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.
C. E. Ragan III, G. F. Auchampaugh, A. Hemmendinger, M. G. Silbert
Nuclear Science and Engineering | Volume 61 | Number 1 | September 1976 | Pages 33-39
Technical Paper | doi.org/10.13182/NSE76-A28458
Articles are hosted by Taylor and Francis Online.
A benchmark measurement of the neutron leakage spectrum from a pulsed 38-kg uranium (93.5% 235U) sphere has been made using time-of-flight techniques. The sphere had a multiplication of ∼11 for 14-MeV neutrons, and a neutron hold-up time of ∼40 nsec. The centrally located source of 14.1 ± 0.8-MeV neutrons, produced by bombarding a tritium gas target with pulses of low-energy deuterons, was isotropic to ±7.7%. Neutrons in the 0.180- to 16.0-MeV energy range were detected at the end of a 39-m flight path by an Ne-213 liquid scintillator employing pulse-shape discrimination. The detector efficiency was measured over this same energy range using monoenergetic neutrons from the T(p,n) T(d,n), and D(d,n) reactions. The measured neutron flux as a function of energy is compared with the results of Monte Carlo calculations performed with the MCN code. Uranium cross sections from ENDF/B-IV and an older set from Lawrence Livermore Laboratory were used in these calculations. The results calculated using the ENDF/B-IV cross sections are in good agreement with the measurements, especially in the 1- to 6-MeV energy region where the uncertainties in both the calculated and experimental results are the smallest.