32 Matching Results

Search Results

Advanced search parameters have been applied.

Statistical Sampling Plans for Prior Measurement Verification and Determination of the SNM Content of Inventories

Description: Current regulations require that prior information on the Special Nuclear Material (SNM) content o f a population o f containers be verified and that periodic measurements o f the SNM inventory of a facility be performed. This report develops and describes statistical sampling plans for accomplishing these tasks and compares results obtained by sampling to those obtained by the current practice o f performing a census (100% sampling)
Date: March 1, 1982
Creator: Piepel, G. F. & Brouns, R. J.
Partner: UNT Libraries Government Documents Department

Strategy for addressing composition uncertainties in a Hanford high-level waste vitrification plant

Description: Various requirements will be imposed on the feed material and glass produced by the high-level waste (HLW) vitrification plant at the Hanford Site. A statistical process/product control system will be used to control the melter feed composition and to check and document product quality. Two general types of uncertainty are important in HLW vitrification process/product control: model uncertainty and composition uncertainty. Model uncertainty is discussed by Hrma, Piepel, et al. (1994). Composition uncertainty includes the uncertainties inherent in estimates of feed composition and other process measurements. Because feed composition is a multivariate quantity, multivariate estimates of composition uncertainty (i.e., covariance matrices) are required. Three components of composition uncertainty will play a role in estimating and checking batch and glass attributes: batch-to-batch variability, within-batch uncertainty, and analytical uncertainty. This document reviews the techniques to be used in estimating and updating composition uncertainties and in combining these composition uncertainties with model uncertainty to yield estimates of (univariate) uncertainties associated with estimates of batch and glass properties.
Date: March 1, 1996
Creator: Bryan, M.F. & Piepel, G.F.
Partner: UNT Libraries Government Documents Department

Strategy for product composition control in the Hanford Waste Vitrification Plant

Description: The Hanford Waste Vitrification Plant (HWVP) will immobilize transuranic and high-level radioactive waste in borosilicate glass. The major objective of the Process/Product Model Development (PPMD) cost account of the Pacific Northwest Laboratory HWVP Technology Development (PHTD) Project is the development of a system for guiding control of feed slurry composition (which affects glass properties) and for checking and documenting product quality. This document lays out the broad structure of HWVP`s product composition control system, discusses five major algorithms and technical issues relevant to this system, and sketches the path of development and testing.
Date: March 1, 1996
Creator: Bryan, M.F. & Piepel, G.F.
Partner: UNT Libraries Government Documents Department

Preliminary Feed Test Algorithm for the Hanford Waste Vitrification Plant product composition control system

Description: The Feed Test Algorithm (FTA) will test the acceptability (conformance with requirements) of process batches in the Hanford Waste Vitrification Plant (HWVP). Although requirements and constraints will be imposed on properties of the material in the melter and the resulting glass, the FTA must test acceptability while the batch is still in the Slurry Mix Evaporator (SME), i.e., before material is transferred to the Melter Feed Tank. Hence, some properties upon which requirements will be imposed must be estimated from data available on the feed slurry. The major type of data to be used in this estimation is feed composition, usually expressed in terms of nine oxide mass fractions and a catchall tenth category, Others. Uncertainties are inherent in the HWVP process. The two major or types of uncertainty are composition uncertainty (that related to measurement and estimation of feed composition and other quantities) and model uncertainty (uncertainty inherent in the models developed to relate melt/glass properties to feed composition). Types of uncertainties, representation of uncertainty, and a method for combining uncertainties are discussed. The FTA must account for these uncertainties in testing acceptability; hence it must be statistical in nature. Three types of statistical intervals (confidence, prediction, and tolerance) are defined, and their roles in acceptance testing are discussed.
Date: March 1, 1996
Creator: Bryan, M.F. & Piepel, G.F.
Partner: UNT Libraries Government Documents Department

Predicting primary crystalline phase and liquidus temperature above or below 1050{degrees}C as functions of glass composition

