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 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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
Nov 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
December 2025
Nuclear Technology
November 2025
Fusion Science and Technology
Latest News
The progress so far: An update on the Reactor Pilot Program
It has been about three months since the Department of Energy named 10 companies for its new Reactor Pilot Program, which maps out how the DOE would meet the goal announced by executive order in May of having three reactors achieve criticality by July 4, 2026.
Sanjay Gupta, Feroz Ahmed, Suresh Garg
Nuclear Science and Engineering | Volume 125 | Number 3 | March 1997 | Pages 362-370
Technical Paper | doi.org/10.13182/NSE97-A24281
Articles are hosted by Taylor and Francis Online.
Results are reported for the space-dependent neutron spectra and tritium breeding ratio (TBR) in a proposed Li + C blanket of a deuterium-tritium fusion reactor. The multigroup diffusion equation is solved as an eigenvalue problem for three concentrations of lithium in graphite. The effect on the value of TBR of increasing the fraction of low-energy neutrons in a completely thermalized source is studied. A comparison of neutron spectra as obtained in the Li + C and 3He + C systems is also made. The results show that TBR increases with the concentration of lithium in graphite as well as with the fraction of low-energy neutrons in the source. [Essentially the same value of TBR (= 0.277) is obtained for the Li + C system with a lithium to graphite concentration of 4 x 10-2 as for a 3He + C system with a natural density of 3He.] Moreover, TBR attains an almost constant value for assembly thicknesses greater than -20 cm. Also, if a source with an increased fraction of low-energy neutrons is used, the effect is more pronounced in the 3He + C system for the range of lithium concentrations considered.