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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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!
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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The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title.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.
Alan B. Rothman, Charles E. W. Ward
Nuclear Science and Engineering | Volume 12 | Number 2 | February 1962 | Pages 293-300
Technical Paper | doi.org/10.13182/NSE62-A26070
Articles are hosted by Taylor and Francis Online.
A new measurement of the effective resonance integral of thorium metal has been made, using reactor oscillator techniques. Fluctuations in reactor power level, caused by oscillation of cadmium-shielded cylindrical samples, were recorded on a strip chart. The signal was Fourier-analyzed, and the coefficient of the fundamental mode determined. For a constant shape reactivity input, the value of this coefficient for each sample is proportional to the effective resonance integral of the sample. The scattering effects of the thorium were determined by oscillating identical samples of lead, and were deducted from the results for the thorium. Absolute calibration of the oscillator measurements was provided by oscillating several dilute solutions of each of three standard absorbers : boron, indium, and gold. The effective resonance integrals of the thorium cylinders were then found to be given by the formula: where S/M is the surface-to-mass ratio of the samples in cm2/gm. The 1/v component of the resonance integral, 3.6 barns, has been removed from the first term of this formula.
