核电站场地断层活动性的识别标准研究

关于核电站场地断层活动性识别标准,作者提出了6点建议:1. 晚更新世、特别是全新世地层被扰动或错断;2. 断层泥年龄小于10万年;3. 沿断裂带存在明显的线性构造;4. 有破坏性地震(Ms≥5. 0) 沿断层发生;5. 现代微小地震沿断裂带形成“地震线”;6. 在断裂带上发现可靠的古地震遗迹。此外,为了使断层活动性评定做到定量化,作者还提出了断层活动度概念。     

Scientific certainty and the laws that govern location of a potential high-level nuclear waste repository

Recent studies have questioned the ability of the Department of Energy to successfully construct and operate a high-level nuclear waste repository at Yucca Mountain, Nevada, USA, consistent with current Environmental Protection Agency standards and Nuclear Regulatory Commission regulations. Questions focus on whether demonstration of compliance with the agency's standards is based too much on numerical calculations and analyses that the Department of Energy must conduct to project the long-term performance of the repository. Unless these questions are resolved, the licensing of the repository could be withheld or delayed by litigation. This article reviews the extent to which laws that govern the siting of high-level nuclear waste repositories require scientific certainty in any findings about the environmental consequences of locating a repository.     

Siting America's geologic repository for high-level Nuclear Waste: Implications for environmental Policy

Siting a geologic repository for isolating highlevel nuclear waste up to 10,000 years is a controversial undertaking never before attempted in the United States. The Nuclear Waste Policy Act of 1982 exempted repository siting from important requirements for environmental review under the National Environmental Policy Act. In December 1987, the Nuclear Waste Policy Amendments Act identified Yucca Mountain as the first site to be characterized for a high-level nuclear waste repository. In light of the unproven nature of the technology being evaluated, the scientific uncertainties associated with Yucca Mountain, and the lack of proven methods for risk evaluation, the environmental policies for repository siting represent a significant departure from more traditional, comprehensive, and interdisciplinary environmental review for siting nuclear projects. The policies warrant further study by those interested in how present as well as future decisions about complex technologies may be made.     

Parametric study of the explosivity of graphite-metals mixtures

The explosivity of dust clouds is greatly influenced by several parameters which depend on the operating conditions, such as the initial turbulence, temperature or ignition energy, but obviously also on the materials composition. In the peculiar case of a mixture of two combustible powders, the physical and chemical properties of both dusts have an impact on the cloud flammability and on its explosivity. Nevertheless, no satisfactory ‘mixing laws’ predicting the mixture behavior are currently available and the composition variable to be considered for such models greatly depend on the safety parameters which have to be determined: from volume ratios for some thermal exchanges and ignition phenomena, to surface proportions for some heterogeneous reactions and molar contents for chemical reactions. This study is mainly focused on graphite/magnesium mixtures as they are encountered during the decommissioning activities of UNGG reactors (Natural Uranium Graphite Gas). Due to the different nature and reactivity of both powders, these mixtures offer a wide range of interests. Firstly, the rate-limiting steps for the combustion of graphite are distinct from those of metals (oxygen diffusion or metal vaporization). Secondly, the flame can be thickened by the presence of radiation during metal combustion, whereas this phenomenon is negligible for pure graphite. Finally, the turbulence of the initial dust cloud is modified by the addition of a second powder. In order to assess the explosivity of graphite/magnesium clouds, a parametric study of the effects of storage humidity, particle size distribution, ignition energy, and initial turbulence has been carried out. In particular, it was clearly demonstrated that the turbulence significantly influences the explosion severity by speeding up the rate of heat release on the one hand and the oxygen diffusion through the boundary layer surrounding particles on the other hand. Moreover, it modifies the mean particle size and the spatial dust distribution in the test vessel, impacting the uniformity of the dust cloud. Thus, the present work demonstrates that the procedures developed for standard tests are not sufficient to assess the dust explosivity in industrial conditions and that an extensive parametric study is relevant to figure out the explosive behavior of solid/solid mixtures subjected to variations of operating conditions.     

环境科学中的核技术应用问题

本文论述核技术发展对环境科学的积极作用，并全面介绍主要包括辐照、示踪、核分析以及同位素测量在内的核技术在该学科中应用的各个方面。通过此项技术的应用现状、前景以及需要具备的基本条件等，提出了有关的具体建议。     

从材料的冲击损伤研究看核电厂的安全防护

论述了核电厂对外来冲击物的安全防护及其与材料受到冲击损伤之间的关系,讨论了材料在外来物冲击作用下的损伤行为、模式及破坏预测的方法,笔者就材料及其结构的冲击损伤研究提出了建议     

Enhancement of radon exposure in smoking areas

Radium-226 is a significant source of radon-222 which enters buildings through soil, construction materials or water supply. When cigarette smoke is present, the radon daughters attach to smoke particles. Thus, the alpha radiation to a smoker’s lungs from the natural radon daughters is increased because of smoking. To investigate whether the cigarette tobacco itself is a potential source of indoor radon, the α potential energy exposure level contents of radon (²²²Rn, 3.82d) and Thoron (²²⁰Rn, 55.60s) were measured in 10 different cigarette tobacco samples using CR-39 solid-state nuclear track detectors (SSNTDs). The results showed that the ^{222, 220}Rn concentrations in these samples ranged from 128 to 266 and 49 to 148 Bqm⁻³, respectively. The radon concentrations emerged from all investigated samples were significantly higher than the background level. Also, the annual equivalent doses from the samples were determined. The mean values of the equivalent dose were 3.51 (0.89) and 1.44 (0.08) mSvy⁻¹, respectively. Measurement of the average indoor radon concentrations in 20 café rooms was, significantly, higher than 20 smoking-free residential houses. The result refers to the dual (chemical and radioactive) effect of smoking as a risk factor for lung cancer.     

