• Corrosion Science and Technology
• /
• 제11권6호
• /
• pp.257-262
• /
• 2012

Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. Rotating cylinder FAC test facility was designed and fabricated and then performance of the facility was evaluated. The facility is very simple in design and economic in fabrication and can be used in material and chemistry screening test. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO), and temperature. Fluid velocity is controlled with rotating speed of the cylinder with a test specimen. FAC test of SA106 Gr. B carbon steel under 4 m/s flow velocity was performed with the rotating cylinder at DO concentration of less than 1 ppb and of 1.3 ppm. Also a corrosion test of the carbon steel at static condition, that is at zero fluid velocity, of test specimen and solution was performed at pH from 8 to 10 for comparison with the FAC data. For corrosion test in static condition, the amount of non adherent corrosion product was almost constant at pH ranging from 8 to 10. But adherent corrosion product decreased with increasing pH. This trend is consistent with decrease of Fe solubility with an increase in pH. For FAC test with rotating cylinder FAC test facility, the amount of non adherent corrosion product was also almost same for both DO concentrations. The rotating cylinder FAC test facility will be further improved by redesigning rotating cylinder and FAC specimen geometry for future work.

• Journal of Trauma and Injury
• /
• 제24권1호
• /
• pp.25-30
• /
• 2011

Purpose: Major trauma patients should be transferred to a definitive care facility as early as possible because prompt management will prevent death. This study was designed to discover the obstacles leading to delayed transfers under the current emergency medical system in Korea and whether there are any negative outcomes associated with conducting procedures at primary care hospitals prior to transferring patients to higher levels of care. Methods: The medical records of major trauma patients with an Injury Severity Score above 15 within the past year were reviewed. Patients were divided three groups as follows: (A) came directly to our emergency center, (B) were transferred without CT or MRI scan at the primary care hospital and (C) transferred with CT or MRI scans. The transfer time of each group were compared and analyzed statistically. Additionally, the number and type of imaging performed at the primary care hospital were analyzed. Results: All qualified patients (n=276) were enrolled in this study: 121 patients in group A; 104 in group B; 51 in group C. There was a statistically significant difference in the transfer time between the three groups (p-value<0.001), and 79 (28.6%) were transferred to an emergency medical center within one hour. In group C, CT or MRI scans were performed an average of 1.86 times at the primary care hospital, and the median transfer time was 4 hours 5 minutes. Conclusion: Only 28.6% of the cases in the study arrived within the golden hour at a definitive care facility. Such delays are in part the result of prolonged times at the primary care hospital for radiologic examinations, such as CT or MRI scans. Major multiple trauma patients should be transferred to a definitive care facility directly or as soon as the primary survey and the resuscitation of Advanced Trauma Life Support guideline are completed at the primary care hospital.

• 한국주거학회논문집
• /
• 제24권5호
• /
• pp.77-88
• /
• 2013

This study is to find out how community facilities of 10-year public rental apartments are currently managed and to propose a new community program management plan by analyzing key characteristics and program needs of tenants. Site visits and questionnaire surveys have been conducted at five different complexes producing 469 results that can be summarized as follows; 1) There were significant differences in the use of facilities and vitality of community among five complexes depending on tenants' participation and efforts of management staff. It was advisable to dispatch specialists, such as housing welfare workers, who were dedicated to managing facilities and supporting community programs; 2) There were high demanded for communication facilitation programs and environmental activities. Development of communication contents and distribution of manuals to inform and educate tenants about various environmental programs will be helpful; 3) The number of community facilities in each complex should be reduced those with high demand and the regional community center should be more vitalized with supporting programs and staff.

• 가정∙방문간호학회지
• /
• 제19권2호
• /
• pp.150-161
• /
• 2012

Purpose: This study was performed to investigate the influencing factors of cognitive function and depression in elderly. Method: From 3 provinces, 282 elders who resided in community and facilities completed structured questionnaires, including cognitive functions, depression, self-esteem, ADL, and IADL. Data were analyzed by applying ${\chi}^2$-test, ANOVA, partial correlation coefficient, and stepwise multiple regression analysis with SAS 8.12. Results: Community dwelling aged people showed higher scores in MMSE-K, self-esteem, ADL and IADL, and showed lower scores in depression than facility elders. MMSE-K was positively correlated in self-esteem, ADL, and personal cognition of health, except depression. Major factors that affect cognitive function of elderly were residual type, age, and IADL. In addition, major factors that affect depression of elderly were self-esteem, personal cognition of health, and marital status. Conclusions: Based on the results above, it is necessary to identify the status of cognition and depression in the elderly, and to develop nursing intervention programs, which improve cognitive function and reduce depression for aged, especially for the facility admitted aged.

