• Title, Summary, Keyword: disposal repository

Search Result 191, Processing Time 0.063 seconds

DEPTH AND LAYOUT OPTIMIZATIONS OF A RADIOACTIVE WASTE REPOSITORY IN A DISCONTINUOUS ROCK MASS BASED ON A THERMOMECHANICAL MODEL

  • Kim, Jhin-Wung;Koh, Yong-Kwon;Bae, Dae-Seok;Choi, Jong-Won
    • Nuclear Engineering and Technology
    • /
    • v.40 no.5
    • /
    • pp.429-438
    • /
    • 2008
  • The objective of the present study is the depth and layout optimizations of a single layer, high level radioactive waste repository in a discontinuous rock mass with special joint set arrangements. A single layer repository model, considering variations in the repository depths, pitches, and tunnel spacings, is used to analyze the thermomechanical interaction behavior. It is assumed that the repository is constructed in saturated granite with joints; the PWR spent fuel in a disposal canister is installed in a deposition drift which is then sealed with compacted bentonite; and the backfill material is filled in the repository tunnel. The decay heat generated by the high level radioactive wastes governs the thermomechanical behavior of the near field rock mass of the repository. The temperature and displacement behavior of the repository is influenced more by the pitch variations than the tunnel spacing and repository depth. However, the stress behavior is influenced more by the repository depth variations than the pitch and tunnel spacing. For the final selection of the tunnel spacing, pitch, and repository depth, other aspects such as the nuclide migration through a groundwater flow path, construction costs, operation costs, and so on should be considered.

Emplacement Process of the HLW in the Deep Geological Repository (지하처분장에서의 고준위폐기물 처분공정 개념)

  • 이종열;김성기;조동건;최희주;최종원
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.1013-1016
    • /
    • 2004
  • High level radioactive wastes, such as spent fuels generated from nuclear power plant, will be disposed in a deep geological repository. To maintain the integrity of the disposal canister and to carry out the process effectively, the emplacement process for the canister system in borehole of disposal tunnel should be well defined. In this study, the concept of the disposal canister emplacement process for deep geological disposal was established. To do this, the spent fuel arisings and disposal rate were reviewed. Also, not only design requirements, such canister and disposal depth but also preliminary repository layout concept were reviewed. Based on the requirements and the other bases, the canister emplacement process in the borehole of the disposal tunnel was established. The established concept of the disposal canister emplacement process will be improved continuously with the future studies. And this concept can be effectively used in implementing the reference repository system of our own case.

  • PDF

Analysis of the Disposal Tunnel and Disposal Pit Spacing for the Spent Fuel Repository Layout (사용후핵연료 지하 처분장 배치를 위한 처분공 및 처분터널 간격 분석)

  • Lee, Jong-Youl;Lee, Yang;Choi, Heui-Joo;Choi, Jong-Won
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.4 no.4
    • /
    • pp.393-400
    • /
    • 2006
  • In design of a deep geological repository for the high level wastes, it is very important that the temperature of the bentonite block should not be over $100^{\circ}C$ to maintain the integrity of the bentonite buffer block from the decay heat. In this study, for the layout of the repository to meet the requirement, the analysis of the disposal tunnel and disposal pit spacing was carried out. To do this, based on the reference repository concept, several cases of cooling times and disposal tunnel and disposal pit spacing were compared. The thermal stabilities of the disposal systems were analyzed in terms of the cooling time and spacing. The results showed that it was more desirable to determine the layout of the repository in terms of disposal pit spacing than the disposal tunnel spacing. The results of these analyses can be used in the deep geological repository design. The detailed analyses with the exact site characteristics data will reduce the uncertainty of the results.

  • PDF

Technology Assessment of the Repository Alternatives to Establish a Reference HLW Disposal Concept

  • Choi, Jong-Won;Choi, Young-Sung;Kwon, Sang-Ki;Kuh, Jung-Eui;Kang, Chul-Hyung
    • Nuclear Engineering and Technology
    • /
    • v.31 no.6
    • /
    • pp.83-100
    • /
    • 1999
  • As disposal packaging concepts of spent fuels generated from the domestic NPP, two types, one is to package PWR and CANDU spent fuels in different containers and the other is to package them together, were proposed. The configuration of the containers and the layout of underground repository, such as the container spacing and the deposition tunnel spacing, were developed. The layout of underground repository satisfies the thermal constraint of the bentonite buffer surrounding disposal container, which should be lower than $100^{\circ}C$ in order to keep the physical and chemical properties of bentonite From the spent fuel packaging concepts and container emplacement methods, seven options were developed. With a typical pair-wise comparison methods, AHP, the most promising disposal concept was selected based on the technology Point of view.

