• The Journal of the Acoustical Society of Korea
• /
• 제19권1E호
• /
• pp.27-37
• /
• 2000

This paper presents a simplified analytical formulation for computing acoustic power radiation from a rectangular plate exposed to random forces such as turbulent boundary layer pressure fluctuations and arbitrary mechanical force in a subsonic flow field. The expression for the acoustic power is derived using modal expansion method and light fluid loading is assumed on the plate. In order to simplify the formulation for acoustic power due to combined excitations of mechanical forces and turbulent pressures, it is assumed that the structural damping of the plate is small and excitations are broadband random forces having frequency spectra above the convective coincidence. Under these assumptions, an approximate solution for the broadband acoustic power radiation from a plate excited by both turbulent pressures and arbitrary mechanical forces is obtained and evaluated considering the effect of modal coupling on the radiated acoustic power. An efficient method is also suggested to compute modal acoustic impedance in a moving fluid medium by using averaged Green function.

• 한국임상수의학회지
• /
• 제20권3호
• /
• pp.364-368
• /
• 2003

Cytogenetic and hematological analysis was performed in peripheral blood from the cattle associated with abnormal delivery around nuclear power plant area. The frequency of micronuclei (MN) in peripheral blood lymphocytes from cattle was used as a biomarker of radiobiological effects resulting from exposure to environmental radiation. An estimated dose of radiation was calculated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 Gy to 4 Gy from the bovine lymphocytes with in vitro irradiation. MN rates in live malformed calf, dams of malformed calves and other cattle living in the same barn from the regions around nuclear power plant, and cattle in control area were 9/1000, 10.8/1000, 13.3/1000 and 10.0/1000, respectively. There were no significant differences in MN frequencies and hematological values between the cattle associated with abnormal delivery around nuclear power plant area and those of control area. This study indicates that the congenital abnormalities near nuclear power plant seemed to be caused by other aetiology.

• 플랜트 저널
• /
• 제14권1호
• /
• pp.42-46
• /
• 2018

The flow and heat transfer characteristics inside a solar chimney power plant system are analyzed in this article. 3-D model with the $k-{\varepsilon}$ turbulence closure was developed. In this model, to solve the radiative transfer equation the discrete ordinates radiation model was implemented, using a two-band radiation model. To simulate radiation effects from the sun's rays, the solar ray tracing algorithm was coupled to the calculation via a source term in the energy equation. Simulations were carried out for a system with the geometry parameters of the Manzanares power plant. Based on the numerical results, the velocity and temperature distributions were illustrated and the results were validated by comparing with experimental data of the Manzanares prototype power plant. Moreover, temperature profile of the ground surface of the system was illustrated.

• Journal of Radiation Protection and Research
• /
• 제41권1호
• /
• pp.15-29
• /
• 2016

연구배경: 방사선이용 및 원자력발전의 외향적 성장에 비해 국민이 우려하는 건강권, 환경권, 안전권, 알권리, 발전권, 생존권 등 기본권과의 관계 분석은 전무한 상태이다. 재료 및 방법: 방사선 및 원자력 관련 실정법 내용을 가능한 높은 수준의 권리보장이라는 최대주의적 관점에서 다수의 기본권 분석을 통해 삶의 질 향상을 위한 법률적 보완 방안을 도출하였다. 결과 및 논의: 한국 헌법에 방사선 및 원자력발전과 직접 관계된 기본권 내용은 최소한 12개 조항으로 다수의 권리와 관계된다. 방사선 및 원자력관련 실정법 14종에 헌법적 기본권이 다양한 조항으로 모두 반영되어 있다. 다수의 기본권이 함께 적용된 방사선 및 원자력 관련 실정법은 인간 삶의 질 향상 목적에서 생존권을 우선으로 한 건강권, 환경권, 알권리, 안전권이 작동되어야 하는 것인지, 생존권, 건강권, 환경권, 알권리, 안전권이 같은 크기로 작동되어야 하는 것인지에 대한 상대적 우위에 대해서는 신중한 결정이 필요하고, 인간영역에서 단시간에 평가하기에는 어려운 문제이다. 결론: 원자력, 방사선의 이용증진 측면과 위험 리스크 발생방지 측면 두 가지 목표를 동시에 조화롭게 추구해야 하는 정책은 우리나라 입장에서는 중요한 일이고, 권리 간 조화를 위해 올바른 가치판단이 필요하다.

