Deep geological disposal is generally accepted to be the most practical approach to handling radioactive wastes. Bentonite has been considered as a buffer material in deep geological disposal repositories (DGR) for high-level radioactive wastes. Evaluating the effect of short-term bentonite alteration on EBS performance has limitations in safety assessment over thousands of years. Information on bentonite characteristics under various conditions obtained from natural systems can be used to evaluate long-term safety of bentonite buffer. The purpose of this study was to investigate mineralogical and physicochemical characteristics of bentonite in the Naah mine located in Yangnam-myeon, Gyeongju-si for a natural analogue of the bentonite barrier in DGR. A total of 15 samples were collected at regular intervals from the bentonite layer and andesitic lapilli tuff (i.e., parent rock) at the boundary with the bentonite layer. The bentonite layer is located at a depth of about 1 m below the ground surface. Each sample was separated into particles < < 75 μm and particles < 2 μm through grinding and sedimentation processes. The separated subsamples were characterized mineralogically and physiochemically using various analytic techniques. Bentonite samples have a similar SiO2/Al2O3 ratio to the parent rock and a lower (Na+K)/Si ratio than the parent rock, indicating depletion of alkali components during bentonitization. The parent rock and bentonite samples have similar mineral composition (i.e., quartz, feldspars, opal-cristobalite-tridymite and montmorillonite). Results of XRD analysis on the randomly distributed particles < 2 μm indicate that bentonite is mostly composed of Ca-montmorillonite, which is a typical dioctahedral smectite. Results of FTIR and VNIR analysis indicate that montmorillonite contained in bentonite is Al-dioctahedral montmorillonite, and Al is substituted with Mg in some octahedron units. The mineralogical and physicochemical characteristics are similar regardless of sampling location. These results suggest that bentonite potentially exposed to weathering, located near the ground surface, has hardly altered.

The structural integrity of concrete silos is important from the perspective of long-term operation of radioactive waste repository. Recently, the application of acoustic emission (AE) is considered as a promising technology for the systematic real-time health monitoring of concrete-like brittle material. In this study, the characteristics of AE wave propagation through concrete silo of Gyeongju radioactive waste repository were evaluated under the effects of groundwater and temperature for the quantitative damage assessment. The attenuation coefficients and absolute energies of AE waves were measured for the temperature cases of 15, 45, 75°C under dry and saturated concrete specimens, which were manufactured based on the concrete mix same as that of Gyeongju concrete silo. The geometric spreading and material loss were taken into account with regard to the wave attenuation coefficient. The attenuation coefficient shows a decreasing pattern with temperature rise for both dry and saturated specimens. The AE waves in saturated condition attenuate faster than those in dry condition. It is found that the effect of water content has a greater impact on the wave attenuation than the temperature. The results from this study will be used as valuable information for estimating the quantitative damage at the location micro-cracks are generated rather than the AE sensor location.

The chelating agent and cellulose generated during the operating and decommissioning of a NPP’s form organic complexing compounds. That is accelerate the migration of radionuclide and have a bad influence of LILW disposal site. In this study, the GoldSim (RT module) program was used for the effects of radionuclide migration by organic complex compounds as described above. A scenario was derived for evaluation, and a conceptual design (Concept Art) of the GoldSim model was performed. 1) Derivation of the scenario. For the scenario, we selected a groundwater flow scenario in which groundwater flows in and radionuclides flow out after a lapse of time after the operation of the LILW disposal site in Gyeongju is closed. The inflowing groundwater comes into contact with radioactive waste and the radionuclides dissolve. The dissolved nuclides move past the drum and out of the disposal vessel due to the advection phenomenon. Radionuclides spilled from the disposal vessel pass through the silo internal filler (crushed stone) and reach the engineering barrier concrete. Radionuclides from degraded concrete are scenarios that move along the flow of groundwater to the near and far. 2) Radionuclide migration concept design. The radionuclide movement section was largely designed with Inner (Inside the silo), Near and Far. (A) Inner (Inside the silo) This section is where radionuclides move from the radiation source to the engineering barrier (silo). The detailed migration path was designed to allow radioactive nuclides to flow out and move to waste drums, solidified matrix of indrum, disposal vessel fillers, disposal vessels, silo fillers (crushed stones), and engineered barriers (concrete). The LILW disposal site in Gyeongju has a total of 6 silos. Each of the 6 silos was modeled and designed in consideration of the structural information and positional impact. (B) Near & Far. In generally design, the near is form source term to engineered barrier and far is beyond the engineered barrier. In this study, the near and far designed by radionuclide in the section from the beyond the engineering barrier (silo) to the sea through the groundwater flow through the natural rock. Especially in the case of near, the design was made by applying the position of the natural rock sampling drill hole.

