초록 ▼

1. 연구개발 목표
방사능 테러 시 방사선 방호 지원을 목적으로 방사능 테러 피해 정량화 기술을 개발 및 의사결정자의 의사결정 지원.

2. 연구수행 내용 및 결과
○ 방사능 테러로 인한 육상오염 해석 기술
□ 방사성 물질 공기 중 폭발 규모에 따른 방사능 플륨 생성 해석 기술 개발
□ 환경 중 방사능 플륨 거동 추정 기술 개발
□ 방사능 테러 신속대응을 위한 피해범위 데이터베이스 개발
○ 방사능 테러로 인한 건물오염 해석 기술
□ 건물 내 방사성 물질 거동 특성 정량화
□ 건물

1. 연구개발 목표
방사능 테러 시 방사선 방호 지원을 목적으로 방사능 테러 피해 정량화 기술을 개발 및 의사결정자의 의사결정 지원.

2. 연구수행 내용 및 결과
○ 방사능 테러로 인한 육상오염 해석 기술
□ 방사성 물질 공기 중 폭발 규모에 따른 방사능 플륨 생성 해석 기술 개발
□ 환경 중 방사능 플륨 거동 추정 기술 개발
□ 방사능 테러 신속대응을 위한 피해범위 데이터베이스 개발
○ 방사능 테러로 인한 건물오염 해석 기술
□ 건물 내 방사성 물질 거동 특성 정량화
□ 건물 내 방사성물질 거동 해석 및 거주민 리스크 평가
○ 상수원 방사능 테러 해석 기술
□ 상수원 방사능 테러로 인한 방사성 물질 수중 거동 해석 기술 개발
□ 상수원 방사능 테러로 인한 피폭선량 추정 기술 개발
□ 어류 방사능 오염 추정 기술 개발

Abstract ▼

Ⅳ. Results

This study analyzed a method that calculated the explosive height of a radioactive plume in a program used in foreign countries in case of the occurrence of radiological terrorism. Modifying the program, we developed RADCONS-AIR, a program for dispersion of radioactive substances.<

Ⅳ. Results

This study analyzed a method that calculated the explosive height of a radioactive plume in a program used in foreign countries in case of the occurrence of radiological terrorism. Modifying the program, we developed RADCONS-AIR, a program for dispersion of radioactive substances.
RADCONS-AIR was designed to use the Gaussian Plume model or the Gaussian Puff model selectively, and it can be used for analysis of a radiological terrorism scenario, real-time analysis of radiological terrorism, and post recovery from the impact of radiological terrorism. For rapid quantification of damage size in case of radiological terrorism, this study developed a database program to estimate the damage caused by radiological terrorism so that we can take actions against radiological terrorism.
In order to analyze the impact of radiological terrorism inside a building, this study used the Box Modeling method and established a mathematical model inputting ventilation rate and total volume of radioactive influx. To analyze movement of radioactive substances in a separate space in a building or between stories, this study developed an analysis module on air pollution caused by radioactive substances in a building and compartment modeling is applied to the module. By using the module, we can analyze air pollution caused by a radiological source exploded or neglected in a building, and estimate exposure dose of a resident staying in the building.
In preparation for radiological terrorism over a resource of drinking water, this study developed an analysis module on behavior of radioactive substances in a lake or river and applied it to Paldang Lake and Han River. We established a mathematical model that can analyze exposure dose and cancer risk of residents through drinking tap water from radioactive contamination of a river and lake, or intake of fish raised in a contaminated drinking water source.
This study tested the technology developed against radiological terrorism. We assumed a situation in which 50 TBq of Cs-137, a radioactive source that was lost in Goiania, Brazil was exploded by a radiological dispersion device with 30 kg TNT. In the event that explosion duration is more than 10 minutes, residents who are exposed to the radioactive plume are assumed to have 4.58 mSv through respiration. Since the inhalation dose was smaller than 10 mSv, which is the radiation standard for evacuation in the case of a radioactive accident, evacuation was not necessary. However, in the long run, decontamination is required for the contaminated region. The area of which exposed volume exceeded 15 mrem/yr, the radiation standard of the US EPA, turned out to be 3.74 km². Therefore, counteraction against terror should be made in a way to minimize intangible damage according to the amplified fear of people in the early stages after radiological terrorism. When the radioactive plume disappears, effective decisions should be made, including setting the priority and procedure of decontamination. In the event that vegetables in a field are contaminated due to the radiological terrorism, the accumulated radioactivity in a human body was very slight unless the intake of the vegetables at the time of the occurrence was made. Considering that the growth cycle of vegetables in a field is about 60 days, which is very short, there was a minor impact of radiation on the human body due to the intake of vegetables that were newly planted after removing the contaminated vegetables. In the event that the same radioactive source is exploded in a building, about 62 mSv of radiation is exposed to a human body through respiration. This represents the estimated radioactivity accumulated in a human body through respiration for 10 minutes, which is the explosion duration, and the mortality due to the respiration was shown to be 1.97E-8.
In the event that the same radioactive source is placed in Paldang Lake, the 95% confidence interval of exposure dose by drinking tap water is estimated to be 2.03E-2mSv~4.8E-2mSv. To satisfy the standard for drinking water of the US DOE, which is less than 4.4 Bq/L, after radiological terrorism, action for prohibiting water intake should be taken for 25 days. In order to maximize social disturbance, the terrorist act of placing a radioactive substance in a water source maybe be delayed in its announcement by said terrorist. It is assumed that about 0.03 mSv of internal exposure in a human body will occur on average. If a 200g fish intakes contaminated radioactive water and plankton, Cs-137 concentration was estimated inside the fish. Cs-137 accumulated in the fish showed a peak value after about 10 days had passed from the radiological terrorism and rapidly decreased as the concentration of water radiation decreased. Most of the radioactivity in a fish is accumulated in the gills or intestines. Accumulation in the meat, the edible part of the fish, was not so high. Considering the radioactivity accumulated in the meat, except for intestines, assuming that 200g is taken every day for 150 days, the Cs-137 exposure dose by fish intake was estimated to be 7.50E-3 mSv.