Waste Package Reliability / Nalysis

1983 ◽  
Vol 26 ◽  
Author(s):  
C. Pescatore ◽  
C. Sastre
Keyword(s):  
Ordinary Sense ◽  
Regulatory Requirements ◽  
Package Design ◽  
Waste Package ◽  
Qualitative And Quantitative ◽  
Future Performance ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Package Reliability ◽  
General Method

ABSTRACTProof of future performance of a complex system such as a high-level nuclear waste package over a period of hundreds to thousands of years cannot be had in the ordinary sense of the word. The general method of probabilistic reliability analysis could provide an acceptable framework to identify, organize, and convey the information necessary to satisfy the criterion of reasonable assurance of waste package performance according to the regulatory requirements set forth in 10 CFR 60. General principles which may be used to evaluate the qualitative and quantitative reliability of a waste package design are indicated and illustrated with a sample calculation of a repository concept in basalt.

A Modest Proposal: A Robust, Cost-Effective Design for High-Level Waste Packages

1997 ◽  
Vol 506 ◽  
Author(s):  
M.J. Apted
Keyword(s):  
Mild Steel ◽  
Cost Effective ◽  
High Level Waste ◽  
Package Design ◽  
Waste Package ◽  
Modest Proposal ◽  
Proposal A ◽  
Cost Efficient ◽  
High Level ◽  
Effective Design

ABSTRACTAn alternative waste-package design for the geological disposal of high-level waste (HLW) glass is presented. In conventional designs, a massive buffer of compacted bentonite is placed around a thick-walled, mild-steel overpack; in the revised design, a much thinner buffer is placed within a thin-walled, mild-steel overpack. This simple expedient eliminates certain performance concerns in existing waste-package designs, while not necessitating the study of any new materials. This integrated waste package (IWP) design has comparable release-rate performance as current package designs for HLW. In addition, the 1WP design requires far-less rock excavation, permits significantly higher temperatures for longer periods, leads to a 20-50% reduction in repository area, and is more cost efficient than previous designs.

Evaluation of the Susceptibility of Astm A216 Grade Wca Mild Steel to Stress Corrosion Cracking in Simulated Salt Repositopy Environments

1986 ◽  
Vol 84 ◽  
Author(s):  
S. G. Pitman
Keyword(s):  
Mild Steel ◽  
Stress Corrosion ◽  
Nuclear Waste ◽  
Dynamic Tests ◽  
Static Tests ◽  
Waste Package ◽  
Test Conditions ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Container Material

AbstractIn current conceptual designs, a mild steel (ASTM A?16 Grade WCA) is the relerence container material for use in high level nuclear waste packages intended for emplacement in a salt repository. The resistance of the steel to stress corrosion crackinq (SCC) is being investigated as part of the effort underway to verify the suitability of the material for waste package applications. Static tests (U-bend and bolt-loaded fracture toughness specimens) and dynamic tests (slow strain rate and corrosion fatigue) were conducted on both as-cast and weldment specimens of the material, in both low-Mg and high-Mg halite-saturated brines, in the temperature range of 90 to 200°C. The investigations indicate that the steel is not susceptible to SCC under the test conditions employed.

Corrosion Model Validation in High Level Nuclear Waste Package Research

1992 ◽  
Vol 294 ◽  
Author(s):  
M. B. Mcneil ◽  
J.B. Moody
Keyword(s):  
Site Specific ◽  
Waste Package ◽  
Naturally Occurring ◽  
Widespread Acceptance ◽  
Natural Analogues ◽  
High Level Nuclear Waste ◽  
Mineral Alteration ◽  
High Level ◽  
Performance Validation

ABSTRACTThe strategies for waste package (WP) performance validation will be based on site specific geologic and hydrogeochemical information plus models which can be used to predict potential WP lifetimes. The development and application of such models will include the evaluation of natural analogues (NA). These analogues are needed to resolve issues related to the validation of models. Natural analogues have not had extensive use or widespread acceptance in the area of waste package failure prediction. This lack of acceptance is due to the anticipated choice of alloys for waste package containers. Few of these alloys are similar to naturally occurring metals, and the proposed HLW repositories are in general in geologic settings not very similar to those in which naturally occurring metals are generally found.Natural and archaeological analogues can be used, however, in analysis of possible waste package failures as a means of testing proposed models for failure. In fact, the analogues are the only available mechanisms for testing models of long-term waste package behavior. A strategy is outlined for incorporating natural and archaeological analogue studies into waste package research, and examples are discussed. The natural/archaeological analogues approach which appears most promising is to use archaeological and mineral samples to develop an understanding of the identities and rates of the mineral alteration reactions at or near the surface of the package, improving present capability for estmating the lifetimes of metallic waste package containers.

scholarly journals Total-System Performance Assessment for the Yucca Mountain Site

2002 ◽  
Vol 713 ◽  
Author(s):  
Michael L. Wilson ◽  
Peter N. Swift ◽  
Jerry A. McNeish ◽  
S. David Sevougian
Keyword(s):  
Performance Assessment ◽  
System Performance ◽  
Safety Assessment ◽  
Yucca Mountain ◽  
Total System ◽  
Package Design ◽  
Waste Package ◽  
Igneous Activity ◽  
Nominal Performance ◽  
High Level

