S Dutt ◽  
Andres Obregon-Henao ◽  
Rachel M Maison ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Rapid Development ◽  
Neutralizing Antibody ◽  
Emerging Diseases ◽  
Effective Vaccine ◽  
Preliminary Evaluation ◽  
Sequencing Data ◽  
Post Challenge ◽  
Vaccine Candidates ◽  
The Impact

The COVID-19 pandemic has generated intense interest in the rapid development and evaluation of vaccine candidates for this disease and other emerging diseases. Several novel methods for preparing vaccine candidates are currently undergoing clinical evaluation in response to the urgent need to prevent the spread of COVID-19. In many cases, these methods rely on new approaches for vaccine production and immune stimulation. We report on the use of a novel method (SolaVAX) for production of an inactivated vaccine candidate and the testing of that candidate in a hamster animal model for its ability to prevent infection upon challenge with SARS-CoV-2 virus. The studies employed in this work included an evaluation of the levels of neutralizing antibody produced post-vaccination, levels of specific antibody sub-types to RBD and spike protein that were generated, evaluation of viral shedding post-challenge, flow cytometric and single cell sequencing data on cellular fractions and histopathological evaluation of tissues post-challenge. The results from this preliminary evaluation provide insight into the immunological responses occurring as a result of vaccination with the proposed vaccine candidate and the impact that adjuvant formulations, specifically developed to promote Th1 type immune responses, have on vaccine efficacy and protection against infection following challenge with live SARS-CoV-2. This data may have utility in the development of effective vaccine candidates broadly. Furthermore, the results of this preliminary evaluation suggest that preparation of a whole virion vaccine for COVID-19 using this specific photochemical method may have potential utility in the preparation of one such vaccine candidate.

scholarly journals Influence of the Spatial Pressure Distribution of Breaking Wave Loading on the Dynamic Response of Wolf Rock Lighthouse

2021 ◽  
Vol 9 (1) ◽  
pp. 55
Author(s):  
Darshana T. Dassanayake ◽  
Alessandro Antonini ◽  
Athanasios Pappas ◽  
Alison Raby ◽  
James Mark William Brownjohn ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Pressure Distribution ◽  
Distinct Element ◽  
Breaking Waves ◽  
Breaking Wave ◽  
Wave Loading ◽  
Wave Impact ◽  
Pressure Distributions ◽  
Impact Area ◽  
The Impact

The survivability analysis of offshore rock lighthouses requires several assumptions of the pressure distribution due to the breaking wave loading (Raby et al. (2019), Antonini et al. (2019). Due to the peculiar bathymetries and topographies of rock pinnacles, there is no dedicated formula to properly quantify the loads induced by the breaking waves on offshore rock lighthouses. Wienke’s formula (Wienke and Oumeraci (2005) was used in this study to estimate the loads, even though it was not derived for breaking waves on offshore rock lighthouses, but rather for the breaking wave loading on offshore monopiles. However, a thorough sensitivity analysis of the effects of the assumed pressure distribution has never been performed. In this paper, by means of the Wolf Rock lighthouse distinct element model, we quantified the influence of the pressure distributions on the dynamic response of the lighthouse structure. Different pressure distributions were tested, while keeping the initial wave impact area and pressure integrated force unchanged, in order to quantify the effect of different pressure distribution patterns. The pressure distributions considered in this paper showed subtle differences in the overall dynamic structure responses; however, pressure distribution #3, based on published experimental data such as Tanimoto et al. (1986) and Zhou et al. (1991) gave the largest displacements. This scenario has a triangular pressure distribution with a peak at the centroid of the impact area, which then linearly decreases to zero at the top and bottom boundaries of the impact area. The azimuthal horizontal distribution was adopted from Wienke and Oumeraci’s work (2005). The main findings of this study will be of interest not only for the assessment of rock lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with steep foreshore slopes) and exposed to harsh breaking wave loading.

scholarly journals Optimal profile for concave slopes under static and seismic conditions

