This paper discusses a preferable solution to mitigate the CT (current transformer) saturation problem, and at same time, reduce the accuracy errors when considering the selection of CTs for installation on the medi...This paper discusses a preferable solution to mitigate the CT (current transformer) saturation problem, and at same time, reduce the accuracy errors when considering the selection of CTs for installation on the medium voltage switchgear of a nuclear power plant. This consideration is important for both measurement and protection functions of the digital protective relays. This is a study to ascertain the best options for a suitable solution to prevent CT saturation in relations to its protective capabilities during short circuit fault without compromising the CT accuracy class during normal operation of the system, while ensuring its conformity to the design requirement is within limit. The advantages of current transformers have proven not only to be reliable and safe, but also are of easy handling, reduction of the cost and components on the MV (medium voltage) switchgear. The purpose of this research is to identify best approach to resolve the existing problems in the current protection system. With the view of LPCT (low power current transformer) which has been newly constructed by few manufacturers to provide good protection and a wide range of measuring function without errors, some other solutions will be considered in this research.展开更多
Uganda principally depends on hydropower for electricity generation. However, expansion of hydropower resources islimited, and with growing population and demand for electricity, the government of Uganda is considerin...Uganda principally depends on hydropower for electricity generation. However, expansion of hydropower resources islimited, and with growing population and demand for electricity, the government of Uganda is considering integration of nuclearpower into its energy mix. With the current and projected grid capacity, SMR (small modular reactor) technology is attractive sincecapacity can be added incrementally. This paper therefore presents results for SMR site selection in Uganda. Starting with twentyregional areas established by the Ugandan government, a site selection process is outlined which uses four levels of screening andranking. First, exclusion criteria including seismicity, volcanic activity, water resources, and transportation distances were applied.This reduced the potential regional areas down to eight. Next, MAUT (multi-attribute utility theory) weighting was assigned to theseeight areas for: (1) distance to large population centers, (2) ease of transportation, and (3) distance to seismically or volcanically activeareas. From this ranking, four regional areas stood out and were then selected. These regions were then compared using variousattributes including access to water and integration with the developing national grid. In the final step, the lead candidate region wassubdivided into subzones to further refine the selection process.展开更多
The Advanced Modern 600 MWe (AM600) project represents the conceptual mechanical design and layout of a Nuclear Power Plant (NPP) Turbine Island intended to address challenges associated with emerging markets interest...The Advanced Modern 600 MWe (AM600) project represents the conceptual mechanical design and layout of a Nuclear Power Plant (NPP) Turbine Island intended to address challenges associated with emerging markets interested in nuclear power. The biggest challenge relates to project financing and the subsidiary issue of maintaining the construction schedule. To address that challenge in part, the AM600 is designed with a single cylinder low pressure turbine rotor matched to a condenser module. The module integrates all low pressure Feedwater Heaters (FWHs) into the condenser neck. This study investigates the design and sizing of a single string of FWHs to demonstrate proof-of-concept of the AM600 design. Specifically, the condenser is designed as a factory fabricated module which includes the installed low pressure FWHs along with major piping and valving. The analysis and design summarized here demonstrate that using industry standards and guidelines, along with accepted engineering practices, the AM600 can accommodate a modular condenser design while allowing for continued operation with an FWH Out-of-Service (OOS).展开更多
To date, nuclear cogeneration applications have been limited, primarily to district heating in Eastern Europe and heavy water production in Canada. With the current global price for oil and energy, this technology is ...To date, nuclear cogeneration applications have been limited, primarily to district heating in Eastern Europe and heavy water production in Canada. With the current global price for oil and energy, this technology is not economically viable for most countries. However, oil and fossil fuel prices are known to be highly volatile, and the Paris Agreement calls for a reduction in fossil fuel use. Under these circumstances, heat supplied by nuclear power may abruptly return to favor. To prepare for such a scenario, this study will investigate design considerations for a prototypical modem nuclear power plant, the Korean APR1400 (advanced power reactor 1400) (e.g., Shin Kori Units 3, 4, Shin Hanul 1, 2, Barakah Units 1, 2, 3, 4). Nuclear cogeneration can impact balance of plant system and component design for the condensate, feedwater, extraction steam, and heater drain systems. The APR1400 turbine cycle will be reviewed for a parametric range of pressures and flow rates of the steam exported for cogeneration to identify major design challenges.展开更多
