Ho-Dong Kim

Bio: Ho-Dong Kim is an academic researcher. The author has contributed to research in topics: Spent nuclear fuel & Neutron. The author has an hindex of 6, co-authored 16 publications receiving 81 citations.

Radioactive Waste Arisings from Various Fuel Cycle Options

Abstract: This study examines all kinds of waste volumes from various fuel cycle options including DUPIC (Direct Use of Spent PWR Fuel In CANDU) fuel cycle and compares each other The fuel cycle option considered the PWR (Pressurized Water Reactor) once-through cycle, the PHWR (Pressurized Heavy Water Reactor) once-through cycle and the thermal recycling option using an existing PWR with MOX (Mixed Oxide) fuel This study focuses on the radioactive wastes including mill waste, low-level waste and high-level waste generated by all fuel cycle steps, which can be one of the effectiveness measures of waste management All waste disposition volume is estimated in terms of m3/GWe-yr We find in the estimation of radioactive waste volume that PWR-MOX option has the lowest mill tailings and spent fuel volumes among the options, but the option has high volume of ILW and HLW Mill tailings and spent fuel volumes of the DUPIC fuel cycle are lower than those of other competitive options such as PWR-PHWR once-through cycle PW

Development of the ACP safeguards neutron counter for PWR spent fuel rods

Abstract: An advanced neutron multiplicity counter has been developed for measuring spent fuel in the Advanced spent fuel Conditioning Process (ACP) at the Korea Atomic Energy Research Institute (KAERI). The counter uses passive neutron multiplicity counting to measure the 244 Cm content in spent fuel. The input to the ACP process is spent fuel from pressurized water reactors (PWRs), and the high intensity of the gamma-ray exposure from spent fuel requires a careful design of the counter to measure the neutrons without gamma-ray interference. The nuclear safeguards for the ACP facility requires the measurement of the spent fuel input to the process and the Cm/Pu ratio for the plutonium mass accounting. This paper describes the first neutron counter that has been used to measure the neutron multiplicity distribution from spent fuel rods. Using multiple samples of PWR spent fuel rod-cuts, the singles (S), doubles (D), and triples (T) rates of the neutron distribution for the 244 Cm nuclide were measured and calibration curves were produced. MCNPX code simulations were also performed to obtain the three counting rates and to compare them with the measurement results. The neutron source term was evaluated by using the ORIGEN-ARP code. The results showed systematic difference of 21–24% in the calibration graphs between the measured and simulation results. A possible source of the difference is that the burnup codes have a 244 Cm uncertainty greater than ±15% and it would be systematic for all of the calibration samples. The S/D and D/T ratios are almost constant with an increment of the 244 Cm mass, and this indicates that the bias is in the 244 Cm neutron source calculation using the ORIGEN-ARP source code. The graphs of S/D and D/T ratios show excellent agreement between measurement and MCNPX simulation results.

Analysis of Nuclear Proliferation Resistance of DUPIC Fuel Cycle

Abstract: This study compares the proliferation resistance of DUPIC (Direct Use of Spent PWR Fuel in CANDU) fuel cycle with other fuel cycle cases. The other fuel cycles considered in this study are PWR of once-through mode (PWR-OT), PWR of reprocessing mode (PWR-MOX), in which spent PWR fuel is reprocessed and recovered plutonium is used for making MOX (Mixed Oxide), CANDU with once-through mode (CANDU-OT), PWR fuel and CANDU fuel in a oncethrough mode with reactor grid equivalent to DUPIC fuel cycle (PWR-CANDU-OT). This study is focused on intrinsic barriers, especially, radiation field of the diverted material, which could be a significant accessibility barrier, amount of special nuclear material based on 1 GWe-yr that has to be diverted and the quality of the separated fissile material. It is indicated from plutonium analysis of each fuel cycle that the MOX spent fuel is containing the largest plutonium per MTHM but PWR-MOX option based on 1 GWe-yr has the best benefit in total plutonium consumption aspects. The DUPIC option is containing a little higher total plutonium based on 1 GWe-yr than the PWR-MOX case, but the DUPIC option has the lowest fissile plutonium content which could be another measure for proliferation resistance. On the whole, the CANDU-OT option has the largest fissile plutonium as well as total plutonium per GWe-yr, which means negative points in nuclear proliferation resistance aspects. It is indicated from the radiation field analysis that fresh DUPIC fuel could play an important radiation barrier role, more than even CANDU spent fuels. In conclusion, due to those inherent features, the DUPIC fuel cycle could include technical characteristics that comply naturally with the Spent Fuel Standard, at all steps along the DUPIC linkage between PWR and CANDU.

Advantages of Irradiated DUPIC Fuels from the Perspective of Environmental Impact

Abstract: This study compares some properties of irradiated Direct Use of Spent Pressurized Water Reactor (PWR) Fuel In Canada Deuterium Uranium reactor (CANDU) (DUPIC ) fuels with properties of other fuel cycles The properties include the radiotoxicity, decay heat, activity, and actinide content embedded in various spent fuels or high-level wastes, which could be measures of the effectiveness of waste management From radiotoxicity analysis of fuel cycles, the toxicity of the DUPIC option based on 1 GW(electric)yr is much smaller than those of other fuel cycle options such as the PWR once-through mode, mixed oxide fuel recycling mode, and CANDU once-through mode The analysis shows that the value is just about half the order of magnitude of other fuel cycles until decayed to a level below the toxicity of initial ore This means that the DUPIC option could have an indirect benefit on the environmental effects of long-term spent-fuel disposal From total activity analysis of various fuel cycle options, the activity per metric ton heavy metal of spent fuel is the lowest in natural uranium CANDU fuel, but in the case of activity based on 1 GW(electric)yr, the DUPIC option has the smallest activity In the meanwhile, from the activity analysismore » of {sup 99}Tc and {sup 237}Np, which are important to the long-term transport in geologic media, the DUPIC option was being contained in only about half of those other options In conclusion, compared to other fuel cycle cases, the irradiated DUPIC fuels would have good properties from the perspective of environmental effects« less

