Nuclear Pollution: Can We Control The Uncontrollable?

Nuclear pollution is a serious threat to the environment and human health, caused by the release of radioactive materials into the atmosphere or environment. These materials emit hazardous ionizing radiation, which can seriously affect and destroy plant, animal, and human life. The extent of the damage caused by nuclear pollution depends on several factors, including the concentration of radioactive material, the energy emitted by the radiation, proximity to those exposed, and the type of radiation.

Radioactive substances can be released into the environment through nuclear accidents, the use of nuclear weapons, nuclear power plant operations, atomic bomb testing, and the use of radioisotopes. These substances can contaminate the air, water, and soil, leading to both immediate and long-lasting effects on the environment and human health.

So, can we control nuclear pollution? While complete control may not be possible, there are measures that can be taken to prevent and mitigate its impact. This includes the safe handling and treatment of nuclear waste, the implementation of safety measures in nuclear facilities, and the regulation of nuclear energy generation. Additionally, the development of alternative energy sources can help reduce the reliance on nuclear power and, consequently, the risk of nuclear pollution.

Safe handling and disposal of nuclear waste

Safe Handling of Nuclear Waste:

• Storage: Nuclear waste should be stored securely to prevent radiation exposure and pollution. High-level waste is typically stored for about 50 years before disposal to allow radioactivity and heat to decay, making handling safer. Used fuel is often stored underwater for at least five years, followed by dry storage.
• Location: Nuclear power plants should be strategically located after careful study of the area's geology, tectonic activity, and other established conditions.
• Occupational Safety: Ensure appropriate protection for workers exposed to radioactive materials. Occupations such as uranium mine workers, technical staff at nuclear power plants, and radium watch dial painters are at risk of radiation exposure.
• Prevention of Accidents: Implement safety measures to prevent the accidental release of radioactive elements from nuclear reactors.
• X-ray Usage: Unless necessary, avoid frequent medical diagnoses using X-rays, as excessive exposure to ionizing radiation can be harmful.
• Monitoring: Regularly monitor high-risk areas for the presence of radioactive substances to detect and mitigate potential hazards promptly.

Safe Disposal of Nuclear Waste:

• Deep Geological Disposal: This method, involving burial at depths of 250-5000 meters, is widely regarded as the best solution for disposing of highly radioactive waste. It utilizes natural barriers like rock, salt, and clay, providing long-term isolation without the need for active maintenance.
• Near-Surface Disposal: Low-level waste can be disposed of safely in near-surface facilities, either at ground level or in caverns below ground. These facilities are typically constructed with protective coverings and may include drainage and gas venting systems.
• Vitrification: Certain high-level mixed waste must be vitrified, or immobilized in glass, before disposal in a deep geologic repository.
• Dilution and Dispersal: Intermediate-level waste should be diluted with inert materials before disposal into the environment.
• Solidification: Small quantities of high-activity wastes are converted into solids, such as concrete, before burial underground or at sea.
• Reprocessing: Used fuel that is not intended for direct disposal can be reprocessed to recycle the uranium and plutonium it contains.
• International Cooperation: Some countries may lack the necessary resources or favourable geology for safe nuclear waste disposal. Multinational or regional repositories can be established in willing host countries to accept waste from multiple nations.

Controlling nuclear accidents

Nuclear accidents can be controlled and mitigated through a variety of measures, including the handling and treatment of nuclear waste, and the implementation of safety protocols and emergency response plans.

Preventative Measures

The design, construction, and operation of nuclear facilities are critical to preventing accidents. This includes choosing an appropriate site, using high-quality construction materials, and conducting thorough testing before operation. The International Atomic Energy Agency's International Nuclear Safety Group (INSAG) emphasises the importance of "defence in depth", which means having multiple levels of protection to prevent accidents and mitigate their consequences.

Safety Protocols

Safety protocols aim to prevent abnormal operation and system failures in nuclear reactors. This involves using very high-quality technologies for safety-critical components and rapid detection and correction of any deviations from normal operation. Nuclear reactors are designed to withstand a range of abnormal occurrences and accidents, and safety functions include activating specific safety systems and containing radioactive materials.

Emergency Response Plans

In the event of a severe accident, plant operators follow guidelines and procedures to manage the situation and minimise the release of radioactivity. These guidelines are kept under constant review and development, and the International Atomic Energy Agency (IAEA) provides toolkits and training to assist operators in developing effective emergency response plans.

Individual Prevention Measures

At an individual level, people can take measures to reduce their exposure to radiation pollution. This includes testing homes for radon, a radioactive gas that can cause health issues, and installing radon reduction systems if necessary. Additionally, choosing a home located away from major sources of radiation pollution can help minimise exposure risks.

Public Response to Nuclear Accidents

In the event of a nuclear accident, the public should follow instructions from local authorities, such as staying indoors, closing doors and windows, covering food and water, and consuming only covered items. It is important to avoid water from open sources, exposed crops, and external food, water, or milk. Returning home as soon as possible, removing clothes, and washing thoroughly are also recommended. Cooperating with local authorities and following their instructions, such as taking medication or evacuating, is crucial for ensuring personal safety.

