The generation of waste is an associated feature of any industrial production. Nuclear power generation plants produce waste much of which is radioactive. The management and disposal of these radioactive wastes are extremely important and are quite different from handling any other physical industrial waste. Handling such wastes is a matter of concern and involves special treatment procedures to tackle its hazardous effects. Radioactive waste management must ensure that it would not produce any harmful effects of radiation on living creatures and the environment. The production of nuclear energy as a non-conventional resource must take care of the issue of safe management of radioactive wastes to protect people and the environment. Radioactive waste generation is not only limited to the nuclear fuel cycle. Radioactive materials are also used extensively in research, manufacturing, testing, and mineral exploration. So, safe management of radioactive waste has become a priority all over the world to reduce the potential risk factors arising from it.
The Objective of Radioactive Waste Management:
The objective of radioactive waste management is to minimize its impact on living creatures and the environment. Radioactive waste management involves the process of isolating or diminishing the radioactive risks by reducing the rate or concentration of any radioactive material that comes in contact with the biosphere. The issue of radioactive waste management has become a matter of concern because of the hazardous radioactive properties of wastes generated from nuclear plants. These wastes need suitable processing, isolation, and storage to reduce their impact on health and safety. The international standards about radioactive waste management recommend a comprehensive and consistent set of principles to be followed by every country.
Types of Radioactive Waste:
Waste refers to those materials which are in no way suitable for use. The wastes that can produce radioactive radiation or are affected by radioactivity are called radioactive waste. Radioactive materials have a life through which their atoms decay and it transforms into non-radioactive materials. This time varies from material to material and the effect it creates through radiation during this period is quite dangerous. Depending on the level of radioactivity, the wastes can be classified into three groups as follows:
- Low-Level Waste (LLW)
These wastes have low radioactive contents that are also short-lived. The handling of such wastes doesn’t require very special protection and is easy to dispose of in compacted form. - Intermediate-Level Waste (ILW)
It has a higher level of radioactivity than low-level waste and requires shielding while handling. This is typically generated by the chemical industry and through contamination from nuclear reactor decommissioning. - High-Level Waste (HLW)
These wastes emit considerable radiation that increases the temperature of the surroundings. Therefore, cooling is required to handle it. It is produced by burning uranium in nuclear reactors. HLW contains short-lived fission products that are required to be separated from the long-lived components for the successful disposal and management of waste.
Important Government Data Regarding Radioactive Waste:
- LLW comprises some 90% of the total radioactive waste but contributes only 1% of the radioactivity.
- ILW constitutes about 7% of the volume and has 4% of the radioactivity of all radioactive waste.
- HLW accounts for just 3% of the volume but contributes to 95% of the total radioactivity of produced waste.
Types of Radioactive Waste
The Process of Radioactive Waste Management:
The processes applied for the management of radioactive waste depend on the type of waste and the level of activities required to control its harmful effect on humans and nature. Radioactive waste management typically involves some structured and well-defined steps that are being followed. These steps are mentioned as follows:
- Planning and Preparation: The aim should be to reduce the volume of radioactive waste generated as an industrial by-product through proper planning and preparation.
- Treatment of Waste: Wastes are treated according to their type and disposal process.
- Packaging: Radioactive wastes required packaging in specially designed containers to make it convenient for storage, transport, and disposal.
- Storage: Safe and secure storing arrangements need to be done for the radioactive wastes till suitable disposal methods are implemented.
- Disposal: This is the process of placing wastes permanently using some specially engineered facilities.
Waste management for Different Levels of Radioactive Waste:
- Low-Level Radioactive Waste Management: The waste with low-level surface radioactivity can be passed through the recycling process to reduce its radioactive content. The waste is cut, placed in special containers, and send to a recycling facility where the surface is removed to separate the radioactive layer leaving behind the non-radioactive part.
- Intermediate-Level Radioactive Waste Management: These wastes need treatments like cutting, compacting, or drying and then packaging into suitable containers for storage and disposal.
- High-level Radioactive Waste Management: This type of waste is generally produced in liquid form, during reprocessing of fuel from nuclear power plants. This liquid waste is mixed with crushed glass to be heated in a furnace. The molten output is put into metal containers to give it a solid and compact form that is ready for long-term storage and suitable disposal. This process is known as vitrification. High-level waste (HLW) management is the most crucial part because the impact is more severe. The scope for volume reduction is possible with low-level waste (LLW) and intermediate-level waste (ILW) radioactive wastes. There are two commonly used methods to reduce the volume of radioactive components in the waste. These processes are as follows:
- Incineration: The waste is treated at a temperature of around 1000 degrees Celsius to produce fumes which are again treated and filtered before being allowed for emission into the atmosphere.
- Compaction: It uses the technology for volume reduction by applying a compaction force of around 1000 tones that reduces the volume by 3 to 10 times, depending on the nature of waste.
Conclusion:
The primary objective of radioactive waste management is to handle the radioactive waste securely so that its harmful effects do not impact human health and the environment. Waste management must focus on protecting present as well as future human generations. Regulations and standards have been developed at the international and national level that provides definite guidelines for radiation protection and radioactive waste management. Continuous studies and Research have developed new processes and technologies in the field of radioactive waste management. The innovative methods focus on minimizing waste volume, isolation of waste, reduction in radioactive discharges, and extracting useful materials from waste. Such developments can make countries well equipped to handle radioactive waste management projects successfully.