Verfication of matrix diffusion by means of natural decay series disequilibria in a profile across a water-conducting fracture in granitic rock

1989 ◽  
Vol 176 ◽  
Author(s):  
W.R. Alexander ◽  
I.G. McKinley ◽  
A.B. MacKenzie ◽  
R.D. Scott
Keyword(s):  
Safety Assessment ◽  
Crystalline Rock ◽  
Assessment Model ◽  
Base Case ◽  
Matrix Diffusion ◽  
Advective Flow ◽  
Model Base ◽  
Decay Series ◽  
Main Fracture ◽  
Natural Decay

ABSTRACTData from a rock drillcore, taken perpendicular to a water-bearing fracture in crystalline rock, clearly indicate water-rock interactions in and around the fracture. Although there is evidence of microfracturing at some distance from the main fracture, and therefore potential advective flow across the entire shear zone, simple calculations indicate that transport of Ra-226 in the vicinity of the main fracture can be described simply by matrix diffusion. This is a useful simplification for safety assessment studies and the consequences to the estimated radionuclide retardation in the vicinity of the fracture are discussed with respect to the probably over-conservative assumptions made in Nagra's safety assessment model base case.

An Analogue Validation Study of Natural Radionuclide Migration in Crystalline Rocks using Uranium-Series Disequilibrium Studies

1985 ◽  
Vol 50 ◽  
Author(s):  
J. A. T. Smellie ◽  
A. B. MacKenzie ◽  
R. D. Scott
Keyword(s):  
Natural Radionuclide ◽  
Hydrothermal Activity ◽  
Crystalline Rock ◽  
Crystalline Rocks ◽  
Radionuclide Migration ◽  
Uranium Series ◽  
Saturated Rock ◽  
Decay Series ◽  
Uranium Migration ◽  
Natural Decay

AbstractConcentrations and isotope ratios of natural decay series radionuclides have been studied in three contrasting crystalline rock drillcore sections intersecting water-conducting fractures deep in the bedrock. Radioactive disequilibria resulting from rock-water interactions were observed in two of the cores. These indicated uranium migration along distances of 40 cm or more on a timescale of 106 years in conjunction with thorium immobility under the same conditions. Fracture surface minerals showed a high affinity for radionuclide retardation and a limit of about 3 cm is suggested for the migration of radionuclides from fracture fluids into the saturated rock. This limit may correspond to enhanced matrix porosities resulting from earlier hydrothermal activity along the same channels.

Safety Assessment Method for Equipment of Urban Rail Transit Network Operation

2014 ◽  
Vol 513-517 ◽  
pp. 3958-3963 ◽  
Author(s):  
Bo Gao ◽  
Ling Xi Zhu ◽  
Xue Mei Xiao
Keyword(s):  
Safety Assessment ◽  
Spatial Information ◽  
Urban Rail Transit ◽  
Assessment Model ◽  
Rail Transit ◽  
Source Information ◽  
Transit Network ◽  
Urban Rail ◽  
Network Operation ◽  
Urban Rail Transit Network

Based on the multi-source information fusion and complex network theory, through studying the effective matching and integration of safety equipment and spatial information of urban rail transit network operation, a safety assessment model is proposed: through equipment fusion and the node fusion, the global safety parameter is obtained, which is accurate in description and evaluation of urban rail transit operating than the partial safety factors and realize the transform from microscopic description to macroscopic description.

Safety Assessment of Railway Dangerous Goods Transportation Based on Set Pair Analysis

2013 ◽  
Vol 869-870 ◽  
pp. 288-292
Author(s):  
Dong Jie Liu ◽  
Zhen Lin Wei
Keyword(s):  
Safety Assessment ◽  
Assessment Model ◽  
Engineering System ◽  
Set Pair Analysis ◽  
System Research ◽  
Analytic Hierarchy ◽  
Dangerous Goods ◽  
Index Weight ◽  
Hierarchy Process ◽  
Pair Analysis

In order to overcome the drawbacks that occur when traditional safety assessment methods do not consider the certain and uncertain characteristics of information and in order to enhance the calculation efficiency, a new Identical Discrepancy Contrary (IDC) system is safety comprehensive assessment model based on Set Pair Analysis is established. Incorporating the Analytic Hierarchy Process (AHP) to obtain the index weight, this model analyses the uncertainties in the degree of connection acquired by assessment, and then makes the identical discrepancy contrary system research on the certainty and uncertainty of information in the engineering system.

The JNC Generic URL Research Program - Providing a Knowledge Base to Support both Implementer and Regulator in Japan

2006 ◽  
Vol 932 ◽  
Author(s):  
Hiroyuki Umeki ◽  
Kazuhiko Shimizu ◽  
Toshihiro Seo ◽  
Akira Kitamura ◽  
Hirohisa Ishikawa
Keyword(s):  
Knowledge Base ◽  
Safety Assessment ◽  
Atomic Energy Commission ◽  
Phase 1 ◽  
Site Characterization ◽  
Crystalline Rock ◽  
Know How ◽  
Safety Regulations ◽  
Site Characteristics ◽  
Underground Research Laboratory

ABSTRACTIn accordance with the R&D framework specified by the Atomic Energy Commission of Japan in 2000 for the implementing phase of HLW disposal, the Japan Nuclear Cycle Development Institute (JNC) continues to be responsible for R&D activities aimed at enhancing the reliability of disposal technologies and safety assessment methodologies and associated databases. JNC has thus been actively promoting technical R&D with a view to contributing to both the implementation of disposal and the formulation of safety regulations.One of JNC's key roles is to establish and demonstrate site characterization methodologies based on investigations in two purpose-built generic URL (underground research laboratory) projects: one at Mizunami in crystalline rock and the other at Horonobe in sedimentary rock.Through the surface-based investigations in the Mizunami and Horonobe projects (phase 1), integration of work from different disciplines into a “geosynthesis” has been illustrated and is planned to be developed further in the underground facilities at these sites (phases 2 and 3). These projects also serve for developing and testing the tools and methodologies required for site characterization. Further know-how will be gained through participation in foreign underground laboratory projects, transfer of experience from these projects to Japan and tailoring it to Japanese conditions and requirements.This experience represents an important knowledge base, which is obviously important for the implementer but is also needed by the regulator, in order to assess how key site characteristics are derived and what uncertainties are associated with this process.

Time basis ship safety assessment model for a novel ship design

2013 ◽  
Vol 59 ◽  
pp. 179-189 ◽  
Author(s):  
Hee Jin Kang ◽  
Young-Soon Yang ◽  
Jin Choi ◽  
Jong-Kap Lee ◽  
Dongkon Lee
Keyword(s):  
Safety Assessment ◽  
Ship Design ◽  
Assessment Model ◽  
Time Basis ◽  
Ship Safety
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