Thesis (M.S.)--University of Michigan, 1970.

Thesis (master's)--University of Michigan, 1973.

No description available.

The aim of the thesis was to define the meaning of radiochemical processes which take place in coolant of the primary circuit of the Nuclear Power Plant; and to describe the way of measurement of chemical parameters. The second aim was to define the significance of dissolved hydrogen to compensate for corrosion-threatening corrosion-safe operation of plant and to describe the method of generating hydrogen by ammonia. The third aim was to investigate the time courses of ammonia and hydrogen concentrations within the two production units. The last aim was to investigate unilateral dependence between ammonia and hydrogen concentrations. The first two aims were met by using system analysis of coolant chemical parameters, methods of measuring them, and ongoing radiochemical processes in the coolant. Ammonia and hydrogen were selected for deeper investigation, because of the results of the analysis. H1, H2 and H3 hypotheses have been formulated to meet the other two aims. The H1 hypothesis was used to verify the empirical distribution of ammonia and hydrogen concentration measurements by non-parametric normality testing. Hypothesis H2 investigated the time dependence of ammonia and hydrogen concentrations by regression analysis. In case of verification of H3 hypothesis the method of regression and correlation dependency was used. The verifying of hypothesis has shown that the empirical distribution of the measurement of hydrogen and ammonia concentrations is more closely related to the theoretical normal distribution. Furthermore, it was verified that the linear regression function of the time dependence of ammonia and hydrogen concentration measurements is close to the parallel to the timeline during the fuel campaign. Linear regression and correlation analysis confirmed that the correlation between hydrogen and ammonia concentrations is similar on both blocks and close to strong positive correlation. Verification of required regressive and correlative bending between ammonia and generated hydrogen can be understood as a practical contribution.

Current regulations specify the minimum number of operators required per nuclear power plant. However, these requirements are based on the operation of large nuclear power plants, which are not inherent safe and can result in a meltdown. For newly developed small nuclear reactors, the current number of operators seems to be excessive causing the technology to be less competitive. Before the number of required operators can be optimised, it should be demonstrated that human errors will not endanger or cause risk to the plant or public. For this study, a small pebble bed High Temperature Reactor (HTR) Nuclear Power Plant (NPP), the Th-100, was evaluated. The inherent safety features of this type of nuclear reactor include independent barriers for fission product capture and passive heat dissipation during a loss of coolant. The control and instrumentation architecture include two independent protection systems. The Control and Limitation System is the first protection system to react if the reactor parameters exceed those of the normal operational safe zone. If the Control and Limitation System fail to maintain the reactor within the safe zone, the Reactor Protection System would at that time operate and force the reactor to a safe state. Both these automated protection systems are installed in a control room local to the reactor building, protected from adverse conditions. In addition, it is connected to a semi-remote control room, anticipated as a multi-unit control room to include the monitoring and control of the auxiliary systems. Probable case studies of human error associated with multi-unit control rooms were evaluated against the logic of the Control and Limitation System. Fault Tree Analysis was used to investigate all possible failures. The evaluation determined the reliability of the Control and Limitation System and highlighted areas which design engineers should take into account if a higher reliability is required. The scenario was expanded, applying the same methods, to include the large release of fission products in order to verify the reliability calculations. The probability of a large release of fission products compared with studies done on other nuclear installations revealed to be much less for the evaluated HTR as was expected. As the study has proved that human error cannot have a negative influence on the safety of the reactor, it can be concluded that the first step has been met which is required, when applying for a waiver to utilise a multi-unit control room for the small pebble bed HTR NPP. Also, from the study, it is recommended that a practical approach be applied for the evaluation of operator duties on a live plant, to optimise the number of operators required. This in turn will position the inherent safe HTR competitively over other power stations. / MIng (Nuclear Engineering), North-West University, Potchefstroom Campus, 2015

Current regulations specify the minimum number of operators required per nuclear power plant. However, these requirements are based on the operation of large nuclear power plants, which are not inherent safe and can result in a meltdown. For newly developed small nuclear reactors, the current number of operators seems to be excessive causing the technology to be less competitive. Before the number of required operators can be optimised, it should be demonstrated that human errors will not endanger or cause risk to the plant or public. For this study, a small pebble bed High Temperature Reactor (HTR) Nuclear Power Plant (NPP), the Th-100, was evaluated. The inherent safety features of this type of nuclear reactor include independent barriers for fission product capture and passive heat dissipation during a loss of coolant. The control and instrumentation architecture include two independent protection systems. The Control and Limitation System is the first protection system to react if the reactor parameters exceed those of the normal operational safe zone. If the Control and Limitation System fail to maintain the reactor within the safe zone, the Reactor Protection System would at that time operate and force the reactor to a safe state. Both these automated protection systems are installed in a control room local to the reactor building, protected from adverse conditions. In addition, it is connected to a semi-remote control room, anticipated as a multi-unit control room to include the monitoring and control of the auxiliary systems. Probable case studies of human error associated with multi-unit control rooms were evaluated against the logic of the Control and Limitation System. Fault Tree Analysis was used to investigate all possible failures. The evaluation determined the reliability of the Control and Limitation System and highlighted areas which design engineers should take into account if a higher reliability is required. The scenario was expanded, applying the same methods, to include the large release of fission products in order to verify the reliability calculations. The probability of a large release of fission products compared with studies done on other nuclear installations revealed to be much less for the evaluated HTR as was expected. As the study has proved that human error cannot have a negative influence on the safety of the reactor, it can be concluded that the first step has been met which is required, when applying for a waiver to utilise a multi-unit control room for the small pebble bed HTR NPP. Also, from the study, it is recommended that a practical approach be applied for the evaluation of operator duties on a live plant, to optimise the number of operators required. This in turn will position the inherent safe HTR competitively over other power stations. / MIng (Nuclear Engineering), North-West University, Potchefstroom Campus, 2015

