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02141 Effects of accident management strategy on the severe accident environmental conditions
05 Nuclear fuels (economics, policy, supplies, forecasts) model for the situation assessment of NPP operators based on Bayesian inference. The proposed model is found to be able to address several important features of the situation assessment of NPP operators, and is expected to provide good approximations to some parts of the situation assessment. A comparison with an existing model and identification of several other features of the situation assessment of NPP operators that should be further addressed are also provided.
06102137 Analysis of loss of flow accident at Pakistan research reactor-1 Bokhari, I. H. and Mahmood, T. Annals of Nuclear Energy, 2005, 32, (18), 1963 1968. The main objective of the reactor safety is to keep the reactor core in a condition, which does not permit any release of radioactivity into the enviromnent. In order to ensure this, the reactor must have sufficient safety margins during all possible operational conditions (normal as well as accidental). To accomplish this, a study has been carried out, for the analysis of loss of flow accident (LOFA), which is one of the probable scenarios among other possible events such as reactivityinduced-accidents, loss of coolant accident, etc. The study has been carried out for Pakistan research reactor, PARR-l, which was initially converted from HEU to LEU fuel. It is a swimming pool type reactor using MTR type fuel. Presently, a new core is proposed to be assembled containing LEU and some of the used (less burnt) HEU fuel elements. The accident is assumed when the reactor is running at a steady-state power level of 9.8 MW. Computer code PARET and standard correlations were employed to compute various parameters. Results predict nucleate boiling in the core but the temperatures would remain far below the fuel clad melting point.
06/02138 Assessment of the WWER-440/V-213 reactor condition Timofeev, B. T. and Karzov, G. P. International Journal of Pressure Vessels and Piping, 2006. 83, (3), 216 226. The current state of materials (steel, welds, anticorrosive cladding metal) of WWER-440/V-213 RPVs has been evaluated with respect to the peculiarities of their manufacturing process and operation for 30 years. The possibility of operating these reactors after the design service life has been assessed considering the degradation of properties due to thermal and radiation embrittlement, as well as damage from cyclic loads. Taking into account that the main results of operating effects were obtained in research laboratories it is necessary first of all to continue the investigations in the commercial reactors. In future, it will be possible to extend the service life of this type of reactors. For example, the positive results have been already obtained for unit No. 3 Kola NPP reactor.
06•02139 Chemical and isotopic characterization of w a t e r rock interactions in shales induced by the intrusion of a basaltic dike: A natural analogue for radioactive waste disposal Techer, I. et al. Applied Geochemistry. 2006, 21, (2), 203 222. Disposal of nuclear waste in deep geological formations is expected to induce thermal fluxes for hundreds of years with maximum temperature reaching about 100-150°C in the nearfield argillaceous environment. The long-term behaviour of clays subjected to such thermal gradients needs to be perfectly understood in safety assessment considerations. In this respect, a Toarcian argillaceous unit thermally disturbed by the intrusion of a 1.1-m wide basaltic dike at the Perthus pass (Herault, France), was studied in detail as a natural analogue. The thermal imprint induced by the dike was evaluated by a mineralogical, chemical and K-Ar study of the <2 ~tm clay fraction of shale samples collected at increasing distance from the basalt. The data suggest that the mineral composition of the shales was not significantly disturbed when the temperature was below 100-150°C. Closer to the dike at 150300°C, changes such as progressive dissolution of chlorite and kaolinite, increased content of the mixed layers illite-smectite with more illite layers, complete decalcification and subsequent increased content of quartz, were found. At the eastern contact with the dike, the mineral and chemical compositions of both the shales and the basalt suggest water-rock interactions subsequent to the intrusion with precipitation of palagonite and renewed but discrete deposition of carbonate. A pencil cleavage developed in the shales during the dike emplacement probably favoured water circulation along the contact. Strontium isotopic data suggest that the fluids of probable meteoric origin, reacted with Bathonian and Bajocian limestones before entering the underlying Toarcian shales. By analogy with deep geological radioactive waste repositories, the results report discrete mineralogical variations of the clays when subjected to temperatures of 100-150°C that are expected in deep storage conditions. Beyond 150°C, significant mineralogical changes may alter the physical and chemical properties of the shales, especially of the clay fraction. Also, the development of structural discontinuities in the so-called thermally disturbed zone might be of importance as these discontinuities might become zones for
330
Fuel and Energy Abstracts
September 2006
preferential fluid circulation. Finally, the study emphasizes the use of Rb-Sr and K-Ar isotopic systems as tracers of local circulating fluids related to low-grade thermal imprints.
