Lots of industries produce radioactive waste. We know that nuclear plants produce it, but some unexpected companies also produce radioactive waste. Take offshore oil and gas production, for example. Along with the minerals, natural radioactive substances are also extracted. Hospitals also produce radioactive waste, in laboratories and radiology, among others.
Infographic (part I - in Dutch)
Radioactive waste
Because relatively little radioactive waste is produced in the Netherlands and because of the required specialist knowledge, in 1982 one recognised organisation that already managed all the waste in one central site in the Netherlands was chosen: the Central Organisation for Radioactive Waste (COVRA), which is located in Nieuwdorp in Zeeland.
COVRA continues to manage Dutch radioactive waste to protect people and the planet. All the radioactive waste is safely stored by COVRA in specially designed buildings for at least a hundred years. The waste is isolated in a central place, where it can be managed and controlled to guarantee safety over that long period. Eventually, the waste must be sent to a final disposal site. This guarantees that the waste will remain outside the living space of people for thousands of years.
infographic (part II - in dutch)
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radioactive waste: the journey
Decay
The basis of managing radioactive waste is decay: over time, radioactive waste becomes harmless. Sometimes waste becomes harmless in seconds, while other types take thousands of years.
When radioactive substances emit their radiation, they eventually change into a substance that is no longer radioactive. We call that 'decay’, which is a normal physical process. The unstable elements are looking for a new balance. When they achieve that balance, the radioactive substance becomes stable and no longer emits radiation. Ultimately, this results in a substance that has lost all its radiation and is therefore no longer dangerous. The time this takes is called half-life, which is the time required for the substance to lose half its radioactivity. After two half-lives, the radioactivity is half of the half. So that is a quarter of the initial value. Each radioactive substance has its own fixed half-life. One radioactive substance is therefore harmless from the moment it is produced. Other radioactive material needs to be stored for thousands of years before it stops emitting radiation.
Types of waste
In radioactive waste management, a distinction is made between two types of waste:
- Low and intermediate-level radioactive waste
- High-level radioactive waste
Low and intermediate-level radioactive waste
Low and intermediate-level radioactive waste (L/ILW) includes medical supplies (gloves, clothing, syringes and laboratory glasswork), smoke detectors and parts of reactors (pipes, pumps and filters). COVRA currently stores 34,000 m³ of low and intermediate-level radioactive waste. This would fill 1/20 of a large container ship. Every year, another 1,100 m³ of L/ILW is added. That is equivalent to the contents of around 16 sea containers.
L/ILW can be solid or liquid. Flammable or inflammable, compressible or non-compressible. Each type of waste requires a specific treatment to ensure it can be stored safely. For low and intermediate-level radioactive waste, a concrete casing can contain the radioactive substances and reduce the radiation. This waste gradually decays in ordinary storage buildings.
NORM waste is a special category of waste. NORM stands for ‘Naturally Occurring Radioactive Material’. This is waste with natural radioactivity, for example depleted uranium and radioactive substances that are extracted in oil and gas production.
High-level radioactive waste
High-level radioactive waste (HLW) consists of recycling waste from nuclear fuel from Borssele nuclear plant and nuclear fuel elements and waste from the production of medical isotopes in the research reactors in Petten and Delft. Currently, around 110 m3 of such waste is stored at COVRA. That is equivalent to the contents of around one and a half sea containers. Every year, another 4.5 m3 is added.
Due to the high radiation level, HLW must be processed with remote-controlled installations and stored behind thick concrete walls. This is done in the HABOG, a big bright orange bunker with 1.70-metre thick walls, which can withstand natural catastrophes (earthquakes and flooding events) and man-made disasters (transport accidents and explosions). HABOG stands for High-Activity Treatment and Storage Building.
The HLW that produces heat is mixed in liquid gas and poured into stainless steel packing, where it solidifies into a basaltic material. The radioactivity is then sealed in the molecular structure of the glass, from where it can no longer escape. Over the coming hundred years, this waste loses its heat and most of its radioactivity, after which the waste is easier to manage. Non-heat producing HLW is stored without glass mixture in stainless steel packing.
Final disposal
The storage of radioactive waste such as that in COVRA is a globally applied and proven safe technology. However, this storage of radioactive waste is not a definitive, long-term solution for radioactive waste. After being stored for a hundred years, some of the waste is still radioactive. This long-lived waste is best stored deep underground. We call that final disposal.
In a stable underground layer of earth, for example clay, salt or granite, a specially designed repository is made to store the waste. After a while, this repository is hermetically sealed. Final disposal is currently the only scientific and technological solution that guarantees that the waste remains outside the living space of people for thousands of years. Coordinating research into final disposal is one of the key tasks of COVRA.
Other countries are also involved in exploring the options for final disposal. Europe does not currently have an underground repository for long-lived, high level radioactive waste. However, experiments are being conducted in underground test laboratories to study final disposal in geologically stable layers. Finland, Sweden and France are engaged in concrete projects to create final disposal facilities. These will be the first countries to use a national final disposal facility for high-level radioactive waste. The first final disposal site for high-level radioactive waste in Europe is expected to open in around 2025. Since 1999, the United States has been using a deep underground repository in salt for all the military radioactive waste.
The research into final disposal of radioactive waste not only explores the options in the Netherlands but also the options for final disposal in a multinational context. A decision about final disposal is expected to be taken in the Netherlands in around 2100.