• 제목/요약/키워드: Near surface disposal

검색결과 64건 처리시간 0.035초

Water Balance Evaluation of Final Closure Cover for Near- surface Radioactive Wastes Disposal Facility

  • Keunmoo Chang;Park, Joo-Wan;Yoon, Jeong-Hyoun;Park, Heui-Joo;Kim, Chang-Lak
    • Nuclear Engineering and Technology
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    • 제32권3호
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    • pp.274-282
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    • 2000
  • The simulation of water balance was conducted for suggested four alternative multi-layer cover design of near-surface radioactive waste disposal facility under domestic climate condition. The analysis was also conducted for the most favorable one out of four alternative cover design under conservative scenarios. Until 100 years after closure of disposal vault, the infiltration flux for the most favorable cover design was negligible even under doubling of the ambient precipitation condition. When the degradation of asphalt and geomembrane after 100 years of closure was considered, the infiltration flux significantly increased almost to the design criteria of cover system in I' Aube disposal facility. And it was found that the hydraulic conductivity of bentonite/sand as a bottom barrier should be no greater than 1$\times$10$^{-7}$ cm/sec recommended by U.S. EPA.

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Artificial Rainfall Test of the Engineered Cover Barriers for Near Surface Disposal of LILW

  • Park, Jin-Beak;Park, Se-Moon;Kim, Chang-Lak
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.306-314
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    • 2003
  • Engineered barrier test facility is specially designed to demonstrate the performance of engineered barrier system for the near-surface disposal facility under the domestic environmental conditions. Comprehensive measurement systems for the water content, temperature, matric potential are installed within each test cell. In this study, short-term monitoring of the behavior of multi-layered cover system is implemented with artificial rainfall system. The periodic measurement data are collected and analyzed by a dedicated database management system, and provide a basis for performance verification of the disposal cover design.

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Important Radionuclides and Their Sensitivity for Ground water Pathway of a Hypothetical Near-Surface Disposal Facility

  • Park, J. W.;K. Chang;Kim, C. L.
    • Nuclear Engineering and Technology
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    • 제33권2호
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    • pp.156-165
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    • 2001
  • A radiological safety assessment was performed for a hypothetical near-surface radioactive waste repository as a simple screening calculation to identify important nuclides and to provide insights on the data needs for a successful demonstration of compliance. Individual effective doses were calculated for a conservative ground water pathway scenario considering well drilling near the site boundary. Sensitivity of resulting ingestion dose to input parameter values was also analyzed using Monte Carlo sampling. Considering peak dose rate and assessment time scale, C-14 and T-129 were identified as important nuclides and U-235 and U-238 as potentially important nuclides. For C-14, the dose was most sensitive to Darcy velocity in aquifer The distribution coefficient showed high degree of sensitivity for I-129 release.

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국내 천층처분시설 방사성폐기물 수용요건 및 이행체계 수립 (Establishment of Radioactive Waste Acceptance Requirements for Near-Surface Repository)

  • 정찬우;안상면;이윤근;석태원;박상훈
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.261-265
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    • 2003
  • 현행 중ㆍ저준위방사성폐기물 인도규정의 개정에 초점을 맞추어 국내 천층처분시설에 대한 폐기물 수용요건의 개발 및 이행 방안을 제시한다. 개정안은 방사성폐기물 세부분류, 표층처분 방사능농도제한, 핵종 inventory 평가 등에 관한 구체적인 기준을 담고 있으며, 그 이행을 위하여 처분전 폐기물관리, 처분시설 안전성평가, 처분시스템 등과의 합리적인 연계를 모색한다.

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폐밀봉선원 처분시스템 예비 폐쇄후 안전성평가 (Preliminary Post-closure Safety Assessment of Disposal System for Disused Sealed Radioactive Source)

  • 이승희;김주열
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제22권4호
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    • pp.33-48
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    • 2017
  • An optimum disposal plan of disused sealed radioactive sources (DSRSs) should be established to ensure long-term disposal safety at the low- and intermediate-level radioactive waste (LILW) disposal facility in Gyeongju. In this study, an optimum disposal system was suggested and preliminary post-closure safety assessment was performed. The DSRSs disposal system was composed of a rock cavern and near surface disposal facilities at the Gyeongju LILW disposal facility. The assessment was conducted using GoldSim program, and probabilistic assessment and sensitivity analysis were implemented to evaluate the uncertainties in the input parameters of natural barriers. Deterministic and probabilistic calculations indicated that the maximum dose was below the regulatory limits ($0.1mSvyr^{-1}$ for the normal scenario, $1mSvyr^{-1}$ for the well scenario). It was concluded that the DSRSs disposal system would maintain environmental safety over a long-time. Moreover, the partition coefficient of Np in host rock, Darcy velocity in host rock, and density of the host rock were the most sensitive parameters in predicting exposure dose in the safety assessment.