  • PDF

Analysis of the Disposal Tunnel Spacing and Disposal Pit Pitch for the HLW Repository Design (심지층 처분시설 설계를 위한 처분터널 및 처분공 간격 분석)

  • Lee, Jong-Youl;Kim, Seong-Ki;Kim, Jhin-Wung;Choi, Jong-Won;Hahn, Pil-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.3 no.4
    • /
    • pp.349-358
    • /
    • 2005
  • In this study, analysis of the disposal tunnel spacing and disposal pit pitch was carried out, as a factor of the design to estimate the scale and layout of the repository. To do this, based on the reference repository concept and the engineered barrier concept, several cross sections of the disposal tunnel and disposal pit were established. After then, the mechanical and thermal stabilities of the established tunnels were analyzed. Also, an optimized disposal tunnel spacing and the disposal pit pitch reducing the excavation volume was proposed. The results of these analyses can be used in the deep geological repository design. The detailed analyses by the exact site characteristics data to reduce the uncertainty of the site and the modification for the optimization are required.

  • PDF

ASSESSMENT OF THE COST OF UNDERGROUND FACILITIES OF A HIGH-LEVEL WASTE REPOSITORY IN KOREA

  • Kim, Sung-Ki;Choi, Jong-Won
    • Nuclear Engineering and Technology
    • /
    • v.38 no.6
    • /
    • pp.561-574
    • /
    • 2006
  • This study presents the results of an economic analysis for a comparison of the single layer and double layer alternatives with respect to a HLW-repository. According to a cost analysis undertaken in the Korean case, the single layer option was the most economical alternative. The disposal unit cost was estimated to be 222 EUR/kgU. In order to estimate such a disposal cost, an estimation process was sought after the cost objects, cost drivers and economic indicators were taken into consideration. The disposal cost of spent fuel differs greatly from general product costs in the cost structure. Product costs consist of direct material costs and direct labor and manufacturing overhead costs, whereas the disposal cost is comprised of construction costs, operating costs and closure costs. In addition, the closure cost is required after a certain period of time elapses following the building of a repository.

Analysis of the Disposal Tunnel Spacing and Disposal Pit Pitch for the HLW Repository Design (심지층 처분시설 설계를 위한 처분터널 및 처분공 간격 분석)

  • 이종열;김성기;김진웅;최종원;한필수
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • /
    • pp.315-321
    • /
    • 2003
  • In this study, analysis of the disposal tunnel spacing and disposal pit pitch was carried out, as a factor of the design to estimate the scale and layout of the repository To do this, based on the reference repository concept and the engineered barrier concept, the cross section of the disposal tunnel and disposal pit are established and the mechanical and thermal stabilities of the tunnels are analyzed. Also, the optimized disposal tunnel spacing and the disposal pit pitch which minimize the excavation volume was proposed. The detailed analyses by the exact site characteristics data are needed to reduce the uncertainty of the site in the future.

  • PDF

Concept of the Encapsulation Process and Equipment for the Spent Fuel Disposal (심지층 처분을 위한 사용후핵연료 포장공정 장비개념 설정)

  • Lee J.Y.;Choi H.J.;Cho D.K.;Kim S.K.;Choi J.W.;Hahn P.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.470-473
    • /
    • 2005
  • Spent nuclear fuels are regarded as a high level radioactive waste and they will be disposed in a deep geological repository. To maintain the safety of the repository for hundreds of thousands of years, the spent fuels are encapsulated in a disposal canister and the canister containing spent fuels should have the structural integrity and the corrosion resistance below the several hundreds meters from the ground surface. In this study, the concept of the spent fuel encapsulation process and the process equipment fur deep geological disposal were established. To do this, the design requirements, such as the functions and the spent fuel accumulations, were reviewed. Also, the design principles and the bases were established. Based on the requirements and the bases, the encapsulation process and the equipment from spent fuel receiving process to transferring canister into the underground repository including hot cell processes was established. The established concept of the spent fuel encapsulation process and the process equipment will be improved continuously with the future studies. And this concept can be effectively used in implementing the reference repository system of our own case.

  • PDF

Overview of Finnish Spent Nuclear Fuel Disposal Programme

  • Siren, Topias
    • Journal of the Korean Society of Mineral and Energy Resources Engineers
    • /
    • v.54 no.4
    • /
    • pp.367-376
    • /
    • 2017
  • Finland is the first country in the world constructing the geological spent nuclear fuel disposal facility. The Finnish programme for spent nuclear fuel is organized through a private company Posiva Oy that has been established by the two power companies currently operating nuclear power plants in Finland to dispose owners spent nuclear fuel. First plans for the disposal of the spent nuclear fuel started already at 1978 when first studies for the geological disposal started. The planning was followed by the site selection programme, culminating to the selection of the Olkiluoto site as the disposal site in 2001 by decision in principle by Parlament of Finland. In 2004 the construction of the rock characterization facility ONKALO$^{TM}$ started on the disposal site. ONKALO has served in confirming underground site studies, while it has been designed to be an inseparable part of the final disposal facility. After 10 years of confirming studies in 2015, Posiva Oy, was granted the construction license for the final repository. In early 2020s the disposal of the spent nuclear fuel is expected to start in ONKALO.