The Canadian Nuclear Safety Commission (CNSC) is conducting Phase 1 of a pre-licensing vendor design review on the Terrestrial Energy molten salt IMSR, which it expects to be completed in September 2017 as it moves into the engineering phase. It plans to submit either an application seeking design certification or a construction permit application for the IMSR-400 no later than October 2019 to the NRC. It hopes to commission its first commercial reactor by the early 2020s. The company and Canadian Nuclear Laboratories are considering the feasibility of siting a commercial plant at Chalk River.
NuScale lodged an application for US design certification in January 2017, and in July 2017 the NRC confirmed that its highly integrated protection system (HIPS) architecture was approved. NuScale has been engaged with the NRC since 2008, having spent some $130 million on licensing to November 2013. It expects the NRC review to take 40 months, so the first unit could be under construction in 2020 and in operation about 2023. A COL application is planned for early 2018. The company also expects to apply for generic design assessment in the UK in a similar timeframe.
Advanced Reactor Concepts LLC (ARC) set up in 2006 is developing a 260 MWt/100 MWe sodium-cooled fast reactor based on the 62.5 MWt Experimental Breeder Reactor II (EBR-II). It will be factory-produced, with components readily assembled onsite, and with ‘walk-away’ passive safety. Installation would be below ground level. The ARC-100 system comprises a uranium alloy metal core cartridge submerged in sodium at ambient pressure in a stainless steel tank.
Thermal efficiency is about 40% and it and could be paired with a supercritical carbon dioxide tertiary circuit to drive a turbine at high efficiency levels. Operating cost is expected to be $50/MWh.
In March 2017 GEH and ARC signed an agreement to collaborate on licensing an SMR design based on ARC-100, which will leverage extensive intellectual property and licensing experience of the GEH PRISM program. Initial deployment is envisaged in Canada, and they will seek a preliminary regulatory review with the CNSC through its Vendor Design Review process, likely to start late in 2017.
In October 2016 GEH signed an agreement with Southern Nuclear Development, a subsidiary of Southern Nuclear Operating Company, to collaborate on licensing fast reactors including PRISM. In June 2017 GEH joined a team led by High Bridge Energy Development Co. and including Exelon Generation, High Bridge Associates and URS Nuclear to license PRISM.
Holtec International has a subsidiary – SMR-160 LLC – to commercialize a 160 MWe factory-built reactor concept called the Holtec Inherently Safe Modular Underground Reactor (HI-SMUR). This has two external horizontal steam generators, and uses fuel similar to that in larger PWRs, including MOX. The 32 full-length fuel assemblies are in a fuel cartridge, which is loaded and unloaded as a single unit from the 31-metre high pressure vessel. Holtec claims a one-week refueling outage every 42 months. It has full passive cooling in operation and after shutdown for an indefinite period, and also a negative temperature coefficient so that it shuts down at high temperatures. The reactor will be offered with optional heat sink to atmosphere, using dry cooling. The whole reactor system will be installed below ground level, with used fuel storage. A 24-month construction period is envisaged for each $800 million unit ($5000/kW). Operational life claimed is 80 years.
Licensing of the SMR-160 in the USA will initially use an NRC process which involves a construction permit followed by an operating license, and later continuing to design certification under other licensing rules. Holtec originally expected to submit an application for design certification to the NRC late in 2016, but is now aiming for a license application by the end of 2018. In July 2017 a partner agreement with SNC-Lavalin based in Ontario was formalized, involving engineering support and licensing.