Experts from 17 countries laid the foundations last week for enhanced international cooperation on a technology that promises to deliver nuclear power with a lower risk of severe accidents, helping to decrease the world’s dependence on fossil fuels and mitigate climate change.
Molten salt reactors – nuclear power reactors that use liquid salt as primary coolant or a molten salt mixture as fuel – have many favourable characteristics for nuclear safety and sustainability. The concept was developed in the 1960s, but put aside in favour of what has become mainstream nuclear technology since. In recent years, however, technological advances have led to growing interest in molten salt technology and to the launch of new initiatives. The technology needs at least a decade of further intensive research, validation and qualification before commercialization.
“It is the first time a comprehensive IAEA international meeting on molten salt reactors has ever taken place,” said Stefano Monti, Head of the Nuclear Power Development Section at the IAEA. “Given the interest of Member States, the IAEA could provide a platform for international cooperation and information exchange on the development of these advanced nuclear systems.”
Molten salt reactors operate at higher temperatures, making them more efficient in generating electricity. In addition, their low operating pressure can reduce the risk of coolant loss, which could otherwise result in an accident. Molten salt reactors can run on various types of nuclear fuel and use different fuel cycles. This conserves fuel resources and reduces the volume, radiotoxicity and lifetime of high-level radioactive waste.
Molten salt reactor technology has attracted private funding over the last few years, and several reactor concepts are under development. One area under research is the compatibility between the salt coolant and the structural materials and, for some designs, the chemical processes related to the associated fuel cycle, Monti said.
The challenges are not only technical. Nuclear regulators will need to review existing safety regulations to see how these can be modified, if necessary, to fit molten salt reactors, since they differ significantly from reactors in use today, said Stewart Magruder, senior nuclear safety officer at the IAEA.
Participants, including researchers, designers and industry representatives, emphasized the need for an international platform for information exchange.
“While the United States is actively developing both technology and safety regulations for molten salt reactors, the meeting is an important platform to exchange knowledge and information with Member States not engaged in the existing forums,” said David Holcomb from the Oak Ridge National Laboratory one of the 35 participants at the meeting last week. The development of molten salt reactors began with an experiment conducted by the Oak Ridge National Laboratory in the 1960s.
From bilateral to multilateral cooperation
To help speed up research, it is essential to move from bilateral to multilateral cooperation, said Chen Kun from the Shanghai Institute of Applied Physics of the Chinese Academy of Sciences. “It is the first time China has the opportunity to share knowledge with India, Indonesia and Turkey on this technology.”
Indonesia is considering building its first nuclear power plant with molten salt reactor design, said Bob Soelaiman Effendi from Indonesia Thorium Energy Community. “For a developing country like Indonesia, a molten salt reactor’s higher efficiency in electricity generation makes it more economical and affordable than fossil-fuel power plants.”
Molten salt reactors and other advanced nuclear reactors have received increased attention over the last few years as the world is looking for alternative technologies for energy production. Advanced reactors, which could increase the sustainability of nuclear power, are at various stages of development. Some advanced reactors, such as the sodium-cooled fast reactor BN-800 in Russia and the High Temperature Reactor Prototype Module in China are already connected to the grid or are in an advanced stage of construction. Others, such as molten salt reactors, are in the design phase.
For a developing country like Indonesia, a molten salt reactor's higher efficiency in electricity generation makes it more economical and affordable than fossil-fuel power plants.