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.
Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
October 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
Richard E. Turley
Nuclear Science and Engineering | Volume 30 | Number 2 | November 1967 | Pages 166-175
Technical Paper | doi.org/10.13182/NSE67-A17327
Articles are hosted by Taylor and Francis Online.
This paper presents an operator-type perturbation method which may be used to solve perturbation problems associated with the neutron diffusion equation. The method is related to the hybrid Schrodinger-Heisenberg operator methods used in quantum mechanics. The operators are derived from the variational principles associated with the neutron diffusion equation; therefore, the method includes the advantages of the variational method. Two applications in one-dimensional, one-group diffusion theory are illustrated. The first example illustrates how a plane source of neutrons can be treated as a perturbation. The solution to this problem is exact. In the second example, the solution to a simplified time-independent problem involving fission-product poisoning is presented. The solution to this example is in open form as expected. It is found by way of comparison that this operator method gives a better result in this particular example than the more familiar method of approximating the perturbed solution by an expansion in terms of eigenfunctions of the unperturbed solution.