• Journal of Radiation Protection and Research
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• v.33 no.4
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• pp.183-196
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• 2008

The internal dose by food consumption mostly accounts for radiological dose of public around nuclear power plants (NPPs). But, food consumption rates applied to off-site dose calculation in Korea which are the result of field investigation around Kori NPP by the KAERI (Korea Atomic Energy Research Institute) in 1988, are not able to reflect the latest dietary characteristics of Korean. The food consumption rates to be used for radiological dose assessment in Korea are based on the maximum individual of US NRC (Nuclear Regulatory Commssion) Regulatory Guide 1.109. However, the representative individual of the critical group is considered in the recent ICRP (International Commission on Radiological Protection) recommendation and European nations' practice. Therefore, the study on the re-establishment of the food consumption rates for individual around nuclear power plant sites in Korea was carried out to reflect on the recent change of the Korean dietary characteristics and to apply the representative individual of critical group to domestic regulations. The Ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. The statistical data such as mean, standard deviation, various percentile values about food consumption rates to be used for the representative individual of the critical group were analyzed by using the raw data of the national food consumption survey in $2001{\sim}2002$. Also, the food consumption rates for maximum individual are re-estimated.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.5
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• pp.389-397
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• 1998

For an effective and efficient management of large amounts of preservice/inservice inspection(PSI/ISI) data in nuclear power plants, an intellegent Windows 95-based data management program was developed. This program enables the prompt extraction of previously conducted PSI/ISI conditions and results so that the time-consuming data management, painstaking data processing and analysis in the past are avoided. The program extracts, and the associated remedies. Furthermore, additional inspection data and comments can be easily added or deleted for subsequent PSI/ISI operation. Although the initial version of the program was applied to Kori nuclear power plant, this program can be equally applied to other nuclear power plant. And also this program can be used to offer the fundamental data for application of evaluation data related to fracture mechanics analysis(FMA), probabilistic reliability assessment(PRA) of PSI/ISI results, performance demonstration initiative(PDI) and risk-informed ISI based on probability of detection(POD) information of ultrasonic examination. Besides, the program can be further developed as a unique PSI/ISI data management expert system that can be apart of PSI/ISI data management expert system that can be a part of PSI/ISI Total Support System(TSS) for Korean nuclear power plants.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.945-953
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• 2006

The researchers in the field of cognitive science and learning science suggest that the teaching activity induces the elaborative and meaningful learning. Actually, lots of research findings have shown the beneficial effect of learning by teaching such as peer tutoring. But peer tutoring has some limitations in the practical learning context. To overcome some limitations, the new concept of "learning by teaching" through the agent called Teachable Agent. The teachable agent is a modified version of traditional intelligent tutoring system that assigns a role of tutor to teach the agent. The teachable agent monitors individual difference and provides a student with a chance for deep learning and motivation to learn by allowing them to play an active role in the process of learning. That is, The teaching activity induces the elaborative and meaningful learning. This study compared the effects of our teachable agent, KORI, and peer tutoring on the cognition and motivation. The field experiment was conducted to examine whether learning by teaching the teachable agent would be more effective than peer tutoring and reading condition. In the experiment, all participants took 30 minutes lesson on rock and rock cycle together to acquire the base knowledge in the domain. After the lesson, participants were randomly assigned to one of the three experimental conditions; reading condition, peer tutoring condition, and teachable agent condition. Next, participants of each condition moved into separated place and performed their own learning activity. After finishing all of the learning activities in each condition, all participants were instructed to rate the interestingness using a 5-point scale on their own learning activity and leaning material, and were given the comprehension test. The results indicated that the teachable agent condition and the peer tutoring condition showed more interests in the learning than the reading condition. It is suggested that teachable agent has more advantages in overcoming the several practical limitations of peer tutoring such as restrictions in time and place, tutor's cognitive burden, unnecessary interaction during peer tutoring. The applicability and prospects of the teachable agent as an efficient substitute for peer tutoring and traditional intelligent tutoring system were also discussed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.3
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• pp.201-209
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• 2015

