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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
The RAIN scale: A good intention that falls short
Radiation protection specialists agree that clear communication of radiation risks remains a vexing challenge that cannot be solved solely by finding new ways to convey technical information.
Earlier this year, an article in Nuclear News described a new radiation risk communication tool, known as the Radiation Index, or, RAIN (“Let it RAIN: A new approach to radiation communication,” NN, Jan. 2025, p. 36). The authors of the article created the RAIN scale to improve radiation risk communication to the general public who are not well-versed in important aspects of radiation exposures, including radiation dose quantities, units, and values; associated health consequences; and the benefits derived from radiation exposures.
E. E. Gross, J. H. Marable
Nuclear Science and Engineering | Volume 7 | Number 4 | April 1960 | Pages 281-291
Technical Paper | doi.org/10.13182/NSE60-A25718
Articles are hosted by Taylor and Francis Online.
The theory of the stable period of a fixed-fuel reactor is developed by considering the gross conservation of neutrons in the reactor. The resulting inhour equation directly relates the dynamic multiplication factor to the actual delayed-neutron fractions. It is shown that the inhour equation may also be written in terms of the conventional multiplication factor if so-called “effective” delayed neutron fractions are introduced. The results are shown to be in agreement with those of the perturbation method.
