Sensitivity and uncertainty analysis applied to one-dimensional radionuclide transport in a layered fractured rock. Part 1: Analytical solutions and local sensitivities

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Nuclear Technology; (United States)

OSTI ID:6032965

Gureghian, A B; Wu, Yihtsuen; Sagar, B ^[1]; Codell, R B ^[2]

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1. Southwest Research Institute, San Antonio, TX (United States)
2. U.S. Nuclear Regulatory Commission, Washington, DC (United States)

Exact analytical solutions based on Laplace transforms are derived for describing the one-dimensional space- and time-dependent advective transport of a decaying species in a layered, fractured, saturated rock system. The rock layers are parallel and horizontal and of uniform thickness. The fracture intersects normally to the rock layers and is of varying aperture across its length. The fracture network is serial in nature and of uniform thickness within each layer. Fluid movement is assumed to be exclusive to the fracture network. These solutions, which account for advection in fracture, molecular diffusion into the rock matrix, adsorption in both fracture and matrix, and radioactive decay, predict the concentrations in both fracture and rock matrix and the cumulative mass in the fracture. The solute migration domain in both fracture and rock is assumed to be semi-infinite with nonzero initial conditions. The concentration of each nuclide at the source is allowed to decay either continuously or according to some periodical fluctuations where both are subjected to either a step or band release mode. Two numerical examples related to the transport of [sup 237]Np and [sup 245]Cm in a five-layered system of fractured rock are used to verify these solutions with several well-established evaluation methods of Laplace inversion integrals in the real and complex domain. In addition, with respect to the model parameters, a comparison of the analytically derived local sensitivities for the concentration and cumulative mass of [sup 237]Np in the fracture with the ones obtained through a finite difference method of approximation is also reported.

• OSTI ID: 6032965
• Journal Information: Nuclear Technology; (United States), Journal Name: Nuclear Technology; (United States) Vol. 104:2; ISSN 0029-5450; ISSN NUTYBB
• Country of Publication: United States
• Language: English

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ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
ANALYTICAL SOLUTION
CURIUM 245
CURIUM ISOTOPES
DATA COVARIANCES
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
EVEN-ODD NUCLEI
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
HEAVY NUCLEI
HIGH-LEVEL RADIOACTIVE WASTES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MANAGEMENT
MASS TRANSFER
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NANOSEC LIVING RADIOISOTOPES
NEPTUNIUM 237
NEPTUNIUM ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE MANAGEMENT
RADIOACTIVE WASTES
RADIOISOTOPES
RADIONUCLIDE MIGRATION
ROCKS
SENSITIVITY ANALYSIS
SPONTANEOUS FISSION RADIOISOTOPES
UNDERGROUND DISPOSAL
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
YEARS LIVING RADIOISOTOPES