Description: This report presents the results of applying statistical empirical modeling techniques to primary crystalline phase at the liquidus temperature (T{sub L}) and (ii) whether liquidus temperature is above or below 1050{degree}C (1OO{degree}C below a melting temperature of 1150{degree}C). Data used in modeling primary crystalline phase and liquidus temperate are from the Composition Variability Study (CVS) of Hanford waste glass compositions and properties. The majority of the 123 CVS glasses are categorized into one of 13 primary crystalline phases (at the liquidus temperature). They are also classified as to having T{sub L} Above or Below 1050{degree}C. Two common statistical methods used to model such categorical data are the multinomial logit and classification tree models. The classification tree models provided an overall better modeling approach than did the multinomial logit models. The performance of models in this report should be compared to the performance of the revised ``Development of Models and Software for Liquidus Temperature of Glasses of HWVP Products`` models from Ecole Polytechnique. If the Ecole Polytechnique models perform better than the models discussed in this report, no additional effort on these models would be needed. However, if the converse is true, it may be worthwhile to invest additional effort on statistical empirical modeling methods.
Date: February 1, 1996
Creator: Redgate, P.E. & Piepel, G.F.
Partner: UNT Libraries Government Documents Department

Viscosity, electrical conductivity, and cesium volatility of ORNL (Oak Ridge National Laboratory) vitrified soils with limestone and sodium additives

Description: Engineering- and pilot-scale tests of the in situ vitrification (ISV) process have been conducted for Oak Ridge National Laboratory (ORNL) to successfully demonstrate the feasibility of applying ISV to seepage trenches and pits at ORNL. These sites contain soil that overlies crushed limestone fill; therefore, the ISV process is applied to a soil-limestone mixture. Previous testing indicated that while a good retention level of {sup 137}Cs and {sup 90}Sr was achieved in the melt, it would be desirable to improve {sup 137}Cs retention to 99.99% if possible to minimize activity in the off-gas system. Previous testing was limited to one soil-limestone composition. Both Cs volatility and ISV power requirements are in part dependent on melt temperature and viscosity, which depend on melt composition. The study described in this report determined the effect of varying soil and limestone compositions, as well as the addition of a sodium flux, on melt viscosity, electrical conductivity, and Cs volatility. 10 refs., 15 figs., 9 tabs.
Date: May 1, 1990
Creator: Shade, J.W. & Piepel, G.F.
Partner: UNT Libraries Government Documents Department

Evaluation of experimental factors that influence the application and discrimination capability of the product consistency test

Description: It is desirable to have a means of monitoring possible changes in waste glass durability during protection so that the product remains within acceptable limits. A leach test called the Product Consistency test (PCT) was developed by Savannah River Laboratory (SRL) as such a production test for the Defense Waste Processing Facility (DWPF). This report examines some of the experimental factors that may be used in the PCT that could influence test precision and its ability to function as intended. An experiment was performed to investigate the effects (on pH and elemental releases of Al, Fe, K, Na, Si, B, Li, and Mn) of modifications to the test conditions of the Product Consistency Test (PCT). The experiment was replicated three times; each replicate involved leach testing two glasses with each of 24 different sets of PCT conditions. 6 refs., 1 fig., 12 tabs.
Date: June 1, 1991
Creator: Shade, J.W. & Piepel, G.F.
Partner: UNT Libraries Government Documents Department

Leach testing of simulated Hanford Waste Vitrification Plant reference glass HW-39

