Nuclear power

Nuclear power is a possible element in society's transition to fossil-free energy sources, potentially making it possible to meet increasing energy demands.

Nuclear energy is energy released from the nucleus of an atom. Atoms are small units that make up all matter in the universe, and in nuclear fission, the nucleus itself is split, releasing a very large amount of energy. This energy can be used to create heat and electricity.

Nuclear energy is energy released from the nucleus of an atom. Atoms are small units that make up all matter in the universe, and in nuclear fission, the nucleus itself is split, releasing a tremendous amount of energy. This energy can be used to create heat and electricity.

According to the IAEA (International Atomic Energy Agency), nuclear power accounted for approximately 10% of the world's total electricity consumption in 2022. The United States and China are the largest producers, but the largest shares of nuclear power in the countries' total energy mix are found in Europe, where countries such as France, Hungary, and Ukraine, in particular, have high shares of over 50% of the electricity supply.

The Danish parliament decided in 1985 that nuclear power should not be produced in Denmark. However, electricity is imported from countries that have nuclear power plants, which is why, according to Energinet (in danish), approximately 5-10% of our electricity in 2022 was produced using nuclear power, primarily in Sweden.

The role of nuclear power in the European and Danish energy mix is constantly being discussed. Some countries, such as Germany, have closed their nuclear power plants, while others are building new ones. The debate has taken on a new perspective as recent years have seen new developments in research into nuclear power technologies that make it possible to build small modular reactors (SMRs). According to developers, they may prove to be more flexible and more economical than the large nuclear power plants in operation today.

Due to the decision not to produce nuclear power on Danish soil, there has not been extensive Danish research into nuclear power technologies. However, DTU has maintained research environments working with nuclear physics and nuclear technologies and has thus maintained professional expertise in the field.

DTU researchers contribute to research in nuclear power and teach students about the technologies. This is done to help Danish companies working with nuclear power in their development work and ensure that Denmark continues to possess strong competencies in the field. This also supports a knowledge-based debate and assessment of the potential for the use of nuclear power in Denmark.

Questions and answers

The answers are produced in collaboration with senior researcher and center manager Bent Lauritzen.

Nuclear power is a method of making electricity using the energy released from nuclear reactions.

Most nuclear power plants use enriched uranium, which is bombarded with neutrons. This process - called fission - splits uranium atoms, releasing more neutrons that set off a chain reaction in the uranium.

This process creates large amounts of heat, which is used to create water vapor. The steam is sent through turbines that drive generators that produce electricity.


Nuclear power is an energy source that emits very little CO2 compared to fossil fuels.

Electricity can be produced reliably and continuously, making it a stable source of electricity and helping to reduce greenhouse gas emissions. Unlike renewables such as solar and wind, nuclear power generation can be regulated on demand.

The most commonly mentioned disadvantage is the risk of accidents involving the release of radioactive material.

In addition, spent fuel from nuclear power plants is highly radioactive and requires special handling and disposal.

Nuclear power plants have several safety systems and strict protocols in place to prevent accidents and reduce their consequences.

For example, modern nuclear power plants have redundant cooling systems and strict regulatory oversight.

Nuclear waste consists of spent fuel and other radioactive materials. It is stored in facilities such as deep geological repositories to prevent environmental contamination.

The safety of waste management is usually the subject of much public debate when it comes to finding new disposal sites.

Although accidents are rare, accidents can happen at nuclear power plants.

Safety measures and technologies have improved significantly since Chernobyl and Fukushima to reduce the risk of accidents and to limit the consequences of an accident.

Around 400 conventional nuclear power plants are in operation worldwide - 93 of them are located in the US.

Nuclear power is a significant source of electricity in many countries, although its growth has slowed due to economic circumstances and public attitudes, among other factors.

Nuclear power has low CO2 emissions compared to fossil fuels, making it an attractive alternative to tackle climate change. In terms of overall material consumption and waste emissions, nuclear power also has a very low environmental impact.

However, safety and waste management issues are still the subject of much debate.

SMRs are smaller, factory-built nuclear power reactors that developers say will be more economical and have better safety, scalability, and potential for simpler deployment.

They are likely to produce less than 300 megawatts of electricity, which is about a third of a conventional nuclear power plant.

SMRs are likely to have lower initial costs, shorter construction times, and greater flexibility in deployment than conventional nuclear power plants.

In addition, they can be used for a variety of purposes, including heat production and seawater desalination.

SMRs are likely to have a higher cost per unit of electricity compared to conventional nuclear power plants.

SMRs incorporate modern safety features, and their smaller size reduces certain risks.

However, their safety depends on proper design, construction, and operation.

There are over 80 projects around the world developing SMRs. Most are based in the USA, Canada, China, Russia, South Korea, and the UK.

In Denmark, development centers around two companies, Seaborg Technologies and Copenhagen Atomics.

News

Show all news
Photo of Bent Lauritzen, Head of Section at DTU Physics, taken at Risø Campus.

DTU offers popular course in nuclear reactor physics for the second time

During the course in nuclear reactor physics, MSc students gain insight into the theory behind modern nuclear power plants and visit a company specializing in nuclear power.
Anders Bjarklev

President: ”We must make our decisions on research-based knowledge.”

DTU’s President, Anders Bjarklev: “We produce new knowledge. Research-based knowledge. To enable our society to make informed decisions.“
Head of Nuclear Energy DTU Bent Lauritzen in his office.

DTU unites nuclear power research in new center

New, interdisciplinary center for nuclear energy technologies strengthens and unites DTU's research environments and will form a common entrance for external partners.
Portrait of Bent Lauritzen, Head of Section at DTU Physics, taken at Risø Campus.

Is nuclear power an option?

Nuclear power in Germany and France supplies electricity to Denmark, but a nuclear power plant in Denmark will not be ready until the 2030s at the earliest.
Show all news