06102140 Completion of Belene nuclear power plant: project perspectives Bogdanov, D. International Journal of Nuclear Governance, Economy and Ecology, 2006, 1, (1), 63-81. The development of Belene NPP began with site selection in the 1970s, site characterization i , 1980-1981, and a decision to proceed in 19~1 Construction was suspended for financial reasons in 1991. Now the state authorities have taken steps to continue the project. Despite the lengthy study period and the subsequent legislative changes, the evaluations indicate that Belene is a suitable NPP site. Studies of the Belene site have been completed and the conclusion is that the site is suitable and eligible for licensing for the construction of a NPP. In order to estimate the different options for completion of the project, different aspects of the plant were estimated. The information for different reactors was analysed, and quantitative assessment was performed by ranking the proposed facilities in different aspects of rated power, technology, safety, operation, licensing (compliance to local regulations), etc.
06•02141 Effects of accident management strategy on the severe accident environmental conditions Lee, B. C. et al. Ammls of Nuclear Energy, 2006, 33, (1), 13 21. This paper presents a methodology utilizing an accident management strategy in order to determine accident environmental conditions to be used as inputs to equipment survivability assessments. In the case that there is a well-established accident management strategy for a specific nuclear power plant (NPP), an application of this tool can provide a technical rationale on equipment survivability assessment so that plantspecific and time-dependent accident environmental conditions could be practically and realistically defined in accordance with the equipment and instrumentation required for the accident management strategy or appropriate actions. For this work, three different tools are introduced; probabilistic safety assessment (PSA) outcomes, major accident management strategy actions, and accident environmental stages (AESs). In order to quantitatively investigate an applicability of accident management strategy on equipment survivability, the accident simulation for most likely scenario in Korean standard nuclear power plants (KSNPs) is performed with the MAAP4 code. The accident management guideline (AMG) actions such as the reactor coolant system (RCS) depressurization, water injection into the RCS, the containment pressure and temperature control, and hydrogen concentration control in containment are applied. The effects of these AMG actions on the accident environmental conditions are investigated by comparison to actions from previous normal accident simulation, especially focusing on equipment survivability assessment. As a result, the AMG-involved case shows the higher accident consequences along the accident environmental stages. This implies that plant-specific AMG actions need to be considered in order to determine accident environmental conditions in equipment survivability assessments.
06•02142 Optimisation of the coupling of nuclear reactors and desalination systems in Morocco Tabet, M. et al. International Journal of Nuclear Desalination, 2006, 2, (1), 1 11. This study has been undertaken in the framework of IAEA CRP on 'optimization of the coupling of nuclear reactors and desalination systems in Morocco'. Two sites have been selected to host nuclear desalination plants, and different combinations with nuclear reactors have been investigated. Other combinations with fossil fuel plants have been examined for comparison. The results obtained showed the competitiveness of nuclear energy, which could be a solution to supply the region that will suffer from water shortage. On the other hand, this study could help the decision makers in the management and planning of water, energy resources and supply.
06•02143 The impacts of nuclear facilities on property values and other factors in the surrounding communities Bezdek, R. H. and Wending, R. M. International Journal of Nuclear Governance, Economy and Ecology, 2006, 1, (1), 122 144. This paper addresses the issue of the impact of the siting of nuclear facilities on the adjacent communities. It reviews previous studies on the issue and then empirically examines the impacts of seven major nuclear facilities located throughout the USA on the surrounding communities. The analysis focuses on the effects on local property values, economic growth, tax revenues, public services, community development, jobs and employment, and schools. Using published data, economic and statistical analyses, literature reviews and interviews, it finds that the impacts of these facilities have been largely positive. The findings are placed in perspective, caveats are noted concerning the generalization of the conclusions derived and recommendations for required further research are provided.
