• Journal of the Korean Society of Radiology
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• v.9 no.5
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• pp.269-277
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• 2015

In recent years, concern about the decommissioning of nuclear power plants has been growing according to the nuclear power plants aging. Although site reuse is one of the most important issues in doing decommissioning of nuclear power plants in view of the internal affairs, there is currently no specific standard of the site release criteria for site reuse in the Republic of Korea. In this study, we analyzed the international safety standards for the site release(IAEA's Safety Guide No. WS-G-5.1) and the present domestic condition. Also, we studied the site release criteria and real life examples about advanced countries such as United states and Europe, which already have experience of decommissioning or site release. As a results of the study, we suggested proper standards and future consideration to establish site release criteria. This will be used for preliminary data for establishing the domestic site release criteria after the decommissioning of nuclear power plants.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1098-1108
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• 2019

Korea's first commercial nuclear power plant at Kori site was permanently shut down in 2017 and is currently in transition stage. Preparatory activities for decommissioning such as historical site assessment, characterization, and dismantling design are being actively carried out for successful D&D (Dismantling and Decontamination) at Kori site. The ultimate goal of decommissioning will be to ensure the safety of workers and residents that may arise during the decommissioning of nuclear facilities and, thereby finally returning the site to its original status in accordance with the release criteria. Upon completion of decommissioning, the resident's safety at a site released will be assessed from the evaluation of dose caused by radionuclides expected to be present or detected at the site. Although the U.S. commercial nuclear power plants with decommissioning experience use different site release criteria, most of them are 0.25 mSv/y. In Korea, both the unrestricted and restricted release criteria have been set to 0.1 mSv/y by the Nuclear Safety and Security Commission. However, since the dose is difficult to measure, measurable concentration guideline levels for residual radionuclides that result in dose equivalent to the site release criteria should be derived. For this derivation, site reuse scenario, selection of potential radionuclides, and systematic methodology should be developed in planning stage of Kori site decommissioning. In this paper, for calculation of a preliminary site-specific Derived Concentration Guideline Levels (DCGLs) for the Nuclear Power Plant site, a novel approach has been developed which can fully reflect practical reuse plans of the Kori site by taking into account multiple site reuse scenarios sequentially, thereby striking a remarkable distinction with conventional approaches which considers only a single site scenario.

• 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.9 no.2
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• pp.107-111
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• 2011

The release of a site and building from regulatory control is the final stage of the decommissioning process. The MARSSIM (Multi-Agency Radiation Survey and Site Investigation Manual) provides overall framework for conducting data collection for a final status survey to demonstrate compliance with site closure requirements. The KAERI carried out establishing a final status survey by using the guidance provided in the MARSSIM for of a site and building of the Korea Research Reactor. The release criteria for a site and building were set up based on these results of the site specific release levels which were calculated by using RESRAD and RESRAD-Build codes. The survey design for a site and building was classified by using the survey dataset and potential contamination. The number of samples in each survey unit was calculated by through a statistical test using the collected data from a scoping and characterization survey. The results of the final status survey were satisfied the release criteria based on an evaluation of the measured data.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.745-754
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• 2012

The correlations between Large Early Release Frequency (LERF) and Early Fatality need to be investigated for risk-informed application and regulation. In Regulatory Guide (RG) -1.174, while there are decision-making criteria using the measures of Core Damage Frequency (CDF) and LERF, there are no specific criteria on LERF. Since there are both huge uncertainties and large costs needed in off-site consequence calculation, a LERF assessment methodology needs to be developed, and its correlation factor needs to be identified, for risk-informed decision-making. A new method for estimating off-site consequence has been presented and performed for assessing health effects caused by radioisotopes released from severe accidents of nuclear power plants in this study. The MACCS2 code is used for validating the source term quantitatively regarding health effects, depending on the release characteristics of radioisotopes during severe accidents. This study developed a method for identifying correlations between LERF and Early Fatality and validates the results of the model using the MACCS2 code. The results of this study may contribute to defining LERF and finding a measure for risk-informed regulations and risk-informed decision-making.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.314-319
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• 2012

Itching is one of the major diagnostic criteria of atopic dermatitis (AD) and one of its most troublesome symptoms that provokes the desire to scratch. Effective control of itching is believed to be one of the basic approaches in controlling AD. The purpose of this study was undertaken to investigate the antipruritic effect of ethanol extracts from Perillae Japonicae Semen leaves (PJSL) and Chaenomelis Fructus (CF) on the scratching behavior induced by pruritogen such as compound 48/80 or substance P in hairless mice. PJSL or CF treatment inhibited histamine release in HMC-1 stimulated compound 48/80 or substance P in a dose-dependant manner. In particularly, co-treatment PJSL ($50{\mu}g/mL$) plus CF ($100{\mu}g/mL$) significantly inhibited histamine release in HMC-1 stimulated compound 48/80 or substance P. PJSL, CF or PJSL plus CF was administered orally for 2 h and then compound 48/80 ($50{\mu}g/site$) or substance P ($100{\mu}g/site$) was injected into rostral back, and scratching of the injected site by the hind paw was counted for 1 h. PJSL or CF administration reduced the scratching behavior induced by compound 48/80 as well as substance P in a dose-dependent manner. Furthermore, co-administration of PJSL and CF markedly suppressed the scratching behavior induced by compound 48/80 as well as substance P. These suppressive effects were synergistically increased by their combination. From the preliminary observations, we considered that ethanol extracts from PJSL and CF could be an effective natural materials for itching treatment.

