The two companies signed a cooperation agreement in October 2022 to jointly develop LFR technology. The agreement will allow the two companies to advance "co-design to maximise synergies, combine experience in design, trials and forensics, and coordinate their respective partners and supply chain organisations". At the time, the two sides said the agreement "builds on development activities already underway in the United Kingdom, the United States, Italy and Romania, where more than a dozen state-of-the-art lead-based test facilities are being installed."

The test activities carried out by PHRF at Ansaldo were carried out under a contract for the second phase of the Advanced Modular Reactor (AMR) project, funded in part by the UK's Department for Business, Energy and Industrial Strategy, awarded to Westinghouse with Ansaldo Nucleare as the main supplier.

As part of this contract, Ansaldo Nucleare led the design, procurement, installation and commissioning of two state-of-the-art test facilities, the Multifunctional Loop Facility (VLF) and the Passive Heat Extraction Facility (PHRF), to support Westinghouse's LFR technology.

The UK government's investment of 10 million pounds (about 87 million yuan) will enable Westinghouse to test the feasibility of key LFR materials, systems and equipment. The VLF will test a fuel-rod beam simulator, a compact heat exchanger and a coolant pump similar to those that will be installed in the reactor coolant system. PHRF will study the characteristics of Westinghouse LFR passive residual heat removal systems to generate test data for evaluation of computer programs dedicated to performance evaluation.

"These trial facilities are critical assets for the collection of experimental data to support the accelerated development of LFR technology," Ansaldo said. .

Riccardo Casale, Chief Executive Officer of Ansaldo Nucleare, said, "With this milestone, we add another important element to the future of fourth-generation reactors. Ansaldo Nucleare, together with its UK subsidiary Ansaldo Nuclear Ltd, remains at the forefront of the development of Westinghouse lead cold fast Reactor. This is a fruitful collaboration that we are proud of." .

"Entering the test phase with these large test facilities clearly demonstrates the maturity of the reactor development projects that Westinghouse and Ansaldo Nucleare are advancing," said Mark Urso, Westinghouse's interim chief Technology Officer. Our project goes beyond design and modeling activities to include hands-on activities that help enhance our hands-on knowledge of LFR technology." .

According to the World Nuclear Association, the LFR is "a flexible fast reactor that can use depleted uranium or thorium based fuels, as well as the combustion of actinides in pressurized water reactor spent fuel. Liquid metal (Pb or PB-Bi eutectic) cooling is carried out by natural convection at atmospheric pressure (at least to derive decay heat). The fuel is metal or nitride, and all actinides are recovered from a regional or central reprocessing plant. A variety of unit capacity designs exist, from factory manufactured "batteries" designed for small grids or developing countries with a life span of 15-20 years, to modular 300-400 MWe units, to large single power plants of 1400 MWe ".

According to Westinghouse, its LFR is "a medium, passive and safe modular reactor that is in the development phase to reduce upfront capital costs and generate flexible and cost-competitive power. "LFR achieves a new level of energy affordability by employing innovative design features to simplify and compact the plant, while enhanced construction modularity shortens construction schedules."

Westinghouse says that using lead as a coolant with a boiling point of more than 1,700 °C allows high temperature operations at atmospheric pressure without fear of coolant boiling. This improves thermodynamic efficiency compared to pressurized systems, reduces capital costs, and helps achieve inherent safety. The LFR has the ability to generate power beyond base load by utilizing the heat storage system for load balancing. Its high-temperature capability allows it to cope with a wider range of applications, such as cogeneration, as well as closed-market desalination.