06102137 Analysis of loss of flow accident at Pakistan research reactor-1 Bokhari, I. H. and Mahmood, T. Annals of Nuclear Energy, 2005, 32, (18), 1963 1968. The main objective of the reactor safety is to keep the reactor core in a condition, which does not permit any release of radioactivity into the enviromnent. In order to ensure this, the reactor must have sufficient safety margins during all possible operational conditions (normal as well as accidental). To accomplish this, a study has been carried out, for the analysis of loss of flow accident (LOFA), which is one of the probable scenarios among other possible events such as reactivityinduced-accidents, loss of coolant accident, etc. The study has been carried out for Pakistan research reactor, PARR-l, which was initially converted from HEU to LEU fuel. It is a swimming pool type reactor using MTR type fuel. Presently, a new core is proposed to be assembled containing LEU and some of the used (less burnt) HEU fuel elements. The accident is assumed when the reactor is running at a steady-state power level of 9.8 MW. Computer code PARET and standard correlations were employed to compute various parameters. Results predict nucleate boiling in the core but the temperatures would remain far below the fuel clad melting point.
06/02138 Assessment of the WWER-440/V-213 reactor condition Timofeev, B. T. and Karzov, G. P. International Journal of Pressure Vessels and Piping, 2006. 83, (3), 216 226. The current state of materials (steel, welds, anticorrosive cladding metal) of WWER-440/V-213 RPVs has been evaluated with respect to the peculiarities of their manufacturing process and operation for 30 years. The possibility of operating these reactors after the design service life has been assessed considering the degradation of properties due to thermal and radiation embrittlement, as well as damage from cyclic loads. Taking into account that the main results of operating effects were obtained in research laboratories it is necessary first of all to continue the investigations in the commercial reactors. In future, it will be possible to extend the service life of this type of reactors. For example, the positive results have been already obtained for unit No. 3 Kola NPP reactor.
06•02139 Chemical and isotopic characterization of w a t e r rock interactions in shales induced by the intrusion of a basaltic dike: A natural analogue for radioactive waste disposal Techer, I. et al. Applied Geochemistry. 2006, 21, (2), 203 222. Disposal of nuclear waste in deep geological formations is expected to induce thermal fluxes for hundreds of years with maximum temperature reaching about 100-150°C in the nearfield argillaceous environment. The long-term behaviour of clays subjected to such thermal gradients needs to be perfectly understood in safety assessment considerations. In this respect, a Toarcian argillaceous unit thermally disturbed by the intrusion of a 1.1-m wide basaltic dike at the Perthus pass (Herault, France), was studied in detail as a natural analogue. The thermal imprint induced by the dike was evaluated by a mineralogical, chemical and K-Ar study of the <2 ~tm clay fraction of shale samples collected at increasing distance from the basalt. The data suggest that the mineral composition of the shales was not significantly disturbed when the temperature was below 100-150°C. Closer to the dike at 150300°C, changes such as progressive dissolution of chlorite and kaolinite, increased content of the mixed layers illite-smectite with more illite layers, complete decalcification and subsequent increased content of quartz, were found. At the eastern contact with the dike, the mineral and chemical compositions of both the shales and the basalt suggest water-rock interactions subsequent to the intrusion with precipitation of palagonite and renewed but discrete deposition of carbonate. A pencil cleavage developed in the shales during the dike emplacement probably favoured water circulation along the contact. Strontium isotopic data suggest that the fluids of probable meteoric origin, reacted with Bathonian and Bajocian limestones before entering the underlying Toarcian shales. By analogy with deep geological radioactive waste repositories, the results report discrete mineralogical variations of the clays when subjected to temperatures of 100-150°C that are expected in deep storage conditions. Beyond 150°C, significant mineralogical changes may alter the physical and chemical properties of the shales, especially of the clay fraction. Also, the development of structural discontinuities in the so-called thermally disturbed zone might be of importance as these discontinuities might become zones for
330
Fuel and Energy Abstracts
September 2006
preferential fluid circulation. Finally, the study emphasizes the use of Rb-Sr and K-Ar isotopic systems as tracers of local circulating fluids related to low-grade thermal imprints.
