What Is To Be Done With Nuclear Waste?
The growth and development of human society has been tightly associated with energy. During the 1960s, nuclear power became a popular option in terms of producing power for civilian use. Since then, nuclear energy has become a constant part of the policy agendas of developed countries.
However, the scientific community has not achieved a general consensus on the issue of disposal. The low-level waste from nuclear plants, as well as from military operations, research labs and hospitals, is usually stored in nearby facilities or on site.
Highly radioactive waste is a bigger issue. The currently popular options for storage (pool storage, individualized and centralized temporary disposal facilities, dry sacks, and geological isolation) result with relatively effective waste management, but the issues associated to them impose the need to explore other possibilities in terms of nuclear waste reusage.
Nuclear waste with high radioactive levels is extremely dangerous to handle. The biggest issue associated to this type of waste is the lack of proper storage sites that wouldn’t allow the radiation to spread. One of the most popular options of dealing with nuclear waste is pool storage at the site.
Radiation levels are kept below acceptable levels when stored under 20 feet of water, but these pools are typically more than 40 feet deep, for the sake of providing extra safety. The concrete pools filled with water act as natural barriers against radiation. The waste is kept cool while its radiation levels decrease.
Although pool storage is relatively safe and manageable, it comes with a serious issue: the nuclear power plants don’t have enough space to store the waste they produce in the pools that are available on site. According to the reports of the Nuclear Regulatory Commission, a great number of nuclear power plants will need an additional source for temporary storage in 2015.
When lack of storage capacity at the pools occurs, some nuclear power plants (such as Ascó Nuclear Power Plant and José Cabrera Nuclear Power Plant in Spain) opt for individualized or centralized temporary disposal facilities. The biggest issue with this type of disposal is that it isn’t a permanent solution to the problem.
Dry casks, which are used on many reactor sites in Japan and USA, seal the used nuclear fuel inside massive cylinders made of steel and concrete. This is a safe and reliable storage system that provides radiation shielding and structural strength. The casks, as a way of storing nuclear waste, have been proven to be safe when they withstood the 2011 earthquake off the Pacific coast of Tōhoku, Japan.
The disadvantage of this type of storage is associated to transportation of the fuel. In addition, the casks must be constantly monitored in order to prevent overheating. Another disadvantage is economical and environmental ineffectiveness, since viable nuclear material remains unused.
Geological isolation is one of the most debated options for long-term disposal of high-level radioactive waste. The Onkalo spent nuclear fuel repository in Finland is a large-scale facility of this type. It is currently being constructed, and is scheduled to open in 2020.
The federal funding for the controversial Yucca Mountain nuclear waste repository were canceled by the U.S. government in 2011, which left the country without a reliable long-term storage site for high-level nuclear waste. The greatest advantage of geological isolation is that the entire waste is stored in a single location and can stay there for indefinite time with very little monitoring.
However, this method is associated to long-distance transportation of radioactive waste, which imposes serious risks to national security, as well as high financial expenses. In addition, the costs for planning and constructing such repositories are extremely high. On the other hand, reprocessing plants provide a more effective way of managing nuclear waste.
These plants dissolve the waste and separate uranium from plutonium. After this process, both materials can be reused. The benefits of this method include minimal residual waste and diminished risks of accidental nuclear reaction. Very little of the waste remains unused. The disadvantages involve high processing expenses, as well as environmental risks associated to transportation of the spent fuel.
Pool storage, individualized and centralized temporary disposal facilities, dry sacks, geological isolation, and reprocessing plants are the most commonly discussed methods of nuclear waste storage and disposal. However, they are associated with great risks and controversy that impose the need of new methods.
Currently, researchers are focused on the idea of storing safely-packaged waste above ground, on the sites of reactors. This option would be effective for an extended period, like a couple hundred years (Brennain Lloyd, 2012). The spent fuel must be kept passively safe, but burying it underground and forgetting about it is not a solution. The waste should be decentralized, so the scientists suggest storage facilities to be built around each reactor site.
Although the debate is making progress and new solutions are coming up to the surface, all of them are associated with risks. Currently, there is not a definite solution to keep the future generations safe from the dangers of nuclear waste.