• Title/Summary/Keyword: repository condition

Search Result 61, Processing Time 0.022 seconds

Knowledge Management Methodology in Design Repository (설계 저장소에시의 지식 관리 기법)

  • Eum K.H.;Kang M.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.73-74
    • /
    • 2006
  • Design repository is considered an effective method to manage a set of heterogeneous design knowledge. In this paper, methodologies for modeling and managing different types of design knowledge - ontology for mold design task as well as mold components, rule bases, and library containing standard parts, material property, molding condition, etc. - in a design repository are described.

  • PDF

The Modified Eulerian-Lagrangian Formulation for Cauchy Boundary Condition Under Dispersion Dominated Flow Regimes: A Novel Numerical Approach and its Implication on Radioactive Nuclide Migration or Solute Transport in the Subsurface Environment

  • Sruthi, K.V.;Suk, Heejun;Lakshmanan, Elango;Chae, Byung-Gon;Kim, Hyun-su
    • Journal of Soil and Groundwater Environment
    • /
    • v.20 no.2
    • /
    • pp.10-21
    • /
    • 2015
  • The present study introduces a novel numerical approach for solving dispersion dominated problems with Cauchy boundary condition in an Eulerian-Lagrangian scheme. The study reveals the incapability of traditional Neuman approach to address the dispersion dominated problems with Cauchy boundary condition, even though it can produce reliable solution in the advection dominated regime. Also, the proposed numerical approach is applied to a real field problem of radioactive contaminant migration from radioactive waste repository which is a major current waste management issue. The performance of the proposed numerical approach is evaluated by comparing the results with numerical solutions of traditional FDM (Finite Difference Method), Neuman approach, and the analytical solution. The results show that the proposed numerical approach yields better and reliable solution for dispersion dominated regime, specifically for Peclet Numbers of less than 0.1. The proposed numerical approach is validated by applying to a real field problem of radioactive contaminant migration from radioactive waste repository of varying Peclet Number from 0.003 to 34.5. The numerical results of Neuman approach overestimates the concentration value with an order of 100 than the proposed approach during the assessment of radioactive contaminant transport from nuclear waste repository. The overestimation of concentration value could be due to the assumption that dispersion is negligible. Also our application problem confirms the existence of real field situation with advection dominated condition and dispersion dominated condition simultaneously as well as the significance or advantage of the proposed approach in the real field problem.

A Numerical analysis of Underground Repository Cavern in Korean Crystalline rocks (우리나라 결정질암내 동굴처분장에 대한 수치해석)

  • 윤건신
    • The Journal of Engineering Geology
    • /
    • v.1 no.1
    • /
    • pp.68-84
    • /
    • 1991
  • A numerical analysis using Universal Distinct Element Code program for the nuclear waste disposal cavern has been performed for a typical Korean crystalline rock condition with same geometry of Swedish low and intermediate nuclear waste disposal repository(S.F.R). The stress concentration, displacement and safety factor for the typical single cross section of cavern, 5 caverns and a silo are analyzed.

  • PDF

Evaluation of mechanical properties of KURT granite under simulated coupled condition of a geological repository (복합 처분환경 모사조건에서의 KURT 화강암의 역학적 물성 변화 평가)

  • Park, Seunghun;Kim, Jin-Seop;Kim, Geon Young;Kwon, Sangki
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.21 no.4
    • /
    • pp.501-518
    • /
    • 2019
  • The rock properties measured under in-situ geological condition can be used to increase the reliability in numerical simulations with regard to the long-term performance of a high-level waste repository. In this study, the change in mechanical properties of KURT (Korea atomic energy research institute Underground Research Tunnel) granite was evaluated under the simulated THM (Thermo-Hydro-Mechanical) coupled condition due to a deep geological formation in the disposal repository. The rock properties such as uniaxial compression strength, indirect tensile strength, elastic modulus and Poisson's ratio were measured under the coupled test conditions (M, HM, TM, THM). It was found that the mechanical properties of KURT granite is more susceptible to the change in saturation rather than temperature within the test condition of this study. The changes in uniaxial compression strength and indirect tensile strength from the rock samples of dried or saturated conditions showed the maximum relative error of about 20% and 13% respectively under the constant temperature condition. Therefore, it is necessary to use the material properties of rock measured under the coupled THM condition as input parameters for the numerical simulation of long-term performance assessment of a disposal repository

Validation of Performance of Engineered Barriers in a Geological Repository: Review of In-Situ Experimental Approach (심지층처분장 공학적방벽 성능 실증: 현장실험적 접근법 검토)

  • Cho, Won-Jin;Kim, Geon Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.16 no.2
    • /
    • pp.137-164
    • /
    • 2018
  • The guarantee of the performance of the engineered barriers in a geological repository is very important for the long-term safety of disposal as well as the efficient design of the repository. Therefore, the performance of the engineered barriers under repository condition should be demonstrated by in-situ experiments conducted in an underground research laboratory. This article provides a review of the major in-situ experiments that have been carried out over the past several decades at underground research laboratories around the world to validate the performance of engineered barriers of a repository, as well as their results. In-situ experiments to study the coupled thermal-hydraulic-mechanical behavior of the engineered barrier system used to simulate the post-closure performance of the repository are analyzed as a priority. In addition, in-situ experiments to investigate the performance of the buffer material under a real repository environment have been reviewed. State-of-the art in-situ validations of the buffer-concrete interaction, and the installation of the buffer, backfill and plug, as well as characterization of the near-field rock and the corrosion of the canister materials are, also performed.

