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Repository Safety Strategy: Strategy for Protecting Public Health and Safety after Closure of a Yucca Mountain Repository, Rev. 1

Description: The updated Strategy to Protect Public Health and Safety explains the roles that the natural and engineered systems are expected to play in achieving the objectives of a potential repository system at Yucca Mountain. These objectives are to contain the radionuclides within the waste packages for thousands of years, and to ensure that annual doses to a person living near the site will be acceptably low. This strategy maintains the key assumption of the Site Characterization Plan (DOE 1988) strategy that the potential repository level (horizon) will remain unsaturated. Thus, the strategy continues to rely on the natural attributes of the unsaturated zone for primary protection by providing a setting where waste packages assisted by other engineered barriers are expected to contain wastes for thousands of years. As in the Site Characterization Plan (DOE 1988) strategy, the natural system from the walls of the underground openings (drifts) to the human environment is expected to provide additional defense by reducing the concentrations of any radionuclides released from the waste packages. The updated Strategy to Protect Public Health and Safety is the framework for the integration of site information, repository design and assessment of postclosure performance to develop a safety case for the viability assessment and a subsequent license application. Current site information and a reference design are used to develop a quantitative assessment of performance to be compared with a performance measure. Four key attributes of an unsaturated repository system that are critical to meeting the objectives: (1) Limited water contacting the waste packages; (2) Long waste package lifetime; (3) Slow rate of release of radionuclides from the waste form; and (4) Concentration reduction during transport through engineered and natural barriers.
Date: January 1, 1998
Creator: United States. Department of Energy.
Partner: UNT Libraries Government Documents Department

Preliminary Saturated-Zone Flow Model

Description: This milestone consists of an updated fully 3D model of ground-water flow within the saturated zone at Yucca Mountain, Nevada. All electronic files pertaining to this deliverable have been transferred via ftp transmission to Steve Bodnar (M and O) and the technical data base. The model was developed using a flow and transport simulator, FEHMN, developed at Los Alamos National Laboratory, and represents a collaborative effort between staff from the US Geological Survey and Los Alamos National Laboratory. The model contained in this deliverable is minimally calibrated and represents work in progress. The flow model developed for this milestone is designed to feed subsequent transport modeling studies at Los Alamos which also use the FEHMN software. In addition, a general-application parameter estimation routine, PEST, was used in conjunction with FEHMN to reduce the difference between observed and simulated values of hydraulic head through the adjustment of model variables. This deliverable in large part consists of the electronic files for Yucca Mountain Site saturated-zone flow model as it existed as of 6/6/97, including the executable version of FEHMN (accession no. MOL.19970610.0204) used to run the code on a Sun Ultrasparc I workstation. It is expected that users of the contents of this deliverable be knowledgeable about the oration of FEHMN.
Date: June 10, 1997
Partner: UNT Libraries Government Documents Department

PREDICTING WATER ACTIVITY IN ELECTROLYTE SOLUTIONS WITH THE CISTERNAS-LAM MODEL

Description: Water activity is an important parameter needed to predict the solubility of hydrated salts in Hanford nuclear waste supernatants. A number of models available in the scientific literature predict water activity from electrolyte solution composition. The Cisternas-Lam model is one of those models and has several advantages for nuclear waste application. One advantage is that it has a single electrolyte specific parameter that is temperature independent. Thus, this parameter can be determined from very limited data and extrapolated widely. The Cisternas-Lam model has five coefficients that are used for all aqueous electrolytes. The present study aims to determine if there is a substantial improvement in making all six coefficients electrolyte specific. The Cisternas-Lam model was fit to data for six major electrolytes in Hanford nuclear waste supernatants. The model was first fit to all data to determine the five global coefficients, when they were held constant for all electrolytes it yielded a substantially better fit. Subsequently, the model was fit to each electrolyte dataset separately, where all six coefficients were allowed to be electrolyte specific. Treating all six coefficients as electrolyte specific did not make sufficient difference, given the complexity of applying the electrolyte specific parameters to multi-solute systems. Revised water specific parameters, optimized to the electrolytes relevant to Hanford waste, are also reported.
Date: March 1, 2011
Creator: JG, REYNOLDS; DA, GREER & RL, DISSELKAMP
Partner: UNT Libraries Government Documents Department

