The Process of Radioactive Cleanup

In March 2011, Japan was still reeling from the destruction caused by a powerful earthquake and tsunami, and as they struggled to recover, they were confronted with an even greater challenge: cleaning up the severely damaged Fukushima Daiichi nuclear power plant. Following the quake and tsunami, which damaged the plant's cooling systems, plant workers scrambled to control the damage, limit the meltdown, and prevent the release of radioactive substances into the surrounding area.

Dealing with radioactive material cleanup is always a complex and costly endeavor, and the Fukushima Daiichi disaster is no different. Hidehiko Nishiyama, a spokesperson for Japan’s nuclear safety agency, stated that it would take months to fully manage the situation at the plant, with some experts predicting that the cleanup could span several years, or even decades. Additionally, the cost of the cleanup could easily surpass the initial expense of building the plant itself [source: Klotz].

To grasp why cleaning up radioactive material is such a challenging and expensive process, it’s important to understand the inherent dangers of radioactive substances. Unlike most forms of matter, radioactive material is unstable by nature. Over time, the nuclei of radioactive atoms release what’s known as ionizing radiation, which manifests in three main forms: alpha particles, beta particles, and gamma rays. Any of these can pose risks to human health, as they can strip electrons from atoms and disrupt chemical bonds. However, unlike alpha and beta particles, gamma rays can pass right through the body, causing extensive internal damage. The body’s attempts to repair this harm can result in cancerous cells.

Uranium and its byproduct, plutonium, both emit gamma rays at levels that are extremely hazardous to human health. For example, even brief exposure to small amounts of plutonium can be fatal. Despite this, nuclear power would not be feasible without these elements. However, due to stringent safety protocols and systems, workers in nuclear power plants (and any location where radioactive material is handled) rarely come into contact with harmful radiation.

Yet, no facility can operate indefinitely, which is why radioactive cleanup becomes necessary. This process is required in various situations, not just after meltdowns. For instance, decommissioning a nuclear weapon or disposing of radioactive medical waste involves the extensive and meticulous task of radioactive cleanup. Before this work can begin, crews need the proper tools. Let’s take a look at the essential equipment technicians rely on for the job.

Tools of the Radioactive Trade

As any agency involved in cleanup operations will emphasize, safety is the top priority. Therefore, all workers exposed to potentially dangerous radiation levels are required to wear heavy-duty vinyl hazmat suits, masks, and rubber boots designed to block at least some degree of harmful radiation.

Naturally, workers prefer to avoid radiation exposure entirely, rather than relying on protective gear. To assist with this, crews often use Geiger counters, which help pinpoint both the direction and intensity of a radiation source. Additionally, workers may carry dosimeters, which are portable devices that measure the level of radiation exposure during their shift. These tools are especially useful when workers anticipate high radiation doses and need a signal to vacate the site before the exposure reaches dangerous levels.

The size of the cleanup crew can vary significantly depending on the operation. For example, at Fukushima Daiichi, a small team of 300 workers worked tirelessly to stabilize the plant before larger-scale cleanup efforts could take place [source: Boyle]. In contrast, after the Chernobyl disaster, which remains one of the most catastrophic nuclear accidents in history, approximately 600,000 workers participated in the cleanup, and the area around the plant is just now safe to visit for brief periods [source: U.S. NRC].

Interestingly, the tools used by decontamination crews are often just basic items like mops, brooms, shovels, and brushes – the same kinds you might find at your local hardware store.

Fortunately, not every aspect of radiation cleanup requires human intervention. For example, Germany contributed two robots to assist in stabilizing and decontaminating Fukushima Daiichi. Other robots are used for tasks ranging from dismantling nuclear bombs to repairing jammed equipment in highly radioactive areas. In some cases, the robots themselves become so contaminated that they are eventually discarded as radioactive waste.

When dealing with spent fuel rods, both heat and radiation present major concerns. To address this, workers use large quantities of water to cool the materials and contain their radiation, sometimes for many years. Along with water, materials like concrete, glass, and dirt are highly effective at storing radioactive materials, especially when used in conjunction with containment vessels and storage facilities.

