ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
April 2026
Nuclear Technology
February 2026
Fusion Science and Technology
Latest News
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.
Edward W. Larsen, Allan B. Wollaber
Nuclear Science and Engineering | Volume 160 | Number 3 | November 2008 | Pages 267-283
Technical Paper | doi.org/10.13182/NSE160-267
Articles are hosted by Taylor and Francis Online.
A quantitative theory of angular truncation errors is developed for three-dimensional discrete-ordinates (SN) particle transport calculations. The theory is based on an analysis of a special problem: a localized radially symmetric source in an infinite homogeneous scattering medium, with an arbitrary scattering ratio c satisfying 0 < c < 1. For both the linear Boltzmann equation and the SN equations, we construct and compare analytic solutions of this problem that are asymptotically valid far from the source region. Comparing these analytic solutions, we find that the relative error in the SN solution increases without bound for large distances from the source region but decreases at each fixed spatial point as the scattering ratio or N (the order of the quadrature set) increases. Also, the SN error patterns conform to classic ray effects for small c but not for larger c. We present numerical results that test and validate the theoretical predictions.