Qualification of equipment essential to safety in NPPs (nuclear power plants) ensures its capability to perform designated safety functions on demand under postulated service conditions. However, a number of inciden...Qualification of equipment essential to safety in NPPs (nuclear power plants) ensures its capability to perform designated safety functions on demand under postulated service conditions. However, a number of incidents identified by the NRC (Nuclear Regulatory Commission) since 1980s catalysed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to suggest the NFC (near field communication) based equipment qualification management system preventing counterfeit and fraudulent items. The NEQM (NFC based equipment qualification management) system works with the support of legacy systems such as PMS (procurement management system) and FMS (facility management system).展开更多
Evaluation of radionuclide concentrations in foodstuffs is of great concern owing to the potential radiological hazards to human health. This study was carried out to assess the radionuclide concentrations of ^40K, ^1...Evaluation of radionuclide concentrations in foodstuffs is of great concern owing to the potential radiological hazards to human health. This study was carried out to assess the radionuclide concentrations of ^40K, ^134Cs, ^137Cs, ^131I, ^90Sr, ^239pu, in selected foodstuffs, in order to assess the effects of the elevated levels of radionuclides concentration in environmental media after the FDNPS (Fukushima Daiichi Nuclear Power Station) accident on imported food. HPGe (high purity germanium) detector based spectrometry system coupled with multi-channel analyzer was used for the assessment. The mean concentrations of ^40K, ^134Cs, ^137Cs, ^131I, ^90Sr, ^239pu, were found to be 50.1 ± 2.44 Bq/Kg, 109.6 ± 0.141 Bq/Kg, 134.2 ± 0.027 Bq/Kg, 2.57 ± 0.019 Bq/Kg, 0.59 ± 0.03 Bq/Kg, 0.160 ± 0.033 Bq/Kg, and 0.227 ± 0.021 Bq/Kg respectively. The analysis showed that the radioactivity levels of ^241Am, ^134Cs and ^137Cs were found to be relatively low and within the acceptable levels.展开更多
文摘This paper discusses a preferable solution to mitigate the CT (current transformer) saturation problem, and at same time, reduce the accuracy errors when considering the selection of CTs for installation on the medium voltage switchgear of a nuclear power plant. This consideration is important for both measurement and protection functions of the digital protective relays. This is a study to ascertain the best options for a suitable solution to prevent CT saturation in relations to its protective capabilities during short circuit fault without compromising the CT accuracy class during normal operation of the system, while ensuring its conformity to the design requirement is within limit. The advantages of current transformers have proven not only to be reliable and safe, but also are of easy handling, reduction of the cost and components on the MV (medium voltage) switchgear. The purpose of this research is to identify best approach to resolve the existing problems in the current protection system. With the view of LPCT (low power current transformer) which has been newly constructed by few manufacturers to provide good protection and a wide range of measuring function without errors, some other solutions will be considered in this research.
文摘Uganda principally depends on hydropower for electricity generation. However, expansion of hydropower resources islimited, and with growing population and demand for electricity, the government of Uganda is considering integration of nuclearpower into its energy mix. With the current and projected grid capacity, SMR (small modular reactor) technology is attractive sincecapacity can be added incrementally. This paper therefore presents results for SMR site selection in Uganda. Starting with twentyregional areas established by the Ugandan government, a site selection process is outlined which uses four levels of screening andranking. First, exclusion criteria including seismicity, volcanic activity, water resources, and transportation distances were applied.This reduced the potential regional areas down to eight. Next, MAUT (multi-attribute utility theory) weighting was assigned to theseeight areas for: (1) distance to large population centers, (2) ease of transportation, and (3) distance to seismically or volcanically activeareas. From this ranking, four regional areas stood out and were then selected. These regions were then compared using variousattributes including access to water and integration with the developing national grid. In the final step, the lead candidate region wassubdivided into subzones to further refine the selection process.
