Nuclear waste management

Nuclear plant operators have the responsibility to ensure safe and secure management of their nuclear waste. Naturally, this has become a highly regulated area. 

The main focus of nuclear waste disposal in the eyes of the public is the disposal of spent fuel rods. However, nuclear power plants produce tiny amounts of radioactive waste every day – from cooling pond water to used protective clothing. 

As such, you should plan the treatment and disposal of radioactive material as part of a defined, approved and documented strategy. 

In facilities for the treatment and conditioning of radioactive residues that arise from the use of radionuclides in research and the dismantling of nuclear facilities or facilities, radioactive residues are collected and treated in such a way that they can either be safely recycled or sent to a final storage facility at a later date. By dismantling and decontamination, part of the mass of the delivered components can be disposed of conventionally as recyclable residues. The rest becomes radioactive waste that is conditioned in accordance with the specifications for a final storage facility. 

As an expert organisation called in in the nuclear regulatory supervisory process, the experts from TÜV SÜD can supervise and inspect the work in such facilities. The facilities can be, for example, simple waste incineration plants that have a portal monitor that monitors delivered nuclear waste batches for radioactive items, or reprocessing or conditioning plants with large equipment.

Here, TÜV SÜD can, in turn, carry out random control measurements of the clearance measurements of the respective operator as part of the commission of a supervisory authority or even carry out complete measurement campaigns for the license holder. We can also check whether the requirements of the underlying regulations are being complied with.

We advise nuclear operators through the four distinct phases of nuclear waste management: 

Avoid and plan 
Naturally, trying to reduce the amount of any possible waste is an ideal and cost-effective solution. But you cannot avoid all waste, so having a plan for its safe disposal is a must. 

Treat
When waste arises, it is advisable to treat it immediately. Depending on its type and classification, this could include decontaminating, shredding, compacting, drying or vitrifying the waste. 

Pack
You need to pack and store some radioactive waste in bespoke, approved containers. This ensures that you can handle and transport it easily for more safe radioactive waste management.

Store and dispose
Packed in suitable containers, waste can be stored for several years or even decades at approved waste storage facilities before it is permanently disposed of at a long-term storage site.

Dealing with all levels of nuclear waste
The vast majority of nuclear waste (around 90% according to the World Nuclear Association) is classed as Low Level Waste (LLW). This comes from day-to-day operation of a nuclear power plant and from hospitals, research facilities, and laboratories. 

Such waste typically comprises scrap metal, paper and plastics exhibiting low levels of radioactivity – not exceeding 4 Giga-Becquerel (GBq) per tonne of alpha activity, or 12 GBq per tonne of beta/gamma activity. The decommissioning and dismantling of a nuclear power plant also creates a lot of LLW in the form of rubble, machine parts, etc. 

Intermediate Level Waste (ILW) exceeds LLW’s upper boundaries. ILW usually comprises nuclear reactor components, graphite from reactor cores, sludge, ion exchange resins and flocculants. ILW may need treatment such as compacting, cutting or drying, before it is packed and stored. 

High Level Waste (HLW) can arise from different sources. It can be a by-product from reprocessing spent fuel rods from nuclear reactors. HLW from this source is typically a liquid which, when mixed with crushed glass and heated, can be poured into stainless steel canisters. The molten waste then turns into a stable, solid form when cooled (a process called vitrification). The canisters can then be transported, stored and disposed of safely. 

Another HLW is the spent fuel itself. The safe handling of spent fuel from the reactor core over the spent fuel pool to the dry interim storage in a cask is very important for the decommissioning. This is because the first goal for a NPP in decommissioning is to be free from fuel rods. 

TÜV SÜD’s experts can call on their experience to support operators in developing an effective, safe, and compliant waste management strategy. This includes waste minimisation and waste pre-treatment options. Our experts use an array of tools to better understand the entire waste cycle. One example is “waste led” decommissioning diagrams based on IAEA guidelines. 

Choosing the right nuclear waste packaging
Some LLW may not require packaging as it may be possible to treat the waste away from Low Level Waste Repositories (LLWR). Options include incineration, metals recycling and alternative disposal via licenced landfill for Very Low Level Waste (VLLW). 

Otherwise, there is a wide choice of standardised packaging for LLW on the market – from bulk bags, liners, to canisters and shielded containers – that are approved by local regulatory authorities. 

TÜV SÜD helps you identify and select packaging options, encapsulation techniques and packaging processes suitable for the waste produced. We also offer radioactive waste package management covering various forms of radioactive waste that arise during decommissioning. 

Safe and secure nuclear waste transport
During its lifecycle, operators need to transport nuclear waste for treatment, storage, and disposal. Every day, nuclear facility operators transport radioactive material safely and securely by road and rail thanks to strict licencing and conditions in place. 

Before moving any nuclear waste, operators need to obtain packaging and shipping approval. TÜV SÜD will support you with waste process and throughput modelling. We also provide criticality and shielding assessments to ensure safe transport of the waste.

Selecting Interim and Long-term Nuclear Waste Storage
At the end of its life, nuclear fuel is usually bundled into fuel assemblies and transferred to cooling pools for around five years. This allows the fuel to cool down in an interim storage facility while its radioactivity decays. Afterwards, operators can put the waste into long-term storage packed in dry casks filled with inert gas. These concrete and steel casks are built to withstand natural and man-made disasters. 

Many countries have specially designed interim surface or sub-surface storage waste facilities. In the long term, the preferred option is “geological disposal”, where packed radioactive waste is stored in an underground repository. These locations are carefully chosen so that the surrounding rock formations form a barrier against any possible radioactive escape, this ensuring safe radioactive waste management. 

Decontaminating waste during decommissioning 
During decommissioning of a nuclear power plant, you can use several decontamination techniques to reduce radiation exposure, to salvage and reuse components, materials, and equipment, and to facilitate waste management. To reduce the material needing specialist storage or disposal, you can use techniques such as washing, heating, mechanical cleaning or even chemical or electrochemical reactions. This can contribute to restoring the site to its previous state. 

TÜV SÜD’s experts can support you during decommissioning by analysing that your nuclear waste decommissioning options meet safety, environmental, practicality and cost criteria. For example, removing contamination from environments and components reduces dosage levels. This means manual dismantling is safe, avoiding the use of more expensive robots. 

We further offer clearance measurement of waste packages for conventional nuclear waste disposal/reuse or recycling.