본 연구는 머신러닝 기법을 토대로 15개 환경 변수를 활용하여 소나무재선충병의 위험지역 분포를 예측하였다. 연구는 최대 엔트로피 모델을 머신러닝 기법으로 활용하였고, 연구 지역은 경주이며 연구 기간은 2018∼2020년이다. 모델의 평가에는 AUC(area under the curve)를 이용하였다. 연구 지역에서 소나무재선충병의 감염목 핵심 분포 지역은 2018년 대비 2019년과 2020년에 각각 2.5배와 4.7배 확대되었다. 소나무재선충병의 감염목 분포 추정 모델의 AUC는 모든 해에 최소 0.86 이상이었다. 모델에서 가장 중요한 변수는 직전 해의 감염목 근접도 이었다. 지형과 도로와의 인접성, 목조건물 인접성, 5월 평균 기온도 중요한 변수이었다. 인간 활동과 매개충의 생장 환경이 소나무재선충병의 공간적 분포에 중요한 역할을 한다는 것을 의미한다. 나아가 연구의 결과는 감염목 분포 정보의 지속적인 구축과 공유가 소나무재선충병 예방을 위한 정책과 연구에 중요하다는 것을 시사한다.

본 연구는 경주시 가로변의 침입외래식물을 조사, 분석하여 가로경관 및 조경수관리에 필요한 기초 자료를 제공하는데 목적이 있다. 분류군수는 24과 69속 94종 1변종 등 95분류군으로 요약되었다. 원산지 분석 결과, 아프리카 2분류군, 오스트레일리아 1분류군, 아시아 5분류군, 유라시아 8분류군, 유럽 40분류군, 북아메리카 26분류군, 남아메리카 6분류군, 열대아메리카 7분류군이었다. 귀화도의 경우 1등급 9분류군, 2등급 22분류군, 3등급 28분류군, 4등급 9분류군, 5등급 27분류군이며, 이입시기는 1기와 3기 각 39분류군, 2기 17분류군이었다. 전국확산 예상종은 콩다닥냉이, 울산도깨비바늘, 만수국아재비, 큰김의털 등 13분류군이었다. 생활형 분석 결과, 교목 2분류군, 관목 1분류군, 지표식물 6분류군, 반지중식물 22분류군, 지중식물 5분류군, 일년생 식물 59분류군으로 나타났다. 생태계교란생물은 애기수영, 가시박, 도깨비가지, 돼지풀, 서양금혼초, 가시상추, 미국쑥부쟁이 7분류군이었다.

The stochastic method is applied to simulate strong ground motions at seismic stations of seven metropolises in South Korea, creating an earthquake scenario based on the causative fault of the 2016 Gyeongju earthquake. Input parameters are established according to what has been revealed so far for the causative fault of the Gyeongju earthquake, while the ratio of differences in response spectra between observed and simulated strong ground motions is assumed to be an adjustment factor. The calculations confirm the applicability and reproducibility of strong ground motion simulations based on the relatively small bias in response spectra between observed and simulated strong ground motions. Based on this result, strong ground motions by a scenario earthquake on the causative fault of the Gyeongju earthquake with moment magnitude 6.5 are simulated, assuming that the ratios of its fault length to width are 2:1, 3:1, and 4:1. The results are similar to those of the empirical Green’s function method. Although actual site response factors of seismic stations should be supplemented later, the simulated strong ground motions can be used as input data for developing ground motion prediction equations and input data for calculating the design response spectra of major facilities in South Korea.

This study is a case study of system improvement measures for urban regeneration of the historical and cultural environment. The example areas are Hwangnam and Inwang Hanok districts in Gyeongju City, which operate various systems to solve the urban decline problem caused by the historical and cultural environment regulations. The subjects of this study are resident support programs and district unit planning systems under the advanced promotion system established in the case area. As research methods, literature studies, field surveys, and in-depth interviews were conducted. Through this, the background and purpose of introduction of each system, major plan contents, and problems of the system application process were analyzed. This study drew the following implications through case studies. First, in order to more effectively promote the urban regeneration of the historical and cultural environment, it is necessary to improve the related systems in an integrated and systematic manner. Second, in order to resolve the policy distrust of local residents in the historical, cultural and environmental management system, a wider variety of planned alternatives to narrow the difference in interests between the public and private sectors should be presented.

