# Copenhagen Atomics

Copenhagen Atomics is a Danish molten salt technology company developing mass manufacturable molten-salt reactors. The company is pursuing small modular, molten fuel salt, thorium fuel cycle, thermal spectrum, breeder reactors using separated plutonium from spent nuclear fuel as the initial fissile load for the first generation of reactors.
Copenhagen Atomics' headquarters and production facility is located in Kastrup close to Copenhagen Airport.

## History

Copenhagen Atomics was founded in 2014 by a group of scientists and engineers meeting at Technical University of Denmark and around the greater Copenhagen area to discuss thorium and molten salt reactors, which were later incorporated in 2015.
In 2016, Copenhagen Atomics was part of MIMOSA, a European nuclear molten salt research consortium.
Copenhagen Atomics became the first private company in 2017, to offer a commercial molten salt loop.
By the end of 2022, Copenhagen Atomics finished a full-size prototype reactor. The prototype is a full-scale test platform, that tests the system in its entirety, with water as its medium. In 2023 a full-scale prototype molten salt reactor was built to test the entire system with non-radioactive molten salts.
In May 2023, Copenhagen Atomics signed a memorandum of understanding with the Scandinavian companies Topsoe, Alfa Laval and Aalborg CSP, and Indonesian companies Pupuk Kalimantan Timur and Pertamina New and Renewable Energy, with the prospect of establishing a green ammonia plant in Bontang, Indonesia. The plant will be capable of producing 1 million tonnes of ultra-low emission ammonia annually, which will save the emission of 1.7 million tonnes of carbon dioxide per year.
In 2023, Copenhagen Atomics moved out of the Alfa Laval Innovation House, to new headquarters and production facilities in Kastrup.
In July of 2024, Copenhagen Atomics announced that their prototype reactors are ready to be tested in a real life scenario, in a critical experiment at the Paul Scherrer Institute in Switzerland. Set to launch in 2026-27, this will be the first time in European history that a critical experiment is carried out with a thorium molten salt reactor.

## Reactor design

The company describes its reactor core as shaped like an onion, with the outermost layer being a breeding blanket of 2,000 liters of FLiNaK (Lithium Sodium Potassium Fluorides) and ThF4 salts at 600°C used to transmute thorium into fissile Uranium-233. The next layer consists of heavy water at 20°C. Farther inward is the pumped fuel salt layer (about 200 liters of FLiNaK and UF4/3), which enters the reactor at 600°C and exits the reactor at 700°C, and serves as both fuel and core coolant. The innermost layer is the moderator, more heavy water at 20°C, with the total amount of heavy water being ~1,200 liters. The layers are separated by stainless steel, in early versions, but later by carbon composites. 2 to 3 centimetres of yttria stabilised zirconia insulate the heavy water from the hot salts.
The design requires that fission products are removed online (while the reactor is operating).

## Research and development

Copenhagen Atomics is pursuing a hardware-driven iterative component-by-component approach to reactor development, instead of a full design license and approval approach. Copenhagen Atomics is actively developing and testing valves, pumps, heat exchangers, measurement systems, salt chemistry and purification systems, and control systems and software for molten salt applications. The company has also developed the world's only canned molten salt pump and are developing an active electromagnetic bearing canned molten salt pump.
Copenhagen Atomics offers many of their technologies commercially available to the market. This includes pumped molten salt loops for use in molten salt reactor research, as well as highly purified salts for high temperature concentrated solar power, molten salt energy storage, and molten salt chemistry research.

## Environmental Impact

According to the website Thorium Energy World: "The CAWB [ed. Copenhagen Atomics Waste Burner] will use thorium to burn out actinides from spent nuclear fuel in order to convert long-lived radioactive waste into short-lived radioactive waste, while producing large amounts of energy and jobs in present time."