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.
F. V. Orestano, F. Pistella
Nuclear Science and Engineering | Volume 46 | Number 3 | December 1971 | Pages 376-384
Technical Paper | doi.org/10.13182/NSE71-A22374
Articles are hosted by Taylor and Francis Online.
The investigation of the neutron spectral effects in actual cell geometry in a plutonium-fueled lattice is the final step of a program undertaken at LFCR of CNEN on the investigation of the physics problems for the plutonium recycle in light water reactors. Spectral indices have been measured by foil activation techniques, in the fuel pins and in the moderator, both in a uniform lattice and in the presence of a cross-shaped water gap; the presence of the water gap reduces the value of the index 239Pu-fission/235U fission by about 8%. The measured values have been compared with the results of the design calculational methods as well as those of a more detailed method and agreement is good. In particular, it has been found that the use of two thermal-energy groups (in a five-group scheme) is necessary to describe properly the effect of water gaps on the plutonium effective cross sections. The 239Pu absorption rate has been evaluated from the measured spectral indices by applying a previously tested correlation method; the presence of the water gap also reduces the 239Pu absorption/235 U-fission-ratio by about 10%.