This study examines the Gyeongju Seokguram Grotto restoration project (1961-1962) by architect Kim Chung Up (1922-1988) and introduces the documents he wrote at the time of planning. The study highlights Kim’s Plan attempt to adopt Buckminster Fuller’s idea of the Geodesic Dome, while inheriting the architect Pai Ki Hyung’s previous design plan which was nullified. As Seokguram Grotto’s water leak and deterioration issues have been brought up, the four-times survey was carried out by experts team between 1958 and 1960, under Ministry of Education’s direction. Pai designed an initial restoration plan based on the survey’s result, which was a double-dome structure with a concrete film on the outer periphery as a way to protect Seokguram Grotto in January 1961. However, as drawbacks, such as the heavy load of the concrete dome, and non-installation of entrance hall, have been indicated in the review process, the Cultural Properties Committee rejected the plan. Subsequently, Kim was appointed as the supervisor of the second restoration project. Kim drew up a process management schedule to be implemented from August 1961 to December 1963 and designed the conception plans for the second restoration design. This study analyzes Kim’s Plan by examining sketches, site plans, floor plans, and sections. Kim planned to maintain the idea of the double-dome structure proposed by Pai while applying Buckminster Fuller’s idea of the Geodesic Dome. Kim planned to lighten the dome structure by applying a steel-frame Geodesic Dome so that the dome structure could be supported by its own. The study is expected to reclaim the omitted parts from Seokguram Grotto's historical description and Kim's careers.

고대 국가에서 가장 중요한 재원은 조세로 거둔 곡물이며 이를 보관하기 위한 창고는 주로 산성 등에서 확인되고 있다. 당시 금석문과 산성에서 출토된 목간 내용으로 볼 때, 사찰 안에 창고가 존재했고, 산성 내 창고에는 보리와 같은 곡물을 60섬(石) 단위로 일정하게 관리했음을 알 수 있다. 이번에 경주 성건동 500-18번지 유적에서 조사된 다 수의 대호를 매납한 대형 건물지는 삼랑사 안에 마련된 창고로 장류와 같은 액상식품과 쌀 등을 보관하던 창고로 추정된다. 성건동 창고유적에서 확인된 대형 창고는 <매호식 건물>로 구분되며 건물 안에 대호를 안전하게 관리하기 위해서 일정한 높이로 흙을 성토한 부분이 존재하고 있는 점이 특징이다. 이 성토부에서는 대호를 절반 정도 묻어둔 모습과 파손된 대호를 수시로 교체한 모습이 확인되며, 대호 위에 토제 뚜껑을 사용한 점은 저장물에 대한 보관관리가 상시적으로 이루어 졌음을 알려준다. 창고 유적에서 출토된 국자는 청동제와 목제 또는 조개껍질로 만들어 사용했는데, 보관중인 저장품이 변질되지 않도록 관리하기 위해서 필요에 따라서 다른 재질의 국자를 사용한 것으로 볼 수 있다. 대호 안에서 출토된 숯으로 보아 삼국시대부터 장류를 담글 때 백탄을 사용했을 가능성이 있다. 이는 당시 식생활 모습을 살펴보는데 있어서 중요한 단서가 될 것이다. 당시 창고유적과 비교한 결과 경주 성건동 500-18번지 유적의 창고건 물은 삼랑사와 관련된 저장시설로 생각되며, 당시 황룡사, 실상사 등 당대 사찰 내 위치한 창고 모습을 알려주는 점에서 의미가 크다. 그리고 이러한 창고가 운영되기 위해서는 국가나 관청의 관리가 존재했음을 알려주므로, 향후 조사가 확대된다면 창고의 구조에 따른 차이가 확인될 것으로 판단된다.

A safety assessment of radioactive waste repositories is a mandatory requirement process because there are possible radiological hazards owing to radionuclide migration from radioactive waste to the biosphere. For a reliable safety assessment, it is important to establish a parameter database that reflects the site-specific characteristics of the disposal facility and repository site. From this perspective, solubility, a major geochemical parameter, has been chosen as an important parameter for modeling the migration behavior of radionuclides. The solubilities were derived for Am, Ni, Tc, and U, which were major radionuclides in this study, and on-site groundwater data reflecting the operational conditions of the Gyeongju low and intermediate level radioactive waste (LILW) repository were applied to reflect the site-specific characteristics. The radiation dose was derived by applying the solubility and radionuclide inventory data to the RESRAD-OFFSITE code, and sensitivity analysis of the dose according to the solubility variation was performed. As a result, owing to the low amount of radionuclide inventory, the dose variation was insignificant. The derived solubility can be used as the main input data for the safety assessment of the Gyeongju LILW repository in the future.