06102140 Completion of Belene nuclear power plant: project perspectives Bogdanov, D. International Journal of Nuclear Governance, Economy and Ecology, 2006, 1, (1), 63-81. The development of Belene NPP began with site selection in the 1970s, site characterization i , 1980-1981, and a decision to proceed in 19~1 Construction was suspended for financial reasons in 1991. Now the state authorities have taken steps to continue the project. Despite the lengthy study period and the subsequent legislative changes, the evaluations indicate that Belene is a suitable NPP site. Studies of the Belene site have been completed and the conclusion is that the site is suitable and eligible for licensing for the construction of a NPP. In order to estimate the different options for completion of the project, different aspects of the plant were estimated. The information for different reactors was analysed, and quantitative assessment was performed by ranking the proposed facilities in different aspects of rated power, technology, safety, operation, licensing (compliance to local regulations), etc.
06•02141 Effects of accident management strategy on the severe accident environmental conditions Lee, B. C. et al. Ammls of Nuclear Energy, 2006, 33, (1), 13 21. This paper presents a methodology utilizing an accident management strategy in order to determine accident environmental conditions to be used as inputs to equipment survivability assessments. In the case that there is a well-established accident management strategy for a specific nuclear power plant (NPP), an application of this tool can provide a technical rationale on equipment survivability assessment so that plantspecific and time-dependent accident environmental conditions could be practically and realistically defined in accordance with the equipment and instrumentation required for the accident management strategy or appropriate actions. For this work, three different tools are introduced; probabilistic safety assessment (PSA) outcomes, major accident management strategy actions, and accident environmental stages (AESs). In order to quantitatively investigate an applicability of accident management strategy on equipment survivability, the accident simulation for most likely scenario in Korean standard nuclear power plants (KSNPs) is performed with the MAAP4 code. The accident management guideline (AMG) actions such as the reactor coolant system (RCS) depressurization, water injection into the RCS, the containment pressure and temperature control, and hydrogen concentration control in containment are applied. The effects of these AMG actions on the accident environmental conditions are investigated by comparison to actions from previous normal accident simulation, especially focusing on equipment survivability assessment. As a result, the AMG-involved case shows the higher accident consequences along the accident environmental stages. This implies that plant-specific AMG actions need to be considered in order to determine accident environmental conditions in equipment survivability assessments.
06•02142 Optimisation of the coupling of nuclear reactors and desalination systems in Morocco Tabet, M. et al. International Journal of Nuclear Desalination, 2006, 2, (1), 1 11. This study has been undertaken in the framework of IAEA CRP on 'optimization of the coupling of nuclear reactors and desalination systems in Morocco'. Two sites have been selected to host nuclear desalination plants, and different combinations with nuclear reactors have been investigated. Other combinations with fossil fuel plants have been examined for comparison. The results obtained showed the competitiveness of nuclear energy, which could be a solution to supply the region that will suffer from water shortage. On the other hand, this study could help the decision makers in the management and planning of water, energy resources and supply.
06•02143 The impacts of nuclear facilities on property values and other factors in the surrounding communities Bezdek, R. H. and Wending, R. M. International Journal of Nuclear Governance, Economy and Ecology, 2006, 1, (1), 122 144. This paper addresses the issue of the impact of the siting of nuclear facilities on the adjacent communities. It reviews previous studies on the issue and then empirically examines the impacts of seven major nuclear facilities located throughout the USA on the surrounding communities. The analysis focuses on the effects on local property values, economic growth, tax revenues, public services, community development, jobs and employment, and schools. Using published data, economic and statistical analyses, literature reviews and interviews, it finds that the impacts of these facilities have been largely positive. The findings are placed in perspective, caveats are noted concerning the generalization of the conclusions derived and recommendations for required further research are provided.