Description: This report summarizes the work performed to investigate the viability of a leach testing methodology for the Hanford Waste Vitrification Plant (HWVP) and provide glass dissolution data for HWVP model determination and validation. Leach tests up to one year in duration were conducted on the HWVP reference glass HW-39-1 (1.3 wt % Cr/sub 2/O/sub 3/), using the Materials Characterization Center Static Leach Test (MCC-1) and the Agitated Powder Leach Test (MCC-3). Glass surface area to leachate volume (SA/V) ratios of 10, 530, 2000, and 20,000 m/sup /minus/1/ were investigated during testing. The data resulting from the leach tests were statistically analyzed to evaluate the testing methodology. Based on these analyses, changes are recommended in the leach testing methodology, including changes in the randomization and replication plans to provide for better statistical characterization of glass durability. The statistical evaluation of the test data found that the current leach testing methodology provides the necessary data for calculating some of the sources of variability in the test results, but not others. Proposed additions and modifications to the testing methodology will provide for collecting the data required to estimate the other variance components so that defensible statistical qualification statements can be made. 17 refs., 15 figs., 5 tabs.
Date: May 1, 1989
Creator: Bates, S.O.; Piepel, G.F. & Johnston, J.W.
Partner: UNT Libraries Government Documents Department

Property/Composition Relationships for Hanford High-Level Waste Glasses Melting at 1150{degrees}C. Volume 2: Chapters 12-16 and Appendices A-K

Description: A Composition Variation Study (CVS) is being performed within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) project in support of a future high-level nuclear waste vitrification plant at the Hanford site in Washington. From 1989 to 1994, over 120 nonradioactive glasses were melted and properties measured in five statistically-designed experimental phases. Glass composition is represented by the 10 components SiO{sub 2}, B{sub 2}O{sub 3}, ZrO{sub 2}, Na{sub 2}O, Li{sub 2}O, CaO, MgO, and Others (all remaining components). The properties measured include viscosity ({eta}), electrical conductivity ({epsilon}), glass transition temperature (T{sub g}), thermal expansion of solid glass ({alpha}{sub s}) and molten glass ({alpha}{sub m}), crystallinity (quenched and canister centerline cooled glasses), liquidus temperature (T{sub L}), durability based on normalized elemental releases from the Materials Characterization Center-1 28-day dissolution test (MCC-1, r{sub mi}) and the 7-day Product Consistency Test (PCT, r{sub pi}), and solution pHs from MCC-1 and PCT. Amorphous phase separation was also evaluated. Empirical first- and second-order mixture models were fit using the CVS data to relate the various properties to glass composition. Equations for calculating the uncertainty associated with property values predicted by the models were also developed. The models were validated using both internal and external data. Other modeling approaches (e.g., non-bridging oxygen, free energy of hydration, phase-equilibria T{sub L}) were investigated for specific properties. A preliminary Qualified Composition Region was developed to identify glass compositions with high confidence of being processable in a melter and meeting waste form acceptance criteria.
Date: December 1, 1994
Creator: Hrma, P. R. & Piepel, G. F.
Partner: UNT Libraries Government Documents Department

Property/composition relationships for Hanford high-level waste glasses melting at 115{degrees}C volume 1: Chapters 1-11

Description: A Composition Variation study (CVS) is being performed within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) project in support of a future high-level nuclear waste vitrification plant at the Hanford site in Washington. From 1989 to 1994, over 120 nonradioactive glasses were melted and properties measured in five statistically-designed experimental phases. Glass composition is represented by the 10 components SiO{sub 2}, B{sub 2}O{sub 3}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, ZrO{sub 2}, Na{sub 2}O, Li{sub 2}O, CaO, MgO, and Others (all remaining components). The properties measured include viscosity ({eta}), electrical conductivity ({epsilon}), glass transition temperature (T{sub g} ), thermal expansion of solid glass ({alpha}{sub s}) and molten glass ({alpha}{sub m}), crystallinity (quenched and canister centerline cooled glasses), liquidus temperature (T{sub L}), durability based on normalized elemental releases from the Materials Characterization Center-1 28-day dissolution test (MCC-1, r{sub mi}) and the 7-day Product Consistency Test (PCT, r{sub pi}), and solution pHs from MCC-1 and PCT. Amorphous phase separation was also evaluated. Empirical first- and second-order mixture models were fit using the CVS data to relate the various properties to glass composition. Equations for calculating the uncertainty associated with property values predicted by the models were also developed. The models were validated using both internal and external data. Other modeling approaches (e.g., non-bridging oxygen, free energy of hydration, phase-equilibria T{sub L}) were investigated for specific properties. A preliminary Qualified Composition Region was developed to identify glass compositions with high confidence of being processable in a melter and meeting waste form acceptance criteria.
Date: December 1, 1994
Creator: Hrma, P. R. & Piepel, G. F.
Partner: UNT Libraries Government Documents Department

