SMR (Small Modular Reactor) is a next-generation nuclear power technology designed to manufacture small reactors with a capacity of 300MW or less in modular form at factories and transport them to sites for installation and scalable expansion.

Key advantages include enhanced safety due to lower design output and a smaller reactor core, which reduces residual heat (decay heat) in the event of an accident. In addition, factory fabrication and standardization are expected to shorten on-site construction time and distribute initial investment costs through modular expansion.

Hwasein Bolt Industry Co., Ltd. was selected in 2025 for the Ministry of Trade, Industry and Energy’s business restructuring program and plans to expand its manufacturing facilities for fasteners used in SMRs. The company is scheduled to supply bolts and nuts for the reactor pressure vessel fastening components of the NuScale SMR supplied to Doosan Enerbility.

Small modular reactors refer to the concept contrasted with existing large-capacity power reactors, meaning small reactors with an electrical output of 300 Mwe or less.

SMRs are gaining global attention as an alternative for carbon reduction because they are safer than existing nuclear power plants and have flexibility in location and output.