scope:

Scope and history

This standard applies to all SFR nuclear power plants, irrespective of level of power production and energy end use. It also applies to configurations in which there are one or more reactor units (modules) on a site. It is intended to apply to all fuel types. The heat transport system is not restricted to a particular configuration, and thus, this standard applies to loop, pool, hybrid, or other arrangements. This standard also pertains to on-site storage of spent fuel prior to its removal for recycling or long-term storage.

The major subjects of this standard are design criteria and guidance on risk-informing the design process. Once the plant is designed according to the design criteria, criteria for adequately executing construction and criteria for safely operating the nuclear plant are largely outside the scope of this standard, although of course they are of great importance to the achievement of the safety performance being sought.

The scope of this standard covers the nuclear safety of these facilities, meaning the elements of the design aimed at preventing or mitigating accidental damage to the facility that could lead to radiological releases that would harm the public or the facility's workers. Any facility design must also be concerned with preventing and mitigating damage caused by a security breach arising from either inside or outside the facility, and a general criterion related to that subject is included in the scope of this standard.

An earlier version of this standard, ANS-54.1-1989, "General Safety Design Criteria for a Liquid Metal Reactor Nuclear Power Plant" [2], was issued in 1989 and withdrawn in 1999 due to waning interest in SFRs, although two LWR counterparts, ANS-51.1/N18.2-1973, "Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants" [3], and ANS-52.1-1978, "Nuclear Safety Criteria for the Design of Stationary Boiling Water Reactor Plants" [4], were completed and approved much earlier (1973 and 1978, respectively). Those standards were subsequently updated in 1983 ([5][6]), adding new riskbased classifications. However, along with the earlier ANS-54.1 standard [2], all remained essentially deterministic compilations of the state-of-the-art design from that era. Revived interest in SFRs spurred by the U.S. Department of Energy (DOE) and several industrial organizations, including the development in the industry of certain small modular reactor designs, has motivated the development of this new standard. Other, more detailed implementation standards are envisioned for detailed designs.

The working group that has prepared this standard was formed in 2010, and a reasonably complete draft was ready in 2014, but at that time the working group decided to put its completion in abeyance until an important effort being undertaken by the DOE and then by the NRC to develop new, broad recommendations for design criteria had reached fruition. When the DOE effort produced a useful report in late 2014, INL/EXT-14-31179, "Guidance for Developing Principal Design Criteria for Advanced (Non- Light Water) Reactors" [7], followed by the NRC's publication of its Regulatory Guide (RG) 1.232, "Guidance for Developing Principal Design Criteria for Non-Light-Water Reactors" [8], the working group resumed its work and completed the draft standard in 2018, beginning the American Nuclear Society's (ANS's) committee approval process.