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[en] Devastating tsunami waves can change the coastal morphology considerably. The effects of vegetation to coastal morphodynamics have been of primary interest for decades, because of their role in coastal protection and ecological environment. The damping of wave and impact of beach evolution are the two significant contributions on emerged vegetation. However, the laboratory study of tsunami erosion and deposition under protection of coastal vegetation was less understood compared to tsunami run-up and tsunami inundation. A set of laboratory experiments were reported in this study on changes of size-selective sandy beach profile under the protection of rigid emergent vegetation. The total of fifteen experiments was carried out in a wave flume including two initial profiles (with vegetation and none vegetation), three different wave conditions and four forest densities. The experiments show that rigid emergent vegetation changes the depth and location of tsunami deposition and erosion in sandy beach. The dimensionless numbers were derived to characterize the cross-shore beach profile response under the protection of rigid emergent vegetation. These parameters were written as a dimensionless group, and based upon this present experimental datum, the empirical equations were developed. The study reveals the internal connection among tsunami deposition and erosion, wave height and forest density. The findings of this study have the potential to assist the tsunami hazards prevention and mitigation.
[en] Tsunami is a Japanese word from a double root: tsu, meaning port or harbour, and nami, meaning wave. The word looks innocuous in simple translation, but to those who live on the rim of the Pacific it can spell disaster. The designers of nuclear installations at coastal sites, in particular, must take the possibility of occurrence of a tsunami into account in their work. (author)
[en] The importance of nuclear power plant PSA has grown up all over the world due to this incident. The main concern of this study is to develop a methodology to carry on an emergency preparedness evaluation and to set an exclusive area, or the emergency response area boundary in order to apply it to domestic reference plants. This study also focuses on evaluating the risk parameter of major nuclides through a sensitivity analysis and a safety assessment by calculating the population dose, early fatality, and cancer fatality rates. A methodology for an emergency preparedness, which can be applied to evaluate the damage of the radioactive release as well as to assess the safety of the accident scenario of a nuclear power plant, has been developed and applied for the reference plants in Korea. By applying a source term analysis, an exclusive zone based on the radioactive dose is obtained. And the results of the health effect assessment based on the release fraction of specific nuclides to public with an effective emergency response activity have been simulated. A methodology utilizing the Level 3 PSA with the actual emergency response activities has been developed and applied to typical nuclear accident situations. The plausible standard for performing an emergency plan is suggested and the valuable information regarding emergency preparedness has been produced in this study. For further works, the sensitivity study on important parameters will be performed to simulate the actual severe accident situations such as sheltering, evacuation, and emergency response activities
[en] In the aftermath of the Great Aceh Tsunami 2004, the Nuclear Energy Regulatory Agency (Badan Pengawas Tenaga Nuklir) performed challenging measures in regaining regulatory control over radioactive sources used by a licensee in the impacted area. At the time of investigation and field search, the activity was designed mainly for emergency response, source recovery, and on the safety aspect. Afterwards, nuclear security part should be reassessed also for a better improvement of regulatory body. (author)
[en] This paper discusses possibilities to improve the Environmental Seismic Intensity Scale (ESI-07 scale), a scale based on the effects of earthquakes in the environment. This scale comprises twelve intensity degrees and considers primary and secondary effects, one of them the occurrence of tsunamis. Terminology and physical tsunami parameters corresponding to different intensity levels are often misleading and confusing. The present work proposes: i) a revised and updated catalogue of environmental and geological effects of tsunamis, gathering all the available information on Tsunami Environmental Effects (TEEs) produced by recent earthquake-tsunamis; ii) a specific intensity scale (TEE-16) for the effects of tsunamis in the natural environment at coastal areas. The proposed scale could be used in future tsunami events and, in historic and paleo-tsunami studies. The new TEE- 16 scale incorporates the size specific parameters already considered in the ESI-07 scale, such as wave height, run-up and inland extension of inundation, and a comprehensive and more accurate terminology that covers all the different intensity levels identifiable in the geological record (intensities VI-XII). The TEE-16 scale integrates the description and quantification of the potential sedimentary and erosional features (beach scours, transported boulders and classical tsunamites) derived from different tsunami events at diverse coastal environments (e.g. beaches, estuaries, rocky cliffs,). This new approach represents an innovative advance in relation to the tsunami descriptions provided by the ESI-07 scale, and allows the full application of the proposed scale in paleoseismological studies. The analysis of the revised and updated tsunami environmental damage suggests that local intensities recorded in coastal areas do not correlate well with the TEE-16 intensity (normally higher), but shows a good correlation with the earthquake magnitude (Mw). Tsunamis generated by earthquakes can then be considered efficient processes in the direct transference of the “energy” released by offshore seismogenic sources to the nearest coastal areas, even over distances of hundreds of kilometres (>200km). This scale, as the previous ones, is independent of the earthquake type (i.e. style of faulting) and only focuses on the environmental effects triggered by tsunamis of seismic origin. (Author)
[en] Nuclear power plant site evaluation should conduct the hazard evaluation on tsunami. Global climate changes and particularly extreme meteorology and hydrology phenomena have an impact on the structure, systems and important components related to safety. Therefore, IAEA makes efforts to revise the IAEA Safety Standard Series NS-G 3.4, Meteorological Events in Site Evaluation for Nuclear Power Plants and IAEA safety standard series NS-G 3.5 Flood Hazard For Nuclear Power Plants On Coastal And River Sites, in order to provide protection against the public and the environment safety due to operation of nuclear power plants. There are two methods used in assessing tsunami hazard, probabilistic and deterministic methods. In the tsunami hazard assessment, some necessary information and data should be obtained to determine the basic design of tsunami hazard during designing nuclear power plants, especially the cooling system design. Flooding caused tsunami must be evaluated to determine the site protection system. Furthermore, There must be an evaluation on either coincident event or meteorological simultaneously tsunami event that caused the worst effect on the site. Therefore, the protection of the site from extreme tsunami can be planned. (author)
[en] The aim of this investigation is to understand the geochemical variation in east coast of marine environment near existing and proposed DAE facilities due to Tsunami. Hence interest in the post Tsunami Environmental Impact study is on the concentration and distribution of radioelement and associated heavy metals. It is therefore essential to study the impact of Tsunami on the marine ecosystem which has been subject to to the impact of industrialization and urbanization of land
[en] By applying the technique of uniform asymptotic approximation to the oscillatory integrals representing tsunami wave profiles, the form of the travelling wave far from the source is calculated for arbitrary initial disturbances. The approximations reproduce the entire profiles very accurately, from the front to the tail, and their numerical computation is much faster than that of the oscillatory integrals. For one-dimensional propagation, the uniform asymptotics involve Airy functions and their derivatives; for two-dimensional propagation, the uniform asymptotics involve products of these functions. Separate analyses are required when the initial disturbance is specified as surface elevation or surface velocity as functions of position, and when these functions are even or odd. 'There was an awful rainbow once in heaven' (John Keats, 1820)
[en] In recent years there has been an evolution in numerical models used to compute tsunami propagation and run-up. Many models currently available offer a wide array of choices to the users. In parallel with the development of such numerical models, it is important that the user only applies the verified and validated numerical models that have undergone a benchmark analysis. This publication provides information and benchmark problems to enable engineers and regulators to select the most appropriate tsunami analysis software and modelling for the evaluation of tsunami hazards for nuclear installations to ensure their safety against those events. In addition, the benchmark problems will enable such users to become familiar with the limitations of the tsunami analysis modelling available in research and commercial software.