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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The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title.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.
B. Grimeland, S. Messelt, L. Sund
Nuclear Science and Engineering | Volume 13 | Number 3 | July 1962 | Pages 261-263
Technical Paper | doi.org/10.13182/NSE62-A26161
Articles are hosted by Taylor and Francis Online.
Neutrons from a D(d, n)He3 neutron source, operating with 150 kev deuterons, were slowed down in blocks of paraffin wax. The distribution of 1.44 ev neutrons was measured with indium foils in five blocks of various dimensions, all facing the target with one of their end planes. The distribution was approximately the same in all blocks with thickness equal to or larger than 22 cm, which is about four times the slowing-down length in paraffin for (D, D) neutrons slowed down to 1.44 ev. Measurements were also made in a block of dimensions 50 x 50 x 100 cm3 with the target at the center. Even here the distribution of 1.44 ev neutrons was nearly the same as in the blocks already mentioned. The slowing-down age for (D, D) neutrons to 1.44 ev in paraffin wax, measured in the direction of the incoming deuteron beam, was found to be (33.0 ± 1.3) cm3.
