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The main objectives of the project were to investigate the interactions of carbon, titanium and aluminium contents, grain size and cold working, with precipitation reactions which occur during heat treatments similar to those experienced as a consequence of commercial PWR Steam Generator (SG) tube processing. In order to carry out this investigation commercial material was supplemented by a range of experimental casts. The selected casts allowed the investigation of the following compositional variables: (i) the effect of C in alloys free from Ti or Al, (ii) the effect of C in alloys containing both Ti and Al, and (iii) the effect of T! in alloys containing constant C and Al contents. As a result of the experimental programme considerable progress has been made in clarifying the complex structure-property relationships which occur in Alloy 600. The microstructures observed have been characterised and understood in terms of thermal and mechanical treatments. Studies involving analysis of the mechanical properties, have led to a clear understanding of the effects of grain size, precipitate type and distribution and residual cold work on mechanical behaviour. It has been shown that the activation energy for normal grain growth increases with increasing carbon and titanium contents. Explanations of the mechanical properties have been discussed in terms of grain size, dislocation hardening and solid solution hardening and it has been possible to understand the overall material properties with respect to these. The kinetics of precipitation have been studied in depth, since it is the precipitation of chromium carbide which ultimately results in the principle mode of material degradation, namely, intergranular corrosion. A range of carbide precipitation 'C-curves' have been established and related to thermal and mechanical processing. Accelerated corrosion testing has provided an insight into the relationship between precipitation and structure on the stability of material in potentially corrosive environments.

This research investigates the implementation of battery-less RFID sensing platforms inside lossy media, such as, concrete and grout. Both concrete and novel grouts can be used for nuclear plant decommissioning as part of the U.S. Department of Energy’s (DOE’s) cleanup projects. Our research examines the following: (1) material characterization, (2) analytical modeling of transmission and propagation losses inside lossy media, (3) maximum operational range of RFID wireless sensors embedded inside concrete and grout, and (4) best positioning of antennas for achieving longer communication range between RFID antennas and wireless sensors. Our research uses the battery-less Wireless Identification and Sensing Platform (WISP) which can be used to monitor temperature, and humidity inside complex materials. By using a commercial Agilent open-ended coaxial probe (HP8570B), the measurements of the dielectric permittivity of concrete and grout are performed. Subsequently, the measured complex permittivity is used to formulate analytical Debye models. Also, the transmission and propagation losses of a uniform plane wave inside grout are calculated. Our results show that wireless sensors will perform better in concrete than grout. In addition, the maximum axial and radial ranges for WISP are experimentally determined. Our work illustrates the feasibility of battery-less wireless sensors that are embedded inside concrete and grout. Also, our work provides information that can be used to optimize the power management, sampling rate, and antenna design of such sensors.

Submitted by Almir Azevedo (barbio1313@gmail.com) on 2015-08-24T17:42:07Z No. of bitstreams: 1 CARLOS ALEXANDRE F. JORGE D.pdf: 11356748 bytes, checksum: 59927b7a303fb41d249f403942824b9a (MD5) / Made available in DSpace on 2015-08-24T17:42:07Z (GMT). No. of bitstreams: 1 CARLOS ALEXANDRE F. JORGE D.pdf: 11356748 bytes, checksum: 59927b7a303fb41d249f403942824b9a (MD5) Previous issue date: 2015-07 / This work proposes the development of a system to evaluate received radiation dose for nuclear plants personnel. The system is conceived to operate in a complementary form to the existing approaches for radiological protection, thus o ering redundancy, what is desirable for critical plants operation. The proposed system must operate in an independent form on the actions to be performed by the operators under evaluation. Therefore, it was decided it would be based on methods used for video surveillance. The nuclear plant used as example is Argonauta Nuclear Research Reactor, belonging to Instituto de Engenharia Nuclear, Comiss~ao Nacional de Energia Nuclear (Nuclear Engineering Institute, National Nuclear Energy Commission). During this thesis research, both radiation dose rate distribution and video databases were obtained. Methods available in the literature, for targets detection and/or tracking, were evaluated for this database. From these results, a new system was proposed, with the purpose of meeting the requisites for this particular application. Given the tracked positions of each worker, the radiation dose received by each one during tasks execution is estimated, and may serve as part of a decision support system.

