How Radioactive Cleanup Works

As any agency involved in the cleanup will tell you, safety is first priority. Accordingly, all personnel working among potentially harmful levels of radiation wear thick vinyl hazmat suits, masks and rubber boots capable of blocking at least a percentage of harmful radiation.

Of course, instead of relying on safety equipment to protect them, workers would rather avoid radiation altogether whenever possible. To that end, crews often carry Geiger counters that give them both the direction and intensity of a radiation source. In addition, workers may carry dosimeters, portable devices that track the amount of radiation exposure workers receive during their shift. These devices prove particularly helpful when workers know they will receive intense doses of radiation and require a warning to leave the site once that dosage approaches harmful levels.

Depending on the type of operation, crew sizes can vary greatly. At Fukushima Daiichi, a relatively small team of 300 workers struggled to stabilize the power plant so that larger cleanup efforts could begin [source: Boyle]. After the Chernobyl disaster -- widely considered to be the worst accident to ever occur at a nuclear power plant -- around 600,000 workers were involved in the cleanup, and the areas surrounding the power plant are only now safe to visit for short intervals [source: U.S. NRC].

Interestingly enough, decontamination crews often use the same mops, brooms, shovels and brushes to perform their jobs that you might find at a local hardware store.

Thankfully, human workers don't have to handle every aspect of a radiation cleanup. For instance, Germany volunteered two robots to aid in stabilizing and, ultimately, decontaminating Fukushima Daiichi. Other robots can handle everything from dismantling nuclear bombs to fixing jammed equipment in highly radioactive environments. In some cases, the robots themselves become so contaminated that they're scrapped eventually as radioactive waste.

In the case of dealing with spent fuel rods, both heat and radiation are a concern. So, workers use a whole lot of water to both cool such materials and to contain their radiation, sometimes for years at a time. Along with water, concrete, glass and dirt prove fairly effective at storing radioactive material, particularly when paired with containment vessels and storage facilities.

Imagine sweeping your kitchen floor and then having to throw away not only the dirt you've swept up but also the broom, the dustpan and even the trashcan you threw everything into. That scenario gives you a glimpse of the difficulty and expense of cleaning up radioactivity; workers have to address the source of the radiation and everything that source has contaminated. Yet as difficult as the process can be, it's not always complicated. In many cases, workers are tasked with simple chores like sweeping up low-level radioactive material, wiping down surfaces with decontaminating chemicals and collecting debris for disposal.

Much of the challenge comes from the fact that radioactive material can spread to the environment in several ways -- particularly when things go wrong -- making cleanup exponentially more difficult. For instance, radioactive particles can seep into groundwater, flow into nearby lakes, rivers and oceans, float through the atmosphere and even contaminate livestock and crops. Each type of environmental contamination requires a different response.

When radioactive material contaminates groundwater, organizations like the U.S. Environmental Protection Agency (EPA) oversee the construction of groundwater extraction and treatment facilities. If the soil itself is contaminated, on the other hand, it may need to be extracted and buried at a containment facility or even encased in concrete. When radioactive material spreads into large bodies of water or into the atmosphere, decontamination can be impossible. In such cases, fish, livestock and produce are closely monitored for increased levels of radioactivity.

Regardless of the type of contamination, mopping up radioactive materials is a dangerous task, and patience is sometimes the best approach to safely decontaminating a site. All radioactive material decays over time, eventually breaking down into stable -- and safe -- daughter elements. And while this process takes thousands of years for high-level radioactive waste, it occurs much more quickly for low-level waste like safety equipment and water used inside of a nuclear power plant. Accordingly, waste is often stored at the site where it was generated for years or even decades before it's properly disposed of.

Because the process of cleaning up radioactive material is so dangerous, it's highly regulated around the world. In the United States, federal agencies like the EPA, the Department of Energy and the Nuclear Regulatory Committee set safety guidelines, issue licenses to operate nuclear power plants and oversee any cleanup efforts.

The decontamination of a site like Fukushima Daiichi isn't truly complete until the radioactive material from the site is safely disposed of. Spent nuclear fuel rods, for instance, remain dangerous for thousands of years after they've been removed from a power plant [source: U.S. EPA]. And while scientists and researchers are working tirelessly to find ways to neutralize the danger from the ever-growing amounts of nuclear waste generated every year, for now the only option we have is to store it. But where? After all, the volume of radioactive waste increases every second, with experts predicting the generation of an additional 400,000 tons (363,000 metric tons) over the next two decades [source: World Nuclear Association].

In the case of waste-emitting low-level radiation, the disposal process isn't markedly different from taking trash to the local landfill. While engineers have to be careful that such materials won't disperse under any circumstances or contaminate the local water supply, these disposal sites are typically located close to the surface.

Facilities designed to hold high-level radioactive waste, on the other hand, are much more robust. The Yucca Mountain facility in Nevada, for instance, cost more than $13 billion to construct and would store radioactive materials 1,000 feet (300 meters) underground in a network of shielded tunnels, but scientists and policy makers still debate its ability to safely contain its cargo [sources: Associated Press, Eureka County].

Constructing a nuclear waste repository is just the first step toward disposing of high level radioactive material. Next, the material must be placed into specially designed metal casks for transport. Because all manner of accidents can occur during transport, the casks are designed to withstand everything from 30-foot (9-meter) drops to 1475 degree Fahrenheit (802 degrees Celsius) fires [source: Eureka County]. These casks, constructed of stainless steel, titanium and other alloys, then make the journey from the site of origin to the nuclear waste repository where the casks can remain for thousands of years.

Not all countries choose to store high-level nuclear waste like the United States does, instead reprocessing the fuel and reusing it to generate more power. Still, reprocessing doesn't eliminate the need to store nuclear materials, making disposal a critical issue for every country using nuclear power

As you might imagine, cleaning up and disposing of nuclear waste is a costly endeavor. Britain's Nuclear Decommissioning Authority estimated the cost of cleaning up all 20 of the country's radioactive sites would top $160 billion, for instance [source: Macalister]. Still, proponents of nuclear energy say access to a reliable, clean and abundant energy source more than justifies the costs associated with maintaining and cleaning nuclear facilities.