• Journal of the Korean Society of Safety
• /
• v.37 no.2
• /
• pp.43-53
• /
• 2022

This paper describes an attempt to improve and optimize the operational safety level of a domestic research reactor by conducting a probabilistic safety assessment (PSA) under full-power operating conditions. The PSA was undertaken to assess the level of safety at an operating research reactor in Korea, to evaluate whether it is probabilistically safe and reliable to operate, and to obtain insights regarding the requisite procedural and design improvements for achieving safer operation. The technical objectives were to use the PSA to identify the accident sequences leading to core damage, and to conduct sensitivity analyses based thereon to derive insights regarding potential design and procedural improvements. Based on the dominant accident sequences identified by the PSA, eight types of sensitivity analysis were performed, and relevant insights for achieving safer operation were derived. When these insights were applied to the reactor design and operating procedure, the risk was found to be reduced by approximately ten times, and the safety was significantly improved. The results demonstrate that the PSA methodology is very effective for improving reactor safety in the full-power operating phase. In particular, it is a highly suitable approach for identifying the deficiencies of a reactor operating at full power, and for improving the reactor safety by overcoming those deficiencies.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2002.05a
• /
• pp.21-21
• /
• 2002

독일, 미국, 일본 등 세계 주요 선진국운 도금전문 중소기업들이 각 산업분야의 첨단 핵심부품의 기능화, 신기능-신제품 창출에 크게 이바지하고 었으며, 도금 및 표면처리 관련 전문연구소와 전문고굽 기술인력이 정부 및 사회단체의 지원으로 끊임없이 관련 기술의 연구와 개발에 여념이 없으며, 관련업계와의 교류에 있어서도 활발하다. 특히 도금설비, 자동화장치, 폐수처리 등 도금관련기술에 1970년대부터 연구개발을 시작 하여 실용화하고 있으며, 최근에는 분자규모 표면제어기술과 제 4세대 도금기술(저가 격-고품질-환경융화-개성화)의 연구 및 상품화를 구축하고 었다. 또한, 도금약품 분야 도 오랜 공업화 역사와 강력한 기초산엽을 기반으로 하여 고효융, 고성능화를 설현 실용화단계에 접어들었으며, 설비자동화와 함께 세계적 환경문제와 관련된 무공해, 저 공해화의 연구를 통해 세계시장을 지속적으로 선점하고 있는 실정이다. 국내의 경우, 근대 공업화의 늦은 출발과 수출을 통한 산업발전에 기인된 대기업 중 심의 산업구조, 그리고 수출목표 지향의 제품생산, 조립위주 등의 원인으로 산업기반 기술인 도금기술과 이와 관련된 기초, 핵심기술이 여전허 낙후되어 있으며, 해외의존 도에 있어서 지리척으로 가까운 일본의 영향이 크고, 기타 선진국으로부터 기술도입, 원자재수입에 의해 영위되어 오고 있는 실정이다 또한 영세성 소규모 업체로 구성되어 기술개발 자체도 수요의 한정 및 연관 산업과의 정보부족으로 실효성이 적으며­관련 전문 연구기관, 연구장벼 및 전문 기술인력이 선진국과 비교하여 절대 부족한 현실에 놓여었다. 연구시설, 연구인력의 절대부족, 기초연구 재원 및 국가적 전략지원 연구 및 기본 INFRA 구축이 부족한 국내 현실을 인식하여 한국기계연구원에서는 업계가 직면하고 있는 표면처리 관련기술 제반문제에 대한 실질적이고 다양한 내용 즉, 기술지도 및 지원, 기술훈현 및 연수, 품질-시험 인증을 위한 실험.측정장비의 구입 및 업계와의 공동활용, 국내.외 최신기술 정보자료의 수집과 신속제공, 국내.외 전문가 초청 활 용, 미래 지향적 목적활용 기초연구사업 수행, 미래기술 동향예측 및 홍보 등을 통해 서 국내 도금기술의 기술자립 및 고도화를 위한 여건마련을 위하여 노력하고 있다.

