Description of Fracture Systems for External Criticality Reports

Technical Report · Wed Sep 19 00:00:00 EDT 2001

DOI:https://doi.org/10.2172/790319· OSTI ID:790319

Nicot, Jean-Philippe ^[1]

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1. Yucca Mountain Project, Las Vegas, NV (United States)

The purpose of this Analysis/Model Report (AMR) is to describe probabilistically the main features of the geometry of the fracture system in the vicinity of the repository. They will be used to determine the quantity of fissile material that could accumulate in the fractured rock underneath a waste package as it degrades. This AMR is to feed the geochemical calculations for external criticality reports. This AMR is done in accordance with the technical work plan (BSC (Bechtel SAIC Company) 2001 b). The scope of this AMR is restricted to the relevant parameters of the fracture system. The main parameters of interest are fracture aperture and fracture spacing distribution parameters. The relative orientation of the different fracture sets is also important because of its impact on criticality, but they will be set deterministically. The maximum accumulation of material depends primarily on the fracture porosity, combination of the fracture aperture, and fracture intensity. However, the fracture porosity itself is not sufficient to characterize the potential for accumulation of a fracture system. The fracture aperture is also important because it controls both the flow through the fracture and the potential plugging of the system. Other features contributing to the void space such as lithophysae are also investigated. On the other hand, no analysis of the matrix porosity is done. The parameters will be used in sensitivity analyses of geochemical calculations providing actinide accumulations and in the subsequent Monte Carlo criticality analyses.

• Research Organization: Yucca Mountain Project, Las Vegas, NV (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); USDOE Office of Civilian Radioactive Waste Management (RW)
• OSTI ID: 790319
• Report Number(s): ANL-NBS-GS-000010-Rev.00; MOL.20010925.0197 , DC 26199; TRN: US0502257
• Resource Relation: Other Information: PBD: 21 Sep 2001
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
ACTINIDES
APERTURES
CRITICALITY
DISTRIBUTION
FISSILE MATERIALS
FRACTURES
GEOMETRY
ORIENTATION
PLUGGING
POROSITY
SENSITIVITY
WASTES
Nuclear Criticality Safety Program (NCSP)
Monte Carlo
Criticality Analyses
AMR
Software
Quality Assurance
Hydraulic Apertures
Lithophysae