New Nuclear Technologies
When the first nuclear reactors were designed and built in the 1940s there was a huge learning curve in creating safe, efficient and cost-effective civil nuclear reactors. Huge improvements in reaction design, partly accelerated by military interests, were seen across the world, where a variety of different reactor systems were developed, built and operated.
However in recent years nuclear innovation has slowed considerably. Although nuclear operators are constantly updating their designs, particularly with regard to safety, it is extremely difficult for new reactor designs to enter the energy market. This is partly because of the stringent regulatory process that nuclear reactor designs must go through. Regulation of the industry is obviously extremely important and should be carried out thoroughly, however it does not help the nuclear industry or society if it creates impassable barriers for potentially better designs.
One of the major barriers in expanding nuclear energy in the UK and across the world is the high cost of building a nuclear power station. In the past 30 years, the construction cost of current reactors has been increasing because of the constant addition of expensive redundant safety features. This has led to the government awarding significant subsidies and political impetus to operators wanting to build new nuclear power stations.
In order to provide a sustainable low carbon future, nuclear energy must be a key feature. However, in order to make nuclear power sustainable it is necessary to ensure that the technology is gaining the optimum use of its fuel. Current reactors produce waste that still contains a reasonably high percentage of usable fuel. The UK also has the largest civil plutonium stock in the world, which can also be used to create more energy. New nuclear reactor designs are not only able to use both plutonium and other reactors waste, but also breed more fuel inside the reactor itself.
In 2001, the Generation IV International Forum (GIF) was founded by Canada, France, Japan, South Africa, South Korea, the United States, Argentina, Brazil and the United Kingdom. This group identified six key technologies which have the potential to be commercialised and offer advantages over the Generation III reactors that are currently in use. These six reactors are:
Fast reactor designs:
Epithermal reactor design:
Thermal reactor designs:
Fast, epithermal and thermal refers to the speed of the neutrons in the reactor that cause nuclear fission. The majority of reactors currently in use are thermal reactors, which is where the neutrons are slowed so they are more likely to cause fission.
A fast reactor has the advantage of being able to change the make up of the fuel, converting fertile materials into more fuel and decreasing the amount of long-lived waste.
Advantages of Gen IV
There are several general advantages of these advanced technologies including:
- Intrinsically safe: These advanced reactor designs are based of different principles than current reactors and so do not require so many extra safety features. Some of the designs use liquid fuel which means that it is impossible to have a meltdown because the fuel is already a liquid. Many designs do not require high pressure systems, so the problems related to a pressurised cooling system are eliminated.
- Low carbon: All nuclear energy is low carbon, but advanced nuclear designs have the potential to be even lower in carbon emissions, which is vital to prevent further damage due to climate change.
- Produce heat – which renewables struggle to achieve: Heat is used in industrial processes as well as for heating homes and workplaces. It is possible to use electricity generated from renewables to generate heat, but it is very difficult to achieve the temperatures required for industrial processes such as steel making. Many of the advanced nuclear designs have multiple uses aside from just producing energy, for example creating high quality heat that industry can easily use.
- They have the potential to be cheaper: Although it is impossible to say for sure because they have not yet been built and operated, there are several indications to suggest that advanced reactors will be significantly cheaper than current reactor designs, and even possible rivalling the fossil fuel industry.
Other Developments in Nuclear Technologies
There has been a great deal of interest and research into reducing the size of nuclear reactors. If the reactor core is smaller then it is possible to reduce the risk of potential incidents dramatically, as well as making it much cheaper to build and operate. Multiple modules could then be built at the same site depending on the required power output. These are called small modular reactors, and almost any nuclear technology can be adapted to this model.
A lot has been made of the potential of thorium fuel, first championed by Alvin Weinberg himself. Although it may not live up to all the hype, there is definite potential, because of the natural abundance of thorium, for it to provide one of the solutions for a sustainable nuclear future.