Neste trabalho apresentamos o estudo da possivilidade de melhores regimes para o uso dos experimentos de aquecimento e geracao de corrente e fluxo de plasma no tokamak TCABR. Apresentamos um estudo dos efeitos de rotacao de plasma em baixa frequencia (low-frequency (LF)), penetração de campo eletromagnético, absorção e forças ponderomotoras no “Tokamak Chauffage Alfvén Brésilien" (TCABR) com ênfase na faixa de frequências de 0, 5–10, 0kHz. Os campos de LF são dirigidos pelo limitador magnético ergódico (ergodic magnetic limiter (EML)) no TCABR. Foi feito um estudo analítico das ondas de Alfvén e ressonância usando modelos simples. Um estudo num´erico tembém foi realizado utilizando três códigos, quais sejam, o código cinético toroidal, o código cilíndrico e o código ALTOK. / In this work we present the study of the determination the best regimes and parameters¶for the heating experiments and current generation and plasma flow in the tokamak TCABR. Study of effects of plasma rotation in low frequency (LF), field penetration, absorption and ponderomotive forces in “Tokamak Chauffage Alfvén Brésilien" (TCABR)is investigated with emphasis in the frequency range of 0, 5–10, 0kHz. The fields of LF are driven by the ergodic magnetic limiter (EML) in TCABR. A qualitative analytical study of the Alfvén waves and their resonances is performed using simple models. A numeric study was carried out using through three codes, called the kinetic totoidal code, the cylindrical code and the ALTOK code.

Neste trabalho apresentamos o estudo da possivilidade de melhores regimes para o uso dos experimentos de aquecimento e geracao de corrente e fluxo de plasma no tokamak TCABR. Apresentamos um estudo dos efeitos de rotacao de plasma em baixa frequencia (low-frequency (LF)), penetração de campo eletromagnético, absorção e forças ponderomotoras no “Tokamak Chauffage Alfvén Brésilien” (TCABR) com ênfase na faixa de frequências de 0, 5–10, 0kHz. Os campos de LF são dirigidos pelo limitador magnético ergódico (ergodic magnetic limiter (EML)) no TCABR. Foi feito um estudo analítico das ondas de Alfvén e ressonância usando modelos simples. Um estudo num´erico tembém foi realizado utilizando três códigos, quais sejam, o código cinético toroidal, o código cilíndrico e o código ALTOK. / In this work we present the study of the determination the best regimes and parameters¶for the heating experiments and current generation and plasma flow in the tokamak TCABR. Study of effects of plasma rotation in low frequency (LF), field penetration, absorption and ponderomotive forces in “Tokamak Chauffage Alfvén Brésilien” (TCABR)is investigated with emphasis in the frequency range of 0, 5–10, 0kHz. The fields of LF are driven by the ergodic magnetic limiter (EML) in TCABR. A qualitative analytical study of the Alfvén waves and their resonances is performed using simple models. A numeric study was carried out using through three codes, called the kinetic totoidal code, the cylindrical code and the ALTOK code.

La presente tesis aborda el caso de estudio del diagnóstico y modelado de los procesos de gestión del reactor nuclear argentino RA-6, relevando y aplicando los requisitos de los estándares de la International Atomic Energy Agency (2005, 2006, 2009, 2012) y el marco regulatorio nacional. Para realizar el diagnóstico y descripción de la situación actual de los procesos de gestión se aplicó el modelo de madurez de ISO 9004. Luego se relevaron y sistematizaron los requisitos de los estándares de seguridad y gestión correspondientes. Finalmente se modelizaron los procesos de gestión aplicando técnicas de Business Process Management, especificándolos de forma coherente e integral. Los resultados obtenidos son novedosos debido a los escasos antecedentes que se conocen y publicaron en bibliografía especializada. Y por otro lado, tienen fines prácticos ya que contribuyen a cumplimentar los requerimientos que la instalación tiene para la futura renovación de su licencia de operación. / The present thesis deals with the case study of the diagnosis and modeling of the processes of management of the Argentine nuclear reactor RA-6, relieving and applying the requirements of the standards of the International Atomic Energy Agency (2005, 2006, 2009, 2012) and the national regulatory framework. In order to carry out the diagnosis and description of the current situation of the management processes, the maturity model of ISO 9004 was applied. The requirements of the corresponding safety and management standards were then reviewed and systematized. Finally, the management processes were modeled applying Business Process Management techniques, specifying them in a coherent and integral system. The results obtained are novel due to the scarce antecedents that are known and published in specialized bibliography. And on the other hand, they have practical purposes as they contribute to fulfill the requirements that the installation has for the future renewal of its operating license.