The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
Tae Ho Woo - One of the best experts on this subject based on the ideXlab platform.
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Analytic study for physical protection system (PPS) in Nuclear power plants (NPPs)
Nuclear Engineering and Design, 2013Co-Authors: Tae Ho WooAbstract:Abstract The Nuclear Safeguard is analyzed in the aspect of the physical protection system (PPS) in Nuclear power plants (NPPs). The PPS is reviewed and its related terror scenarios are investigated. The PPS is developed using analytical methods. In the terror scenarios, there are 8 possible cases for the terror attacks to the NPPs. Then, the likelihood of terror is classified by the general terror incidents. The consequence of terror is classified by Design Basis Threat (DBT) of the International Atomic Energy Agency (IAEA) scale. The physical protection method is suggested by defense-in-depth constraints and severe accident countermeasures. Finally, the advanced PPS is constructed, which could be used for the preparation for the possible terror attacks in the NPPs.
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Nuclear Safeguard assessment in Nuclear power plants npps using loss function with modified random numbers
Annals of Nuclear Energy, 2012Co-Authors: Tae Ho WooAbstract:Abstract The energy production in Nuclear power plants (NPPs) is investigated for the Safeguard risk management using economic factors. The economic loss function is used for the life quality in the social and natural objects. For the basic event elements, the game theory is applied for the basic elements of the incidents in non-secure situations. The Safeguard Factor (SF) is introduced for the quantifications of simulation. The results are shown by the standard productivity comparisons with the designed power operations, which is obtained as the range of secure life extension in 2000 MWe is between 0.0000 and 9.1985 and the range in 600 MWe is between 0.0000 and 2.7600. So, the highest value in the range of secure power operation increases about 3.33 times higher than that of the interested power operation in this study, which means the Safeguard assessment is quantified by the power rate in the life extension of the NPPs. The Nuclear Safeguard Protocol (NSP) is constructed for the safe operation successfully.
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Nuclear Safeguard management of operation security in Nuclear power plants
2012Co-Authors: Tae Ho WooAbstract:Safeguard modeling is developed for the successful operations in the Nuclear power plants (NPPs). The characteristics of the secure operation in NPPs are investigated using the network effect method which is quantified by the Monte-Carlo algorithm. Fundamentally, it is impossible to expect the time of terror incident exactly. So, the random sampling for the event frequency is a reasonable method including the characteristics of network effect method incorporated with the zero-sum quantification. The performance of operation with Safeguard is the major concern of the study. There are three kinds of considerations as the neutronics, thermo-hydraulics, and Safeguard properties which are organized as an aspect of Safeguard considerations. The result, therefore, can give the stability of the operations when the power is decided. The maximum value of secure operation is the 12.0 in third month and the minimum value is 1.0 in 18th and 54th month in 10 years. So, the stability of the secure power operation increases 12 times higher than the lowest value in this study. This means the secure operation is changeable in the designed NPPs and the dynamical situation of the secure operation is shown to the operator.
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life extension assessment for Safeguard in Nuclear power plants npps using a production function
2012Co-Authors: Tae Ho WooAbstract:Life extension is investigated as a Safeguard assessment for the stability on operation of the Nuclear power plants (NPPs). The Cobb-Douglas function, one of production function, is modified for the Nuclear Safeguard in NPPs, which was developed for the life quality for the social and natural objects. Nuclear Safeguard estimator function (NSEF) is developed for the application in NPPs. The cases of NPPs are compared each other in the aspect of the secure performance. The results are obtained by the standard productivity comparisons with the designed power operations. The range of secure life extension is between 1.008 and 5.353 in 2,000 MWe and the range is between 0.302 and 0.994 in 600 MWe. So, the successfulness of the power operation increases about 5 times higher than the interested power in this study, which means the Safeguard assessment has performed in the life extension of the NPPs. The technology assessment (TA) is suggested for the safe operation which is an advanced method comparing conventional probabilistic safety assessment (PSA).
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dynamical Nuclear Safeguard investigations in Nuclear materials using analytic pair values
Annals of Nuclear Energy, 2011Co-Authors: Tae Ho WooAbstract:Abstract The operation of Nuclear power plants (NPPs) has been investigated from the view point of Safeguard assessment. The risk of terrorist attack on NPPs is one of the critical points in the secure plant operations. The basic event of the related incidents is quantified by the random sampling using a Monte-Carlo method. The Analytic Hierarchy Process (AHP) is developed leading to the maximum pair values with multiplications which are decided by reactor characteristics. The matrix form analysis is compared with five NPP types of interest. Using a life cycle of 60 years, the range of the secure operation is between 0.020628 and 0.0212986, as relative numbers. This means the highest value in the range of secure power operation is about 1.043 times larger than the lowest one in this study. The consistency has the highest consistent values in the 24th and 54th years, as represented by C . I . (Consistency Index) and C . R . (Consistency Ratio). Finally, a Nuclear Safeguard protocol (NSP) is successfully constructed for the safe operation.
