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.
Seungsu Yuk, Nam Zin Cho
Nuclear Science and Engineering | Volume 184 | Number 2 | October 2016 | Pages 151-167
Technical Paper | doi.org/10.13182/NSE15-128
Articles are hosted by Taylor and Francis Online.
Two two-dimensional/one-dimensional (2-D/1-D) methods, fusion and hybrid, have been developed and reported in the literature to deal with three-dimensional (3-D) heterogeneous reactor problems and to avoid direct 3-D transport calculations. The 2-D/1-D fusion method transforms a 3-D transport problem into 2-D and 1-D transport problems that have a smaller computational burden than the original problem. The hybrid method uses an additional diffusion (or SP3) approximation in the axial direction to enhance the efficiency of the calculation.
This paper presents and compares the stability and the accuracy of the two methods. To this end, a 2-D transport problem is considered by reducing one dimension in the radial direction, leading to 1-D/1-D fusion or hybrid method. Fourier stability analysis is used to study the stability and the convergence behaviors of the two methods. With respect to accuracy, the two methods are compared via numerical solutions on a typical 2-D reactor problem. The results indicate that the fusion method is stable and gives a very accurate transport solution. On the other hand, the hybrid method requires a stabilizing scheme, and the diffusion approximation in the axial calculation causes significant errors.