• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.24-31
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• 2004

In order to decommission safely nuclear power plant, it is necessary for the procedure of residual radioactivity investigation in site to provide detailed guidance for planning, implementing, and evaluating environmental and facility radiological surveys conducted to demonstrate compliance with a dose or risk-based regulation. This study presents the procedure of residual radioactivity investigation in decommissioning site - Historical Site Assessment, Scoping Survey, characterization Survey, Remedial Action Support Survey, Final Status Survey - on the basis of MARSSIM(Multi-Agency Radiation Survey and Site Investigation Manual) and investigation cases of decommissioned or decommissioning nuclear power plant.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.17-18
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• 2002

Last year, a three-year research program was started in order to establish an external audit system to radiotherapy QA in Japan. It consists of questionnaire surveys, mailed (off-site) dosimetry and visited (on-site) dosimetry at radiotherapy facilities in Japan. The first questionnaire was sent to all Japanese radiotherapy facilities in October 2001, surveying basic QA procedures at each facility. 628 answers were returned with the return rate of 87%. In February 2002, the second questionnaire was sent. Off-site and on-site dosimetry have been tested in several facilities, and will be started soon. We anticipates that this program will gradually grow to a radiotherapy quality control center similar to Radiological Physics Center at MD Anderson Hospital.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.1-8
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• 2017

The U.S. NRC establishes a radiological criteria with regard to restricted or unrestricted use of nuclear plant site after decommissioning in NUREG-1757. According to this, a nuclear plant site can be released in a restricted way or unrestricted way only if a licensee demonstrates that the dose criteria is fulfilled after the site decontamination and remediation. In order to prove compliance with the radiological criteria of site release, LTP(License Termination Plan) must include the site release criteria, site characterization, final survey plan with major radionuclides and DCGL(Derived Concentration Guideline Levels), etc. Based on the decommissioning case of Rancho Seco nuclear power plant in the United States, this paper analyzed a method of setting the DCGL that can be applied to Kori NPP Unit 1 which will be permanently disabled in 2017.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.267-277
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• 2016

For the decommissioning of a nuclear power plant, a site characterization and final status survey require a site-specific suite of radionuclides that could potentially still be present in the site during or after the decontamination processes. The United States Nuclear Regulatory Commission (U.S. NRC) requires a Decommissioning Technical Base Document (DTBD) along with a Site Characterization and Historical Site Assessment (HSA) from the utility for decommissioning to proceed. Both the DTBD and HSA are preliminary components of the Radiological Site Survey investigation process and should be included in the final License Termination Plan (LTP) for site release and reuse consideration from the U.S. NRC and the utility company. This study reviews the United States Nuclear Power Plants (U.S. NPPs) decommissioning cases and is especially focused on the methodologies used for determining a site-specific suite of radionuclides before and during the site characterization and final status surveys. In 2017, Kori-1 will be ready for decommissioning and related preparations are ongoing, this review will help Korea to prepare regulatory guidelines and give technical background for the safe and successful decommissioning of NPPs.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.297-304
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• 2018

U.S. nuclear power plant decommissioning guidelines(MARSSIM and MARLAP) are recommends to use DQOs when planning and conducting site surveys. The DQOs which is constructed in the site survey planning stage provide a way to make the best use of data. It helps we can get the important information and data to make decisions as well. From fifth to seventh steps of DQOs are the process of designing a site survey by using the collected data and information in the previous step to make reasonable and reliable decisions. The gray region that is set up during this process is defined as the range of concentrations where the consequences of type II decision errors are relatively small. The gray region can be set using DCGL and the average concentration of radionuclide in the sample collected at the survey unit. By setting up the gray region, site survey plan can be made most resource-efficient and the consequences on decision errors can be minimized. In this study, we set up the gray region by using the DCGL of Kori-1 which was derived from the previous research. In addition, we proposed a method to assess the concentration of radionuclide in samples for making decisions correctly.

• 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.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3788-3794
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• 2022

The possibility of denuclearization of the Korean Peninsula has been continuously debated, and the initiative participation of the Republic of Korea has necessitated preemptive measures against neighboring countries. In this study, we present a proposal for formulating a site survey plan when the amount of site information provided is insufficient and the accuracy of the information is not guaranteed. Considering a case wherein "a soil sample analysis is used to determine the presence or absence of nuclear activity" in a radiochemical laboratory, which is a typical key facility for denuclearization, the optimal soil sample collection plan is designed based on international guidelines and public information. In the event of denuclearization, a scenario that is not based on the expertise of the sample collector is set, and the data quality objective (DQO) process is applied to ensure reality. Consequently, the primary sample collection points can be derived in consideration of accessibility, and the sample collection scale can be adjusted according to the cost. By applying the DQO process to ensure sample representativeness and reality, reliable and resource-efficient soil sample collection can be achieved in radiochemical laboratories and other denuclearization facilities.

