• Tunnel and Underground Space
• /
• v.14 no.6 s.53
• /
• pp.429-439
• /
• 2004

The deep underground High Level Waste (HLW) repository to dispose of 36,000tons of spent fuel from the reactors in Korea needs about $4km^2$ repository area. In this study, the deep undergrond repository layout was optimized to minimize the excavation rock volume as well as underground repository area. In the optimization, the results from thermal analysis were used to define the influence of tunnel and deposition hole spacings on repository layout. The repository area and excavation rock volume could be reduced with longer disposal tunnel length. When it is necessary to reduce the repository area with satisfying thermal criteria, it is better to reduce tunnel spacing and increase deposition hole spacing. In contrast, the excavation rock volume can be reduced by increasing the tunnel spacing and decreasing the hole spacing.

• 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.

• Nuclear Engineering and Technology
• /
• v.32 no.3
• /
• pp.244-253
• /
• 2000

A Simple Large Model (SLM), which can be used to make thermal calculation for a deep geological repository with finite number of HLW canisters, was developed. In order to develop the SLM, a Simple Basic Model (SBM), which will be a unit of the SLM, was optimized first. The SBM was optimized to achieve the same maximum buffer temperature as that of the Detailed Basic Model (DBM) representing the real geometric aspects of the repository. In contrast to the models with the assumption of infinite number of canisters which cannot consider boundary effect, the SLM can model the real repository with finite number of canisters and thus consider the boundary effect. Thermal results from the SLM can be used to evaluate the reliability of the models, which do not consider boundary effect. This model can also be used to simulate the thermal layout design and to analyze the thermal safety of a deep geological repository as well as an underground laboratory.

• 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.

• 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.

• 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.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• 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.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2004.05a
• /
• pp.395-400
• /
• 2004

This study is that STEP based Data Repository of APR1400 Nuclear Power Plant Reactor Coolant System is developed. The STEP based Data Repository is accessed by Web-based and an attribute data of Reactor Coolant System Equipment is offered. Also, a P&ID drawing file & 3D CAD Model of Reactor Coolant System is loaded. The P&ID drawing file of Reactor Coolant System Equipment Model is connected with 3D CAD Model file. This 2D/3D CAD Model connected Prototype system confirms a real layout of Reactor Coolant System.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• 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.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2005.11b
• /
• pp.225-235
• /
• 2005

This paper outlined the status of the development of Korean Reference Disposal (KRS­1) system for high-level radioactive wastes. The repository concept was based on the engineering barrier system which KAERI has developed through a long-term research and development program. The design requirements were prepared for the conceptual design of the repository. The amount of PWR and CANDU spent fuels were projected with the current nuclear power plan. The disposal rates of PWR and CANDU spent fuels were analyzed. The reference geologic characteristics including classification of fracture zones were set for the KRS. The disposal concepts and the layout of the repository were described.