The purpose of this study was to identify the structure and characteristics for the reproduction of the armor in the Unified Silla period, and then reproduce and utilize it as a cultural content. In the armor reproduction project excavated from Jaemaejeong, Gyeongju. Jaemaejeong armor is consisting of Singap (身甲, body armor), Sanggap (裳甲, hip armor), and Sangbakgap (上膊甲, upper arm armor) at the time of excavation. Unlike the armor of the Three Kingdoms period, Singap and Sanggap are separated. Singap is Yangdangsik (裲襠式, side opening method) and Gyunggap (頸 甲, gorget) was not unearthed, Sangbakgap was divided into a part that protects the left and right upper arms and a part that protects the chest, so that the unexcavated head and neck cover of the helmet can be protected to the shoulder. In addition, in the case of Chalgap (札甲, lamellar armor), the Oejungsik (外重式, folded from outside to inside) is mainly used, but it is peculiar that Naejungsik (內重式, folded from inside to outside) is used in Sangbakgap of Jaemaejeong armor. It is presumed that this was used as a method to ensure that the armor were closely attached to the human body. In order to design with the parade armor of Gochwidae in Gyeongju based on the reproduced Jaemaejeong armor, the designer’s imagination and historical work of the times were involved due to the characteristics of performance costumes. Reproduced armor as a cultural content should be considered indispensable to simplify and lighten clothing suitable for performances based on the excavated historical armor.

Sodium intake has been associated with the health-related quality of life (HRQoL). This study examined the demographic factors related to HRQoL and whether there is an association between sodium intake and HRQoL in adults residing in rural areas. A total of 1,980 adults (aged ≥20 years) were selected from a cross-sectional study conducted between December 2013 and February 2014 in Gyeongju, South Korea. The sodium intake and HRQoL were measured using a validated food frequency questionnaire and the EuroQol Five-Dimension (EQ-5D) (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), respectively. The education levels (<5 years) were inversely associated with all five dimensions of HRQoL. Men had better EQ-5D scores for each of the five components examined. Adults living with spouses had better scores related to usual activities and anxiety/depression, whereas widowers had decreased scores of mobility and self-care. Unlike older adults aged 70-79 years, adults aged <60 years were more likely to have greater scores related to mobility, usual activities, and pain/discomfort. The income levels were also inversely related to the scores for self-care, usual activities, pain/discomfort, and anxiety/depression. Sodium intake was positively associated with the HRQoL related to self-care, usual activities, and pain/discomfort, but it was negatively associated with anxiety/depression. In conclusion, these findings suggest that the demographic factors and sodium intake were independently associated with HRQoL. The results highlight the need to provide tailored, targeted policies and interventions that consider personal characteristics and dietary intake to improve the overall HRQoL in adults residing in rural areas.

The empirical Green’s function method is applied to the foreshock and the mainshock of the 2016 Gyeongju earthquake to simulate strong ground motions of the mainshock and scenario earthquake at seismic stations of seven metropolises in South Korea, respectively. To identify the applicability of the method in advance, the mainshock is simulated, assuming the foreshock as the empirical Green’s function. As a result of the simulation, the overall shape, the amplitude of PGA, and the duration and response spectra of the simulated seismic waveforms are similar with those of the observed seismic waveforms. Based on this result, a scenario earthquake on the causative fault of Gyeongju earthquake with a moment magnitude 6.5 is simulated, assuming that the mainshock serves as the empirical Green’s function. As a result, the amplitude of PGA and the duration of simulated seismic waveforms are significantly increased and extended, and the spectral amplitude of the low frequency band is relatively increased compared with that of the high frequency band. If the empirical Green’s function method is applied to several recent well-recorded moderate earthquakes, the simulated seismic waveforms can be used as not only input data for developing ground motion prediction equations, but also input data for creating the design response spectra of major facilities in South Korea.

경주시 사적지, 도시공원지역, 그리고 하천 86개소의 현지조사를 통하여 귀화식물을 조사한 결과 21과 59속 78종 1아종 5변종으로 총 84분류군으로 조사되었다. 이중 사적지는 68분류군, 근린공원 43분류군, 하천 59분류군, 소공원 42분류군 등으로 나타났다. 출현식물 중 널리 분포하나 개체수는 많지 않은 귀화도 3등급 분류군이 31.0%, 널리 분포하고 개체수도 많은 5등급이 29.8%, 국지적으로 분포하고 개체수도 많지 않은 분류군인 2등급이 20.2% 등으로 나타났다. 생태계교란식물은 미국쑥부쟁이, 가시상추, 애기 수영 등 7분류군으로 가시상추는 41.9%로 가장 빈번하게 출현하였고, 미국쑥부쟁이는 34.9%로 하천변에서, 애기수영은 25.6%로 사적지나 소공원 일원에서 빈번하게 출현하였다. 생태계교란식물의 확산을 방지하기 위해서는 지속적인 모니터링이 필요하며, 특히, 정착초기에 물리적 제거나 토양의 대체 등 관리 계획이 필요하다.