Radiological Risk Assessment for $^{99m}Tc$ Generator using Uncertainty Analysis

불확실성 분석을 이용한 $^{99m}Tc$ 발생기 사용의 방사선위험도 평가

  • Jang, H.K. (Dept. of Nuclear Engineering, Hanyang University) ;
  • Kim, J.Y. (Dept. of Nuclear Engineering, Hanyang University) ;
  • Lee, J.K. (Dept. of Nuclear Engineering, Hanyang University)
  • 장한기 (한양대학교 원자력공학과) ;
  • 김주연 (한양대학교 원자력공학과) ;
  • 이재기 (한양대학교 원자력공학과)
  • Published : 2004.06.30


Recently, much attentions are paid to the risk associated with increased uses of medium size radiation sources in medical and industrial fields. In this study, radiation risks to the worker and to the general public due to $^{99m}Tc$ generator were assessed for both normal and accident conditions. Based on the event tree technique, exposure scenarios for various situations were derived. Uncertainty analysis based on the Monte-Carlo technique was applied to the risk assessment for workers and members of the public in the vicinity of the work place. In addition, sensitivity analysis was performed on each of the five independent input parameters to identify importance of the parameters with respect to the resulting risk. Because the frequencies of normal tasks are fat higher than those of accidents, the total risk associated with normal tasks were higher than the accident risk. The annual dose due to normal tasks were $0.6mSv\;y^{-1}$ for workers and $0.014mSv\;y^{-1}$ for public, while in accident conditions $3.96mSv\;y^{-1}\;and\;0.0016mSv\;y^{-1}$, respectively. Uncertainty range of accident risk was higher by 10 times than that of normal risk. Sensitivity analysis revealed that source strength, working distance and working time were crucial factors affecting risk. This risk analysis methodology and its results will contribute to establishment of risk-informed regulation for medium and large radioactive sources.


  1. 방사성동위원소협회, 방사선 방사성동위원소 이용진흥 연차대회, (2003)
  2. H. G. Menzel, 'Radiation Protection Research and Standards in the European Union', Proc. of 1997 International Conference on Radiation Dosimetry and Safety, Taiwan, (1997)
  3. Korea Institute of Nuclear Safety, Developments . of Radiation Safety, Requirements for the Managements of Radiation Devices, KINSIHR-469(2002)
  4. International Commission on Radiological Protection, Radiological Protection and Safety in Medicine, ICRP publication 73, Pergamon Press(1996)
  5. U. S. Nuclear Regulatory Commission, Risk Analysis and Evaluation of Regulatory Options for Nuclear Byproduct Material Systems, NUREG/CR-6642(2000)
  6. International Commission on Radiological Protection, Protection from Potential Exposures-Application to Selected Radiation Sources, ICRP publication 76, Pergamon Press(1997)
  7. D. J. Moschandreas and S. Karuchit, 'Scenario-model-parameter: a new method of cumulative risk uncertainty analysis,' Environment International 28, 247-261 (2002)
  8. Korea Institute of Nuclear Safety, Risk Analysis for Radioisotopes and Radiation Generators, KINS/HR-501(2003)
  9. Alison C. Cullen and H. Christopher Frey, Probabilistic Techniques In Exposure Assessment: a handbook for dealing with variability and uncertainty in. models and inputs, New York and London(1998)
  10. U. S. Environment Protection Agency, Risk Assessment Guidance for Superfund: Volume 3 - part A, Process for Conducting Probabilistic Risk Assessment, EPA540/R02/002(2001)
  11. U. S. Environment Protection Agency, Guiding principles for Monte Carlo analysis, EPA630/R-97/001(1997)
  12. Christopher Z. Mooney, Monte Carlo Simulation, Sage publications, 07-116 Thousand Oaks(1997)
  13. R. Sargent and E. Wainwringht, Crystal Ball Version 4.0 User Manual, Decisioneering(1996)
  14. A. Yegnan, D.G. Williamson and A.J. Graettinger, 'Uncertainty analysis in air dispersion modeling,' Environment Modeling & Software 17, 639-649(2002)
  15. M. Alexander, A. Franklin and C. Duane, Introduction to the Theory of Statistics, 3rd ed., McGraw-Hill, New York(1974)