Minimising personal exposure to radiation

• Choose a suitable living location: Select a home located away from major sources of radiation pollution. This proactive approach ensures that you and your family are not constantly exposed to high levels of radiation in your immediate environment.
• Test for radon: Radon is a naturally occurring radioactive gas that can accumulate in homes. Use inexpensive testing kits or specialised consulting services to check for radon in your residence. If elevated levels are detected, consider installing an active soil depressurisation (ASD) system. ASD employs a vent pipe and an inline centrifugal fan to continuously remove radon and other toxic gases from beneath the house.
• Apply the principles of time, distance, and shielding: These three basic protective measures are crucial in a radiation emergency. Minimise the time spent near radioactive sources, and increase your distance from them as much as possible. Additionally, use shielding materials such as lead or dense substances to protect yourself from radiation.
• Limit medical radiation exposure: While medical procedures like X-rays and CT scans are essential for diagnosis and treatment, they contribute to overall radiation exposure. Discuss alternative diagnostic methods with your healthcare provider and only undergo medically necessary procedures.
• Avoid frequent X-rays for diagnosis: Unless absolutely necessary, minimise the use of X-rays for diagnostic purposes. Explore other diagnostic tools and techniques to reduce your exposure to ionising radiation.
• Occupational precautions: Certain occupations, such as uranium mine workers and technical staff at nuclear power plants, carry a higher risk of radiation exposure. Ensure that appropriate safety measures, such as personal protective equipment (PPE), are in place to minimise exposure for workers in these fields.
• Safe handling of radioactive materials: Prevent careless handling, use, and transportation of radioactive isotopes. This includes proper waste management and disposal techniques to avoid accidental releases and contamination.
• Regular monitoring: Implement regular monitoring procedures in high-risk areas to detect the presence of radioactive substances. This proactive approach helps identify potential sources of exposure and facilitates timely remedial actions.

Choosing safe locations for nuclear power plants

Nuclear power plants should be located in areas after careful study of the geology of the area, tectonic activity, and other established conditions.

Nuclear power plants are usually built close to water bodies for cooling purposes. The site license takes into account worst-case flooding scenarios, other possible natural disasters, and the possible effects of climate change. As a result, all buildings with safety-related equipment are situated on high enough platforms to remain above submerged areas in the event of flooding.

Nuclear power plants are designed with sensors to shut them down automatically in an earthquake, and this is a vital consideration in many parts of the world.

Nuclear plants are also designed with multiple safety systems, each with backups, to control damage to the fuel and prevent significant radioactive releases. These include physical barriers between the radioactive reactor core and the environment, such as solid ceramic pellets, sealed zirconium alloy tubes, a large steel pressure vessel, and a reinforced concrete containment structure.

The safety of operating staff is a prime concern in nuclear plants. Radiation exposure is minimized by the use of remote handling equipment for many operations in the core of the reactor. Other controls include physical shielding and limiting the time workers spend in areas with significant radiation levels.

Reducing the volume of nuclear waste

Nuclear waste is neither particularly hazardous nor hard to manage relative to other toxic industrial waste. However, it is important to reduce its volume to make storage and disposal easier. Here are some ways to reduce the volume of nuclear waste:

Treatment and Conditioning of Nuclear Waste

Treatment and conditioning processes are used to convert radioactive waste materials into forms suitable for transportation, storage, and final disposal. The principal aims are to minimize waste volume and reduce potential hazards. While processes like compaction and incineration reduce waste volume, they do not decrease radioactivity, so the waste becomes more concentrated.

High-Level Waste (HLW)

HLW comprises only about 1% of radioactive waste by volume but receives the most attention. It includes highly radioactive fission products and transuranic elements with long-lived radioactivity. HLW is managed by immobilizing it in containers, such as metal drums or concrete boxes, and isolating it in deep geological disposal sites.

Low-Level Waste (LLW)

LLW comprises about 90% of the volume but only 1% of the radioactivity of all radioactive waste. It is generated from hospitals, industry, and the nuclear fuel cycle, including paper, rags, tools, and clothing containing small amounts of radioactivity. LLW is often compacted or incinerated before disposal to reduce its volume.

Intermediate-Level Waste (ILW)

ILW is more radioactive than LLW and requires some shielding. It includes resins, chemical sludges, metal fuel cladding, and contaminated materials from reactor decommissioning. Smaller items and non-solids may be solidified in concrete or bitumen for disposal, reducing their volume.

Transuranic Waste

Transuranic waste, contaminated by nuclear elements heavier than uranium, is disposed of in deep geological repositories like the Waste Isolation Pilot Plant (WIPP) in New Mexico, USA.

Dilution and Dispersal

When containment and isolation are not possible, nuclear waste may be diluted until it reaches background values. However, this method is not suitable for highly radioactive waste.

Cementation and Vitrification

Conditioning processes like cementation and vitrification are used to convert waste into stable solid forms that are insoluble and prevent dispersion into the environment. For example, high-level waste is immobilized in borosilicate glass and sealed in stainless steel canisters for storage and disposal.

Frequently asked questions