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
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
October 2025
Nuclear Technology
September 2025
Fusion Science and Technology
Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
Om Prakash Joneja, Vijay R. Nargundkar
Fusion Science and Technology | Volume 18 | Number 2 | September 1990 | Pages 310-316
Technical Paper | Blanket Engineering | doi.org/10.13182/FST90-A29302
Articles are hosted by Taylor and Francis Online.
Monte Carlo calculations are performed for a full-coverage spherical system consisting of a stainless steel first wall and a lead-beryllium neutron multiplier. All the calculations use the MORSE-CG code, employing the Los Alamos National Laboratory 30-group neutron cross-section set CLAW-IV in P3 approximation. For multiplier thicknesses varying from 3 to 22.5 cm, the ratio of neutrons leaking from the system with and without 1.5-cm-thick stainless steel decreases from 1.48 to 1.41 for lead and from 1.78 to 1.58 for beryllium. For a three-region system consisting of a first wall, multiplier, and a homogeneous mixture of water and natural lithium, the tritium breeding ratio for the stainless steel-beryllium-homogeneous (natural lithium + water) system is only ∼9% more than that of the stainless steel-lead-homogeneous (natural lithium + water) system. Recent measurements and calculations on neutron multiplication suggest a downward correction for Be(n,2n) and an upward correction for Pb(n,2n) in the ENDF/B-IV cross-section set. In light of such changes in cross sections, a comparison is made between beryllium and lead as a multiplier with a stainless steel first wall.