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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title.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.
Lynn E. Weaver, Kenneth R. Katsma
Nuclear Science and Engineering | Volume 14 | Number 4 | December 1962 | Pages 380-383
Technical Paper | doi.org/10.13182/NSE62-A26245
Articles are hosted by Taylor and Francis Online.
An analytical approach is taken to develop a model of an optimum linear control system for a linearized approximation to a boiling water reactor. The optimization criterion used is the minimization of the mean-square error of the random fluctuation in the output variable due to boiling voids. In optimizing the system an acceleration constraint is placed on the control rod drive mechanism. The mean-square error of the output variable is calculated for various constraint levels. Results show that a considerable reduction in the mean-square error of the reactor output can be realized through external control.