Determining the cost of implementing a nuclear energy policy is very important due to the high costs associated with nuclear programs. Such programs may be unattainable to certain countries due to the many requirements that ensure a safe and secure nuclear sector. The IAEA has a large number of publications that indicate the requirements for implementing nuclear energy sectors. By using these publications, a framework was developed costing each of the main sectors of a nuclear energy program. These sectors correspond to the sectors that the South African government proposed for its nuclear energy policy. The main sectors are: * Basic infrastructure development * Nuclear power plant (NPP) sector * Nuclear fuel cycle (NFC) sector * Industrial involvement An outline of the framework is attached as Appendix A. A more elaborative development of the framework is given in Chapter 2. The Government proposes the development of 20 GWe (Eskom Holdings Limited, 2010:3) of nuclear power over the next 20 to 25 years along with the development of the entire nuclear fuel cycle and an industrial base that will ensure that South Africa is independent of other countries and has the capability to develop nuclear power plants and associated technology. By applying the framework it was possible to estimate the costs of the different sectors. It was found by the author that the basic infrastructure and power plant sector will cost approximately R 889 billion (2008 Rand value), excluding financing costs. The fuel cycle sector is very sensitive to global resistance and will require considerable planning to ensure that international bodies and countries are satisfied with the local intention of pursuing fuel cycle implementation. To ensure that costs are minimized the implementation of the different fuel cycle steps is crucial and will depend on the rollout plan of the power plants and the local demand for fuel and the influence of security of fuel supply. To implement the entire front end and reprocessing step it was estimated that the cost will amount to approximately R 52,3 billion. The cost of implementing the industrial sector development was not determined, due to the many factors involved. The different requirements in the sector may be supplied by similar industries currently active in South Africa. Most of the current industries will require further accreditation and may have to increase capacity if South Africa is to become a global supplier of nuclear technology. Sources indicated that the different sectors will require trained personnel numbers in the region of 77 000 (direct jobs). The amount of indirect jobs that will be created will be in the regions of 300 000. Government therefore has a huge responsibility to ensure that training and education programs are developed that can supply the demand of trained personnel. The different industries involved should also ensure that the relevant personnel are trained in advance, to obtain the required accreditation and experience. The final outcome of the revised Integrated Resource Plan (IRP2) was not yet available when this dissertation was completed. The outcomes of the future nuclear programs may therefore be different from the extent of developments and investments estimated by this study. The cost of reactors and basic infrastructure will have to be scaled to the revised objectives while the costs of the fuel cycle may change considerably due to a possible decrease in local demand. These changes will affect the economy of scale on many of the sectors of development. The framework is generic and may be applied to different nuclear development programs and countries. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.

Determining the cost of implementing a nuclear energy policy is very important due to the high costs associated with nuclear programs. Such programs may be unattainable to certain countries due to the many requirements that ensure a safe and secure nuclear sector. The IAEA has a large number of publications that indicate the requirements for implementing nuclear energy sectors. By using these publications, a framework was developed costing each of the main sectors of a nuclear energy program. These sectors correspond to the sectors that the South African government proposed for its nuclear energy policy. The main sectors are: * Basic infrastructure development * Nuclear power plant (NPP) sector * Nuclear fuel cycle (NFC) sector * Industrial involvement An outline of the framework is attached as Appendix A. A more elaborative development of the framework is given in Chapter 2. The Government proposes the development of 20 GWe (Eskom Holdings Limited, 2010:3) of nuclear power over the next 20 to 25 years along with the development of the entire nuclear fuel cycle and an industrial base that will ensure that South Africa is independent of other countries and has the capability to develop nuclear power plants and associated technology. By applying the framework it was possible to estimate the costs of the different sectors. It was found by the author that the basic infrastructure and power plant sector will cost approximately R 889 billion (2008 Rand value), excluding financing costs. The fuel cycle sector is very sensitive to global resistance and will require considerable planning to ensure that international bodies and countries are satisfied with the local intention of pursuing fuel cycle implementation. To ensure that costs are minimized the implementation of the different fuel cycle steps is crucial and will depend on the rollout plan of the power plants and the local demand for fuel and the influence of security of fuel supply. To implement the entire front end and reprocessing step it was estimated that the cost will amount to approximately R 52,3 billion. The cost of implementing the industrial sector development was not determined, due to the many factors involved. The different requirements in the sector may be supplied by similar industries currently active in South Africa. Most of the current industries will require further accreditation and may have to increase capacity if South Africa is to become a global supplier of nuclear technology. Sources indicated that the different sectors will require trained personnel numbers in the region of 77 000 (direct jobs). The amount of indirect jobs that will be created will be in the regions of 300 000. Government therefore has a huge responsibility to ensure that training and education programs are developed that can supply the demand of trained personnel. The different industries involved should also ensure that the relevant personnel are trained in advance, to obtain the required accreditation and experience. The final outcome of the revised Integrated Resource Plan (IRP2) was not yet available when this dissertation was completed. The outcomes of the future nuclear programs may therefore be different from the extent of developments and investments estimated by this study. The cost of reactors and basic infrastructure will have to be scaled to the revised objectives while the costs of the fuel cycle may change considerably due to a possible decrease in local demand. These changes will affect the economy of scale on many of the sectors of development. The framework is generic and may be applied to different nuclear development programs and countries. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.

This diploma work is engaged in replacement of gasket main dividing plane of reactor coolant pumps in nuclear power plant Paks. Of the newly suggested gasket is kammprofile gasket with expanded graphite layer. This work contain suggestion and calculation of new sealing a knot and calculation existing sealing the knot. Results are confrontacion and sequentially is discussed influence on main dividing plane HCČ 317 by use the new and the existing gasket. In this work is contained description brief of legislation. This legislation must keep by design components dedicated for nuclear equipment. Next this work contain view of the most important sealing knots used in primary system of Nuclear Power Plant type VVER 440.