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GAO: Clarification of HLW definition could save DOE billions
A clearer definition of what constitutes high-level radioactive waste could save the Department of Energy’s Office of Environmental Management “tens of billions of dollars” in waste management costs and accelerate its cleanup schedule by decades, according to a report by the U.S. Government Accountability Office.
DOE-EM’s efforts to manage waste resulting from legacy spent nuclear fuel reprocessing have been hindered for decades by the ambiguity of the statutory definition of HLW as laid out in the Atomic Energy Act and Nuclear Waste Policy Act, the report states. While admitting that the DOE has taken steps to overcome this ambiguity, the GAO says that the department has not fully evaluated all available opportunities to treat and dispose of waste more economically as either transuranic or low-level radioactive waste.
Justin D. Talley, Seungjin Kim, Tangwen Guo, Gunol Kojasoy
Nuclear Technology | Volume 167 | Number 1 | July 2009 | Pages 2-12
Technical Paper | NURETH-12 / Thermal Hydraulics | doi.org/10.13182/NT167-2
Articles are hosted by Taylor and Francis Online.
The present study investigates the geometric effects of a 45-deg elbow on the development and distribution of local two-phase flow parameters in horizontal bubbly flow. A round pipe with an inner diameter of 50.3 mm is used as a test section throughout the study. The test section consists of a 90-deg elbow followed farther downstream by a 45-deg elbow. Local two-phase flow parameters and pressure measurements are made at three different axial locations, one upstream and two downstream of the 45-deg elbow. In total, 15 different flow conditions are investigated for the present analysis. At the measurement port just downstream of the 45-deg elbow, the local parameters are acquired in both the vertical and horizontal directions along the radius of the pipe cross section to capture geometric effects of the flow restriction. The local two-phase flow parameters acquired in the present study include void fraction, bubble velocity, interfacial area concentration, and Sauter mean diameter. In view of one-dimensional transport, the local void fraction and interfacial area concentration are area averaged and plotted along the axial direction. The characteristic geometric effects of the flow restrictions are clearly demonstrated in the distribution of the two-phase flow parameters and pressure, as well as their development along the flow direction. The drastic changes in the interfacial area concentration across the elbow suggest that a 45-deg elbow induces significant changes in bubble interaction mechanisms.