Currently, 23 nuclear power plants are in operation at Kori, Uljin, Younggwang and Wolsong site and a reference deep geological disposal system has been developed for the spent fuels generated by them. The reference spent fuel for this disposal system has 4.5wt% of initial enrichment, 55 GWd/MtU of burn-up, and 40 years of cooling time. In this paper, to improve disposal efficiency and economic feasibility, the characteristics of spent fuels from nuclear power plants, such as type and burn-up, were reviewed. A disposal canister concept for shorter length and relatively lower burn-up spent fuels than the reference spent fuels was developed. Based on this canister concept, thermal analyses were carried out and a deep geological disposal concept was proposed. Measures of disposal efficiency such as unit disposal area and disposal density were compared between this disposal system and the reference disposal system. Also, economic feasibility, such as the volume reduction of copper, cast iron, and bentonite, was analyzed and the results of these analyses showed that the disposal system proposed in this paper has an efficiency of at least 20%. These results could be used for establishing spent fuel management policy and designing practical disposal systems for spent fuels.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.291-303
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• 2020

The Kori-Unit 1 nuclear power plant, which is scheduled to be decommissioned after permanent shutdown, is expected to generate large amounts of various types of radioactive waste during the decommissioning process. Among these, nuclear reactors and internal structures have high levels of radioactivity and the dismantled structure must have the proper size and weight on the primary side. During decommissioning, it is important to prepare an appropriate and efficient disposal method through analysis of the disposal status and the legal restrictions on wastes generated from the reactors and internal structures. Nuclear reactors and internal structures generate radioactive wastes of various levels, such as medium, very low, and clearance. A radiation evaluation indicates that wastes in the clearance level are generated in the reactor head and upper head insulation. In this study, a clearance waste safety evaluation was conducted using the RESRAD-RECYCLE code, which is a safety evaluation code, based on the activation evaluation results for the clearance level wastes. The clearance scenario for the target radioactive waste was selected and the maximum individual and collective exposure doses at the time of clearance were calculated to determine whether the clearance criteria limit prescribed by the Nuclear Safety Act was satisfied. The evaluation results indicated that the doses were significantly low, and the clearance criteria were satisfied. Based on the safety assessment results, an appropriate metal recycle and disposal method were suggested for clearance, which are the subject of the deregulation of internal structures of nuclear power plant.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.115-122
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• 2018

In this paper, the feasibility of recycling concrete waste as a method to reduce final disposal amount of wastes generated through decommissioning of nuclear power plant has been analyzed based on experimental results of existing literature. When recycled concrete waste was used as recycled aggregate, it was investigated through literature that the concrete strength decreased by 30~40% depending on the mixing ratio. It was also investigated that concrete with recycled aggregate can be used as a structural material when the quality of recycled aggregate is well managed since no significant problem was found. When recycled cement produced from concrete waste was used, the strength of concrete or mortar decreased considerably as the recycled cement content increased. Therefore, it can be concluded that concrete or mortar with recycled cement can be used as a filling material for final disposal of large radioactive waste rather than for structural use. This paper is expected to be useful for reduction on disposal volume and decommissioning cost for nuclear power plants such as Kori 1.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.165-172
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• 2003

Humic acids present in the soils at the vicinity of domestic atomic power plants(NPPs), located in Yeongkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area were isolated, and characterized using elemental analysis and UV/Vis, IR, CPMAS $^{13}C$ NMR spectroscopic methods. The characteristics were compared with one another and with commercial humic acid (Aldrich Co.). Molecular size distributions of the humic acids were determined using a stirred cell ultrafiltration technique. The results of elemental analysis showed that soil humic acid from UJ contains higher oxygen content than humic acids from KR and KS (O/C ratios: 0.51 (UJHA) us. 0.45(KRHA), 0.43(KSHA)). The molecular size distribution revealed that the soil humic acids of UJ and YK contained a higher percentage of larger molecules of > 30,000 daltons, compared to those of KR and KS. The spectral features obtained from UV/vis., IR and CPMAS $^{13}C$ NMR showed that the aromatic character and oxygen containing functional groups in the humic acids from UJ and YK were relatively higher than those of KR and KS. These results indicate that the soil humic acids from UJ and YK were in a higher degree of humification, which may suggest higher affinity of the humic acids with radionuclides released in the soil environments.

