38 research outputs found
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Performance demonstration requirements for eddy current steam generator tube inspection
This paper describes the methodology used for developing performance demonstration tests for steam generator tube eddy current (ET) inspection systems. The methodology is based on statistical design principles. Implementation of a performance demonstration test based on these design principles will help to ensure that field inspection systems have a high probability of detecting and correctly sizing tube degradation. The technical basis for the ET system performance thresholds is presented. Probability of detection and flaw sizing tests are described
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Application of the risk-based strategy to the Hanford tank waste organic-nitrate safety issue
This report describes the results from application of the Risk-Based Decision Management Approach for Justifying Characterization of Hanford Tank Waste to the organic-nitrate safety issue in Hanford single-shell tanks (SSTs). Existing chemical and physical models were used, taking advantage of the most current (mid-1997) sampling and analysis data. The purpose of this study is to make specific recommendations for planning characterization to help ensure the safety of each SST as it relates to the organic-nitrate safety issue. An additional objective is to demonstrate the viability of the Risk-Based Strategy for addressing Hanford tank waste safety issues
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Tank characterization report for single-shell Tank B-201
The purpose of this report is to characterize the waste in single shell Tank B-201. Characterization includes the determination of the physical, chemical (e.g., concentrations of elements and organic species), and radiological properties of the waste. These determinations are made using analytical results from B-201 core samples as well as historical information about the tank. The main objective is to determine average waste properties: but in some cases, concentrations of analytes as a function of depth were also determined. This report also consolidates the available historical information regarding Tank B-201, arranges the analytical information from the recent core sampling in a useful format, and provides an interpretation of the data within the context of what is known about the tank
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Preliminary Safety Criteria for Organic Watch List Tanks at the Hanford Site
Condensed-phase, rapid reactions of organic salts with nitrates/nitrites in Hanford High Level Radioactive Waste single-shell tanks could lead to structural failure of the tanks resulting in significant releases of radionuclides and toxic materials. This report establishes appropriate preliminary safety criteria to ensure that tank wastes will be maintained safe. These criteria show that if actual dry wastes contain less than 1.2 MJ/kg of reactants reaction energy or less 4.5 wt % of total organic carbon, then the waste will be safe and will not propagate if ignited. Waste moisture helps to retard reactions; when waste moisture exceeds 20 wt %, rapid reactions are prevented, regardless of organic carbon concentrations. Aging and degradation of waste materials has been considered to predict the types and amounts to organic compounds present in the waste. Using measurements of 3 waste phases (liquid, salt cake, and sludge) obtained from tank waste samples analyzed in the laboratory, analysis of variance (ANOVA) models were used to estimate waste states for unmeasured tanks. The preliminary safety criteria are based upon calorimetry and propagation testing of likely organic compounds which represent actual tank wastes. These included sodium salts of citrate, formate, acetate and hydroxyethylethylenediaminetricetate (HEDTA). Hot cell tests of actual tank wastes are planned for the future to confirm propagation tests performed in the laboratory. The effects of draining liquids from the tanks which would remove liquids and moisture were considered because reactive waste which is too dry may propagate. Evaporation effects which could remove moisture from the tanks were also calculated. The various ways that the waste could be heated or ignited by equipment failures or tank operations activities were considered and appropriate monitoring and controls were recommended
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Statistical evaluations of current sampling procedures and incomplete core recovery
This document develops two formulas that describe the effects of incomplete recovery on core sampling results for the Hanford waste tanks. The formulas evaluate incomplete core recovery from a worst-case (i.e.,biased) and best-case (i.e., unbiased) perspective. A core sampler is unbiased if the sample material recovered is a random sample of the material in the tank, while any sampler that preferentially recovers a particular type of waste over others is a biased sampler. There is strong evidence to indicate that the push-mode sampler presently used at the Hanford site is a biased one. The formulas presented here show the effects of incomplete core recovery on the accuracy of composition measurements, as functions of the vertical variability in the waste. These equations are evaluated using vertical variability estimates from previously sampled tanks (B110, U110, C109). Assuming that the values of vertical variability used in this study adequately describes the Hanford tank farm, one can use the formulas to compute the effect of incomplete recovery on the accuracy of an average constituent estimate. To determine acceptable recovery limits, we have assumed that the relative error of such an estimate should be no more than 20%