Ylva Ranebo - One of the best experts on this subject based on the ideXlab platform.
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improved isotopic sims measurements of uranium particles for Nuclear Safeguard purposes
Journal of Analytical Atomic Spectrometry, 2009Co-Authors: Ylva Ranebo, P M L Hedberg, Martin J Whitehouse, K Ingeneri, S LittmannAbstract:The isotopic analysis of particles containing sub-pg to pg levels of uranium, released from Nuclear material handling, has been proven as an efficient tool for international Safeguard purposes. Precise and accurate measurement of both enrichment and the minor isotopes is, however, a challenging analytical task due to the low levels of material. One of the mainstay techniques for particle measurement is Secondary Ion Mass Spectrometry (SIMS), this study evaluates the analytical benefit of an alternative in the form of large geometry SIMS (LG-SIMS), which combines high transmission with high mass resolution. We report here that LG-SIMS instruments provide a significantly better measurement quality than the small geometry SIMS as almost all isobaric background interferences are removed at a high useful ion yield. Useful yield measurements, performed on uranium oxide particles with calibrated uranium content, showed an overall useful yield of 1.2% for the LG-SIMS at a mass resolution of 3000. These improvements were then demonstrated by comparing results from actual Nuclear inspection samples measured on both instruments. Additional benefits include an increased ability to detect particles of interest in a dust matrix while simultaneously reducing the time of sample analysis. An evaluation on the performance of LG-SIMS compared to Thermal Ion Mass Spectrometry (TIMS) is also presented. This evaluation shows that LG-SIMS has an advantage due to its high ion yield but with a limitation in the detection limit of 236U at higher enrichments due to the necessity for a hydrogen correction.
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physical characterization of actinide particles a study on novel techniques for radiological and Nuclear Safeguard investigations
2009Co-Authors: Ylva RaneboAbstract:This thesis presents a study of advanced analytical techniques, for the characterization of actinide particles originating from the non-peaceful use of Nuclear technology and from international inspections of the Nuclear fuel cycle associated with non-proliferation agreements. The thesis is based on five papers, which will be referred to by Paper I-V in the text. Individual particle analysis has several advantages over bulk analysis as it can give detailed information on elemental surface and internal compositions, elemental distributions, and compositional information. This information is valuable in tracing the source of the material, and in modelling and predicting the transport of radionuclides in the environment, for instance, in a release scenario. In bulk sample analysis, these characteristics are largely masked. The specific objectives of this work, which was aimed at improving the techniques used in actinide particle analysis, were: 1) the analysis of microscopic materials from Nuclear weapons tests and an accidental release involving Nuclear weapons (Papers I and II) and materials from Nuclear inspection samples (Paper III) in order to obtain elemental and isotopic fingerprints. Single-particle analysis were performed using techniques such as secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM) to characterize the particles, regarding elemental, isotopic, size and morphology structures, and fundamental limitations were identified; 2) the optimization of SIMS analysis of uranium particles by tuning the instrument to obtain the highest obtainable efficiency (Paper III); 3) the investigation of large-geometry SIMS applied to inspection samples to allow isotopic analysis of particles that is not possible with conventional SIMS (Paper III); 4) the production and characterization of new particle materials suitable for calibration purposes (Papers IV and V); and 5) the application of the calibration material produced for the evaluation of SIMS and SEM (Papers III and V). (Less)
M Betti - One of the best experts on this subject based on the ideXlab platform.
