Understanding the super safety of the Moltex nuclear plant which will be built in Canada

In July, 2018, Moltex was selected by New Brunswick Energy Solutions Corporation and New Brunswick Power to progress development of its SSR-W (Stable Salt Reactor – Wasteburner) technology in New Brunswick, with the aim of deploying its first SSR-W at the Point Lepreau nuclear reactor site before 2030.

The agreement provides $5 million of financial support to Moltex for its immediate development activities and Moltex will open its North America headquarters in Saint John and build its development team there.

The Moltex SSR-W reactor will use Candu fuel assemblies for its Canadian prototype.
The design does not use complex controls for managing risks, the Stable Salt Reactor – Wasteburner design eliminates risks.
The non-nuclear portion of the plant uses standard high-temperature natural gas plant turbines and other systems. Those have proven costs and build times from many projects.

The SSR design permits all complex and hazardous high-pressure equipment to be outside the nuclear island, indeed outside the licensed nuclear site in many cases. Thus it has costs similar to those in natural gas-powered stations, which are dramatically lower than in nuclear stations.

The reactor module will generate 150 MWe and weight only 18 tons and take up 50 cubic meters. This is three times the power as the Nuscale 50 MWe reactor module and take less than one-eighth of the volume.

Stable Salt Reactors build on the fundamental safety and simplicity breakthrough of molten salt fuel in essentially standard nuclear fuel tubes.

* The fuel salt is held in vented tubes. Venting is safe because in our reactors the dangerous fission products form stable compounds, not gases.
* The tubes are bundled into fuel assemblies similar to those in a conventional PWR. These are held in the support structure which forms the reactor modules.
* The tank is filled with a safe molten salt coolant, which is not pressurised like gas or water coolants in today’s power reactors and not violently reactive with air and water like sodium in today’s Fast Breeder reactors. A second similar coolant salt system takes heat from the primary coolant salt to steam generators kept well away from the reactor.
* Refuelling is simple: Fuel assemblies are simply moved sideways out of the core and replaced with fresh fuel assemblies. This results in a near on-line refuelling process.
* The entire construction is simple, with no high-pressure systems, few moving parts, and no Pressure Vessel needing specialist foundries.
* The reactor is continuously cooled by natural air flow, giving complete security against overheating