Radioactive waste processing

Types of radioactive waste processing

Radioactive waste processing refers to the treatment of excess waste that has high levels of radioactivity. Such wastes cannot be recycled or reused and, if left unattended, pose a significant threat to the environment and human health. There are many different types of radioactive waste that are generally grouped into categories according to the level of radioactivity and the source from which they are generated.

• Low-level waste: This typically includes items like gloves, tools, clothing, and other materials that have become contaminated with low amounts of radioactivity. They account for 90% of the radioactivity found in nuclear waste sites. However, they only make up about 1% of the total volume of nuclear waste. Low-level radioactive waste processing will usually include dirty laundry from hospitals and institutions that use radioactive materials for research and medical purposes, such as medical isotopes for diagnostics and treatment. It can also include industrial items that have been exposed to radioactive sources. This waste is not immediately hazardous and can be safely handled by the public after a short period of decay.
• Intermediate-level waste: This type of waste has radioactivity enough to require shielding from human beings and the environment. Intermediate-level waste will include materials that give off heat, such as used reactor fuel and some medical procedures, that must be stored in engineered facilities. It includes chemical separation from nuclear power plants, sealed sources, and ionizing radiation apparatus. Like low radioactive waste, intermediate-level waste is further divided into solid waste or liquid waste. The liquid is then transformed into the solid by using a gelation process.
• High-level waste: High-level waste consists of radioactive elements like plutonium, uranium, and neptunium. It is thermally conductive and highly radioactive. This type of waste is further divided into spent fuel from the nuclear reactor or high-level waste. Approximately 95% of the volume of high-level radioactive waste is from used uranium fuel that is exposed to fission in nuclear reactors. Because of the dangers that high-level radioactive waste presents, processing and disposal are long-term and remote from human habitation.

Specifications and Maintenance

Specifications

Some of the key specifications concerning radioactive waste treatment plants are as follows.

• Type of Waste: The kind of radioactive waste processing handled by a facility. The choices include high-level, intermediate-level, low-level, or mixed radioactive waste.
• Treatment Technologies: The methods used for processing radioactive waste, such as vitrification,incineration, extractionion, solidification, transmutation, or separation.
• Waste Management Capacity: The amount or volume of radioactive waste that a processing facility can handle within a specific period. It is usually measured in cubic meters or tons per year. For example, a nuclear power plant may generate approximately 3,000 cubic meters of low-level radioactive waste annually. A centralized radioactive waste processing facility could have a capacity to manage up to 10,000 tons of high-level waste annually.
• Location: The geographical site of a radioactive waste processing facility. It is very important since it has to be in an area suitable for the safe management of radioactive waste. For example, the facility must be in a stable geological formation to protect against potential natural disasters. The location would also ensure that the population is sufficiently far away to minimize any possible exposure to radiation.

In addition to the specifications mentioned above, radioactive waste processing plants typically have several crucial features. Some of these are highlighted below.

Key Features

• Containment: A containment feature like a robust building, capsule, or tank is constructed of thick, reinforced concrete or steel. It is always used to store or transport hazardous waste safely.
• Separation: The processing facility has features to separate the different radioactive wastes. Special extraction or filtration techniques may sometimes be necessary to remove specific contaminants, such as transuranic elements or iodine.
• Treatment: A variety of methods are used to treat radioactive waste. For example, thermal methods such as incineration change the physical and chemical properties of the waste through high temperatures. Similarly, chemical methods like solidification or encapsulation involve using polymers, cement, or glass matrices to immobilize and stabilize hazardous waste.
• Packaging: Packages for storing radioactive waste are usually made from materials resistant to radiation and corrosion. They are durable containers or drums designed to protect the environment and public health from radioactive contamination. The packaging for radioactive waste is distinct from the packages used for other hazardous materials. For instance, Class 7 Packages for Radioactive Material under the IATA Dangerous Goods Regulation is a specific packaging system. It is designed to meet the relevant international standards when transporting radioactive materials. The packaging typically includes strong outer boxes, inner containers, and absorbent materials.

Maintenance Tips

It is crucial to carry out regular maintenance of devices used for handling radioactive waste. Some of the crucial maintenance tips are given below.

• Perform routine inspections to assess any signs of deterioration, such as damage, leakage, or corrosion, and address them promptly.
• Implement preventive measures, such as periodic cleaning, decontamination, and disinfection of devices, to minimize the risk of cross-contamination.
• Keep operators and waste away from devices that handle radioactive waste, as far as possible, to reduce exposure and ensure the continued effectiveness of the equipment.
• Regularly calibrate and maintain any monitoring or detection systems installed in the waste processing devices to ensure their accuracy and reliability.
• Develop and implement a comprehensive maintenance plan that includes routine servicing, repairs, and upgrades for all handling radioactive waste devices.