• Journal of Radiation Protection and Research
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• v.18 no.1
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• pp.9-24
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• 1993

The time-dependent radioecological model applicable to Korean environment has been developed in order to assess the radiological consequences following the short-term deposition of radionuclides in an accident of nuclear power plant. Time-dependent radioactivity concentrations in foodstuffs can be estimated by the model called 'KORFOOD' as well as time-dependent and time-integrated ingestion doses. Three kinds of critical radionuclides and thirteen kinds of foodstuffs were considered in this model. Dynamic variation of radioactivities were simulated by considering several effects such as deposition, weathering and washout, resuspension, root uptake, translocation, leaching, senescence, intake and excretion of soil by animals, intake and excretion of feedstuffs by animals, etc. The input data to the KORFOOD are the time of the year when the deposition occurs, the kinds of radionuclides and foodstuffs for estimation. The time-dependent specific activities in rice and the ingestion doses due to the consumption of all considered foodstuffs were calculated with deposition time using agricultural data-base in Kori region. In order to validate results of KORFOOD, the calculated results were compared with those by a leading German model, ECOSYS-87. The comparison of results shows good agreements within a factor of ten.

• Environmental and Resource Economics Review
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• v.27 no.2
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• pp.261-286
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• 2018

This paper evaluated the economic feasibility of the life extension of Kori unit 1 and Wolsong unit 1 according to the types of the nuclear power plants (NPPs) and the life extension period comparing to the levelized costs of energy (LCOE) of the new NPPs, coal-fired plants (CFPs), and combined cycle gas turbine (CCGTs) which proposed in the $7^{th}$ Basic Plan for Electricity Supply and Demand. The economic feasibility of the life extension of NPPs using LCOE method is affected by the types of NPPs, lifetime extension periods, discount rate, and capacity factor. According to the analysis results, the pressurized light water reactor (PWR) is more economical than the pressurized heavy water reactor (PHWR). Comparing the economical efficiency between the life extension of NPPs and other alternatives, the operation of the PWR for 20 years is more economical than the one of new NPPs and CFPs. However, 20 years of life extension of PHWR is more economical than the CCGTs, but less economical than new NPPs and CFPs. In summary, the 20 years of life extension of the NPPs seems to be more, especially for the PWR, which is more cost effective than other generation alternatives. Therefore, the government policy of the life extension of NPPs need to be a selective approach that simultaneously considers both safety and economics rather than closing all NPPs.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.25-31
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• 2009

An analytical method of $^{99}Tc$ concentration in soil was set up and discussed considering the $^{99}Tc$ concentration in Korean soil measured with its analytical method. A selective TEVA resin was used to separate and purify the $^{99}Tc$ in the soil sample. $^{99m}Tc$ from a commercial $^{99}Mo/^{99m}Tc$ generator was used as a yield tracer for the chemical separation of $^{99}Tc$ and its problem when using $^{99m}Tc$ as a tracer was discussed. The chemical recovery yield of $^{99}Tc$ was above 70%. The optimum conditions of inductively coupled plasma mass spectrometry system(ICP-MS) were set up to determine the $^{99}Tc$ after the separation process. The minimum detectable activity(MDA) was 15 mBq/kg-dry in this analytical procedure. The $^{99}Tc$ concentration in soils of Jeju and Kori were measured in the rage of 33.73-89.16 mBq/kg-dry. Those values were less than those reported in other countries and seemed to be originated from atmospheric fallout.