Traveling wave reactor

A type of nuclear reactor that uses a slow-moving wave of fission to sustain a reaction.

Animation of a traveling wave reactor in operation

A traveling wave reactor (TWR) is a type of nuclear reactor that can convert fertile material into fissile fuel as it operates. This process allows the reactor to use fuel more efficiently and potentially reduce nuclear waste.

Principle of Operation

The traveling wave reactor operates on the principle of a slow-moving wave of nuclear fission that travels through the reactor core. Unlike traditional reactors that require enriched uranium or plutonium, TWRs can use depleted uranium or natural uranium as fuel. The wave of fission moves through the core, converting fertile isotopes like uranium-238 into fissile isotopes such as plutonium-239.

Fuel Cycle

The TWR is designed to breed its own fuel in situ, meaning it can theoretically operate for decades without the need for refueling. This is achieved by maintaining a balance between the breeding of new fissile material and the consumption of existing fuel. The reactor starts with a small amount of enriched fuel to initiate the reaction, and as the wave progresses, it converts fertile material into usable fuel.

Advantages

One of the main advantages of the traveling wave reactor is its potential to utilize the vast amounts of depleted uranium that are currently considered waste. This could significantly extend the fuel supply for nuclear power. Additionally, TWRs produce less long-lived radioactive waste compared to conventional reactors.

Challenges

Despite its potential benefits, the traveling wave reactor faces several technical and economic challenges. The design and construction of a TWR are complex, and the technology is still in the experimental stage. There are also concerns about the proliferation risks associated with breeding plutonium in the reactor core.

Development

The concept of the traveling wave reactor was first proposed in the 1950s, but it gained renewed interest in the early 21st century. TerraPower, a company founded by Bill Gates, is one of the leading organizations working on the development of TWR technology. They aim to build a prototype reactor to demonstrate the feasibility of the concept.

Related pages

• Nuclear reactor
• Nuclear fuel cycle
• Breeder reactor
• Depleted uranium