ABSTRACTYucca Mountain, Nevada, is under consideration as a potential site for a repository for high-level radioactive waste. Total-system performance-assessment simulations are performed to evaluate the safety of the site. Features, events, and processes have been systematically evaluated to determine which ones are significant to the safety assessment. Computer models of the disposal system have been developed within a probabilistic framework, including both engineered and natural components. Selected results are presented for three different total-system simulations, and the behavior of the disposal system is discussed. The results show that risk is dominated by igneous activity at early times, because the robust waste-package design prevents significant nominal (non-disruptive) releases for tens of thousands of years or longer. The uncertainty in the nominal performance is dominated by uncertainties related to waste-package corrosion at early times and by uncertainties in the natural system, most significantly infiltration, at late times.

scholarly journals Functions of the Materials Review Board

1984 ◽  
Vol 44 ◽  
Author(s):  
M. J. Steindler ◽  
W. B. Seefeldt
Keyword(s):  
Nuclear Waste ◽  
Environmental Protection Agency ◽  
Nuclear Regulatory Commission ◽  
Department Of Energy ◽  
Waste Package ◽  
Performance Predictions ◽  
High Level Nuclear Waste ◽  
Regulatory Commission ◽  
High Level ◽  
Nuclear Waste Policy

Some nuclear waste is destined for disposal in deep geological formations. The disposal system for wastes from commercial nuclear activities, and perhaps also for high-level wastes from defense-related activities, is to be designed and operated by the Department of Energy (DOE) and licensed by the Nuclear Regulatory Commission (NRC). The Nuclear Waste Policy Act [1] outlines some of the procedures and schedules that are to be followed by DOE in carrying out its assignment in the disposal of high-level nuclear waste (HLW). The regulations of the NRC that deal with HLW [2] are only partly in place, and amendments (e.g., related to the unsaturated zone) are yet to be approved and issued. The Environmental Protection Agency (EPA) has issued only draft versions of the regulations pertaining to HLW disposal [3], but key features of these drafts are at present in adequate agreement with NRC documents. On the basis of the trends that have become evident in the last few years, the DOE will be required to substantiate performance predictions for all pertinent aspects of a repository, especially the performance of the engineered waste package. The basis for demonstrating that the waste package performance in the repository will be in concert with the requirements is data on the waste package materials. These key materials data must clearly be highly reliable, and DOE will be required to assure this reliability. This paper addresses the organization and functions that have been assembled to aid in establishing the quality of materials data that are important in the licensing of a waste repository.

Development of a Backfill for Containment of High-Level Nuclear Waste

1981 ◽  
Vol 11 ◽  
Author(s):  
Floyd N. Hodges ◽  
Joseph H. Westsik ◽  
Lane A. Bray
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Nuclear Waste ◽  
Release Rate ◽  
Sodium Bentonite ◽  
Waste Package ◽  
Diffusivity Measurements ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Host Rocks

ABSTRACTSodium and calcium bentonites, pressed to densities between 1.9 and 2.2 g/cm3, have hydraulic conductivities in the range of 10−11 to 10−13 cm/s. Batch sorption distribution ratios (Rd) indicate that Sr, Cs, and Am are strongly sorbed on bentonites and zeolites, that Np and U are moderately sorbed on bentonites and zeolites, and that Am, Np, U, I, and Tc are strongly sorbed on charcoal. Sorption results with basalt and tuff ground waters are similar; however, iodine in tuff ground water sorbs more strongly on bentonites Thermal diffusivity measurements for dry, compacted (p ∼ 2.1 g/cm3) sodium bentonite indicate that the thermal conductivity of a high density bentonite backfill should be roughly similar to that of silicate host rocks (basalt, granite, tuff). These results indicate that a bentonite backfill can significantly delay the first release of many radionuclides into the host rock and that by forming a diffusion barrier a bentonite backfill can significantly decrease the longterm release rate of radionuclides from the waste package.

A Review Process and a Database for Waste-Package Documents

1990 ◽  
Vol 212 ◽  
Author(s):  
Charles G. Interrante ◽  
Carla A. Messina ◽  
Anna C. Fraker
Keyword(s):  
Information Needs ◽  
Review Process ◽  
Nuclear Regulatory Commission ◽  
Waste Package ◽  
Long Term Storage ◽  
High Level Nuclear Waste ◽  
Regulatory Commission ◽  
High Level ◽  
Term Storage

ABSTRACTThe work reported here is part of a program conducted by the Nuclear Regulatory Commission on the efficacy of proposed plans for radionuclide containment for long-term storage of high-level nuclear waste (HLW). An important element of that program is the review and evaluation of available literature on components of a waste package. A review process and a database have been developed and tailored to provide information quickly to an individual who has a question about a particular material or component of a waste package. The database is uniquely suited to serve as a guide to indicate special areas where data and information needs exist on questions related to radionuclide containment. Additions to the database are made as information becomes available, and this source is as current as the published literature. A description of the review process and the database is given.

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