초록 ▼

본 과제에서 동아시아 방사능 물질 확산 예측 시스템을 개발하였다. 먼저 방사성물질 확산 모델 관련 기술을 연구 조사 하고, 동아시아 원전 위치 및 원자로 종류에 대한 데이터 베이스와 방사성 물질에 대한 데이터 베이스를 작성하였다. 방사성 물질의 특성이 고려된 이동, 확산, 침착을 포함한 방사성 물질 확산 모델을 개발하고 이를 예측 기상장과 연동하여 방사성 물질 확산 예측이 가능하도록 하였다. 방사성 물질 별 대기중 농도와 지면 침착량에 따라 단기 방사선 피폭량 산정 모듈을 개발하였다. 방사선 피폭량 산정 및 예, 경보 시스템을 개발

본 과제에서 동아시아 방사능 물질 확산 예측 시스템을 개발하였다. 먼저 방사성물질 확산 모델 관련 기술을 연구 조사 하고, 동아시아 원전 위치 및 원자로 종류에 대한 데이터 베이스와 방사성 물질에 대한 데이터 베이스를 작성하였다. 방사성 물질의 특성이 고려된 이동, 확산, 침착을 포함한 방사성 물질 확산 모델을 개발하고 이를 예측 기상장과 연동하여 방사성 물질 확산 예측이 가능하도록 하였다. 방사성 물질 별 대기중 농도와 지면 침착량에 따라 단기 방사선 피폭량 산정 모듈을 개발하였다. 방사선 피폭량 산정 및 예, 경보 시스템을 개발하였다. 방사성 물질 확산 모델의 검증을 위해 후쿠시마 원전 사고 모의를 하고 이를 관측 자료와 비교하였으며 UM 예측 기상장과 연동하여 국내 원전 사고 발생시에 대한 가상 사례를 모의하였다.

Abstract ▼

Ⅳ. Results of this study
1. Archive of data base on the nuclear power facilities in East Asia
At present (December 2011), nuclear power plants are operating in 30 countries with 435 nuclear reactors in the world and 63 reactors are under construction in 14 countries.
The operational reactor