• Nuclear Engineering and Technology
• /
• 제32권1호
• /
• pp.57-66
• /
• 2000

The RELAP5 code has been developed for best-estimate simulation of transients and accidents for pressurized water reactors and their associated systems, but it has not been fully assessed for those of CANDU reactors. However, a previous study suggested that the RELAP5 code could be applicable to simulate the transients and accidents for CANDU reactors. Nevertheless, it is indicated that there are some works to be resolved, such as modeling of headers and multi-channel simulation for the reactor core, etc. Therefore, this study has been initiated with an aim to identify the code applicability for all the postulated transients and accidents in CANDU reactors. In the present study, the small inlet header break experiment (B8604) in the RD-14 test facility was simulated with RELAP5/MOD3.2 code. The RELAP5 results were also compared with both experimental data and those of CATHENA analyses performed by AECL and the analyses demonstrated the code's capability to predict major . phenomena occurring in the transient with sufficient accuracy for both Qualitative and quantitative viewpoint However, some discrepancies in the depressurization of the primary heat transport system after the break and the consequent time delay of the major phenomena were also observed.

• Membrane and Water Treatment
• /
• 제10권1호
• /
• pp.19-28
• /
• 2019

To minimize the impact of urbanization, accurate performance evaluation of Low Impact Development (LID) facilities is needed. In Korea, the method designed to evaluate large-scale non-point pollution reduction facilities is being applied to LID facilities. However, it has been pointed out that this method is not suitable for evaluating the performance of relatively small-scale installed LID facilities. In this study, a new design formula was proposed based on the ratio of LID facility area and contributing drainage area, for estimating the Stormwater Interception Ratio (SIR) for LID facilities. The SIR was estimated for bio-retentions, infiltration trenches and vegetative swales, which are typical LID facilities, under various conditions through long-term stormwater simulation using the LID module of EPA SWMM. Based on the results of these numerical experiments, the new SIR formula for each LID facility was derived. The sensitivity of the proposed SIR formula to local rainfall properties and design variables is analysed. In addition, the SIR formula was compared with the existing design formula, the Rainfall Interception Ratio (RIR).

• 한국안전학회지
• /
• 제36권2호
• /
• pp.111-119
• /
• 2021

Multi-dimensional analysis of reactor safety-KINS standard (MARS-KS) is a thermal-hydraulic code to simulate multiple design basis accidents in reactors. The code has been essential to assess nuclear safety, but has mainly focused on light water reactors, which are in the majority in South Korea. Few previous studies considered pressurized heavy water reactor (PHWR) applications. To verify the code applicability for PHWRs, it is necessary to develop MARS-KS input decks under various transient conditions. This study proposes an input model to simulate small-break loss of coolant accidents for PHWRs. The input model includes major equipment and experimental conditions for test B9802. Calculation results for selected variables during steady-state closely follow test data within ±4%. We adopted the Henry-Fauske model to simulate break flow, with coefficients having similar trends to integrated break mass and trip time for the power supply. Transient calculation results for major thermal-hydraulic factors showed good agreement with experimental data, but further study is required to analyze heat transfer and void condensation inside steam generator u-tubes.

• 방사성폐기물학회지
• /
• 제19권1호
• /
• pp.113-121
• /
• 2021

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.

• 인터넷정보학회논문지
• /
• 제19권3호
• /
• pp.79-88
• /
• 2018

세계 주요 국가들은 미래성장 동력 육성과 신기술 확보를 위하여 국가차원의 R&D 지원을 확대하고 있으며, 우리나라에서도 R&D 투자 규모를 지속적으로 확대하고 있다. 또한, 우리나라의 국가 R&D의 규모와 GDP 대비 면에서 세계 최고수준에 이른 상황이여서 R&D예산의 양적인 확대와 함께 효율적인 활용이 더욱 중요해지고 있다. 이러한 흐름에 따라 정부R&D혁신방안('15.5)의 주요 과제 중 세부실행과제로 '연구시설 장비 활용도 제고'가 선정되었다. 본 연구에서는 현재 구축중인 국방연구시설장비 정보시스템(DRES)를 통해 국방분야 연구시설장비의 관리방안을 연구하였다. 이를 위해 현재 국가차원의 연구시설장비 관리절차를 파악하였고 기존 국방분야 연구시설 장비의 관리현황과 문제점, 관련규정을 분석하였다. 이러한 분석 설계를 통하여 국방분야 연구시설 장비를 관리할 수 있는 정보체계를 설계 분석하였으며 이를 통해 관리방안을 연구하였다.

• 대한토목학회논문집
• /
• 제31권2D호
• /
• pp.285-293
• /
• 2011

국내 하수처리시설의 발전으로 인해 최근 유지관리 측면에서의 중요성이 높아지고 있으나, 국내 여건의 부족으로 인해 하수처리 시설의 자산관리가 제대로 정착되지 못하고 있다. 현재 수많은 하수처리시설이 가동 중에 있음에도 불구하고 운영비용의 정확한 통계와 분석, 특히 대수선비와 보수비에 있어서는 대부분의 지방자치단체에서 일반 경상수선비 또는 보수비 하나로만 집계하고 있으며, 민간투자사업으로 시행되고 있는 사업들은 정부기관이나 어떠한 민간기관에서도 운영비용 산정에 있어 명확한 기준에 의해 분석이 이루어지지 못하고 있는 실정에 있다. 본 연구에서는 현재 수행된 하수처리시설 대수선비를 자산화 할 경우의 영향을 분석하여 자산관리의 효율성을 분석하였다. 또한 대수선비 산정에 있어서의 현행 문제점을 분석하고, 제도개선 방안을 제시하였다.