Advanced nuclear design gets Canadian approval

THE Canadian Nuclear Safety Commission (CNSC) has given the first regulatory nod to a commercial Integral Molten Salt Reactor (IMSR) design in North America.

The advanced power plant is designed by Terrestrial Energy, which says that sites being assessed for feasibility include Chalk River, Ontario.

CNSC’s approval was for the first stage of three in a prelicensing review, and does not certify or license the reactor, but provides a chance to highlight issues that require resolution. It is the first step in what is likely to be a long process, and verifies that the reactor’s design meets the basic requirement for a nuclear power plant in Canada.

Terrestrial’s proposed 190 MW liquid-fuel IMSR400 reactor addresses issues of heat dissipation and construction costs, and risks associated with traditional reactors.

A fly-by of the Terrestrial Energy IMSR (Credit: Terrestrial Energy/YouTube)

Using molten salts to dissipate heat from fission is considered safer than using water, as reactors can operate at ambient atmospheric pressure. This lowers containment costs and enables cooling if the system were to lose power, which was a cause of the Fukushima Daachi meltdown, following an earthquake and tidal wave in 2011.

IMSRs are small, modular reactors, meaning that construction cost and risk can be lowered by mass-producing components in factories off-site. Furthermore, Terrestrial’s design includes a replaceable reactor core with an operating lifetime of seven years, allowing the safe and cheap replacement of degradation-prone graphite moderators with high energy densities.

Terrestrial Energy CEO Simon Irish said: “Completing phase one of the vendor design review – the first advanced reactor to do so – is a landmark achievement. It places the company as an early leader in a fast-growing technology sector.

“The IMSR nuclear power plant is a transformative energy technology that is now one step closer to making a major contribution to the world’s growing demand for low-cost, clean and reliable energy,” he added.

Advanced nuclear refers to the next generation of reactors, which aims to dramatically improve performance and eliminate known problems associated with existing reactors.

Other reactor designs include using thorium as a fuel in an MSR, as being developed by Netherlands-based NRG, while UK-based Moltex Energy and Advanced Reactor Concepts of Delaware are also pursuing early approval by the CNSC for salt-based reactors.