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The 2025 edition is a reinvigoration of the withdrawn ANS-54.8-1988 of the same title.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.

The Advanced Reactor Codes and Standards Collaborative (ARCSC) held its second workshop on November 30, 2023, in Washington, D.C. The hybrid event had just over 200 participants, including representatives from standards development organizations (SDOs), the Electric Power Research Institute, the Nuclear Energy Institute, national laboratories, government agencies, vendors, advanced reactor designers, and consultants. Also in attendance were representatives from other U.S. industry and international organizations, including the International Atomic Energy Agency. ANS Standards Board chair Andrew Sowder, senior technical executive at EPRI, welcomed attendees to EPRI’s offices, where the workshop was held.

The Advanced Reactor Codes and Standards Collaborative (ARCSC) held its second workshop on November 30, 2023, in Washington, D.C. The hybrid event had just over 200 participants, including representatives from standards development organizations (SDOs), the Electric Power Research Institute, the Nuclear Energy Institute, national laboratories, government agencies, vendors, advanced reactor designers, and consultants as well as representatives from other U.S. industry and international organizations, including the International Atomic Energy Agency. ANS Standards Board chair Andrew Sowder, senior technical executive at EPRI, welcomed attendees to EPRI’s offices, where the workshop was held.