Publications

Results 26–50 of 116
Skip to search filters

Technology readiness assessment process adapted to geologic disposal of HLW/SNF

ANS IHLRWM 2017 - 16th International High-Level Radioactive Waste Management Conference: Creating a Safe and Secure Energy Future for Generations to Come - Driving Toward Long-Term Storage and Disposal

Sevougian, S.D.; MacKinnon, R.J.

Technology Readiness Assessment (TRA) is a formal process to aid in defining the remaining R&D needed to bring a new, complex technology system to full technical maturity. A geologic repository for high-level radioactive waste is a prototypical complex system, comprised of novel technologies and complex environmental conditions, but because it is intended to function passively and is comprised of both engineered and geologic barriers, the standard, engineered-system ("hardware") TRA process must be modified. Longstanding precedence employs a Safety Case (or Licensing Case) as the preferred vehicle for assembling all facets of knowledge to make a determination of repository system safety and deployment readiness. However, certain modifications to the established TRA process allow it to be applied advantageously in conjunction with the Safety Case. In particular, an adaptation of the established Features, Events, and Processes (FEPs) methodology can serve as a basis for a "TRA-like" maturity evaluation for various major components and subsystems of a deep geologic repository. The newly proposed Knowledge Readiness Assessment (KRA) process combines the best of both methodologies, i.e., of FEPs analysis and standard TRA evaluation, for establishing confidence in the post-closure performance of major repository components and subsystems.

More Details
TYPE Conference Poster YEAR 2017
ScopusOSTI

Deep Borehole Disposal Safety Analysis

Freeze, Geoffrey A.; Stein, Emily S.; Price, Laura L.; MacKinnon, R.J.; Tillman, Jackie B.

This report presents a preliminary safety analysis for the deep borehole disposal (DBD) concept, using a safety case framework. A safety case is an integrated collection of qualitative and quantitative arguments, evidence, and analyses that substantiate the safety, and the level of confidence in the safety, of a geologic repository. This safety case framework for DBD follows the outline of the elements of a safety case, and identifies the types of information that will be required to satisfy these elements. At this very preliminary phase of development, the DBD safety case focuses on the generic feasibility of the DBD concept. It is based on potential system designs, waste forms, engineering, and geologic conditions; however, no specific site or regulatory framework exists. It will progress to a site-specific safety case as the DBD concept advances into a site-specific phase, progressing through consent-based site selection and site investigation and characterization.

More Details
TYPE Other Report YEAR 2016
OSTIDOI

Deep Borehole Field Test Laboratory and Borehole Testing Strategy

Kuhlman, Kristopher L.; Brady, Patrick V.; MacKinnon, R.J.; Heath, Jason; Herrick, Courtney G.; Jensen, Richard P.; Gardner, W.P.; Sevougian, Stephen D.; Bryan, Charles R.; Jang, Jay J.; Stein, Emily S.; Bauer, Stephen J.; Daley, Tom D.; Freifeld, Barry M.; Birkholzer, Jens T.; Spane, Frank A.

Deep Borehole Disposal (DBD) of high-level radioactive wastes has been considered an option for geological isolation for many years (Hess et al. 1957). Recent advances in drilling technology have decreased costs and increased reliability for large-diameter (i.e., ≥50 cm [19.7”]) boreholes to depths of several kilometers (Beswick 2008; Beswick et al. 2014). These advances have therefore also increased the feasibility of the DBD concept (Brady et al. 2009; Cornwall 2015), and the current field test design will demonstrate the DBD concept and these advances. The US Department of Energy (DOE) Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013) specifically recommended developing a research and development plan for DBD. DOE sought input or expression of interest from States, local communities, individuals, private groups, academia, or any other stakeholders willing to host a Deep Borehole Field Test (DBFT). The DBFT includes drilling two boreholes nominally 200m [656’] apart to approximately 5 km [16,400’] total depth, in a region where crystalline basement is expected to begin at less than 2 km depth [6,560’]. The characterization borehole (CB) is the smaller-diameter borehole (i.e., 21.6 cm [8.5”] diameter at total depth), and will be drilled first. The geologic, hydrogeologic, geochemical, geomechanical and thermal testing will take place in the CB. The field test borehole (FTB) is the larger-diameter borehole (i.e., 43.2 cm [17”] diameter at total depth). Surface handling and borehole emplacement of test package will be demonstrated using the FTB to evaluate engineering feasibility and safety of disposal operations (SNL 2016).

More Details
TYPE Other Report YEAR 2016
OSTIDOI

A Control Variate Method for Probabilistic Performance Assessment. Improved Estimates for Mean Performance Quantities of Interest

MacKinnon, R.J.; Kuhlman, Kristopher L.

We present a method of control variates for calculating improved estimates for mean performance quantities of interest, E(PQI) , computed from Monte Carlo probabilistic simulations. An example of a PQI is the concentration of a contaminant at a particular location in a problem domain computed from simulations of transport in porous media. To simplify the presentation, the method is described in the setting of a one- dimensional elliptical model problem involving a single uncertain parameter represented by a probability distribution. The approach can be easily implemented for more complex problems involving multiple uncertain parameters and in particular for application to probabilistic performance assessment of deep geologic nuclear waste repository systems. Numerical results indicate the method can produce estimates of E(PQI)having superior accuracy on coarser meshes and reduce the required number of simulations needed to achieve an acceptable estimate.

More Details
TYPE SAND Report YEAR 2016
OSTIDOI
Results 26–50 of 116
Results 26–50 of 116