文摘The Advanced Modern 600 MWe (AM600) project represents the conceptual mechanical design and layout of a Nuclear Power Plant (NPP) Turbine Island intended to address challenges associated with emerging markets interested in nuclear power. The biggest challenge relates to project financing and the subsidiary issue of maintaining the construction schedule. To address that challenge in part, the AM600 is designed with a single cylinder low pressure turbine rotor matched to a condenser module. The module integrates all low pressure Feedwater Heaters (FWHs) into the condenser neck. This study investigates the design and sizing of a single string of FWHs to demonstrate proof-of-concept of the AM600 design. Specifically, the condenser is designed as a factory fabricated module which includes the installed low pressure FWHs along with major piping and valving. The analysis and design summarized here demonstrate that using industry standards and guidelines, along with accepted engineering practices, the AM600 can accommodate a modular condenser design while allowing for continued operation with an FWH Out-of-Service (OOS).
文摘To date, nuclear cogeneration applications have been limited, primarily to district heating in Eastern Europe and heavy water production in Canada. With the current global price for oil and energy, this technology is not economically viable for most countries. However, oil and fossil fuel prices are known to be highly volatile, and the Paris Agreement calls for a reduction in fossil fuel use. Under these circumstances, heat supplied by nuclear power may abruptly return to favor. To prepare for such a scenario, this study will investigate design considerations for a prototypical modem nuclear power plant, the Korean APR1400 (advanced power reactor 1400) (e.g., Shin Kori Units 3, 4, Shin Hanul 1, 2, Barakah Units 1, 2, 3, 4). Nuclear cogeneration can impact balance of plant system and component design for the condensate, feedwater, extraction steam, and heater drain systems. The APR1400 turbine cycle will be reviewed for a parametric range of pressures and flow rates of the steam exported for cogeneration to identify major design challenges.
文摘Qualification of equipment essential to safety in NPPs (nuclear power plants) ensures its capability to perform designated safety functions on demand under postulated service conditions. However, a number of incidents identified by the NRC (Nuclear Regulatory Commission) since 1980s catalysed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to suggest the NFC (near field communication) based equipment qualification management system preventing counterfeit and fraudulent items. The NEQM (NFC based equipment qualification management) system works with the support of legacy systems such as PMS (procurement management system) and FMS (facility management system).
文摘Evaluation of radionuclide concentrations in foodstuffs is of great concern owing to the potential radiological hazards to human health. This study was carried out to assess the radionuclide concentrations of ^40K, ^134Cs, ^137Cs, ^131I, ^90Sr, ^239pu, in selected foodstuffs, in order to assess the effects of the elevated levels of radionuclides concentration in environmental media after the FDNPS (Fukushima Daiichi Nuclear Power Station) accident on imported food. HPGe (high purity germanium) detector based spectrometry system coupled with multi-channel analyzer was used for the assessment. The mean concentrations of ^40K, ^134Cs, ^137Cs, ^131I, ^90Sr, ^239pu, were found to be 50.1 ± 2.44 Bq/Kg, 109.6 ± 0.141 Bq/Kg, 134.2 ± 0.027 Bq/Kg, 2.57 ± 0.019 Bq/Kg, 0.59 ± 0.03 Bq/Kg, 0.160 ± 0.033 Bq/Kg, and 0.227 ± 0.021 Bq/Kg respectively. The analysis showed that the radioactivity levels of ^241Am, ^134Cs and ^137Cs were found to be relatively low and within the acceptable levels.