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
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Mar 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
March 2025
Nuclear Technology
Fusion Science and Technology
April 2025
Latest News
Nuclear News 40 Under 40 discuss the future of nuclear
Seven members of the inaugural Nuclear News 40 Under 40 came together on March 4 to discuss the current state of nuclear energy and what the future might hold for science, industry, and the public in terms of nuclear development.
To hear more insights from this talented group of young professionals, watch the “40 Under 40 Roundtable: Perspectives from Nuclear’s Rising Stars” on the ANS website.
I. Lux
Nuclear Science and Engineering | Volume 66 | Number 2 | May 1978 | Pages 258-264
Technical Note | doi.org/10.13182/NSE78-A27208
Articles are hosted by Taylor and Francis Online.
The estimation of the variances of different estimators is always a crucial point in practical Monte Carlo calculations. The purpose of this Note is to formulate conditions that, in simplified situations, make track-length estimators more efficient than collision estimators for the estimation of reaction rates in a region. Starting from recent results of Amster and Djomehri in the first section of the Note, an upper limit is given for maximum extension of a nonmultiplying region. In the second section, assuming homogeneous medium and monoenergetic nonmultiplying transport with isotropic collision in the laboratory system, approximate conditions are described concerning the optical mean-chord-length of the region in terms of first-flight collision probabilities. Wigner rational approximation to the first-flight collision probability results in a surprisingly simple upper limit for the mean-chord-length of the region. Finally, the effect of the approximations to the results is discussed and lower and upper bounds, depending on the nonabsorption probability, are established for the reaction rate to be estimated. It is shown that, in practical cases, the approximations provide a lower value of the maximum extension still favorable from the viewpoint of the track-length estimator than the exact calculation.