원전 해체 시 방사성 콘크리트 폐기물 내부 방사능 분포 예측을 위한 컴프턴 영상 재구성 방법의 비교 = Comparison of Compton Image Reconstruction Algorithms for Estimation of Internal Radioactivity Distribution in Concrete Waste During Decommissioning of Nuclear Power Plant

다국어 초록 (Multilingual Abstract)

Concrete waste accounts for approximately 70~80% of the total waste generated during the decommissioning of nuclear power plants (NPPs). Based upon the concentration of each radionuclide, the concrete waste from the decommissioning can be used in the determination of the clearance threshold used to classify waste as radioactive. To reduce the cost of radioactive concrete waste disposal, it is important to perform decontamination before self-disposal or limited recycling. Therefore, it is necessary to estimate the internal radioactivity distribution of radioactive concrete waste to ensure effective decontamination. In this study, the performance metrics of various Compton reconstruction algorithms were compared in order to identify the best strategy to estimate the internal radioactivity distribution in concrete waste during the decommissioning of NPPs. Four reconstruction algorithms, namely, simple back-projection, filtered back-projection, maximum likelihood expectation maximization (MLEM), and energy-deconvolution MLEM (E-MLEM) were used as Compton reconstruction algorithms. Subsequently, the results obtained by using these various reconstruction algorithms were compared with one another and evaluated, using quantitative evaluation methods. The MLEM and E-MLEM reconstruction algorithms exhibited the best performance in maintaining a high image resolution and signal-to-noise ratio (SNR), respectively. The results of this study demonstrate the feasibility of using Compton images in the estimation of the internal radioactive distribution of concrete during the decommissioning of NPPs.

참고문헌 (Reference)

1 이근영, "방사성 콘크리트 폐기물의 국내외 처리기술 개발 동향" 한국방사성폐기물학회 16 (16): 93-105, 2018

2 천주현, "기존 문헌 분석을 통한 원전 콘크리트 해체 폐기물 재활용 가능성에 대한 연구" 한국건설순환자원학회 6 (6): 115-122, 2018

3 S.G. Jeong, "Utilization on Industry of NPP Decommissioning of Large-Area Compton Imaging System for Concrete Internal Activation" 2019

4 Electric Power Research Institute, "Use of Portable Gamma Detector Systems During Decommissioning" EPRI 2019

5 P. T. Durrant, "The application of pinhole and coded aperture imaging in the nuclear environment" 422 (422): 667-671, 1999

6 전철승, "The Dismantling and Disposal Strategy of a Biological Shield for Minimization of Radioactive Concrete Waste During Decommissioning of a Nuclear Power Plant" 한국방사성폐기물학회 15 (15): 355-367, 2017

7 L. C. Parra, "Reconstruction of cone-beam projections from Compton scattered data" 47 (47): 1543-1550, 2000

8 International Atomic Energy Agency, "Managing Low Radioactivity Material from the Decommissioning of Nuclear Facilities" IAEA 2008

9 D.B. Pelowitz, "MCNP-A General Monte Carlo N Particle Transport Code, Version 5" Oak Ridge National Laboratory 2011

10 L. Parra, "List-mode likelihood : EM algorithm and image quality estimation demonstrated on 2-D PET" 17 (17): 228-2335, 1998

11 R. Reid, "Lessons Learned from EPRI Decommissioning Program-Decommissioning and Demolition" 2015

12 E. Michel-González, "Geometric nonlinear diffusion filter and its application to X-ray imaging" 10 (10): 2011

13 D. Xu, "Gamma-ray energy-imaging integrated spectral deconvolution" 574 (574): 98-109, 2007

14 E. E. Fenimore, "Coded aperture imaging with uniformly redundant arrays" 17 (17): 337-347, 1978

15 M. Singh, "An electronically collimated gamma camera for single photon emission computed tomography Part I : Theoretical consideration and design criteria" 10 : 421-427, 1983

16 C.H. Jumg, "A State of the Art on the Technology for Reduction and Reuse of the Decommissioning Concrete Wastes" Korea Atomic Energy Research Institute 1-5, 2008

17 C. E. Lehner, "4π Compton imaging using a 3-D position-sensitive CdZnTe detector via weighted list-mode maximum likelihood" 51 (51): 1618-1624, 2004