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
Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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.
W. L. Dutré, A. F. Debosscher
Nuclear Science and Engineering | Volume 62 | Number 3 | March 1977 | Pages 355-363
Technical Paper | doi.org/10.13182/NSE77-A26977
Articles are hosted by Taylor and Francis Online.
This paper presents an exact and complete statistical analysis of the neutron density fluctuations resulting from Gaussian white reactivity noise in a point reactor model with proportional power feedback, but without delayed neutrons. The analysis includes the multiplicative effect of neutron density and reactivity variations. An exact solution of the time-independent Fokker-Planck equation is found, resulting in a gamma density function for the stationary first-order probability density of the power fluctuations. The time-dependent Fokker-Planck equation is solved for the Laplace transformed function, which can be written in terms of confluent hypergeometric functions. The subsequent inversion yields the transition probability density function. The most common first- and second-order statistical characteristics, such as moments, autocovariance function, and power spectral density, are calculated and compared to the results of a linearized analysis.