Ⅳ. Results of this study
1. Archive of data base on the nuclear power facilities in East Asia
At present (December 2011), nuclear power plants are operating in 30 countries with 435 nuclear reactors in the world and 63 reactors are under construction in 14 countries.
The operational reactors in Asian countries including Japan, Korea, India and China are 132 reactors and 44 reactors are now under construction. Additional 105 reactors are going to be built within 8-10 years and 229 units will be added within 15 years. In particular China will construct 220 reactors within 15 years in the eastern coastal region of China. Detailed data on the location, reactor type, capacity, connected year and operational condition of each nuclear power plant are archived.
2. Archive of data base on the radionuclide characteristics
The important radionuclide species and types of emitted radioactive rays, the half-life time and application of each radionuclide are archived.
3. Development of radioactive substance dispersion model
The Lagrangian particle dispersion model(LPDM) for the detailed analysis of dispersion process near the source region and the Eulerian dispersion model (EDM) for the long-range transport and dispersion have been developed.
The Lagrangian particle dispersion model based on Park (1998) has been developed. This model utilized the distribution of particles that are released from the source point with the mass corresponding to the emission rate. The released particle will move by the resolved wind vector and turbulent wind velocity that the particle will experiences along the path way. With these particle distribution the concentration is calculated with the Gaussian Kernel density estimator. The model domain is 600×600 km² centered at the power plant with the horizontal grid distance 3×3 km². This model takes into account dry and wet deposition processes and the haf-life time of each radionuclide for the calculation of concentration.
The Eulerian dispersion model(EDM) has been developed based on Park et al (2010). The model domain is the whole Asian domain with the horizontal grid distance of 27×27 km². The model can be run with the MM5 or UM model. This model uses the 3-D concentration field as source data produced by the LPDM model for every two-hour period.
4. Development of a scheme for the calculation of a short-term radiological dose
The scheme includes the external dose caused by the exposion of a body to the radioactive plume and the radioactive rays emitted from the deposited radioactive substances and the internal dose caused by the inhalation of the radioactive contaminated air.
5. The verification of the developed models
To verify the usefulness of the developed models (LPDM and EDM), The accident of the Fukushima nuclear power plant is taken as a case study. The accident occurred for the period from 00 UTC 12 March to 30 April 2011. The model has been performed for this period with the estimated emission rates of I-131 and Cs-137 (Chino et al., 2011). It is assumed that I-131 is in a gas phase while Cs-137 is in an aerosol phase having a log-normal distribution of the concentration with the mean diameter of 0.4 μm and a standard deviation of 0.3 μm.
The LPDM model is performed in the 600×600 km² domain with releasing particles continuously at the first level of the meteorological model at the power plant site from 00 UTC 12 March to 00 UTC April 2011. the particle releasing rate is one particle perminute.
The model produces hourly mean near surface concentration (Bq m^-3), column integrated concentration (Bq m^-2), and dry and wet deposition (Bq m^-2) in a horizontal grid distance of 3×3 km² for the whole period (00 UTC 13 March to 00 UTC April 2011).
The model simulated near surface concentration is compared with the monitored data at 9 sites near the power plant site. It is found that the model simulates quite reasonablely the observed concentrations at these sites. However, the model performance statistics can be obtained due to the lack of continuously monitored data.
The Eulerian dispersion model (EDM) is performed for the accident period described above. The 3-D concentration field for every two hours period produced by LPDM is used as a source of the EDM model. The hourly mean near surface concentration (Bq m^-3), column integrated concentration (Bq m^-2) and dry and wet depositions (Bq m^-2) are produced in the horizontal grid distance of 27×27 km² in the Asian domain.
The distribution pattern of near surface concentration simulated by EDM shows a similar to that of LPDM. However, the near surface concentration obtained by EDM is as low as one order magnitude that of LPDM. The EDM model can identify the effect of I-131 and Cs-137 emitted from the Fukushima power plant to the Korean peninsular through the long-range transport in association with the regional circulation.
6. The experimental test of the LPDM model with the use of the UM forecasting meteorological data
The LPDM model is performed with the use of forecasted meteorological fields in a horizontal resolution of 30×30 km² produced by the UM model. It is found that LPDM produces a reasonable result even though interpreted data in space and time are used, suggesting the use of high resolution of 12×12 km² or 1.5×1.5 km² of UM resulting in better results in the estimation of the concentration.
7. Development of a radiological dose calculation system
Usig the results of estimated near surface concentration and deposition by LPDM and EDM, the system to calculate the radiological dose due to each nuclide or all kinds of nuclides emitted from the source is developed. This is implemented for the case of the Fukushima power plant. It is found that the accident can affect all of the model domain exceeding 1 mSv/yr that is the upper limit of allowable dose. The isoline of the dose value can be used for the warning area.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 보고서 요약서 ... 3
• 요 약 문 ... 4
• SUMMARY ... 8
• CONTENTS ... 12
• 목차 ... 14
• List of Figures ... 16
• List of Tables ... 20
• 제 1 장 연구개발과제의 개요 ... 21
• 제 1 절 연구의 배경 및 필요성 ... 21
• 제 2 장 국내외 기술개발 현황 ... 24
• 제 1 절 국외 현황 ... 24
• 1. 방사성 물질 확산 모델 ... 24
• 2. 재난 관리 시스템 ... 25
• 제 2 절 국내 현황 ... 27
• 1. 기상청 ... 27
• 2. 원자력안전기술원 ... 28
• 제 3 장 연구개발수행 내용 및 결과 ... 29
• 제 1 절 방사성 물질 확산 모델 입력자료 DB ... 29
• 1. 동아시아 원자력 발전소 DB ... 29
• 2. 방사성 물질의 특성 DB ... 33
• 제2절 방사성 물질 확산 모델의 개발 ... 35
• 1. 방사성 물질 확산 모델의 개요 ... 35
• 2. 라그랑지안 입자 확산 모델 ... 38
• 3. 오일러리안 확산 모델 ... 47
• 4. 단기 방사선 피폭량 산정 ... 48
• 제3절 방사성 물질 확산 모델의 검증 ... 52
• 1. 방사성물질 배출량 ... 52
• 2. Lagrangian Particle Dispersion M odel (LPDM) ... 53
• 3. 오일러리안 확산 모델 (EDM) ... 77
• 제4절 UM의 예측기상장을 이용한 LPDM 모델실험 ... 100
• 1. 라그랑지 입자의 공간분포 ... 101
• 2. 농도장 및 침착량의 수평분포 ... 101
• 제5절 방사선 피폭량 산정 및 예ㆍ경보 시스템 ... 105
• 1. LPDM모델로 모의한 피폭선량 ... 105
• 2. 오일러리안 확산 모델(EDM)로 모의한 피폭선량 ... 110
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 116
• 제 5 장 연구 개발 결과 활용 계획 ... 118
• 제 6 장 연구개발과정에서 수집한 해외과학 기술정보 ... 122
• 제 7 장 연구개발결과의 보안등급 ... 125
• 제 8 장 국가과학기술종합정보 시스템에 등록한 연구시설ㆍ장비현황 ... 126
• 제 9 장 참고문헌 ... 127
• Appendix A ... 130
• 끝페이지 ... 133