Methods for estimation of covariance matrices and covariance components for the Hanford Waste Vitrification Plant Process

Description: The high-level waste (HLW) vitrification plant at the Hanford Site was being designed to transuranic and high-level radioactive waste in borosilicate class. Each batch of plant feed material must meet certain requirements related to plant performance, and the resulting class must meet requirements imposed by the Waste Acceptance Product Specifications. Properties of a process batch and the resultlng glass are largely determined by the composition of the feed material. Empirical models are being developed to estimate some property values from data on feed composition. Methods for checking and documenting compliance with feed and glass requirements must account for various types of uncertainties. This document focuses on the estimation. manipulation, and consequences of composition uncertainty, i.e., the uncertainty inherent in estimates of feed or glass composition. Three components of composition uncertainty will play a role in estimating and checking feed and glass properties: batch-to-batch variability, within-batch uncertainty, and analytical uncertainty. In this document, composition uncertainty and its components are treated in terms of variances and variance components or univariate situations, covariance matrices and covariance components for multivariate situations. The importance of variance and covariance components stems from their crucial role in properly estimating uncertainty In values calculated from a set of observations on a process batch. Two general types of methods for estimating uncertainty are discussed: (1) methods based on data, and (2) methods based on knowledge, assumptions, and opinions about the vitrification process. Data-based methods for estimating variances and covariance matrices are well known. Several types of data-based methods exist for estimation of variance components; those based on the statistical method analysis of variance are discussed, as are the strengths and weaknesses of this approach.
Date: March 1996
Creator: Bryan, M. F.; Piepel, G. F. & Simpson, D. B.
Partner: UNT Libraries Government Documents Department

Demonstrating compliance with WAPS 1.3 in the Hanford waste vitrification plant process

Description: The high-level waste (HLW) vitrification plant at the Hanford Site was being designed to immobilize transuranic and high-level radioactive waste in borosilicate glass. This document describes the statistical procedure to be used in verifying compliance with requirements imposed by Section 1.3 of the Waste Acceptance Product Specifications (WAPS, USDOE 1993). WAPS 1.3 is a specification for ``product consistency,`` as measured by the Product Consistency Test (PCT, Jantzen 1992b), for each of three elements: lithium, sodium, and boron. Properties of a process batch and the resulting glass are largely determined by the composition of the feed material. Empirical models are being developed to estimate some property values, including PCT results, from data on feed composition. These models will be used in conjunction with measurements of feed composition to control the HLW vitrification process and product.
Date: March 1996
Creator: Bryan, M. F.; Piepel, G. F. & Simpson, D. B.
Partner: UNT Libraries Government Documents Department

Technical Note: Updated durability/composition relationships for Hanford high-level waste glasses

Description: This technical note presents empirical models developed in FYI 995 to predict durability as functions of glass composition. Models are presented for normalized releases of B, Li, Na, and Si from the 7-day Product Consistency Test (PCT) applied to quenched and canister centerline cooled (CCC) glasses as well as from the 28-day Materials Characterization Center-1 (MCC-1) test applied to quenched glasses. Models are presented for Composition Variation Study (CVS) data from low temperature melter (LTM) studies (Hrma, Piepel, et al. 1994) and high temperature melter (HTM) studies (Vienna et al. 1995). The data used for modeling in this technical note are listed in Appendix A.
Date: March 1, 1996
Creator: Piepel, G.F.; Hartley, S.A. & Redgate, P.E.
Partner: UNT Libraries Government Documents Department