• Journal of Korean Foot and Ankle Society
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• v.25 no.4
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• pp.149-156
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• 2021

Purpose: Given the lack of definite evidence-based guidelines in clinical practice, there may be a wide variation in treatment protocols for osteochondral lesions of the talus (OLT). Based on the Korean Foot and Ankle Society (KFAS) member survey, this study aimed to report the current trends in the management of OLT. Materials and Methods: A web-based questionnaire containing 30 questions was sent to all KFAS members in September 2021. The questions were mainly related to clinical experience and preferences in diagnosis, conservative, and surgical treatments for patients with OLT. Answers with a prevalence of ≥50% of respondents were considered a tendency. Results: Sixty-two (11.3%) of the 550 surgeons queried responded to the survey. The responses to 9 (30.0%) of the total of 30 questions established a tendency. Answers exhibiting a tendency were as follows; additional diagnostic tools except for plain radiograph (magnetic resonance imaging), most common conservative treatment method (oral medication, rest), most important radiological factor in decision making for surgical treatment and method (size of the lesion, ankle instability, loose bodies), most important patient factors in decision making for surgical treatment and method (age, activity or occupation), infrequently requiring posterior arthroscopy (less than 3%), most common revision surgery for failed bone marrow stimulation procedure (osteochondral autograft transplantation [OAT]), not requiring additional procedure for donor site in OAT, the main reason for unsatisfactory result after OAT (persistent pain without radiological abnormality), no generalization of autologous chondrocyte implantation or chondrogenesis using stem cells. Conclusion: This study presents updated information on current trends in the management of OLT in Korea. Both consensus and variations in the approach to patients with OLT were revealed through this survey. Since recent biologic efforts to regenerate cartilage have been unsuccessful, further studies to identify clinical evidence would be needed.

• Journal of Radiation Protection and Research
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• v.44 no.4
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• pp.128-148
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• 2019

Massive environmental monitoring has been conducted continuously since the Fukushima Daiichi Nuclear Power accident in March of 2011 by different monitoring methods that have different features together with migration studies of radiocesium in diverse environments. These results have clarified the characteristics of radiological environments and their temporal change around the Fukushima site. At three months after the accident, multiple radionuclides including radiostrontium and plutonium were detected in many locations; and it was confirmed that radiocesium was most important from the viewpoint of long-term exposure. Radiation levels around the Fukushima site have decreased greatly over time. The decreasing trend was found to change variously according to local conditions. The air dose rates in environments related to human living have decreased faster than expected from radioactive decay by a factor of 2-3 on average; those in pure forest have decreased more closely to physical decay. The main causes of air dose rate reduction were judged to be radioactive decay, movement of radiocesium in vertical and horizontal directions, and decontamination. Land-use categories and human activities have significantly affected the reduction tendency. Difference in the air dose rate reduction trends can be explained qualitatively according to the knowledge obtained in radiocesium migration studies; whereas, the quantitative explanation for individual sites is an important future challenge. The ecological half-lives of air dose rates have been evaluated by several researchers, and a short-term half-life within 1 year was commonly observed in the studies. An empirical model for predicting air dose rate distribution was developed based on statistical analysis of an extensive car-borne survey dataset, which enabled the prediction with confidence intervals. Different types of contamination maps were integrated to better quantify the spatial data. The obtained data were used for extended studies such as for identifying the main reactor that caused the contamination of arbitrary regions and developing standard procedures for environmental measurement and sampling. Annual external exposure doses for residents who intended to return to their homes were estimated as within a few millisieverts. Different forms of environmental data and knowledge have been provided for wide spectrum of people. Diverse aspects of lessons learned from the Fukushima accident, including practical ones, must be passed on to future generations.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.947-955
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• 2023

This study was conducted to investigate the awareness of spent nuclear fuel among residents in nuclear power plant areas and use it as basic data for establishing a disposal facility for high-level radioactive waste. 204 questionnaires collected online were analyzed using SPSS Window Ver 28.0. To verify differences between groups, t-test and one-way ANOVA were performed. And correlation analysis was conducted to confirm the relationship between variables. As a result, first, risk perception regarding nuclear-related accidents showed statistically significant differences depending on gender and educational level. The position on the construction of a permanent disposal facility for spent nuclear fuel showed a statistically significant difference depending on gender, education, and age, and the perception of the importance of each evaluation standard for establishing a spent nuclear fuel management plan showed a statistically significant difference depending on education and age. In terms of trust in information-providing institutions, trust in the National Assembly was found to be the lowest. Second, the results of the correlation analysis between variables showed that local residents are aware that an alternative to the current disposal of spent nuclear fuel is needed, and that financial support for the construction of a permanent disposal facility is needed. Therefore, in order to build a high-level radioactive waste disposal site, it is believed that it is necessary to increase trust in the government, collect opinions from local residents, and provide economic support.