Ecological Survey of Coastal I Water Adjacent to Nuclear Power I Plants in Taiwan

A total of six nuclear reactors installed in three power plants, two along the northern and one along the southern coasts of Taiwan, started their operations one after another since October 1977. Owing to the large quantities of cooling water intake into and discharge from the plants, some environmental factors such as water temperature, chlorine, environmental radioactivity and nearshore currents may be significantly changed. Variations of these abiotic environmental factors may influence the biological activities in the ecosystem, particularly doing some kinds of damage to marine biological resources. Therefore, the possible environmental impact upon the biological systems including the fishery resources along the northern and southern coasts of Taiwan should be studied before and during the plant operation.

We have started the long-term programmes of biological, chemical and hydro-graphical surveys of the nuclear power plant sites on both northern (since July 1974) and southern (since July 1979) coasts of Taiwan. the survey items include ocean currents, physical and chemical properties of sea water, primary productivity, specific compositions and interspecific relationships among phyto- and zooplankton, algae, invertebrates, corals, and fishes; and radionuclides in water and biological specimens, and fishery statistics. in general, except for a few events, the operations of the six units of nuclear power plants have not produced detectable effects on the marine ecosystem. Radio activity levels and radionuclides in water and the biological specimens remained the same as background levels throughout the survey period. However, the events of coral bleaching and fish body anomalies caused by thermal discharges were observed respectively along the outlets of third and second Nuclear Power Plants. the purposes of this paper are to report and evaluate these two events during the operations of nuclear power plants in Taiwan.     

Environmental disaster education at the university level: an integrative approach

Because of the highly complex nature of chemical and nuclear accidents, efforts aimed at prevention, preparedness and response require the melding of many types of knowledge and the close collaboration of a wide range of professions. Nevertheless, the need for such integration and cooperation is not always strongly emphasized in university-level curricula. As a result, developing professionals have few opportunities to learn and practise unified models of environmental accident management. In an effort to foster a more integrative approach, the University of Alabama at Birmingham, USA, has launched the “Environmental Disasters” project. The project crosses disciplinary boundaries with respect to both curriculum and enrollment. In terms of curriculum, the project examines chemical and nuclear accidents from a multi-dimensional perspective, considering not only regulatory, scientific and policy issues, but also the public health, social, and psychological implications. In terms of enrollment, the project brings together students from the full range of fields that are involved with environmental accidents, including engineering, public health, public administration, social work, psychology, nursing, communications, medicine, and environmental studies. Emphasizing the need for a collaborative approach, students work in multi-disciplinary teams as they explore theory, case studies and current research. In addition, the student teams develop detailed plans for addressing the effects of a chemical or nuclear disaster. With environmental accidents representing an on-going threat to health and safety, the approach discussed in this article may provide a useful model for environmental disaster education at the university level.     

Multicriteria Relocation Analysis of an Off-site Radioactive Monitoring Network for a Nuclear Power Plant

Due to increasing environmental consciousness in most countries, every utility that owns a commercial nuclear power plant has been required to have both an on-site and off-site emergency response plan since the 1980s. A radiation monitoring network, viewed as part of the emergency response plan, can provide information regarding the radiation dosage emitted from a nuclear power plant in a regular operational period and/or abnormal measurements in an emergency event. Such monitoring information might help field operators and decision-makers to provide accurate responses or make decisions to protect the public health and safety. This study aims to conduct an integrated simulation and optimization analysis looking for the relocation strategy of a long-term regular off-site monitoring network at a nuclear power plant. The planning goal is to downsize the current monitoring network but maintain its monitoring capacity as much as possible. The monitoring sensors considered in this study include the thermoluminescence dosimetry (TLD) and air sampling system (AP) simultaneously. It is designed for detecting the radionuclide accumulative concentration, the frequency of violation, and the possible population affected by a long-term impact in the surrounding area regularly while it can also be used in an accidental release event. With the aid of the calibrated Industrial Source Complex–Plume Rise Model Enhancements (ISC-PRIME) simulation model to track down the possible radionuclide diffusion, dispersion, transport, and transformation process in the atmospheric environment, a multiobjective evaluation process can be applied to achieve the screening of monitoring stations for the nuclear power plant located at Hengchun Peninsula, South Taiwan. To account for multiple objectives, this study calculated preference weights to linearly combine objective functions leading to decision-making with exposure assessment in an optimization context. Final suggestions should be useful for narrowing the set of scenarios that decision-makers need to consider in this relocation process.