Scenarios of radioactive waste processing

The scenarios of radioactive waste management are primarily associated with the nuclear energy industry and sectors that use radioactive isotopes in their manufacturing processes. Here are some usage scenarios for the radioactive waste processing industry.

• Nuclear power stations: It plays an integral role in ensuring that the radioactive waste produced from the nuclear fission process is securely and effectively dealt with. In such cases, radioactive waste processing of the most vital importance. Data from the World Nuclear Association indicated that nuclear energy generated around 10% of the global electricity supply in 2020. In some countries, it comprised a significant portion of the total electricity production.
• Medical industry: Radioactive waste processing also applies in the field of medicine. Hospitals and healthcare facilities employ radionuclide therapy to treat patients afflicted with diseases like cancer. Nonetheless, radioisotopes employed for diagnostic and therapeutic endeavors yield radioactive waste that must be meticulously processed and disposed of. The International Atomic Energy Agency (IAEA) affirmed in a release that radioactive waste is an indispensable byproduct of medical applications. The IAEA additionally underscored the necessity of efficiently handling and processing such waste to safeguard both individuals and the environment.
• Industrial use: A multitude of sectors, encompassing manufacturing, energy production, and research endeavors, utilize radioactive substances for diverse objectives. These aims may involve non-destructive testing, radiography, calibration, and tracing, among others. The industries that apply radioactive waste processing include the oil and gas sector, power generation, pipeline construction, metallurgy, and semiconductor manufacturing. According to a market research report by Kinsley, the global radioactive waste management market was valued at approximately $11 billion in 2022, with a projected compound annual growth rate (CAGR) of 7.7% from 2023 to 2030.
• Research and development: Scientific sectors frequently exploit radioactive elements for undertaking inquiries, crafting novel substances, and executing assessments. Such undertakings can generate hazardous radioactive refuse that demands disposal through processing techniques. This kind of scenario could happen in universities and educational institutions where nuclear science and technology are the focus of research. It can also happen in government laboratories where a large number of radioisotope experiments are carried out.

How to choose radioactive waste processing equipment

When purchasing radioactive waste management equipment, the following factors should be considered:

• Type of radioactive waste

  The type of radioactive waste producers generate is a key determinant in their choice of waste-processing equipment. Different types of radioactive waste (solid, liquid, or gas) require distinct waste-processing equipment. For example, waste incinerators are suitable for combustible solid radioactive waste, while waste treatment plants are more applicable for liquid radioactive waste.

• Capacity and scalability

  Facilities must assess the capacity of waste processing equipment to handle current and future volumes of radioactive waste. They should choose equipment with a suitable processing capacity for their existing waste generation rates. In addition, scalability is an important parameter to consider. As waste volumes increase, waste processing equipment should be able to scale up its processing capacity without incurring prohibitive costs or causing disruptions to operations.

• Safety features and regulatory compliance

  Safety features of radioactive waste processing equipment, such as containment systems, radiation shielding, and monitoring/safety interlock systems, should be prioritized. In addition, waste processing equipment must comply with established regulations and standards. Facilities need to ensure that the equipment they purchase meets relevant regulatory requirements to avoid potential legal and financial risks.

• Cost and economic factors

  Purchasers need to consider the capital and operating costs of radioactive waste processing equipment. They should evaluate equipment's upfront investment, installation expenses, energy, maintenance, and consumables costs over its lifespan. In addition, the cost-effectiveness of different equipment options should be compared to ensure optimal use of financial resources.

Q&A

Q1: How do incineration systems work in radioactive waste processing?

A1: Incineration is a thermal radioactive waste processing method that reduces the volume of solid waste by about 90% to 95%. The method involves burning the waste in a controlled atmosphere at high temperatures to destroy organic materials. The remains of the process are ash, which is still radioactive and requires storing.

Q2: What are the benefits of compaction in radioactive waste processing?

A2: Compaction is a useful method in radioactive waste processing because it helps to reduce the volume of waste by up to 80% in one single operation. The method is simple and involves crushing or squeezing the waste into a smaller bulk. This reduces the storage space required for radioactive waste.

Q3: What are the benefits of filtration in gaseous waste processing?

A3: The benefits of filtration in gaseous waste processing using filters are many. The method can remove up to 99% of the hazardous substances in the waste. Secondly, it reduces the volume of waste by about 90% to 95%, which makes it a very efficient method of processing waste.

Q4: What are the various methods of physical waste processing?

A4: There are many methods of physical waste processing. Some of the common ones put to use include comminution, which is cutting or shredding waste into smaller pieces; immobilization, which involves converting waste into a solid form like concrete, and filtration, which separates harmful gaseous substances using filters.