• Elastomers and Composites
• /
• 제55권3호
• /
• pp.222-228
• /
• 2020

Rubber materials, used in nuclear power plants, need high heat-oxidation resistance to curing or cracking under a heat aging environment. This is because they are applied to environments with high temperature, high humidity, and radiation exposure. Nuclear radiation causes additional hardening or degradation, therefore, rubber materials need radiation resistance that satisfies the general and any accidental conditions produced in the power plant. Therefore, in this study, we developed a rubber material with excellent heat and radiation resistance for the diaphragm seal of a nuclear steam generator nozzle dam. The rubber material greatly improved the reliability of the steam generator nozzle dam. In addition, 30 inch and 42 inch diaphragm seals were manufactured using the developed rubber material. A nozzle dam was installed in a nuclear power plant and tested under the same conditions as a steam generator to evaluate safety and reliability. In the future, the performance and safety of diaphragm seals developed through field tests of nuclear power plants will be evaluated and applied to currently operating and new nuclear power plants.

• 한국전자통신학회논문지
• /
• 제13권6호
• /
• pp.1145-1154
• /
• 2018

주파수의 혼신 간섭 방지를 위해 실제 공중에 방사되는 복사전력 중심으로 규제기준 전환이 요구된다. 복사전력 규제는 기술기준, 허가, 검사 등 전파관리 전반에 관련되는 사항이므로 적용 용이성, 시급성 등을 고려해 점진적으로 도입하고, 주요국의 복사전력 관련 법제도 현황 조사를 통해 국내 환경에 적합한 복사전력 방식에 따른 측정, 검사, 인증 등의 무선설비 출력관리 방식을 마련한다. 국내는 현재 안테나 공급 전력의 비중이 높고, 유럽의 경우는 복사전력의 비중이 높음. 향후 무선국의 수가 점점 증가하고 다양해지므로 공간 관리인 복사전력 기반을 병행하여 측정이 가능하도록 제도개선 마련 필요하고, 복사전력 관리체계로 전환하기 위해서는 관련 전파 제도(기술기준, 인증, 무선국 검사, 사후 관리 등)에 대한 제도개선 필요하다.

• Journal of Radiation Protection and Research
• /
• 제23권3호
• /
• pp.197-210
• /
• 1998

IAEA는 1996년 방사성물질 안전 운송규정을 개정하였다. 이 규정은 방사성물질의 우송이나 포장에 관하여 우리나라를 비롯한 각국의 운송관련 규정의 기준이 되는 것으로 전반부에서는 IAEA가 1991년에 출간된 국제방사선방호위원회 (ICRP)의 신권고(Publication 60)를 받아들여 개정한 Safety Series No.115(전리방사선에 대한 방호 또는 방사선원의 안전을 위한 기본 안전기준)의 내용 등을 개정의 배경으로 하여 요약하였다. 후반부에서는 이들 개정된 기본 안전 기준들에 기초하여 IAEA의 새로운 운송규정에서 방사선방호의 목적으로 고찰된 요건들에 관한 주요 검토 개정사항을 방사선방어체계, 운송물등의 방사선준위, 방사선방호계획의 규정화, Q 시스템의 개념, 규제면제 등의 측면에서 Safety Series No.6 1985년판과 비교 검토하였다.