• Journal of Radiation Protection and Research
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• v.44 no.4
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• pp.161-165
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• 2019

Background: Not only regulatory framework including radiation protection quantities and regulatory standards, but also methodology for regulatory compliance may be different in each country due to inherent philosophy for radiation protection. Materials and Methods: Based on the Korean regulatory models, off-site radiological dose resulting from the routine releases of gaseous radioactive effluents was calculated by applying the parameter values and assumptions recommended in the Korean and Japanese regulations. Results and Discussion: Effective dose for adult based on the Korean recommendation were 17.5 and 1.6 times higher than those of Japanese recommendation for ¹³¹I and ¹³³I, respectively, for the same atmosphere dispersion and ground deposition factors. Conclusion: It was due to different parameter values and assumptions recommended for the purpose of evaluating compliance with dose criteria for the radiation protection of the public in each country.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.109-116
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• 2024

The Rapid Hardening Composite Mat (RHCM) is a product that improves the initial strength development speed of conventional Geosynthetic Cementitious Composite Mats (GCCM). It offers the advantage of quickly securing sufficient strength in railway slopes with insufficient formation level, and provides benefits such as preventing slope erosion and inhibiting vegetation growth. In this study, an analysis of the practical applicability of RHCM in railway settings was conducted through experimentation. The on-site applicability was assessed by categorizing it into fire resistance, durability, and stability, and conducting combustibility test, ground contact pressure test, and daily displacement analyses. In the case of South Korea, where a significant portion of the territory is composed of forested areas, the prevention of slope fires is imperative. To analyze the fire resistance of RHCM, combustibility tests were conducted as an essential measure. Durability was assessed through ground contact pressure tests to analyze the deformation and potential damage of RHCM caused by the inevitable use of small to medium-sized equipment on the construction surface. Furthermore, daily displacement analysis was conducted to evaluate the structural stability by comparing and analyzing the displacement and behavior occurring during the application of RHCM with railway slope maintenance criteria. As a result of the experiments, the RHCM was analyzed to meet the criteria for heat release rate and gas toxicity. Furthermore, the ground contact pressure was observed to be consistently above 50 kPa during the curing period of 4 to 24 hours under all conditions. Additionally, the daily displacement analyzed through field site experiments ranged from -1.7 mm to 1.01 mm, confirming compliance with the criteria.

• Nuclear Engineering and Technology
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• v.34 no.3
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• pp.232-241
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• 2002

A safety assessment is carried out for the near-surface radioactive waste disposal in the reference engineered vault facility. The analysis is mainly divided into two parts. One deals with the release and transport of radionuclide in the vault and unsaturated zone. The other deals with the transport of radionuclide in the saturated zone and radiological impacts to a human group under well drinking water scenario. The parameters for source-term, geosphere and biosphere models are mainly obtained from the site specific data. The results show that the annual effective doses are dominated by long lived, mobile radionuclides and their associated daughters. And it is found that the total effective dose for drinking water is far below the general criteria of regulatory limit for radioactive waste disposal facility.

• Journal of The Korean Society of Clinical Toxicology
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• v.13 no.2
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• pp.78-86
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• 2015

Purpose: The purpose of this study is to understand what kinds of chemical substances have been used annually and to investigate incidents that occurred due to chemical hazard release and to analyze statistically clinically chemical injury patients who visited one regional emergency medical center in Gumi city with documented references review. Methods: Annual chemical waste emission quantity (Kg/Year) (Cwep) was reproduced using national web site data governed by the Ministry of Environment and 5 years (from 1 .Jan. 2010 to 31. Dec. 2014) of medical records of chemical injury patients who visited our emergency department were reviewed retrospectively. By applying exclusion criteria, 446 patients of 460 patients were selected. Results: Dichloromethane, Toluene, Trichloroethylene, and Xylene were always included within Top 5 of Cweq. Six cases of chemical incidents were reported and in 3 of 6 cases involving Hydrogen fluoride were included during the study period. Male gender and twenties were the most prevalent group. Injury evoking chemicals were Hydrogen fluoride, unknown, complex chemicals (over 2 substances) in sequence. The most frequent site of wounds and injuries was the respiratory tract. Gas among status, intoxication among diagnosis, and discharge among disposition was most numerous in each group. Conclusion: There have been no uniform clinical protocols for chemical wounds and injuries due to various kinds of chemicophysical properties and ignorance of antidotes. Therefore conduct of a multicenter cohort study and experiments for ruling out chemicals according to chemicophysical priority as well as development of antidotes and clinical protocols for chemical injury patients is needed.