World Champions in radioactivity

Monday 28 Nov 16


Jens-Peter Lynov
DTU Physics

The history of Risø and DTU Nutech

The Atomic Energy Commission was founded in 1955 to build up a public sector research institution tasked with researching peaceful exploitation of atomic energy. This took the form of Risø National Laboratory, which was inaugurated in 1958. In 2003, Danish Decommissioning was set up as an independent business with the overarching objective of decommissioning nuclear installations. Decommissioning is one of the biggest environmental assignments ever taken on in Denmark.

Risø became part of DTU in 2007. In 2012, Risø was discontinued as an independent institution, and DTU Nutech has since picked up the torch as Denmark’s national skills centre for nuclear technologies. The focus here is on biomedical uses, measuring radiation doses, and the detection and analysis of radioactive isotopes in the environment, foods and materials.


  • Dosimetry: The measurement of ionizing radiation and calculation of its effect.

  • Hot cell: An advanced fume cupboard where researchers can work safely with radioactive substances.

  • Ionizing radiation: To ‘ionize’ means to have an influence on a substance such that its molecules or atoms form ions.

  • Isotope: ‘Isotope’ is the Greek for ‘in the same place’ and is now used to refer to different versions of the same element.

  • Mass-spectroscopy: A method of determining atomic and molecular mass.

  • Plutonium: An isotope used to make nuclear weapons and to produce energy in nuclear reactors.

  • Radioactivity: Spontaneous transformation (decay) of an atomic nucleus caused by high-energy radiation.

  • Radioecology: A research field devoted to measuring radioactive substances in the environment.
Researchers at DTU Nutech develop and apply knowledge about radioactive substances and ionizing radiation. Nuclear technologies are put to uses as diverse as curing cancer and dating cave paintings.


Every day, researchers from DTU Nutech pass the graphic timeline illustrating the level of radiation in the Danish environment. The timeline is positioned just inside the main entrance to Building 204 on Risø Campus and testifies to the unbroken measurement of radioactive substances in Denmark dating back to 1957. Even before the official opening of the Atomic Energy Commission’s Research Establishment Risø in 1958, Danish scientists were already taking local samples of the air, water, plants and fish to map the background radiation at the site where the facility was to be built.

Photo: DTU

Since then, researchers from DTU Nutech have carried on building on the work of these pioneers. Today, they continue to develop and utilize the huge volume of knowledge about radioactive substances and ionizing radiation to the benefit of society as a whole.

The findings from their research are transformed into a wide variety of products and services for companies, hospitals, public authorities, other research institutions and media. This has made DTU Nutech a world champion in the application of nuclear technologies.

“Over the past 60 years, we have built up a pool of knowledge which means we are specialists in an area that has been largely forgotten elsewhere in the world. This applies, for example, to the determination of certain radioactive isotopes that are formed inside nuclear power plants, but which are difficult to measure. We thought that interest in measuring these substances was dying out, but it has recently become relevant again because the time has now come to close and decommission (i.e. demolish, ed) a large number of nuclear facilities. Germany and Sweden are turning to us for help in performing advanced chemical analyses,” relates Jens-Peter Lynov, Director of DTU Nutech.

Always radioactive
He explains that we are exposed to radiation 24/7. In addition to cosmic radiation from space, we are affected by radiation from radioactive substances stemming from the formation of the Earth itself. All life on Earth therefore has the capacity to withstand a degree of radioactivity. But not everyone is aware of that.

“Towards the end of the 1970s, we witnessed appreciable public opposition to nuclear power in Denmark. There was the accident on Three Mile Island in Pennsylvania in the United States, and people started to question whether this was a form of energy we wanted here. This opposition gradually expanded to encompass all forms of radioactivity, but no mention was made of the fact that radioactivity is natural. It’s always there. In fact, a precondition for life on Earth is that radioactive decay takes place in the Earth’s crust. Otherwise, the planet would be too cold to support life.”

Four major fields of research at DTU Nutech


1. Radioecology

Photo: Joachim Rode  

Dongxia Zhang is a visiting PhD student at DTU Nutech, where she is using Danish analysis methods to measure the plutonium content of a soil sample from China.

In the same way as Dongxia Zhang, researchers travel from all parts of the world to DTU Nutech to carry out chemical analyses, radiation measurements and mass-spectroscopy.In the Radioecology section, researchers examine issues such as how radioactive substances are transported in the environment, and how to develop methods for determining the environmental impact of the substances.

DTU Nutech also maps the radiation level in the Danish environment, i.e. in people, vegetation and foods. This assignment is performed by arrangement with the Radiation Protection Section of the Danish Health Autority (SIS).

Photo: Joachim Rode


Gunnar Jakobs, Development Engineer, initiates examination of the radioactive content in a water sample through evaporation. DTU Nutech regularly receives water samples from the sea around countries including Iceland, Greenland and the Faroe Islands.

The water samples make up one aspect of an assignment in which DTU Nutech is using radioactive substances as tracing agents to map the ocean currents from The English Channel up along the coasts of Norway and Greenland.The samples provide researchers with new knowledge about how the ocean currents behave, which is of significance to how the climate is likely to develop in future.


2. Dosimitry

Photo: Mikal Schlosser  

Cancer can be treated—and, in many cases, actually cured—by sending powerful X-rays through the cancer tumour to kill the cancerous cells.

Researchers at DTUNutech are looking at methods for precisely measuring the radiation used in cancer treatment. This is known as ‘medical dosimetry’. Research is being carried out with the assistance of equipment including an electron accelerator, which is an ultra-modern radiation cannon. The findings are helping hospitals to improve their radiation therapy. One of the new areas of research is called ‘proton therapy’, which is a more accurate form of radiation treatment.

Photo: Mikal Schlosser


Retrospective dosimetry is used to date geological and archaeological subjects. Using this technology, researchers have, for instance, concluded that a cave painting in Australia was created thousands of years earlier than originally thought.

DTU Nutech also provides consultancy services in the field of industrial dosimetry, where ionizing radiation is used to sterilize medical products.


3. Radioactive pharmaceuticals

Photo: Joachim Rode  

At 3.30 a.m. Bente Sørensen, Laboratory Technician, arrives for work in the clean room at Hevesy Laboratory, where her job is to prepare fluids for scanning cancer patients.

The radioactive fluids are collected at 6 a.m. by a driver, who then delivers them to hospitals in Næstved, Bispebjerg and Køge, where they are injected into cancer patients to enable doctors to locate cancer tumours.

Hevesy Laboratory is tasked with researching, developing and producing radioactive isotopes and radioactive medicines for diagnosing and treating a wide range of illnesses: various forms of cancer, heart complaints and diseases of the brain.

Photo: Joachim Rode


Helle Demant Rasmussen, Laboratory Technician, works in the basement of Hevesy Laboratory, where researchers use a biomedical cyclotron to generate radioactive isotopes.


4. Design and construction of ESS 

Illustration: ESS  

Researchers from DTU Nutech are heavily involved in the work to construct the European Spallation Source (ESS), which, on completion, will be the biggest neutron microscope in the world.

Firstly, they are helping with the design and construction of what is known as a ‘moderator’, whose taks is to slow and cool the neutrons so that they can be used by material researchers. Secondly, they are working to examine and characterize the gaseous, radioactive isotopes generated in the area where the neutrons are formed in ESS. This work is of importance to guaranteeing safe operation of the installation from the perspective of health.

In future, DTU Nutech hopes to be able to contribute to teaching students how to use neutrons for scattering. A project is currently under way to examine the possibility of building a ‘mini-ESS’ on Risø Campus. If everything goes according to plan, this may be green-lit within the next few years.