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Short-term static tests were conducted with a surrogate high-level waste glass to measure the effects of pH and dissolved iron on the glass dissolution rate. The tests were conducted to determine if a term to account for the effects of dissolved iron is needed in the glass degradation model developed for Total System Performance Assessment (TSPA) calculations for the Yucca Mountain disposal system license application. The glass degradation model includes terms for dependencies on temperature, pH, and chemical affinity. A series of tests was conducted at 90 °C in various pH solutions without iron and with added FeCl3, Fe2O3, Fe3O4, and FeOOH. Tests were conducted at glass surface area/solution volume (S/V) ratios about 2 and 10 m-1for between 2 and 21 days. Solution concentrations of boron were used to measure the extent of reaction and calculate the glass dissolution rates. Similar rates were measured in tests conducted with and without iron at each pH. Both the results of the tests with and without iron showed V-shaped pH dependence curves with minima at near-neutral pH values. The pH dependencies (η) are about 0.44 in basic solutions and –0.49 in acidic solutions, based on the combined results of tests with and without iron. These are within the range of values for the pH dependence in the TSPA model for site recommendation.

Abstract. On the basis of previous survey results of indoor radon for schools, detailed radon survey was conducted in one hundred three selected schools in Korea during the second semester in 2010. According to the results of effective dose assessment due to inhaled radon of during occupancy time, fourteen schools for requiring urgent mitigation action were selected, and recommended to the government.

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This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or rcsponsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recornmendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expresstd herein do not necessarily state or reflect those of the United States Government or any agency thereof.

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A glass-bonded sodalite ceramic w aste form (CWF) has been developed to immobilize electrorefiner salt wastes from electrometallurgical treatment of spent sodium-bonded reactor fuel for disposal. A degradation model is being developed to support qualification of the CWF for disposal in the federal high-level waste disposal system. The parameter values in the waste form degradation model were previously determined from the dissolution rates measured in MCC-1 tests conducted at 40, 70, and 90°C. The results of several series of tests that were conducted to confirm the applicability of the dissolution rate model and model parameters are presented in this paper: (1) Series of MCC-1 tests were conducted in five dilute buffer solutions in the pH range of 4.8 -9.8 at 20°C with HIP sodalite, HIP glass and HIP CWF. The results show that the model adequately predicts the dissolution rate of these materials at 20°C. (2) Tests at 20 and 70°C with CWF made by pressureless-consolidation (PC CWF) indicate that the model parameters extracted from the results of tests with HIP CWF can be applied to PC CWF. (3) The dissolution rates of a glass made with a composition corresponding to 80% glass and 20% sodalite were measured at 70°C to evaluate the sensitivity of the rate to the composition of binder glass in the CWF. The dissolution rates of the modified binder glass were indistinguishable from the rates of the binder glass.