• Journal of Radiation Protection and Research
• /
• v.38 no.2
• /
• pp.100-105
• /
• 2013

With the export of commercial nuclear power plants to UAE and that of a research reactor to Jordan, as well as the additional construction of domestic nuclear power plants, the demand of nuclear manpower is expected to increase sharply. Accordingly, nuclear manpower development is recently becoming an important issue. Major institutes involved in nuclear programs are well equipped with education and training procedures and resources. However, small and medium sized businesses have difficulties to educate their employees due to their limited resources and capacity for the education. Addressing the difficulties, this study is intended to develop and education course in accordance with the "Systematic Approach to Training (SAT)". For this, a survey is conducted on the need of education in small and medium sized businesses, based on which a pilot course on the basics of radiation is developed and operated. An assessment on the development and operation using a survey regarding participants response has shown high grades of performance, i.e. above 4.0 points (full mark: 5.0 points) on each level of expectancy, satisfaction and lecturers' capacity. The experience from this study will be used to develop other programs of nuclear power and ASME code, which are also identified from the need analysis.

• Korean Journal of Health Education and Promotion
• /
• v.26 no.5
• /
• pp.115-127
• /
• 2009

Objectives: To compare alcohol secondhand effects among US and Korean students. Methods: Nationally representative 4-year colleges of two countries were involved in this cross-national comparison study. Data from the 2001 U.S. College Alcohol Study and the 2003 Korean College Alcohol Study came from 120 colleges in 38 U.S. states and the District of Columbia and 60 colleges in Korea. Randomly selected 4-year college students from the U.S. (10,924) and Korea (2,385) participated in the study using self-reports of alcohol use and perceptions of drinking as assessed by College Alcohol Study questionnaires. Results: Korean students were tend to more likely to have being a victim of sexual assault or date rape, having to take care of drunken students and finding vomit in the hall or bathroom of residence, than US students, while US students were tend to more likely to have being insulted or humiliated, having a serious argument and quarrel, being pushed, hit, or assaulted, having study/sleep interrupted, and experiencing an unwanted sexual advance than Korean students. Conclusion: In general, US students were more likely to suffer interrelationship problems after drinking while Korean students were more likely to have physical and individual drinking related problems.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.2
• /
• pp.179-184
• /
• 2009

The Fuel Test Loop(FTL) which is capable of an irradiation testing under a similar operating condition to those of PWR(Pressurized Water Reactor) and CANDU(CANadian Deuterium Uranium reactor) nuclear power plants has been developed and installed in HANARO, KAERI(Korea Atomic Energy Research Institute). It consists of In-Pile Section(IPS) and Out-of Pile System(OPS). The IPS, which is located inside the pool is divided into 3-parts; the in-pool pipes, the IVA(IPS Vessel Assembly) and the support structures. The test fuel is loaded inside a double wall, inner pressure vessel and outer pressure vessel, to keep the functionality of the reactor coolant pressure boundary. The IVA is manufactured by local company and the functional test and verification were done through pressure drop, vibration, hydraulic and leakage tests. The brazing technique for the instrument lines has been checked for its functionality and performance. An IVA has been manufactured by local technique and have finally tested under high temperature and high pressure. The IVA and piping did not experience leakage, as we have checked the piping, flanges, assembly parts. We have obtained good data during the three cycle test which includes a pressure test, pressure and temperature cycling, and constant temperature.

• The Journal of the Korea Contents Association
• /
• v.15 no.11
• /
• pp.298-306
• /
• 2015

This study is the material of the additional filter(Cu, Ni, CaWO4, Gd+Ba) being used when the diagnosis X-ray was varied to evaluate the spatial dose distribution accordingly. And it suggest to find a suitable material. Experiments using MCNPX program based on the Monte Carlo simulation method was carried out by selecting the chest and abdomen taken. As a result, each material per dose, the average scatter dose is approximately 62%, 100 cm radius of the point of the simulated body surface exposure dose and 50 cm radius centered on the point average about 47%. It is determined that an Al material is currently available in accordance with the result to be replaced by Cu, Ni material is sufficient. With just the thickness due to the difference in the atomic number and density adjusted to be about one-tenth of the Al it will be suitable.

• Journal of Radiation Protection and Research
• /
• v.29 no.1
• /
• pp.17-23
• /
• 2004

In order to save time and money needed in the purchase commonly used gamma-ray standard sources, a new radioactive standard source was manufactured by the neutron activation of some regent in the research reactor HANARO. The source was manufactured with an aqueous solution by mixing and dissolving the irradiated reagents. The manufactured source was compared with a commercial standard source. It was confirmed that it could be used as an efficiency calibration source. Also, in order to compare the variation of efficiency due to the volume difference for various containers used in radioactivity assay, the efficiency variation as a function of sample volume was investigated.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.57.1-57.1
• /
• 2012

