Underground nuclear power plant siting

This study is part of a larger evaluation of the problems associated with siting nuclear power plants in the next few decades. This evaluation is being undertaken by the Environmental Quality Laboratory of the California Institute of Technology in conjunction with The Aerospace Corporation and several other organizations. Current efforts are directed toward novel approaches to siting plants within the State of California. This report contains the results of efforts performed by The Aerospace Corporation to provide input information to the larger evaluation relative to underground siting of large central station nuclear power plants. Projections of electric power demand in California and the country as a whole suggest that a major increase in generating capacity will be required. The problem is complicated beyond that of a large but straightforward extension of capital investment by increased emphasis on environmental factors combined with the early stage of commercial application and regulation of nuclear power sources. Hydroelectric power generation is limited by the availability of suitable sites, and fossil fueled plants are constrained by the availability of high quality fuels and the adverse environmental and/or economic impact from the use of more plentiful fuels. A substantial increase in the number of nuclear power plants is now under way. This source of power is expected to provide the maj or portion of increased capacity. Other power sources such as geothermal and nuclear fusion are unlikely to satisfy the national needs due to technical problems and the lack of a comprehensive development program. There are several problems associated with meeting the projected power demand. Chief among these is the location of acceptable and economic plant sites. Indeed a sufficient number of sites may not be found unless changes occur in the procedures for selecting sites, the criteria for accepting sites, or the type of site required. Placement of a nuclear plant underground has been suggested as an alternative to present siting practices. It is postulated that the advantages of underground siting in some situations may more than compensate for added costs so that such facilities could be preferred even where surface sites are available. By virtue of greater safety, reduced surface area requirements, and improved aesthetics, underground sites might also be found where acceptable surface sites are not available. Four small European reactors have been constructed partially underground but plans for large size commercial plants have not progressed. Consequently, the features of underground power plant siting are not well understood. Gross physical features such as depth of burial, number and size of excavated galleries, equipment layout, and access or exit shafts/tunnels must be specified. Structural design features of the gallery liners, containment structure, foundations, and gallery interconnections must also be identified. Identification of the nuclear, electrical, and support equipment appropriate to underground operation is needed. Operational features must be defined for normal operations, refueling, and construction. Several magazine articles have been published addressing underground concepts. but adequate engineering data is not available to support an evaluation of the underground concept. There also remain several unresolved questions relative to the advantages of underground siting as well as the costs and other possible penalties associated with this novel approach to siting. These include the degree of increased safety through improved containment; the extent and value of isolation from falling objects, e. g. aircraft; the value of isolation from surface storms and tidal waves; the value of protection from vandalism or sabotage; the extent by which siting constraints are relieved through reduced population-distance requirements or aggravated by underground construction requirements; and the value to be placed upon the aesthetic differences of a less visible facility. The study described in this report has been directed toward some of these questions and uncertainties. Within the study an effort has been made to identify viable configurations and structural liners for typical light water reactor nuclear power plants. Three configurations are summarized in Section 3. A discussion of the underground gallery liner design and associated structural analyses is presented in Section 4. Also addressed in the study and discussed in Section 5 are some aspects of containment for underground plants. There it is suggested that the need for large separations between the plant and population centers may be significantly reduced, or perhaps eliminated. Section 6 contains a brief discussion of operational considerations for underground plants. The costs associated with excavation and lining of the underground galleries have been estimated in Section 7. These estimates include an assessment of variations implied by different seismic loading assumptions and differences in geologic media. It is shown that these costs are a small percentage of the total cost of comparable surface plants. Finally, the parameters characterizing an acceptable underground site are discussed in Section 8. Material is also included in the appendices pertaining to foreign underground plants, span limits of underground excavations, potential siting areas for underground plants in the State of California, pertinent data from the Underground Nuclear Test Program, and other supporting technical discussions

Field Report on the Excavation of Indian Villages in the Vicinity of the Spiro Mounds, Leflore County, Oklahoma

A wealth of strikingly unusual and beautiful objects of Indian manufacture were excavated from the burials of the Spiro Mound, Leflore (sic.) County, Oklahoma during 1936-37. Engraved Gulf Coast conch shells, shell beads of a dozen types, river pearls, effigy pipes, long delicately chipped flint blades, feather and textile cloths and precisely incised pottery vessels were excavated in quantities. So unusual was this material that, at the time, the archaeological science was unable to answer a host of questions which immediately arose concerning the identity of the tribe who had made the artifacts and who were buried with them. How long ago had they occupied the region? From where had they come, and where did they go? The chronological relationship of the Spiro Mound Culture to the known cultures of the United States was of particular concern to the investigators. How and where did this tribe fit into the picture of America\u27s past

Knowledge Transfer for Melanoma Screening with Deep Learning

Knowledge transfer impacts the performance of deep learning -- the state of the art for image classification tasks, including automated melanoma screening. Deep learning's greed for large amounts of training data poses a challenge for medical tasks, which we can alleviate by recycling knowledge from models trained on different tasks, in a scheme called transfer learning. Although much of the best art on automated melanoma screening employs some form of transfer learning, a systematic evaluation was missing. Here we investigate the presence of transfer, from which task the transfer is sourced, and the application of fine tuning (i.e., retraining of the deep learning model after transfer). We also test the impact of picking deeper (and more expensive) models. Our results favor deeper models, pre-trained over ImageNet, with fine-tuning, reaching an AUC of 80.7% and 84.5% for the two skin-lesion datasets evaluated.Comment: 4 page

Economic Complexity Unfolded: Interpretable Model for the Productive Structure of Economies

Economic complexity reflects the amount of knowledge that is embedded in the productive structure of an economy. It resides on the premise of hidden capabilities - fundamental endowments underlying the productive structure. In general, measuring the capabilities behind economic complexity directly is difficult, and indirect measures have been suggested which exploit the fact that the presence of the capabilities is expressed in a country's mix of products. We complement these studies by introducing a probabilistic framework which leverages Bayesian non-parametric techniques to extract the dominant features behind the comparative advantage in exported products. Based on economic evidence and trade data, we place a restricted Indian Buffet Process on the distribution of countries' capability endowment, appealing to a culinary metaphor to model the process of capability acquisition. The approach comes with a unique level of interpretability, as it produces a concise and economically plausible description of the instantiated capabilities

Double-Sided Externalities and Vertical Contracting : Evidence from European Franchising Data

This paper deals with contractual design and vertical relationships within a franchise chain, in the field of the literature on share contracts. Within a double-sided moral hazard, the contract sharing the profit generated by the vertical decentralized structure results from the necessity to incite both the franchisee and the franchisor. This paper takes into account the five franchisor incentive mechanisms in order to study the chosen type of vertical coordination in different contexts. Using a multinational European dataset, we provide evidence that the two-sided externalities and monitoring costs have an influence on the type of vertical coordination in the networkAgency theory; econometrics of contracting; vertical restraints

Girikihaciyan: A Halafian Site in Southeastern Turkey

This report presents the results of excavations undertaken at the site of Girikihaciyan in southeastern Turkey during 1968 and 1970 by the Joint Prehistoric Project, Istanbul-Chicago under the overal direction of Professor Halet Cambel, University of Istanbul, and Professor Robert J. Braidwood, Oriental Institute, University of Chicago.Series: Monographs 3