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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
New coolants, new fuels: A new generation of university reactors
Here’s an easy way to make aging U.S. power reactors look relatively youthful: Compare them (average age: 43) with the nation’s university research reactors. The 25 operating today have been licensed for an average of about 58 years.
K. Shure, J. A. O'Brien, D. M. Rothberg
Nuclear Science and Engineering | Volume 35 | Number 3 | March 1969 | Pages 371-375
Technical Paper | doi.org/10.13182/NSE69-A20016
Articles are hosted by Taylor and Francis Online.
Effective removal cross sections for iron and lead that can be applied to fast-neutron dose rate calculations have been determined from calculated spatial-spectral neutron distributions as a function of succeeding polyethylene thickness. These cross sections increase with polyethylene thickness, and for large polyethylene thicknesses, they are in agreement with those derived from experiment. From the spatial-spectral neutron distributions, relative contributions of various neutron energy ranges to the neutron dose rate have been calculated as a function of succeeding polyethylene thickness. For polyethylene thicknesses > 30 cm, fast (E > 302 keV), epithermal (302 keV > E > 0.625 eV), and thermal (E < 0.625 eV) neutrons contribute 83, 6, and 11%, respectively, to the neutron dose rate.
