Radiological Risk Assessment for the Public Under the Loss of Medium and Large Sources Using Bayesian Methodology

베이지안 기법에 의거한 중대형 방사선원의 분실 시 일반인에 대한 방사선 위험도의 평가

  • Kim, Joo-Yeon (Dept. of Nuclear Engineering, Hanyang University) ;
  • Jang, Han-Ki (Dept. of Nuclear Engineering, Hanyang University) ;
  • Lee, Jai-Ki (Dept. of Nuclear Engineering, Hanyang University)
  • 김주연 (한양대학교 원자력공학과) ;
  • 장한기 (한양대학교 원자력공학과) ;
  • 이재기 (한양대학교 원자력공학과)
  • Published : 2005.06.30

Abstract

Bayesian methodology is appropriated for use in PRA because subjective knowledges as well as objective data are applied to assessment. In this study, radiological risk based on Bayesian methodology is assessed for the loss of source in field radiography. The exposure scenario for the lost source presented in U.S. NRC is reconstructed by considering the domestic situation and Bayes theorem is applied to updating of failure probabilities of safety functions. In case of updating of failure probabilities, it shows that 5 % Bayes credible intervals using Jeffreys prior distribution are lower than ones using vague prior distribution. It is noted that Jeffreys prior distribution is appropriated in risk assessment for systems having very low failure probabilities. And, it shows that the mean of the expected annual dose for the public based on Bayesian methodology is higher than the dose based on classical methodology because the means of the updated probabilities are higher than classical probabilities. The database for radiological risk assessment are sparse in domestic. It summarizes that Bayesian methodology can be applied as an useful alternative lot risk assessment and the study on risk assessment will be contributed to risk-informed regulation in the field of radiation safety.

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