Development of the Flow Sheet for Incinerating Contaminated Combustible Waste: Engineering Research Final Report

Description: From introduction: This report serves as a recommendation that a full-scale incineration process be installed at Mound Laboratory and provides a complete flow sheet for this process and recommended designs for the critical parts of the processing equipment. It contains justification for the process, a history of the investigation including early work and pilot plant results, an explanation of the values and information given in the flow sheet, and the reasons for the recommended design features.
Date: May 15, 1951
Creator: McEwen, M.; Schauer, P. J. & Aponyi, T.
Partner: UNT Libraries Government Documents Department

PROBABILISTIC SENSITIVITY AND UNCERTAINTY ANALYSIS WORKSHOP SUMMARY REPORT

Description: Stochastic or probabilistic modeling approaches are being applied more frequently in the United States and globally to quantify uncertainty and enhance understanding of model response in performance assessments for disposal of radioactive waste. This increased use has resulted in global interest in sharing results of research and applied studies that have been completed to date. This technical report reflects the results of a workshop that was held to share results of research and applied work related to performance assessments conducted at United States Department of Energy sites. Key findings of this research and applied work are discussed and recommendations for future activities are provided.
Date: June 25, 2008
Creator: Seitz, R
Partner: UNT Libraries Government Documents Department

REAL TIME DATA FOR REMEDIATION ACTIVITIES [11505]

Description: Health physicists from the CH2M HILL Plateau Remediation Company collaborated with Berkeley Nucleonics Corporation to modify the SAM 940 isotope identifier instrument to be used for nuclear waste remediation. These modifications coupled with existing capabilities of the SAM 940 have proven to be invaluable during remediation activities, reducing disposal costs by allowing swift remediation of targeted areas that have been identified as having isotopes of concern (IOC), and eliminating multiple visits to sites by declaring an excavation site clear of IOCs before demobilizing from the site. These advantages are enabled by accumulating spectral data for specific isotopes that is nearly 100 percent free of false positives, which are filtered out in 'real time.'
Date: January 13, 2011
Creator: CT, BROCK
Partner: UNT Libraries Government Documents Department

Results From an International Simulation Study on Couples Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories

Description: As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.
Date: August 2, 2006
Creator: Rutqvist, J.; Barr, D.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O.; Liu, Q. et al.
Partner: UNT Libraries Government Documents Department

Comparative Simulation Syudy of Coupled THM Processes near Back-Filled and Open-Drift Nuclear Waste Repositories in Task D of International DECOVALEX Project

Description: As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near underground waste emplacement drifts. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower post-closure temperature, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses are currently being resolved. Good agreement in the basic thermal-mechanical responses was also achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglect complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.
Date: May 8, 2006
Creator: Rutqvist, J.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O.; Liu, Q.S.; Oda, Y. et al.
Partner: UNT Libraries Government Documents Department

ANALYSIS OF MPC ACCESS REQUIREMENTS FOR ADDITION OF FILLER MATERIALS

Description: This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) in response to a request received via a QAP-3-12 Design Input Data Request (Ref. 5.1) from WAST Design (formerly MRSMPC Design). The request is to provide: Specific MPC access requirements for the addition of filler materials at the MGDS (i.e., location and size of access required). The objective of this analysis is to provide a response to the foregoing request. The purpose of this analysis is to provide a documented record of the basis for the response. The response is stated in Section 8 herein. The response is based upon requirements from an MGDS perspective.
Date: September 3, 1996
Creator: Wallin, W.
Partner: UNT Libraries Government Documents Department

The use of TOUGH2/iTOUGH2 in support of the Yucca MountainProject: Successes and limitations