금속을 용해 응고시킬 때 생성되는 소위, 주조 결함이나 소결금속 내의 기공은 재료의 성능이나 강도를 현저하게 낮추는 결함으로서 예전부터 기피되어 왔다. 또한, 재료공정에 있어서도 여하의 기공이나 기포가 없는 치밀한 고강도 및 고기능성 재료를 개발하는 것에 최대한의 주의와 관심을 기울여 왔다. 반면에 자연계의 천연물이나 인공물을 둘러보면 그 대부분이 다공질임을 쉽게 눈치챌 수 있다. 예를 들어 목재, 지엽 등의 생물을 시작해서 콘크리트 등의 인공물, 우리 체내의 뼈도 전형적인 다공질구조로 구성되어 있다. 이러한 구조로부터 재료의 재질제어 이외에 구조제어라는 새로운 어프로치를 고려할 수 있고, 최근 들어, 금속재료에 있어서도 이러한 다공질 구조에 관한 연구가 활성화되어 충격흡수재, 생체재료, 베어링재료 등의 다양한 응용이 전개되고 있다. 원주상의 방향성 기공을 갖는 로터스 금속의 제조 원리는 용융금속의 높은 가스용해도와 고체금속의 낮은 가스고용도의 차이를 이용하여 응고할 때 고용되지 않는 가스원자가 기포를 형성시키는 것이다. 수소용해도는 모든 금속에 있어서 온도상승에 따라 증가하지만 융점에 있어서 용해도의 불연속적 증가를 나타내며 응고할 때 고액계면에서 다량의 가스를 방출하고 기공 생성을 야기한다. 특히, 고 액상에 있어서 수소용해도 차가 큰 마그네슘, 니켈, 철, 동 등은 기포를 생성하기 쉽다. 또한 기공의 배열구조를 제어하기 위해 일방향응고법를 이용하여 기공에 방향성을 부여한다. 외관상 기공구조가 연근뿌리를 닮은 것으로 부터 로터스 금속이라는 명칭이 널리 알려져 있다. 이와 같은 제조방법에 의해 로터스 금속은 기공 방향, 기공크기, 기공률을 자유롭게 제어할 수 있고 우수한 기계적 성질이 기존의 발포금속, 소결금속과 전혀 다른 특성을 가지고 있다. 이러한 기공구조는 용해온도, 응고속도, 분위기 가스압, 불활성가스와의 혼합체적비 등의 제어를 통해서 조절할 수 있다. 이와 같이 제조한 방향성 다공질금속은 BT (인플란트, 생체적합성, 저탄성, 경량), ST (초음속기엔진부품, 경량), IT (고성능수냉모듈), ET(고온촉매, 필터)의 분야로의 응용을 기대한다.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.310-315
• /
• 2007

The FTL has been developed to be able to irradiate test fuels at the irradiation hole(IR1 hole) by considering its utility and user's irradiation requirements. FTL consists of In-Pile Test Section (IPS) and Out-of-Pile System (OPS). Test condition in IPS such as pressure, temperature and the water quality, can be controlled by OPS. For safety assurance IPS is designed to have dual stainless steel pressure vessel and OPS is composed of main cooling water system, emergency cooling water system, LMP(letdown, make-up, purification) system, etc. FTL Conceptual design was set up in 2001, basic design had completed including a design requirement, basic piping & instrument diagram (P&ID), and the detail design in 2004. In 2005, the development team carried out purchase and manufacture hardware and make a contract for construction work. FTL construction work began on August, 2006 and ended on March, 2007. After FTL development which is expected to be finished by 2008, FTL will be used for the irradiation test of the new PWR-type fuel and can maximize the usage of HANARO.

• Korean Chemical Engineering Research
• /
• v.57 no.4
• /
• pp.455-460
• /
• 2019

Hydrotreating catalysis refers to a various hydrogenation which saturate an unsaturated hydrocarbon, together with removing heteroatoms such as sulfur, nitrogen, oxygen, and trace metals from different petroleum streams in a refinery. Most refineries include at least three hydrotreating units for upgrading naphtha, middle distillates, gas oils, intermediate process streams, and/or residue. Among them, hydrotreating catalysis for residue are the core of the process, because of its complexity. This article reviews recent progress in tackling the issues found in the upgrading residues by hydrotreating, focusing on the chemistry of hydrodemetallization (HDM) and hydrodesulfurization (HDS). We also discuss the composition and functions of hydrotreating catalysts, and we highlight areas for further improvement.