Experimental design of a waste glass study

Description: A Composition Variation Study (CVS) is being performed to support a future high-level waste glass plant at Hanford. A total of 147 glasses, covering a broad region of compositions melting at approximately 1150{degrees}C, were tested in five statistically designed experimental phases. This paper focuses on the goals, strategies, and techniques used in designing the five phases. The overall strategy was to investigate glass compositions on the boundary and interior of an experimental region defined by single- component, multiple-component, and property constraints. Statistical optimal experimental design techniques were used to cover various subregions of the experimental region in each phase. Empirical mixture models for glass properties (as functions of glass composition) from previous phases wee used in designing subsequent CVS phases.
Date: April 1, 1995
Creator: Piepel, G.F.; Redgate, P.E. & Hrma, P.
Partner: UNT Libraries Government Documents Department

Product consistency test round robin conducted by the Materials Characterization Center - Summary Report

Description: The Savannah River Laboratory (SRL) Product Consistency Test (PCT) was developed as a short duration leach test that could be used to evaluate the consistency of Defense Waste Processing Facility (DWPF) glass. The goals were to develop a test that would be sensitive to glass composition and homogeneity, rapid enough to support quality control of the production process, and easily conducted remotely to facilitate working with highly radioactive materials. The long-term SRL goal is to show that the PCT can be used to demonstrate that DWPF glass meets the elemental and radionuclide release requirements of the Waste Acceptance Preliminary Specifications (WAPS). The Materials Characterization Center (MCC) at Pacific Northwest Laboratory (PNL) was requested by SRL to conduct a multi-laboratory round robin to evaluate the effectiveness of the PCT methodology. 12 figs., 10 tabs.
Date: September 1, 1989
Creator: Piepel, G.F.; Jones, T.E.; Eggett, D.L. & Mellinger, G.B.
Partner: UNT Libraries Government Documents Department

First-order model for durability of Hanford waste glasses as a function of composition

Description: Two standard chemical durability tests, the static leach test MCC-1 and product consistency test PCT, were conducted on simulated borosilicate glasses that encompass the expected range of compositions to be produced in the Hanford Waste Vitrification Plant (HWVP). A first-order empirical model was fitted to the data from each test method. The results indicate that glass durability is increased by addition of Al{sub 2}O{sub 3}, moderately increased by addition of ZrO{sub 2} and SiO{sub 2}, and decreased by addition of Li{sub 2}O, Na{sub 2}O, B{sub 2}O{sub 3}, and MgO. Addition of Fe{sub 2}O{sub 3} and CaO produce an indifferent or reducing effect on durability according to the test method. This behavior and a statistically significant lack of fit are attributed to the effects of multiple chemical reactions occurring during glass-water interaction. Liquid-liquid immiscibility is suspected to be responsible for extremely low durability of some glasses.
Date: April 1, 1992
Creator: Hrma, P.; Piepel, G.F.; Schweiger, M.J. & Smith, D.E.
Partner: UNT Libraries Government Documents Department

A manual for applying the allowable residual contamination level method for decommissioning facilities on the Hanford Site

Description: This report describes the modifications that have been made to enhance the original Allowable Residual Contamination Level (ARCL) method to make it more applicable to site-specific analyses. This version considers the mixture of radionuclides present at the time of site characterization, the elapsed time after decommissioning when exposure to people could occur, and includes a calculation of the upper confidence limit of the potential dose based on sampling statistics that are developed during the site characterization efforts. The upper confidence limit of potential exposure can now be used for comparison against applicable radiation dose limits (i.e., 25 mrem/yr at Hanford). The level of confidence can be selected by the user. A wide range of exposure scenarios were evaluated; the rationale used to select the most limiting scenarios is explained. The radiation dose factors used for the inhalation and ingestion pathways were also updated to correspond with the radiation dosimetry methods utilized in the International Commission of Radiological Protection Publications 26 and 30 (ICRP 1977; 1979a,b, 1980, 1981, 1982a,b). This simplifies the calculations, since ''effective whole body'' doses are now calculated, and also brings the dosimetry methods used in the ARCL method in conformance with the rationale used by DOE in developing the 25 mrem/yr limit at Hanford. 46 refs., 21 figs., 15 tabs.
Date: August 1, 1988
Creator: Napier, B.A.; Piepel, G.F.; Kennedy, W.E. Jr. & Schreckhise, R.G.
Partner: UNT Libraries Government Documents Department