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Preliminary heat flow estimates for Wyoming and Montana
A table is presented containing basic thermal data for preliminary heat flow estimates in Wyoming and Montana. The thermal data include thermal conductivities of rock samples from drill holes, temperature gradients, depth ranges for the least-squares calculation of the temperature gradients, and the computed heat flow values. Other data listed the country code, the locality, and the elevation of each drill hole
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Piping inspection round robin
The piping inspection round robin was conducted in 1981 at the Pacific Northwest National Laboratory (PNNL) to quantify the capability of ultrasonics for inservice inspection and to address some aspects of reliability for this type of nondestructive evaluation (NDE). The round robin measured the crack detection capabilities of seven field inspection teams who employed procedures that met or exceeded the 1977 edition through the 1978 addenda of the American Society of Mechanical Engineers (ASME) Section 11 Code requirements. Three different types of materials were employed in the study (cast stainless steel, clad ferritic, and wrought stainless steel), and two different types of flaws were implanted into the specimens (intergranular stress corrosion cracks (IGSCCs) and thermal fatigue cracks (TFCs)). When considering near-side inspection, far-side inspection, and false call rate, the overall performance was found to be best in clad ferritic, less effective in wrought stainless steel and the worst in cast stainless steel. Depth sizing performance showed little correlation with the true crack depths
Thermopolis hydrothermal system, with an analysis of Hot Springs State Park. Preliminary report No. 20
Thermopolis is the site of Hot Springs State Park, where numerous hot springs produce nearly 3000 gallons per minute (gpm) of 130/sup 0/F (54/sup 0/C) water. The University of Wyoming Geothermal Resource Assessment Group has studied a 1700-square-mile area centered roughly on the State Park. Available literature, bottom-hole temperatures from over 400 oil well logs, 62 oil field drill stem tests, the Wyoming State Engineer\u27s water well files, 60 formation water analyses, thermal logs of 19 holes, and field investigations of geology and hydrology form the basis of this report. Analysis of thermal data reveals that temperatures of up to 161/sup 0/F (72/sup 0/C) occur along the crest of the Thermopolis Anticline within 500 feet of the surface. The hydrology and heat flow of these geothermal anomalies was studied
Thermopolis hydrothermal system, with an analysis of Hot Springs State Park. Preliminary report No. 20
Thermopolis is the site of Hot Springs State Park, where numerous hot springs produce nearly 3000 gallons per minute (gpm) of 130/sup 0/F (54/sup 0/C) water. The University of Wyoming Geothermal Resource Assessment Group has studied a 1700-square-mile area centered roughly on the State Park. Available literature, bottom-hole temperatures from over 400 oil well logs, 62 oil field drill stem tests, the Wyoming State Engineer\u27s water well files, 60 formation water analyses, thermal logs of 19 holes, and field investigations of geology and hydrology form the basis of this report. Analysis of thermal data reveals that temperatures of up to 161/sup 0/F (72/sup 0/C) occur along the crest of the Thermopolis Anticline within 500 feet of the surface. The hydrology and heat flow of these geothermal anomalies was studied
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Organic carbon in Hanford single-shell tank waste
This report documents an analysis performed by Pacific Northwest Laboratory (PNL) involving the organic carbon laboratory measurement data for Hanford single-shell tanks (SSTS) obtained from a review of the laboratory analytical data. This activity was undertaken at the request of Westinghouse Hanford Company (WHC). The objective of this study is to provide a best estimate, including confidence levels, of total organic carbon (TOC) in each of the 149 SSTs at Hanford. The TOC analyte information presented in this report is useful as part of the criteria to identify SSTs for additional measurements or monitoring for the organic safety program. This report is a precursor to an investigation of TOC and moisture in Hanford SSTS, in order to provide best estimates for each together in one report. Measured laboratory data were obtained for 75 of the 149 SSTS. The data represent a thorough investigation of data from 224 tank characterization datasets, including core-sampling and process laboratory data. Liquid and solid phase TOC values were investigated by examining selected tanks with both reported TOC values in solid and liquid phases. Some relationships were noted, but there was no clustering of data or significance between the solid and liquid phases. A methodology was developed for estimating the distribution and levels of TOC in SSTs using a logarithmic scale and an analysis of variance (ANOVA) technique. The methodology grouped tanks according to waste type using the Sort On Radioactive Waste Type (SORWT) grouping method. The SORWT model categorizes Hanford SSTs into groups of tanks expected to exhibit similar characteristics based on major waste types and processing histories. The methodology makes use of laboratory data for the particular tank and information about the SORWT group of which the tank is a member. Recommendations for a simpler tank grouping strategy based on organic transfer records were made