The International Atomic Energy Agency

Abstract: Plant roots perform a myriad of functions right from the anchorage of plants to storage of reserve food material for the adverse weather. Roots forage around the soil for acquisition of ions and water and continually develop new branches. However, very little is known about the molecular mechanisms regulating root development and differentiation. We have endeavoured to decipher the genetic regulation of root formation in tomato by screening mutants defective in root development. We have isolated several mutants with altered morphology of roots. These mutants have been characterized for their phenotypes throughout the life cycle. In this report we show that for few of the mutants the vigour of plant is directly related to modification in the root structure. The potential utility of these mutants in understanding root development and also improving yield of tomato is discussed.

Evaluation Methodology for Proliferation Resistance and Physical Protection of Generation IV Nuclear Energy Systems: An Overview.

Abstract: This paper provides an overview of the methodology approach developed by the Generation IV International Forum Expert Group on Proliferation Resistance & Physical Protection for evaluation of Proliferation Resistance and Physical Protection robustness of Generation IV nuclear energy systems options. The methodology considers a set of alternative systems and evaluates their resistance or robustness to a collection of potential threats. For the challenges considered, the response of the system to these challenges is assessed and expressed in terms of outcomes. The challenges to the system are given by the threats posed by potential proliferant States and sub-national adversaries on the nuclear systems. The characteristics of the Generation IV systems, both technical and institutional, are used to evaluate their response to the threats and determine their resistance against the proliferation threats and robustness against sabotage and theft threats. System response encompasses three main elements: (1) System Element Identification. The nuclear energy system is decomposed into smaller elements (subsystems) at a level amenable to further analysis. (2) Target Identification and Categorization. A systematic process is used to identify and select representative targets for different categories of pathways, within each system element, that actors (proliferant States or adversaries) might choose to use ormore » attack. (3) Pathway Identification and Refinement. Pathways are defined as potential sequences of events and actions followed by the proliferant State or adversary to achieve its objectives (proliferation, theft or sabotage). For each target, individual pathway segments are developed through a systematic process, analyzed at a high level, and screened where possible. Segments are connected into full pathways and analyzed in detail. The outcomes of the system response are expressed in terms of PR&PP measures. Measures are high-level characteristics of a pathway that include information important to the evaluation methodology users and to the decisions of a proliferant State or adversary. They are first evaluated for segments and then aggregated for complete pathways. Results are aggregated as appropriate to permit pathway comparisons and system assessment. The paper highlights the current achievements in the development of the Proliferation Resistance and Physical Protection Evaluation Methodology. The way forward is also briefly presented together with some conclusions.« less

Proliferation Resistance Assessment Methodology for Nuclear Fuel Cycles

Abstract: A methodology, based on the multiattribute utility analysis, for the assessment of diverse fuel cycles for proliferation resistance was developed. This methodology is intended to allow for the assessment of the effectiveness of safeguards implementation at facilities within a large-scale fuel cycle and allow for the ability to choose technologies based in part on their effectiveness to deter the proliferation of nuclear materials. Fuel cycle facilities under consideration include nuclear reactors, reprocessing facilities, fuel storage facilities, enrichment plants, fuel fabrication plants, uranium conversion plants, and uranium mining and milling operations. The method uses a series of attributes (for example, Department of Energy attractiveness level, weight fraction of even Pu isotopes, measurement uncertainty, etc.) to determine a proliferation resistance measure for each step in a process flow sheet. Each of the attributes has a weighting that determines its importance in the overall assessment. Each attribute also has an associated utility function derived from both expert knowledge and physical characteristics that relates changes in the value of the attribute to its overall effect on the proliferation resistance measure. A method for aggregating proliferation resistance values for each process in a flow sheet into an overall nuclear security measure for the complete-cycle was also developed. This method is focused on preventing host nation diversion; however, a similar technique could be used to analyze the risk due to theft by an insider or outsider. This methodology has been applied successfully for example fuel cycles to demonstrate its viability as an assessment methodology and its capability in discriminating diverse fuel cycle options.

Advanced Safeguards Approaches for New Reprocessing Facilities

Abstract: U.S. efforts to promote the international expansion of nuclear energy through the Global Nuclear Energy Partnership (GNEP) will result in a dramatic expansion of nuclear fuel cycle facilities in the United States. New demonstration facilities, such as the Advanced Fuel Cycle Facility (AFCF), the Advanced Burner Reactor (ABR), and the Consolidated Fuel Treatment Center (CFTC) will use advanced nuclear and chemical process technologies that must incorporate increased proliferation resistance to enhance nuclear safeguards. The ASA-100 Project, “Advanced Safeguards Approaches for New Nuclear Fuel Cycle Facilities,” commissioned by the NA-243 Office of NNSA, has been tasked with reviewing and developing advanced safeguards approaches for these demonstration facilities. Because one goal of GNEP is developing and sharing proliferation-resistant nuclear technology and services with partner nations, the safeguards approaches considered are consistent with international safeguards as currently implemented by the International Atomic Energy Agency (IAEA). This first report reviews possible safeguards approaches for the new fuel reprocessing processes to be deployed at the AFCF and CFTC facilities. Similar analyses addressing the ABR and transuranic (TRU) fuel fabrication lines at AFCF and CFTC will be presented in subsequent reports.