• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.367-384
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• 2016

Many countries have developed a safety case suitable to their own countries in order to improve the confidence of disposal safety in deep geological disposal of high-level radioactive waste as well as to develop a disposal program and obtain its license. This study introduces and summarizes the meaning, necessity, and development process of the safety case for radioactive waste disposal. The disposal safety is also discussed in various aspects of the safety case. In addition, the status of safety case development in the foreign countries is briefly introduced for Switzerland, Japan, the United States of America, Sweden, and Finland. The strategy for the safety case development that is being developed by KAERI is also briefly introduced. Based on the safety case, we analyze the efforts necessary to improve confidence in disposal safety for high-level radioactive waste. Considering domestic situations, we propose and discuss some implementing methods for the improvement of disposal safety, such as construction of a reliable information database, understanding of processes related to safety, reduction of uncertainties in safety assessment, communication with stakeholders, and ensuring justice and transparency. This study will contribute to the understanding of the safety case for deep geological disposal and to improving confidence in disposal safety through the development of the safety case in Korea for the disposal of high-level radioactive waste.

• The Journal of Engineering Geology
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• v.34 no.1
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• pp.117-136
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• 2024

Deep geological disposal of high-level radioactive waste is imperative to national safety and environmental protection and it relies on establishing siting criteria suited to the geological and social conditions of each country. This paper compares the various geological and social criteria applied by different countries in the process of securing sites for the deep geological disposal of high-level radioactive waste. The present comparative analysis considers the siting criteria established by the worlds leading countries in high-level radioactive waste disposal with the aims of establishing detailed criteria appropriate to Korea's conditions and applying the criteria to explore safe and suitable sites for deep geological disposal. The findings of this research are expected to serve as a foundation for establishing criteria for the selection of disposal sites for high-level radioactive waste in Korea and are anticipated to contribute significantly to sustainable national development and environmental protection.

• Tunnel and Underground Space
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• v.34 no.1
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• pp.28-53
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• 2024

In general, high-level radioactive waste (HLW) generated as a result of nuclear power generation should be disposed within the country. Determination of the disposal site and host rock for HLW deep geological repository is an important issue not only scientifically but also politically, economically, and socially. Considered host rock types worldwide for geological disposal include crystalline rocks, sedimentary rocks, volcanic rocks, and salt dome. However, South Korea consists of various rock types except salt dome. This paper not only analyzed the geological and rock mechanical characteristics on a nationwide scale with the preliminary results on various rock type studies for the disposal host rock, but also reviewed the characteristics and possibility of various rock types as a host rock through deep drilling surveys. Based on the nationwide screening for host rock types resulted from literature review, rock distributions, and detailed case studies, Jurassic granites and Cretaceous sedimentary rocks (Jinju and Jindong formations) were derived as a possible candidate host rock types for the geological disposal. However, since the analyzed data for candidate rock types from this study is not enough, it is suggested that the disposal rock type should be carefully determined from additional and detailed analysis on disposal depth, regional characteristics, multidisciplinary investigations, etc.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.4
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• pp.447-457
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• 2019

Japan enacted the "Designated Radioactive Waste Final Disposal Act" for the geological disposal of high-level radioactive waste in 2000 and began the site selection process. However, no local government wanted to participate in the siting process. Therefore, in 2015, the Japanese government developed a new site selection process during the literature survey step, and on June 28, 2017 they published a "Nationwide Map of Scientific Features for Geological Disposal" created with the aim of promoting public participation from local governments. This map illustrated the requirements and criteria to be considered in the early or conceptual stages of securing a geological repository and was useful for improving public understanding and exchanging opinions with local governments by analyzing the suitability of different geological disposal sites.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.435-450
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• 2022

In step-by-step site selection for geological disposal of high-level radioactive waste, parameters necessary for site selection will be acquired through deep drilling surveys from the basic survey stage. Unlike site investigations of rock mass structures such as tunnels and underground oil storage facilities, those related to the geological disposal of high-level radioactive waste are not only conducted in relatively deep depths, but also require a high level of quality control. In this report, based on the 750 m depth drilling experience conducted to acquire the parameters necessary for deep geological disposal, the methodology for deep drilling and the geology, geophysics, geochemistry, hydrogeology and rock mechanics obtained before, during, and after deep drilling are discussed. The procedures for multidisciplinary geoscientific investigations were briefly described. Regarding in-situ stress, one of the key evaluation parameter in the field of rock engineering, foreign and domestic cases related to the geological disposal of high-level radioactive waste were presented, and variations with depth were presented, and matters to be considered or agonized in acquiring evaluation parameters were mentioned.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.133-141
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• 2012

The impacts influenced on the performance and safety of a repository are classified as units of Features, Events, and Processes (FEP), for the total system performance assessment (TSPA) related to the permanent disposal of HLW. The importance is evaluated in consideration of the frequency, consequence, regulation, suitability of a specific site, etc. and then these are grouped as a similar FEP. A scenario describing the migration of radionuclide from the repository to the biosphere is derived from understanding the interaction among these groups. KAERI has developed the KAERI FEP lists by review and collation of the foreign studies. The KAERI FEP list has been reviewed by several Korean experts. The five major scenarios describing possible future evolutions of the geological disposal system have been developed by RES and PID methods. Also the CYPRUS which is a KAERI integrated database management system for the total system performance assessment (TSPA) related to the permanent disposal of HLW has been developed and the results of the FEP and scenario development have been uploaded in this system.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.05a
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• pp.157-158
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• 2016

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.229-230
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• 2016

• Economic and Environmental Geology
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• v.56 no.6
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• pp.887-897
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• 2023

Leading waste disposal countries, such as Sweden, Switzerland, and the United Kingdom, conduct safety assessments across all stages of High-Level Radioactive Waste Deep Geological Disposal Facilities-from planning and site selection to construction, operation, closure, and post-closure management. As safety assessments are repeatedly performed at each stage, generating vast amounts of diverse data over extended periods, it is essential to construct a database for safety assessment and establish a data management system. In this study, the safety assessment data management systems of leading countries, were analyzed, categorizing them into 1) input and reference data for safety assessments, 2) guidelines for data management, 3) organizational structures for data management, and 4) computer systems for data management. While each country exhibited differences in specific aspects, commonalities included the classification of safety assessment input data based on disposal system components, the establishment of organizations to supply, use, and manage this data, and the implementation of quality management systems guided by instructions and manuals. These cases highlight the importance of data management systems and document management systems for securing the safety and enhancing the reliability of High-Level Radioactive Waste Disposal Facilities. To achieve this, the classification of input data that can be flexibly and effectively utilized, ensuring the consistency and traceability of input data, and establishing a quality management system for input data and document management are necessary.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.312-338
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• 2023

The underground disposal facility for spent nuclear fuel demands a specialized design, distinct from conventional practices, to ensure long-term thermal, mechanical, and hydraulic integrity, preventing the release of radioactive isotopes from high-temperature spent nuclear fuel. SKB has established design criteria for such facilities and executed practical design implementations for Forsmark. Moreover, in response to subsurface uncertainty, SKB has proposed an empirical approach involving monitoring and adaptive design modifications, alongside stepwise development. SKB has further introduced a unique support system, categorizing ground types and behaviors and aligning them with corresponding support types to confirm safety through comparative analyses against existing systems. POSIVA has pursued a comparable approach, developing a support system for Onkalo while accounting for distinct geological characteristics compared to Forsmark. This demonstrates the potential for domestic implementation of spent nuclear fuel disposal facility designs and the establishment of a support system adapted to national attributes.