DOI QR코드

DOI QR Code

Measurement of Environmental Radiation Using Medical Scintillation Detector in Well Counter System

의료용 우물형 섬광계수기를 이용한 환경 방사선 측정

  • Lyu, Kwang Yeul (Department of Radiological Technology, Shingu College) ;
  • Park, Yeon-joon (Department of Radiological Technology, Shingu College) ;
  • Kim, Min-jeong (Department of Radiological Technology, Shingu College) ;
  • Ham, Eun-hye (Department of Radiological Technology, Shingu College) ;
  • Yoon, Ji-yeol (Department of Radiological Technology, Shingu College) ;
  • Kim, Hyun-jin (Department of Radiological Technology, Shingu College) ;
  • Min, Jung Hwan (Department of Radiological Technology, Shingu College) ;
  • Park, Hoon-Hee (Department of Radiological Technology, Shingu College)
  • Received : 2015.10.23
  • Accepted : 2015.12.03
  • Published : 2015.12.31

Abstract

After the Fukushima nuclear accident in 2011, concerns about radiation by people are increasing rapidly. If people could know how much they will be exposed by radiation, it may help them avoiding it and understand what exactly radiation is. By doing this, we were helping to reduce the anxiety of radiation contamination. In this study, we have researched figures of radioactivity with 'Captus-3000 thyroid uptake measurement systems' in well counter detector system. The materials were measured with Briquette, Shiitake, Pollock, Button type battery, Alkaline battery, Topsoil, Asphalt, Gasoline, Milk powder, Pine, Basalt stone, Pencil lead, Wasabi, Coarse salt, Tuna(can) Cigar, Beer, and then we categorized those samples into Land resources, Water resources, Foodstuff and Etc (Beer classified as a water resources has been categorized into Foodstuff). Also, we selected the standard radiation source linear 137Cs to measure the sensitivity of well counter detector. After that, we took cpm(counter per minute) for the well counter detector of thyroid uptake system's sensitivity. Then we compared the results of each material's cpm and converted those results to Bq/kg unit. There were a little limitation with the measurement equipment because it has less sensitivity than other professional equipment like 'High purity germanium radiation detector'. Moreover, We didn't have many choices to decide the materials. As a result, there are macroscopic differences among the rates of material's spectrum. Therefore, it had meaningful results that showed how much each material had emitted radiation. To compare the material's cpm with BKG, we've compounded their spectrums. By doing that, we were able to detect some differences among the spectrums at specific peak section. Lastly, Button type battery, Alkaline Battery, Briquette, Asphalt and Topsoil showed high value. There were classified emitting high radiation Group A and emitted lower radiation Group B. The Group A, alkaline battery showed higher rate of radiation by 7.67 %, and Button type battery was yield 4.65 % higher rate than BKG. Additionally, Asphalt (8.03 %), Topsoil (3.76 %), Briquette (7.46 %) were yield for higher values. Several samples of the daily supplies were yield little higher, but it seems safe to use in daily lives. In the case of the 'Foodstuff', all of the samples were safe and they were under the radiation limits of the Ministry of Food and Drug Safety for Food; thus, we highly recommend this study to you as a reference of common daily routine.

2011년 발생한 후쿠시마 원전 사고 이후, 국민의 방사선에 대한 관심이 급속히 증가하였으며 그에 따른 방사선의 위험성에 대한 우려 또한 증대되고 있다. 따라서 본 연구에서는 일상생활 속에서 접할 수 있는 물질의 방사선 및 환경방사선을 측정하여 그 실태를 알아봄으로써, 국민의 방사선에 대한 올바른 이해를 돕고 더불어 방사선 피폭에 대한 우려를 경감하고자 하였다. 본 연구에서는 'Captus - 3000 갑상샘 섭취율 측정장치'를 이용하여 일상생활에서 쉽게 접할 수 있는 17가지 시료들을 대상으로 방사능을 측정하였으며, 측정에는 우물형 계수기를 이용하였다. 측정한 시료로는 연탄, 표고버섯, 명태, 전지분유, 알카라인 건전지, 단추형 건전지, 표토, 아스팔트, 휘발유, 솔잎, 현무암, 흑연(석탄), 고추냉이, 천일염, 담배, 맥주, 참치(캔)으로 선정하였고 각각의 시료에 대하여 토양자원, 수자원, 식품, 기타자원으로 분류하였다. 수자원으로 선정한 맥주는 식품으로 분류하였다. 또한 우물형 계수기의 감도측정을 위하여 기준선원으로 선 선원 형태의 137Cs을 이용하였다. 우물형 계수기로 137Cs 선선원의 계수값(cpm)을 측정한 후, 각각의 시료에서 얻은 계수값과 스펙트럼을 분석하였고, 식품의 경우에는 식약처의 방사능 허용기준단위인 Bq/Kg으로 환산하여 그 안전성을 판단하였다. 실험 결과, 측정한 시료들 중 유의할 만한 시료들을 집단 A로 분류하였고, 그 외에 배후 방사능과 큰 차이를 보이지 않은 시료들을 집단 B로 분류하였다. 집단 A의 경우 배후 방사능에 비해 알카라인 건전지가 7.67 %, 단추형 건전지가 4.65 %, 아스팔트가 8.03 %, 표토가 3.76 %, 연탄이 7.46% 높은 값을 보였다. 사용된 시료들 모두에서 측정된 방사능이 생활용품의 일부와, 식품의 경우에는 식약처에서 제시한 방사능 허용기준치 이내에 들어 있음을 확인하였다.

Keywords

References

  1. Kwang-Yeul Lyu: Research for QC program Formulations of Nuclear Medicine Equipment, 3(1), 51-59, 1998
  2. Hoon-Hee Park, Chun Goo Kang, Ki Beak Oh:Medical Radiation Exposure Dose of Workers in the Private Study of the Job Function, Journal of Nuclear Medicine Technology, 15(2), 3-12, 2011
  3. Sang-Jun Han, Seung-Jin Lee, Goung-Jin Lee, Na-Young Lee, Hee-Gang Kim, Ji-Yeon Mun: Evaluation and Consideration on Environmental Radiation Analysis of Yeong-Gwang Nuclear Power Plant Site Inside&Outside, Journal of Radiation Protection and Research , 36(2), 71-78, 2011
  4. Seung Hwan Choo: Issues on Indoor Radon Activities, 29(5), 32-40, 1996
  5. Ji Sun Ku: The Study on the Safety Management of Radioactive Rays around Living Environment, Research of Environmental Law, 36(3) 1-32, 2014
  6. Sang tae Lee: Radiation Protection and Safety, Chungu Munhwasa, 195-201, 2014
  7. Capintec.Inc: Captus 3000 Thyroid uptake system powner's manual, Capintec.Inc, 2-8, 2001
  8. Hyun ki Kim, Jae kwon Jang, Korea Radioisotope Association: Radiation Theory and Practice, 450-457, 470, 2013
  9. Myeong chul Lee: Radioactive Isotope Dictionary, Korea Radioisotope Association, 4, 8, 9, 15, 29, 66, 70, 97, 2010
  10. Gui soon Shin: Radiation Physics, Shinkwang publishing company, 171-175, 311-312
  11. Gopal B. saha: Physics and radiobiology of nuclear medicine, SpringerVerlag, 89, 2007
  12. Ministry of Food and Drug Safety: http://fse.foodnara.go.kr/residue/rdg/jsp/frm_b_01_01.jsp, 2015