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Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Shih-Hai Li, Shean-Lang Chiou
Nuclear Technology | Volume 104 | Number 2 | November 1993 | Pages 258-271
Technical Paper | Special Issue on Waste Management / Radioactive Waste Management | doi.org/10.13182/NT93-A34889
Articles are hosted by Taylor and Francis Online.
An analytical solution based on Laplace transforms is developed for the problem of radionuclide transport along a discrete planar fracture in porous rock. The solution takes into account advective transport in the fracture, longitudinal hydrodynamic dispersion in the fracture along the fracture axis, molecular diffusion from the fracture into the rock matrix, sorption within the rock matrix, sorption onto the surface of the fracture, and radioactive decay. The longitudinaldispersion-free solution, which is of closed form, is also reported. The initial radionuclide concentrations in both the fracture and the rock matrix are assumed to be zero. A kinetic solubility-limited dissolution model is used as the inlet boundary condition. In addition to the radionuclide concentrations in both the fracture and the rock matrix, the mass flux in fracture is provided. The analytical solution is in the form of a single integral that is evaluated by a Gauss-Legendre quadrature for each point in space and time. As the dissolution rate constant approaches infinity, the inlet boundary condition of the kinetic solubility-limited dissolution model can be replaced by the boundary condition of constant concentration, as is shown by numerical illustration. Restated, the constant concentration boundary condition represents a conservative upper limit to the solubility-limited dissolution rate. Diffusion into the rock matrix enhances the dissolution rate, even though it can also enhance the retardation of solute transport in fracture. This analytical solution has been verified by the results generated from a numerical inversion of the Laplace transforms. The agreement is excellent.