Cleaning Up Radioactive Contamination

Picture yourself sweeping the kitchen floor, and then imagining that after you’re done, you have to throw away not just the dirt, but also the broom, dustpan, and even the trash can you placed it all into. This paints a rough picture of how complicated and costly radioactive cleanup can be. Workers need to address the source of radiation and all the areas that source has contaminated. Although the process can be intricate, it isn’t always complex. In many instances, workers simply perform basic tasks like sweeping up low-level radioactive material, wiping surfaces with decontamination chemicals, and gathering debris for disposal.

One of the primary challenges in radioactive cleanup arises from the fact that radioactive substances can spread throughout the environment in numerous ways, especially during incidents. For example, radioactive particles can infiltrate groundwater, flow into nearby lakes, rivers, and oceans, drift through the air, or even affect livestock and crops. Each type of environmental contamination requires a distinct approach to remedy it.

When radioactive contamination affects groundwater, agencies like the U.S. Environmental Protection Agency (EPA) are responsible for overseeing the creation of extraction and treatment systems. However, if the soil itself becomes contaminated, it may need to be removed and buried at a containment facility, or even sealed in concrete. In cases where radioactive material spreads to vast bodies of water or into the atmosphere, cleanup becomes nearly impossible. In such situations, fish, livestock, and crops are continuously monitored for heightened levels of radioactivity.

No matter the type of contamination, cleaning up radioactive materials is an inherently hazardous job, and at times, patience proves to be the best method for safely decontaminating a site. All radioactive materials decay over time, eventually breaking down into stable and harmless daughter elements. While this process may take thousands of years for high-level radioactive waste, it happens much more rapidly with lower-level waste, such as safety equipment or water used inside a nuclear power plant. Consequently, waste is often stored at the site of generation for many years or even decades before proper disposal occurs.

Given the dangers associated with cleaning radioactive material, the process is tightly regulated worldwide. In the United States, agencies like the EPA, the Department of Energy, and the Nuclear Regulatory Commission establish safety standards, issue nuclear plant operating licenses, and oversee any cleanup operations.

Handling Radioactive Waste Disposal

A site like Fukushima Daiichi cannot truly be deemed fully decontaminated until the radioactive waste is safely disposed of. For example, spent nuclear fuel rods remain hazardous for thousands of years even after removal from a power plant [source: U.S. EPA]. While scientists and researchers continue their efforts to neutralize the increasing nuclear waste generated annually, currently, the only viable solution is storage. But where? The volume of radioactive waste grows constantly, with experts forecasting an additional 400,000 tons (363,000 metric tons) to be produced in the next 20 years [source: World Nuclear Association].

When it comes to disposing of low-level radioactive waste, the process is not all that different from taking regular garbage to a landfill. While engineers must ensure that these materials are securely contained and won't contaminate nearby water supplies, these disposal sites are generally situated relatively close to the surface.

In contrast, facilities designed to hold high-level radioactive waste are much sturdier. A prime example is the Yucca Mountain facility in Nevada, which cost over $13 billion to build. It is designed to store radioactive materials 1,000 feet (300 meters) underground in a network of shielded tunnels, but there is ongoing debate among scientists and policymakers about whether it can reliably contain its radioactive contents [sources: Associated Press, Eureka County].

Building a nuclear waste repository is only the beginning of the process of managing high-level radioactive material. After construction, the material must be placed into specialized metal casks for transport. Given the risks of accidents, these casks are engineered to withstand extreme conditions, including drops from heights of 30 feet (9 meters) and fires reaching 1,475 degrees Fahrenheit (802 degrees Celsius) [source: Eureka County]. Made from stainless steel, titanium, and other durable alloys, these casks then make their journey from the original site to the nuclear waste repository where they can remain securely for thousands of years.

Not every country stores high-level nuclear waste the way the United States does. Some nations choose to reprocess nuclear fuel and use it to generate more energy. However, even with reprocessing, there remains a need to safely store the resulting nuclear materials, making disposal an ongoing concern for all countries relying on nuclear power.

As you can imagine, cleaning up and disposing of nuclear waste is a costly process. For example, the UK's Nuclear Decommissioning Authority estimated that cleaning up the nation's 20 radioactive sites would cost more than $160 billion [source: Macalister]. Nonetheless, advocates of nuclear energy argue that the benefits of a reliable, clean, and abundant energy source far outweigh the costs of maintaining and decontaminating nuclear facilities.