2016 ◽  
Vol 53 (9) ◽  
pp. 1522-1532 ◽  
Author(s):  
Farshid Vahedifard ◽  
Shahriar Shahrokhabadi ◽  
Dov Leshchinsky
Keyword(s):  
Limit Equilibrium ◽  
Stable Configuration ◽  
Preliminary Evaluation ◽  
Construction Technology ◽  
Stability Of Slopes ◽  
Optimal Profile ◽  
Stabilized Soil ◽  
The Stability ◽  
Comparison Of The Results ◽  
The Impact

This study presents a methodology to determine the stability and optimal profile for slopes with concave cross section under static and seismic conditions. Concave profiles are observed in some natural slopes suggesting that such geometry is a more stable configuration. In this study, the profile of a concave slope was idealized by a circular arc defined by a single variable, the mid-chord offset (MCO). The proposed concave profile formulation was incorporated into a limit equilibrium–based log spiral slope stability method. Stability charts are presented to show the stability number, MCO, and mode of failure for homogeneous slopes corresponding to the most stable configuration under static and pseudostatic conditions. It is shown that concave profiles can significantly improve the stability of slopes. Under seismic conditions, the impact of concavity is most pronounced. Good agreement was demonstrated upon comparison of the results from the proposed method against those attended from a rigorous upper bound limit analysis. The proposed methodology, along with recent advances in construction technology, can be employed to use concave profiles in trenches, open mine excavations, earth retaining systems, and naturally cemented and stabilized soil slopes. The results presented provide a useful tool for preliminary evaluation for adopting such concave profiles in practice.

Twin Pregnancies Complicated by a Single Malformed Fetus: Chorionicity, Outcome and Management

2010 ◽  
Vol 13 (5) ◽  
pp. 501-507 ◽  
Author(s):  
Ali Gedikbasi ◽  
Alpaslan Akyol ◽  
Gokhan Yildirim ◽  
Ali Ekiz ◽  
Ahmet Gul ◽  
...  
Keyword(s):  
Gestational Age ◽  
Statistical Significance ◽  
Expectant Management ◽  
Control Group ◽  
Study Group ◽  
Preliminary Evaluation ◽  
Gestational Age At Birth ◽  
The Impact ◽  
Twin Pregnancies ◽  
Age At Birth

The objective of this study was to evaluate the impact of one abnormal fetus in a twin pregnancy, to compare impact of chorionicity and clinical outcome of intervention and expectant management. Thirty-seven dichorionic (DC) twins and 18 monochorionic (MC) twins complicated with one malformed fetus were evaluated for gestational age, birthweight and perinatal outcome. Six hundred and forty-two twin pregnancies were evaluated in the database. The control groups consisted of 429 DC and 86 MC twins without anomalous fetus. Mean birthweight and gestational age at birth for DC control group were (n= 429; 2137g and 34.71 weeks), DC study group,n= 37; 2117g (p= .338) and 33.97 weeks (p= .311), and DC study group with major malformations,n= 30; 2019g (p= .289) and 33.3 weeks (p= .01), and showed only significance for gestational age. There was no statistical significance between MC control group,n= 86; 2097g and 34.93 weeks, and MC study group,n= 18; 2237g (p= .338), and 34.42 weeks (p= .502). Because of limited data, the preliminary evaluation for expectant management and intervention, and survival of at least one normal fetus showed no impact. We conclude that, although, all DC twin pregnancies have a risk for preterm delivery, DC twins complicated with major malformation of one twin, have a lower mean gestational age at birth. Preliminary results for intervention does not improve fetal outcome for DC and MC twins and needs further evaluation with greater studies of impact or review.

Considerations Concerning Vehicle Collisions Through Simplified Calculations of the Impact Forces

1996 ◽  
Author(s):  
Helcio Onusic ◽  
José Augusto P. Campos ◽  
Paulo Sergio P. dos Santos
Keyword(s):  
Vehicle Collisions ◽  
Impact Forces ◽  
The Impact
Sign in / Sign up

Export Citation Format

Share Document