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The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title.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.
C. D. Watson, G. A. West, W. F. Schaffer, JR.
Nuclear Science and Engineering | Volume 17 | Number 1 | September 1963 | Pages 149-164
Technical Paper | doi.org/10.13182/NSE63-A17220
Articles are hosted by Taylor and Francis Online.
Experimental mechanical equipment for removing the stainless steel jackets from the liquid-metal-bonded fuels of the Sodium Reactor Experiment (SRE), Fermi, and Hallam reactors was evaluated on a pilot scale. A hydraulic dejacketing method and two alternative methods were tested with spent, NaK-bonded stainless-steel-jacketed fuel from Core 1 of the SRE. This four-year-old fuel, consisting of 2.7% enriched uranium slugs, was exposed to an average irradiation of 675 Mw-day/tonne during a period of two years. It was discharged from the reactor after abnormal temperatures had damaged 30% of the core. About 1.8 metric tonnes of spent Core 1 fuel were dejacketed mechanically at rates up to 9.2 kg of uranium per hour. A production rate 2 to 3 times higher had been predicted from the processing of unirradiated fuel. The hydraulic method, by which it was planned that all fuel would be processed (by expansion of the jackets and expulsion of the slugs) worked with only 16.5% of the fuel. The remainder of the fuel had to be processed by one of the two alternative methods. Dislodgment of fuel slugs from the jackets was extremely difficult because the jacket and some slugs were stuck together by a eutectic alloy of stainless steel-uranium. Also, the irradiated jackets had lost their ductility from the midpoint of a fuel rod to the top and, in addition, showed evidence of carburization, work hardening, sensitization, and embrittlement. Dejacketing of the abnormal SRE Core 1 fuel was accomplished successfully but none of the three dejacketing methods evaluated appeared to be sufficiently versatile to accommodate abnormal fuel and thus cannot be guaranteed as reliable production methods for the liquid-metal-bonded fuels.