Long-term leach rates of simulated borosilicate waste glasses under a repository condition (처분환경조건에서 모의 방사성폐기물 붕규산유리고화체의 장기침출률)

  • 전관식;김승수;최종원
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.1 no.1
    • /
    • pp.41-46
    • /
    • 2003
  • To understand the long-term leach behavior of a borosilicate Waste glass in a repository, the leaching experiment with three kinds of simulated borosilicate waste glasses has been carried out since the middle of 1997. The five years results indicate that a boron would be applied as an indicator of a long-term leaching of their borosilicate waste glasses and that their long-term leach rates have a tendency to be close to about 0.03g/$m^2$-day even though their compositions and their ratios of the surface area to the volume of leachate are different.

  • PDF

Policy Acceptance's Change and Forecasting: Simulation Modelling for High Level Radioactive Repository Site (정책수용성의 변화와 예측: 고준위방사성폐기물처분장 입지사례)

  • Oh, Young-Min
    • Korean System Dynamics Review
    • /
    • v.12 no.1
    • /
    • pp.39-57
    • /
    • 2011
  • This paper is the result of simulation modeling concerning high-level radioactive waste repository(HLRWR) and people's mind for the facility. We describe a procedure of simulation modeling for resident's policy acceptance and perceived risk of HLRWR facility by using System Dynamics approach. To Complete some complicated works, we made the 20 pieces of stock-flow diagrams based on the causal loop diagram that is a blue print of whole variables and relations. The simulation outputs clearly show that cental government efforts to siting the HLRWR will be failed if nothing to give for the region's residents. On the contrary, a monetary incentive and a regional development program help to turn this gloomy situation into a desirable and acceptable condition dramatically. Government has to prepare the schemes considering the HLRWR acceptance and total supporting program including the cash and local development programs.

  • PDF

A Representation of Engineering Change Objects and Their Integrity Constraints Using an Active Object-Oriented Database Model (능동형 객체지향적 데이터베이스 모텔을 이용한 설계변경 개체 및 제약조건의 표현)

  • 도남철
    • Journal of Information Technology Applications and Management
    • /
    • v.10 no.1
    • /
    • pp.111-125
    • /
    • 2003
  • This paper proposes a product data model that can express and enforce integrity constraints on product structure during engineering changes (ECs). The model adopts and extends an active object-oriented database model in order to Integrate IC data and their integrity constraints. Tightly integrated with product structure, It will enable designers to maintain and exchange consistent EC data throughout the product life cycle. In order to properly support operations for ECs, the model provides the data, operations, and Event-Condition-Action rules for nested ECs and simultaneous EC applications to multiple options. in addition, the EC objects proposed In the model integrate the data and Integrity constraints into a unified repository. This repository enables designers to access all EC data and integrity constraints through the product structure and relationships between EC objects. This paper also describes a prototype product data management system based on the proposed model In order to demonstrate its effectiveness.

  • PDF

Statistical analysis of effects of test conditions on compressive strength of cement solidified radioactive waste

  • Hyeongjin Byeon;Jaeyeong Park
    • Nuclear Engineering and Technology
    • /
    • v.55 no.3
    • /
    • pp.876-883
    • /
    • 2023
  • Radioactive waste should be solidified before being disposed of in the repository to eliminate liquidity or dispersibility. Cement is a widely used solidifying media for radioactive waste, and cement solidified waste should satisfy the minimum compressive strength of the waste acceptance criteria of a radioactive repository. Although the compressive strength of waste should be measured by the test method provided by the waste acceptance criteria, the method differs depending on the operating repository of different countries. Considering the measured compressive strength changes depending on test conditions, the effect of test conditions should be analyzed to avoid overestimation or underestimation of the compressive strength during disposal. We selected test conditions such as the height-to-diameter ratio, loading rate, and porosity as the main factors affecting the compressive strength of cement solidified radioactive waste. Owing to the large variance in measured compressive strength, the effects of the test conditions were analyzed via statistical analyses using parametric and nonparametric methods. The results showed that the test condition of the lower loading rate, with a height-to-diameter ratio of two, reflected the actual cement content well, while the porosity showed no correlation. The compressive strength assessment method that reflects the large variance of strengths was suggested.