MoltexFLEX, Ltd.

MoltexFLEX is a British nuclear energy company developing small modular molten salt reactors. Known as a stable salt reactor, the design features a unique hybrid approach whereby fuel assemblies similar to current light water reactor technology containing the liquid salt fuel mixture are submerged in a pool of liquid salt coolant.
==History==
MoltexFLEX Ltd was launched in 2022 to develop the FLEX reactor in the UK. The company is a subsidiary of Moltex Energy Limited, which was created in 2014 to develop stable salt reactor technology. MoltexFLEX has a laboratory in Warrington, Cheshire.
==The FLEX reactor==
MoltexFLEX’s proposed product, the FLEX reactor, operates in the thermal spectrum and uses low enriched uranium. Stable salt reactors fundamentally differ from all other molten salt reactor designs under development around the world in that the radioactive fuel salt is confined within fuel tube assemblies similar to those found in conventional light water reactors A separate, non-radioactive molten salt transfers the heat from the reactor core to heat exchangers.
A second unique feature of the stable salt reactor is that it requires no moving parts; the cooling salt circulates through the core using natural convection, removing the need for pumps and complex engineering, and greatly simplifying the design.
The FLEX reactor outputs 40MWt, equivalent to 16 MWe. Each reactor unit is stated to be roughly the size of a three-bedroom house. MoltexFLEX claims the reactors can be used singly or combined in arrays of any number. Used in combination with the company’s GridReserve molten salt thermal storage system, large arrays could be used to provide baseload or peaking power at an estimated cost of $40/MWe. The company states that 500MWe plant employing 32 FLEX reactors could be constructed in approximately 24 months. MoltexFLEX intends FLEX reactors to complement intermittent generation from renewables such as wind and solar power.
Additionally, the FLEX reactor generates heat at 750°C, which is intended to be used in several downstream decarbonisation applications. These include: high temperature electrolysis to efficiently produce hydrogen for use in industry or fuel cells for heavy transport; desalination; process heat for industry; and maritime propulsion.
In common with other small modular designs, components of the FLEX reactor are intended to be factory-produced and readily transportable to reduce on-site work, thereby increasing speed of construction and minimising overall costs. The company claims the physics of the molten salt ensure passive safety, and so FLEX reactors do not require redundant, active safety systems. The FLEX reactor operates at atmospheric pressures, and therefore the large and expensive concrete and steel containment structures inherent in conventional nuclear plants are deemed unnecessary. Time between refuelling is claimed to be approximately 20 years, with a plant lifetime of 60 years.
==Research and development==
MoltexFLEX states it intends to use as many existing and already available components and materials as possible, with the turbine island using standard electricity generation industry technology. A research initiative with the University of Manchester to examine the behaviour of standard industrial-grade graphite for neutron moderation was announced in early 2023. The company aims to have a first-of-a-kind prototype in operation by 2029.
Category:Nuclear energy companies
Category:Companies based in Warrington
Category:Nuclear power companies of the United Kingdom
Category:Companies established in 2022