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production and characterization of monodisperse plutonium uranium and mixed uranium plutonium particles for Nuclear Safeguard applications
Analytical Chemistry, 2010Co-Authors: Y Ranebo, N Niagolova, N Erdmann, M Eriksson, G Tamborini, M BettiAbstract:In Safeguards work under the Non-Proliferation Treaty, the isotopic analysis of uranium and plutonium micro particles has strengthened the means for detecting undeclared Nuclear activities. In order to assure accuracy and precision in the analytical methodologies used, the instrumental techniques need to be calibrated. The objective of this study was to produce and characterize particles consisting of U, Pu and mixed U–Pu, suitable for such reliability verifications. A TSI vibrating orifice aerosol generator in connection with a furnace system was used to produce micrometer sized, monodispersed particles from reference U and Pu materials in solutions. The particle masses (in the range of 3-6 pg between batches) and sizes (~1.5 μm) were controlled by the experimental conditions and the parameters for the aerosol generator. Size distributions were obtained from scanning electron microscopy, and energy-dispersive X-ray analysis confirmed that the particle composition agreed with the starting material used. A secondary ion mass spectrometer (SIMS) was used to characterize the isotopic composition of the particles. Isobaric and polyatomic interference in the SIMS spectra was identified. In order to obtain accurate estimates of the interference, a batch of Pu particles were produced of mainly 242Pu. These were used for SIMS analysis to characterize the behavior of Pu hydride and to determine the SIMS useful yields of U and Pu. It was found that Pu had a higher propensity to form the hydride than U. Useful yields were determined at a mass resolution of 450 for U–Pu particles: (1.71 ± 0.15) % for Pu and (0.72 ± 0.06) % for U, and for Pu particles: (1.65 ± 0.14) % for Pu. This gave a relative sensitivity factor between U and Pu of 2.4 ± 0.2. (Less)
S Littmann - One of the best experts on this subject based on the ideXlab platform.
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improved isotopic sims measurements of uranium particles for Nuclear Safeguard purposes
Journal of Analytical Atomic Spectrometry, 2009Co-Authors: Ylva Ranebo, P M L Hedberg, Martin J Whitehouse, K Ingeneri, S LittmannAbstract:The isotopic analysis of particles containing sub-pg to pg levels of uranium, released from Nuclear material handling, has been proven as an efficient tool for international Safeguard purposes. Precise and accurate measurement of both enrichment and the minor isotopes is, however, a challenging analytical task due to the low levels of material. One of the mainstay techniques for particle measurement is Secondary Ion Mass Spectrometry (SIMS), this study evaluates the analytical benefit of an alternative in the form of large geometry SIMS (LG-SIMS), which combines high transmission with high mass resolution. We report here that LG-SIMS instruments provide a significantly better measurement quality than the small geometry SIMS as almost all isobaric background interferences are removed at a high useful ion yield. Useful yield measurements, performed on uranium oxide particles with calibrated uranium content, showed an overall useful yield of 1.2% for the LG-SIMS at a mass resolution of 3000. These improvements were then demonstrated by comparing results from actual Nuclear inspection samples measured on both instruments. Additional benefits include an increased ability to detect particles of interest in a dust matrix while simultaneously reducing the time of sample analysis. An evaluation on the performance of LG-SIMS compared to Thermal Ion Mass Spectrometry (TIMS) is also presented. This evaluation shows that LG-SIMS has an advantage due to its high ion yield but with a limitation in the detection limit of 236U at higher enrichments due to the necessity for a hydrogen correction.
Y Ranebo - One of the best experts on this subject based on the ideXlab platform.
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production and characterization of monodisperse plutonium uranium and mixed uranium plutonium particles for Nuclear Safeguard applications
Analytical Chemistry, 2010Co-Authors: Y Ranebo, N Niagolova, N Erdmann, M Eriksson, G Tamborini, M BettiAbstract:In Safeguards work under the Non-Proliferation Treaty, the isotopic analysis of uranium and plutonium micro particles has strengthened the means for detecting undeclared Nuclear activities. In order to assure accuracy and precision in the analytical methodologies used, the instrumental techniques need to be calibrated. The objective of this study was to produce and characterize particles consisting of U, Pu and mixed U–Pu, suitable for such reliability verifications. A TSI vibrating orifice aerosol generator in connection with a furnace system was used to produce micrometer sized, monodispersed particles from reference U and Pu materials in solutions. The particle masses (in the range of 3-6 pg between batches) and sizes (~1.5 μm) were controlled by the experimental conditions and the parameters for the aerosol generator. Size distributions were obtained from scanning electron microscopy, and energy-dispersive X-ray analysis confirmed that the particle composition agreed with the starting material used. A secondary ion mass spectrometer (SIMS) was used to characterize the isotopic composition of the particles. Isobaric and polyatomic interference in the SIMS spectra was identified. In order to obtain accurate estimates of the interference, a batch of Pu particles were produced of mainly 242Pu. These were used for SIMS analysis to characterize the behavior of Pu hydride and to determine the SIMS useful yields of U and Pu. It was found that Pu had a higher propensity to form the hydride than U. Useful yields were determined at a mass resolution of 450 for U–Pu particles: (1.71 ± 0.15) % for Pu and (0.72 ± 0.06) % for U, and for Pu particles: (1.65 ± 0.14) % for Pu. This gave a relative sensitivity factor between U and Pu of 2.4 ± 0.2. (Less)
