41 research outputs found

    Supplemental Immobilization Cast Stone Technology Development and Waste Form Qualification Testing Plan

    Get PDF
    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the wastes into high-level waste (HLW) and low-activity waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). The pretreatment facility will have the capacity to separate all of the tank wastes into the HLW and LAW fractions, and the HLW Vitrification Facility will have the capacity to vitrify all of the HLW. However, a second immobilization facility will be needed for the expected volume of LAW requiring immobilization. A number of alternatives, including Cast Stone—a cementitious waste form—are being considered to provide the additional LAW immobilization capacity

    Letter Report: LAW Simulant Development for Cast Stone Screening Test

    Get PDF
    More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second facility will be needed for the expected volume of additional LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with waste acceptance criteria for the IDF disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long term performance of the waste form in the IDF disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. A testing program was developed in fiscal year (FY) 2012 describing in some detail the work needed to develop and qualify Cast Stone as a waste form for the solidification of Hanford LAW (Westsik et al. 2012). Included within Westsik et al. (2012) is a section on the near-term needs to address Tri-Party Agreement Milestone M-062-40ZZ. The objectives of the testing program to be conducted in FY 2013 and FY 2014 are to: • Determine an acceptable formulation for the LAW Cast Stone waste form. • Evaluate sources of dry materials for preparing the LAW Cast Stone. • Demonstrate the robustness of the Cast Stone waste form for a range of LAW compositions. • Demonstrate the robustness of the formulation for variability in the Cast Stone process. • Provide Cast Stone contaminant release data for PA and risk assessment evaluations. The first step in determining an acceptable formulation for the LAW Cast Stone waste form is to conduct screening tests to examine expected ranges in pretreated LAW composition, waste stream concentrations, dry-materials sources, and mix ratios of waste feed to dry blend. A statistically designed test matrix will be used to evaluate the effects of these key parameters on the properties of the Cast Stone as it is initially prepared and after curing. The second phase of testing will focus on selection of a baseline Cast Stone formulation for LAW and demonstrating that Cast Stone can meet expected waste form requirements for disposal in the IDF. It is expected that this testing will use the results of the screening tests to define a smaller suite of tests to refine the composition of the baseline Cast Stone formulation (e.g. waste concentration, water to dry mix ratio, waste loading)

    Effects of Particulate Air Pollution on Cardiovascular Health: A Population Health Risk Assessment

    Get PDF
    Particulate matter (PM) air pollution is increasingly recognized as an important and modifiable risk factor for adverse health outcomes including cardiovascular disease (CVD). However, there are still gaps regarding large population risk assessment. Results from the nationwide Behavioral Risk Factor Surveillance System (BRFSS) were used along with air quality monitoring measurements to implement a systematic evaluation of PM-related CVD risks at the national and regional scales. CVD status and individual-level risk factors were collected from more than 500,000 BRFSS respondents across 2,231 contiguous U.S. counties for 2007 and 2009. Chronic exposures to PM pollutants were estimated with spatial modeling from measurement data. CVD outcomes attributable to PM pollutants were assessed by mixed-effects logistic regression and latent class regression (LCR), with adjustment for multicausality. There were positive associations between CVD and PM after accounting for competing risk factors: the multivariable-adjusted odds for the multiplicity of CVD outcomes increased by 1.32 (95% confidence interval: 1.23–1.43) and 1.15 (1.07–1.22) times per 10 µg/m3 increase in PM2.5 and PM10 respectively in the LCR analyses. After controlling for spatial confounding, there were moderate estimated effects of PM exposure on multiple cardiovascular manifestations. These results suggest that chronic exposures to ambient particulates are important environmental risk factors for cardiovascular morbidity

    Sedation and Analgesia for Reduction of Pediatric Ileocolic Intussusception

    Get PDF
    IMPORTANCE: Ileocolic intussusception is an important cause of intestinal obstruction in children. Reduction of ileocolic intussusception using air or fluid enema is the standard of care. This likely distressing procedure is usually performed without sedation or analgesia, but practice variation exists. OBJECTIVE: To characterize the prevalence of opioid analgesia and sedation and assess their association with intestinal perforation and failed reduction. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study reviewed medical records of children aged 4 to 48 months with attempted reduction of ileocolic intussusception at 86 pediatric tertiary care institutions in 14 countries from January 2017 to December 2019. Of 3555 eligible medical records, 352 were excluded, and 3203 medical records were eligible. Data were analyzed in August 2022. EXPOSURES: Reduction of ileocolic intussusception. MAIN OUTCOMES AND MEASURES: The primary outcomes were opioid analgesia within 120 minutes of reduction based on the therapeutic window of IV morphine and sedation immediately before reduction of intussusception. RESULTS: We included 3203 patients (median [IQR] age, 17 [9-27] months; 2054 of 3203 [64.1%] males). Opioid use was documented in 395 of 3134 patients (12.6%), sedation 334 of 3161 patients (10.6%), and opioids plus sedation in 178 of 3134 patients (5.7%). Perforation was uncommon and occurred in 13 of 3203 patients (0.4%). In the unadjusted analysis, opioids plus sedation (odds ratio [OR], 5.92; 95% CI, 1.28-27.42; P = .02) and a greater number of reduction attempts (OR, 1.48; 95% CI, 1.03-2.11; P = .03) were significantly associated with perforation. In the adjusted analysis, neither of these covariates remained significant. Reductions were successful in 2700 of 3184 attempts (84.8%). In the unadjusted analysis, younger age, no pain assessment at triage, opioids, longer duration of symptoms, hydrostatic enema, and gastrointestinal anomaly were significantly associated with failed reduction. In the adjusted analysis, only younger age (OR, 1.05 per month; 95% CI, 1.03-1.06 per month; P \u3c .001), shorter duration of symptoms (OR, 0.96 per hour; 95% CI, 0.94-0.99 per hour; P = .002), and gastrointestinal anomaly (OR, 6.50; 95% CI, 2.04-20.64; P = .002) remained significant. CONCLUSIONS AND RELEVANCE: This cross-sectional study of pediatric ileocolic intussusception found that more than two-thirds of patients received neither analgesia nor sedation. Neither was associated with intestinal perforation or failed reduction, challenging the widespread practice of withholding analgesia and sedation for reduction of ileocolic intussusception in children
    corecore