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
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
A new ANSI/ANS standard for liquid metal fire protection published
ANSI/ANS-54.8-2025, Liquid Metal Fire Protection in LMR Plants, received approval from the American National Standards Institute on September 2 and is now available for purchase.
The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title. The Advanced Reactor Codes and Standards Collaborative (ARCSC) identified the need for a current version of the standard via an industry survey.
Typical liquid metal reactor designs use liquid sodium as the coolant for both the primary and intermediate heat-transport systems. In addition, liquid sodium and NaK (a mixture of sodium and potassium that is liquid at room temperature) are often used in auxiliary heat-removal systems. Since these liquid metals can react readily with oxygen, water, and other compounds, special precautions must be taken in the design, construction, testing, and maintenance of the sodium/NaK systems to ensure that the potential for leakage is very small.
Wolfgang Rothenstein
Nuclear Science and Engineering | Volume 8 | Number 2 | August 1960 | Pages 122-127
Technical Paper | doi.org/10.13182/NSE60-A25787
Articles are hosted by Taylor and Francis Online.
Detailed Monte Carlo studies of the resonance capture in the lowest U238 resonances have been made for uranium-water lattices and a uranium-graphite lattice. Direct comparison with calculated values is a good test of the validity of the assumptions made in obtaining the theoretical estimates. Good agreement is obtained for the over-all capture in a single resonance and for the energy distribution of absorptions. Monte Carlo tests have also shown that the asymptotic flux is fairly well re-established between the two strongest U238 resonances, and that the number of neutrons captured in this energy region is only slightly affected by Doppler broadening and interference between resonance and potential scattering. Finally the calculated resonance escape probability in a uranium-water lattice for 26 resolved resonances is compared with the Monte Carlo value. There is quite close agreement.