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.
S. F. Su, Y. Orechwa, H. Henryson II
Nuclear Technology | Volume 52 | Number 3 | March 1981 | Pages 370-382
Technical Paper | Fission Reactor | doi.org/10.13182/NT81-A32711
Articles are hosted by Taylor and Francis Online.
Two-dimensional multigroup space-time kinetics calculations with thermal-hydraulic feedback were performed for 1000- and 1800-MW(electric) homogeneous and heterogeneous liquid-metal fast breeder reactors. The initiating transient was due to the asymmetric withdrawal of a single control rod. It was found that the point kinetics model can, in many cases, be used for predicting integral reactor characteristics. For accurate predictions of local reactor conditions, space-time kinetics calculations are needed. In the case of both homogeneous and heterogeneous cores, for design basis reactivity insertions with scram, smaller reactivity insertion rates will lead to a greater fuel and cladding temperature rise than large reactivity insertion rates. Heterogeneous cores, because of their inherently greater power shape sensitivity, show a larger temperature rise than the homogeneous cores despite the fact that the transient is of much shorter duration because of an earlier reactor trip due to a lower negative Doppler feedback.