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The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title.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.
Rubin Goldstein, E. Richard Cohen
Nuclear Science and Engineering | Volume 13 | Number 2 | June 1962 | Pages 132-140
Technical Paper | doi.org/10.13182/NSE62-1
Articles are hosted by Taylor and Francis Online.
A treatment of resonance absorption intermediate between the usual narrow and wide resonance approximations is developed for homogeneous systems. An arbitrary parameter, λ, is introduced into the flux and two distinct approximations are employed to determine λ as a function of the resonance parameters. One is based upon a method of equating successive orders of approximation and the other is based upon a variational principle. Formulas are given, from which the resonance integral may be calculated. The parameter λ characterizes, in essence, the location between the narrow and wide resonance extremes, of the actual resonance. When λ is set equal to 0 or 1, the usual first order wide or narrow resonance integrals are obtained. Sample calculations are carried out for a good intermediate case (the 192 ev resonance of U238 in a 1:1 atomic mixture with hydrogen) using linear and nonlinear trial functions for both types of approximations. All results agree to within less than one percent of 0.172 barns. In comparison, the usual extreme energy-loss assumptions yield results which differ by more than a factor of 2 (0.121 barns for the narrow resonance approximation and 0.253 barns for the wide resonance approximation).