• 한국음향학회지
• /
• 제42권1호
• /
• pp.1-6
• /
• 2023

구조진동 소음 문제의 평가에 있어 방사소음은 중요한 물리적 특성으로 음향 인텐시티 측정으로 확인이 가능하지만, 시간이 오래 걸리고 까다로운 측정 조건 때문에 시험을 꺼리는 경향이 많다. 그 대안으로 시뮬레이션이 사용되고 있으며, 그 정확도도 높다. 문제는 방사소음 파워와 방사효율 같은 중요한 물리량을 얻기 위해서는 이를 계산해 주는 특정한 소프트웨어가 필요하다는 점이다. 본 연구에서는 이런 관점에서 일반적인 유한요소 해석 소프트웨어를 사용하여 방사소음 파워와 방사 효율을 계산하는 후처리 기법을 제안한다. 제안된 두가지 방법은 기본적으로 시험에서 사용하는 방법을 시뮬레이션에 활용하는 것이다. 첫번째 방법은 상반성 기법을 이용하는 것이며, 두번째 방법은 인접한 2개의 위치에서 계산된 음압을 이용하는 방법이다. 두가지 방법이 모두 효과적으로 방사소음 파워를 예측할 수 있음을 보였으며, 그 한계도 설명하였다.

• 전기학회논문지
• /
• 제67권6호
• /
• pp.745-752
• /
• 2018

ICs(Integrated circuits) for nuclear power plant exposed to radiation environment occur malfunctions and data errors by the TID(Total ionizing dose) effects among radiation-damage phenomenons. In order to protect ICs from the TID effects, this paper proposes a radiation-hardening of the logic circuit(D-latch) which used for the data synchronization and the clock division in the ICs design. The radiation-hardening technology in the logic device(NAND) that constitutes the proposed RH(Radiation-hardened) D-latch is structurally more advantageous than the conventional technologies in that it keeps the device characteristics of the commercial process. Because of this, the unit cell based design of the RH logic device is possible, which makes it easier to design RH ICs, including digital logic circuits, and reduce the time and cost required in RH circuit design. In this paper, we design and modeling the structure of RH D-latch based on commercial $0.35{\mu}m$ CMOS process using Silvaco's TCAD 3D tool. As a result of verifying the radiation characteristics by applying the radiation-damage M&S (Modeling&Simulation) technique, we have confirmed the radiation-damage of the standard D-latch and the RH performance of the proposed D-latch by the TID effects.

• Journal of Radiation Protection and Research
• /
• 제48권3호
• /
• pp.153-161
• /
• 2023

Background: Fukushima Medical University (FMU) is located 57 km northwest of the Fukushima Daiichi Nuclear Power Plant. Our laboratory has been conducting environmental radiation measurements continuously before and after the nuclear accident. We aimed to report the observed behavior of radiation originating from the released radioactive materials due to the accident, predict future trends, and disseminate the results to the local residents. Materials and Methods: Measurements of the counting rate by a diameter of 76 mm and a length of 76 mm thallium-doped sodium iodide (NaI[Tl]) scintillation detector (S-1211-T; Teledyne Brown Engineering Environmental Services) in the central part of the laboratory, and the dose rate outward at the window by NaI(Tl) scintillation detector and digital processor (EMF211; EMF Japan Co. Ltd.) were conducted. Results and Discussion: Measurements by Teledyne S-1211-T showed that in the early stages, radiation from radioactive isotopes with short half-lives was dominant, while radiation from radioactive isotopes with longer half-lives became dominant as the measurement period became longer. Through nonlinear least squares regression, both short and long half-lives were successfully determined. It was also possible to predict how the radiation dose would decrease. The environmental radiation trends around FMU were measured by the EMF211. Both measurements were affected by rainfall and snow accumulation. Decontamination work on the FMU campus impacted measurements by the EMF211 especially. Conclusion: The results of two types of measurements, one at the center and the other at the window side of the laboratory, were presented. By applying a simplified model, radiation from radioactive isotopes with short and long half-lives was identified. Based on these results, future trends were predicted, and the information was used for public communication with the local residents.