Second-order model selection in mixture experiments

Description: Full second-order models for q-component mixture experiments contain q(q+l)/2 terms, which increases rapidly as q increases. Fitting full second-order models for larger q may involve problems with ill-conditioning and overfitting. These problems can be remedied by transforming the mixture components and/or fitting reduced forms of the full second-order mixture model. Various component transformation and model reduction approaches are discussed. Data from a 10-component nuclear waste glass study are used to illustrate ill-conditioning and overfitting problems that can be encountered when fitting a full second-order mixture model. Component transformation, model term selection, and model evaluation/validation techniques are discussed and illustrated for the waste glass example.
Date: July 1, 1992
Creator: Redgate, P.E.; Piepel, G.F. & Hrma, P.R.
Partner: UNT Libraries Government Documents Department

West Valley glass product qualification durability studies, FY 1987--1988: Effects of composition, redox state, thermal history, and groundwater

Description: The product qualification subtask of the West Valley Support Task (WVST) at Pacific Northwest Laboratory (PNL) provides support for the waste form qualification efforts at West Valley Nuclear Services Co. Testing is being conducted to determine waste form chemical durability in support of these efforts. The effects of composition, ferrous/ferric ratio (redox state), thermal history, and groundwater are being investigated. Glasses were tested using modified Materials Characterization Center (MCC) -3 and MCC-1 test methods. Results obtained in fiscal years (FY) 1987 and 1988 are presented here. 13 refs., 27 figs., 36 tabs.
Date: November 1, 1988
Creator: Reimus, M.A.H.; Piepel, G.F.; Mellinger, G.B. & Bunnell, L.R.
Partner: UNT Libraries Government Documents Department

First-order model for durability of Hanford waste glasses as a function of composition

Description: Two standard chemical durability tests, the static leach test MCC-1 and product consistency test PCT, were conducted on simulated borosilicate glasses that encompass the expected range of compositions to be produced in the Hanford Waste Vitrification Plant (HWVP). A first-order empirical model was fitted to the data from each test method. The results indicate that glass durability is increased by addition of Al{sub 2}O{sub 3}, moderately increased by addition of ZrO{sub 2} and SiO{sub 2}, and decreased by addition of Li{sub 2}O, Na{sub 2}O, B{sub 2}O{sub 3}, and MgO. Addition of Fe{sub 2}O{sub 3} and CaO produce an indifferent or reducing effect on durability according to the test method. This behavior and a statistically significant lack of fit are attributed to the effects of multiple chemical reactions occurring during glass-water interaction. Liquid-liquid immiscibility is suspected to be responsible for extremely low durability of some glasses.
Date: April 1, 1992
Creator: Hrma, P.; Piepel, G. F.; Schweiger, M. J. & Smith, D. E.
Partner: UNT Libraries Government Documents Department

EVALUATION OF CONCRETE PROPERTY DATA AT ELEVATED TEMPERATURES FOR USE IN THE SAFE-CRACK COMPUTER CODE

Description: Design and analysis of Hanford double-shell waste storage tanks has made use of the finite element computer code SAFE-CRACK as a check of the concrete portion of the tank design after cmpletion of design. Rockwell Hanford Operations, the site contractor responsible for operation of the tanks, has requested Battelle Pacific Northwest Laboratory (PNL) to evaluate the use of the Hanford concrete property data at elevated temperatures by the SAFE-CRACK code. The purpose of this investigation is to evaluate the proper use of the mathematical expressions in SAFE-CRACK to best define the physical concrete properties extrapolated from the documented concrete property data when subjected to elevated temperatures and cyclic temperature variations.
Date: October 1, 1986
Creator: Henager, C. H.; Piepel, G. F.; Anderson, W. E.; Koehmstedt, P. L. & Simonen, F. A.
Partner: UNT Libraries Government Documents Department