Description: The TOUGH2/iTOUGH2 family of codes is being used to analyze various processes and phenomena in the unsaturated zone at the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. Various models have been developed that help quantify properties of the volcanic tuffs, water flow, seepage into drifts, and thermally driven coupled processes arising from the heat emitted by radioactive waste. These models are based on various assumptions and approximations that are generally accepted in the literature, but can give rise to different degrees of uncertainty. Some of the key approaches utilized include the continuum approximation, the van Genuchten formulation, the active fracture model, and homogeneous sublayers. These and other approximations are presented separately for the five different models considered, and the resulting levels of uncertainty are discussed.
Date: May 12, 2003
Creator: Bodvarsson, G. S.; Birkholzer, J. T.; Finsterle, S.; Liu, H. H.; Rutqvist, J. & Wu, Y. S.
Partner: UNT Libraries Government Documents Department

Discovery of Apparent Inconsistency Between Saltstone Waste Acceptance Criteria and the Saltstone Performance Assessment

Description: The intent of this document is to provide an evaluation to determine if the discovered condition (apparent inconsistency between the Saltstone Waste Acceptance Criteria (WAC) and the Saltstone PA) is within the assumptions, parameters, and bases of the approved PA and CA. If it is, then this document serves as the technical basis for authorizing the condition. If not, then, in order to authorize the activity, the PA and CA would need to be updated as appropriate and DOE approval sought of the update (special analysis or revision of the PA or CA).
Date: June 3, 2002
Creator: Wilhite, E.L.
Partner: UNT Libraries Government Documents Department

Feed Basis for Processing Relatively Low Radioactivity Waste Tanks

Description: This paper presents the characterization of potential feed for processing relatively low radioactive waste tanks. The feed characterization is based on waste characterization data extracted from the waste characterization system. This data is compared to salt cake sample results from Tanks 37, 38, and 41.
Date: February 18, 2003
Creator: Jones (contact), R.T.
Partner: UNT Libraries Government Documents Department

Using Modeling and Simulation to Analyze Application and Network Performance at the Radioactive Waste and Nuclear Material Disposition Facility

Description: Telecommunication services customers at the Radioactive Waste and Nuclear Material Disposition Facility (RWNMDF) have endured regular service outages that seem to be associated with a custom Microsoft Access Database. In addition, the same customers have noticed periods when application response times are noticeably worse than at others. To the customers, the two events appear to be correlated. Although many network design activities can be accomplished using trial-and-error methods, there are as many, if not more occasions where computerized analysis is necessary to verify the benefits of implementing one design alternative versus another. This is particularly true when network design is performed with application flows and response times in mind. More times than not, it is unclear whether upgrading certain aspects of the network will provide sufficient benefit to justify the corresponding costs, and network modeling tools can be used to help staff make these decisions. This report summarizes our analysis of the situation at the RWNMDF, in which computerized analysis was used to accomplish four objectives: (1) identify the source of the problem; (2) identify areas where improvements make the most sense; (3) evaluate various scenarios ranging from upgrading the network infrastructure, installing an additional fiber trunk as a way to improve local network performance, and re-locating the RWNMDF database onto corporate servers; and (4) demonstrate a methodology for network design using actual application response times to predict, select, and implement the design alternatives that provide the best performance and cost benefits.
Date: June 1, 2003
Creator: LIFE, ROY A.; MAESTAS, JOSEPH H. & BATEMAN, DENNIS B.
Partner: UNT Libraries Government Documents Department

Rheology Modifiers for Radioactive Waste Slurries

Description: The goals of this study were to determine if trace levels of chemical additives could be used to reduce the rheological characteristics of radioactive waste slurries, identify potential chemical additives for this work and future testing, test a limited set of chemical additive candidates on simulated radioactive wastes, and develop advanced techniques to visualize the internal slurry structure and particle-particle interaction within the slurry.
Date: February 19, 2003
Creator: Calloway, T.B. Jr.
Partner: UNT Libraries Government Documents Department