Multi-Modular Integral Pressurized Water Reactor Control and Operational Reconfiguration for a Flow Control Loop

This dissertation focused on the IRIS design since this will likely be one of the designs of choice for future deployment in the U.S and developing countries. With a net 335 MWe output IRIS novel design falls in the “medium” size category and it is a potential candidate for the so called modular reactors, which may be appropriate for base load electricity generation, especially in regions with smaller electricity grids, but especially well suited for more specialized non-electrical energy applications such as district heating and process steam for desalination. The first objective of this dissertation is to evaluate and quantify the performance of a Nuclear Power Plant (NPP) comprised of two IRIS reactor modules operating simultaneously with a common steam header, which in turn is connected to a single turbine, resulting in a steam-mixing control problem with respect to “load-following” scenarios, such as varying load during the day or reduced consumption during the weekend. To solve this problem a single-module IRIS SIMULINK model previously developed by another researcher is modified to include a second module and was used to quantify the responses from both modules. In order to develop research related to instrumentation and control, and equipment and sensor monitoring, the second objective is to build a two-tank multivariate loop in the Nuclear Engineering Department at the University of Tennessee. This loop provides the framework necessary to investigate and test control strategies and fault detection in sensors, equipment and actuators. The third objective is to experimentally develop and demonstrate a fault-tolerant control strategy using this loop. Using six correlated variables in a single-tank configuration, five inferential models and one Auto-Associative Kernel Regression (AAKR) model were developed to detect faults in process sensors. Once detected the faulty measurements were successfully substituted with prediction values, which would provide the necessary flexibility and time to find the source of discrepancy and resolve it, such as in an operating power plant. Finally, using the same empirical models, an actuator failure was simulated and once detected the control was automatically transferred and reconfigured from one tank to another, providing survivability to the system

"Determinação do Tempo de Resposta de Transdutores de Pressão Utilizando o Método Direto".

Neste trabalho são discutidos os diversos métodos para medida de tempo de resposta de transdutores de pressão ligados ao sistema de proteção de uma central nuclear, e apresentados os resultados obtidos através do método de medida direta. Para a realização das medidas foi utilizado um gerador hidráulico de rampa que permite gerar transientes de pressão dos tipos degrau e rampa gerando, simultaneamente, um sinal de teste para o transdutor analisado e para um transdutor de referência. O tempo de atraso entre a resposta do transdutor analisado e o transdutor de referência é chamado de tempo de atraso do transdutor, e indica quão rápido o transdutor analisado responde a uma variação. Foram analisados, neste trabalho, 11 (onze)transdutores de pressão, todos na faixa entre 25 e 400KPa, sendo 9 convencionais (de uso na indústria em geral) e 2 produzidos com classe nuclear (para uso em centrais nucleares

"Determinação do Tempo de Resposta de Transdutores de Pressão Utilizando o Método Direto".

Neste trabalho são discutidos os diversos métodos para medida de tempo de resposta de transdutores de pressão ligados ao sistema de proteção de uma central nuclear, e apresentados os resultados obtidos através do método de medida direta. Para a realização das medidas foi utilizado um gerador hidráulico de rampa que permite gerar transientes de pressão dos tipos degrau e rampa gerando, simultaneamente, um sinal de teste para o transdutor analisado e para um transdutor de referência. O tempo de atraso entre a resposta do transdutor analisado e o transdutor de referência é chamado de tempo de atraso do transdutor, e indica quão rápido o transdutor analisado responde a uma variação. Foram analisados, neste trabalho, 11 (onze)transdutores de pressão, todos na faixa entre 25 e 400KPa, sendo 9 convencionais (de uso na indústria em geral) e 2 produzidos com classe nuclear (para uso em centrais nucleares

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data