Feasibility Study of Using High-Temperature Raman Spectroscopy for On-Line Monitoring and Product Control of the Glass Vitrification Process

Description: A pulse-gating Raman spectroscopy setup was developed in this project. The setup was capable of performing in-situ high-temperature Raman measurements for glasses at temperatures as high as 1412 C. In the literature, high-temperature Raman measurements have only been performed on thin films of glass to minimize black-body radiation effects. The pulse-gating Raman setup allows making high-temperature measurements for bulk melts while effectively minimizing black-body radiation effects. A good correlation was found between certain Raman characteristic parameters and glass melt temperature for sodium silicate glasses measured in this project. Comparisons were made between the high-temperature Raman data from this study and literature data. The results suggest that an optimization of the pulse-gating Raman setup is necessary to further improve data quality (i.e., to obtain data with a higher signal-to-noise ratio). An W confocal Raman microspectrometer with continuous wave laser excitation using a 325 nm excitation line was evaluated selectively using a transparent silicate glass ad a deep-colored high-level waste glass in a bulk quantity. The data were successfully collected at temperatures as high as approximately 1500 C. The results demonstrated that the UV excitation line can be used for high-temperature Raman measurements of molten glasses without black-body radiation interference from the melt for both transparent and deep-color glasses. Further studies are needed to select the best laser system that can be used to develop high-temperature Raman glass databases.
Date: January 4, 1999
Creator: Windisch, C.F. Jr.; Piepel, G.F.; Li, H.; Elliott, M.L. & Su, Y.
Partner: UNT Libraries Government Documents Department

Interim results from UO/sub 2/ fuel oxidation tests in air

Description: An experimental program is being conducted at Pacific Northwest Laboratory (PNL) to extend the characterization of spent fuel oxidation in air. To characterize oxidation behavior of irradiated UO/sub 2/, fuel oxidation tests were performed on declad light-water reactor spent fuel and nonirradited UO/sub 2/ pellets in the temperature range of 135 to 250/sup 0/C. These tests were designed to determine the important independent variables that might affect spent fuel oxidation behavior. The data from this program, when combined with the test results from other programs, will be used to develop recommended spent fuel dry-storage temperature limits in air. This report describes interim test results. The initial PNL investigations of nonirradiated and spent fuels identified the important testing variables as temperature, fuel burnup, radiolysis of the air, fuel microstructure, and moisture in the air. Based on these initial results, a more extensive statistically designed test matrix was developed to study the effects of temperature, burnup, and moisture on the oxidation behavior of spent fuel. Oxidation tests were initiated using both boiling-water reactor and pressurized-water reactor fuels from several different reactors with burnups from 8 to 34 GWd/MTU. A 10/sup 5/ R/h gamma field was applied to the test ovens to simulate dry storage cask conditions. Nonirradiated fuel was included as a control. This report describes experimental results from the initial tests on both the spent and nonirradiated fuels and results to date on the tests in a 10/sup 5/ R/h gamma field. 33 refs., 51 figs., 6 tabs.
Date: August 1, 1987
Creator: Campbell, T.K.; Gilbert, E.R.; Thornhill, C.K.; White, G.D.; Piepel, G.F. & Griffin, C.W.j
Partner: UNT Libraries Government Documents Department

Effects of composition on properties in an 11-component nuclear waste glass system

Description: Ninety simplified nuclear waste glass compositions within an 11-component oxide composition matrix were tested for crystallinity, viscosity, volatility, and chemical durability. Empirical models of property response as a function of glass composition were developed using statistical experimental design and modeling techniques. A new statistical technique was developed to calculate the effects of oxide components on each property. Independent melts were used to check the prediction accuracy of the models.
Date: September 1, 1981
Creator: Chick, L.A.; Piepel, G.F.; Mellinger, G.B.; May, R.P.; Gray, W.J. & Buckwalter, C.Q.
Partner: UNT Libraries Government Documents Department