A Method for Operational Safety Assessment of a Deep Geological Repository for Spent Fuels

  • Received : 2020.08.31
  • Accepted : 2020.09.17
  • Published : 2020.11.30


The operational safety assessment is an important part of a safety case for the deep geological repository of spent fuels. It consists of different stages such as the identification of initiating events, event tree analysis, fault tree analysis, and evaluation of exposure doses to the public and radiation workers. This study develops a probabilistic safety assessment method for the operational safety assessment and establishes an assessment framework. For the event and fault tree analyses, we propose the advanced information management system for probabilistic safety assessment (AIMS-PSA Manager). In addition, we propose the Radiological Safety Analysis Computer (RSAC) program to evaluate exposure doses to the public and radiation workers. Furthermore, we check the applicability of the assessment framework with respect to drop accidents of a spent fuel assembly arising out of crane failure, at the surface facility of the KRS+ (KAERI Reference disposal System for SNFs). The methods and tools established through this study can be used for the development of a safety case for the KRS+ system as well as for the design modification and the operational safety assessment of the KRS+ system.


  1. International Atomic Energy Agency. The Safety Case and Safety Assessment for the Disposal of Radioactive Waste, IAEA Specific Safety Guide No. SSG-23, IAEA, Vienna (2012).
  2. U.S. Department of Energy. Yucca Mountain Repository License Application, Safety analysis report, U.S. DOE Report, DOE/RW-0573 (2008).
  3. B. Dasgupta, G. Adams, R. Benke, R.K. Johnson, and M. Waters, "Safety Assessment Tool Developed for Nuclear Fuel Handling Facility", Proc. of the 8th Int. Conf. on Probabilistic Safety Assessment & Management (PSAM), May 14-19, 2006, New Orleans.
  4. T. Maxwell, B. Dasgupta, G. Adams, R. Benke, and N. Eisenberg, "PCSA Tool Version 3.0 User Guide", Center for Nuclear Waste Regulatory Analyses (2005).
  5. K. Yamashina, S, Suzuki, and S. Kubota, "Preliminary Study of Pre-closure Safety Assessment in the NUMO Safety Case", Proc. of 6th East Asia Forum on Radwaste Management Conference, November 27-29, 2017, Osaka.
  6. J. Jeong, J.W. Choi, and C.H. Kang. High-level Waste Long-term Management Technology Development: Radwaste Disposal Safety Analysis/Integrated Safety Assessment of a Waste Repository, Korea Atomic Energy Research Institute Report, KAERI/RR-3455/2011 (2012).
  7. J.W. Kim, D.K. Cho, N.Y. Ko, J. Jeong, and M.H. Baik, "Model Development for Risk-based Safety Assessment of a Geological Disposal System of Radioactive Wastes Generated by Pyro-processing of PWR Spent Fuel in Korea", Nucl. Technol., 203(1), 1-16 (2018).
  8. POSIVA Oy. Safety Case for the Disposal of Spent Nuclear Fuel at Olkiluoto, POSIVA Oy Report, TRUVA-2012 (2012).
  9. A. Hedin. Long-term Safety for KBS-3 Repositories at Forsmark and Laxemar-a First Evaluation, Svensk Karnbranslehantering AB Technical Report, SKBTR-06-09 (2006).
  10. U.S. Nuclear Regulatory Commission. Probabilistic Safety Analysis Procedures Guide, U.S. NRC Report, NUREG/CR-2815 (1984).
  11. S.H. Han, S.H. Kim, J.J. Ha, and J.E. Yang. Integrated PSA Analysis Software AIMS, AIMS-EzASQ 1.0, Registered No. 2005-01-129-2504 (2005).
  12. D.R. Wenzel. The Radiological Safety Analysis Program (RSAC-5) User's Manual, Westinghouse Idaho Nuclear Company Report, WINCO-1123, Rev. 1 (1994).
  13. J.W. Choi, H.J. Choi, S.G. Kim, and K.S. Chun. HighLevel Radwaste Disposal Technology Development, Korea Atomic Energy Research Institute Report, KAERI/RR-2765/2006 (2006).
  14. J. Jeong, M.H. Baik, and K.S. Kim, "Establishment of an Operational Safety Assessment Framework for a High-Level Radioactive Waste Repository", Proc. of the 13th Int. Conf. on Probabilistic Safety Assessment and Management (PSAM 13), October 2-7, 2016, Seoul.
  15. Bechtel SAIC Companny. Design Calculation or Analysis Cover Sheet - Initial Handling Facility Event Sequence Development Analysis, Bechtel SAIC Companny Document, 51A-PSA-IH00-00100-000-00A (2008).
  16. U.S. Nuclear Regulatory Commission. Technical Assessment Generic Issue 186: Potential Risk and Consequences of Heavy Load Drops in Nuclear Power Plants, U.S. NRC Report, Draft-XXXX (ML012620352) (2001).