How High-level Nuclear Waste Works

dioxide into the atmosphere. You don't release any other pollutants like sulfur or mercury into the atmosphere either, and you also are not creating huge quantities of coal ash, which at many power plants ends up being stored in immense lagoons. These lagoons raise a lot of questions in terms of long term stability, especially during floods. So as a nuclear power plant operator, you are feeling pretty good. There is in fact, only one fly in your ointment at the moment.

That fly is called high level nuclear waste, and it appears every time you need to refuel your reactor. In fact, the fly grows a little bigger with each refueling. Let's take a look at how this high level nuclear waste works. First, little background The goal of a nuclear reactor is to create heat so that it can produce steam that drives a generator. The nuclear fuel in the reactor creates the

heat through nuclear fission. The fuel consists of a mixture of uranium two thirty five about four percent mixed with uranium two thirty eight and other elements. The uranium two thirty five is the actual fuel for the reactor. Each fuel pellet containing the U two thirty five is very small, about the size of your little toe, but it contains the equivalent heat of perhaps a ton of coal. A typical reactor contains several tons of these all it's arranged

in rods that fill the reactor core. The YouTube thirty five sitting in the core undergoes a fission process. In this process, it creates a tremendous amount of heat. In a nuclear bomb, this heat is all released in less than a second to create a gigantic explosion. In a nuclear reactor, the heat is released gradually over the course of a year or two to boil water that drives

the electric generators. At the end of that year or two, the reactor shuts down for a month for refueling, and the fly in the ointment appears, between one quarter and one third of the fuel in the core is removed and replaced with fresh fuel rods. Several tons of highly radioactive material, also known as spent fuel or high level nuclear waste, now has to be managed. The spent fuel is still quite hot. It's so hot that it must be stored in a spent fuel pool. It's like a

gigantic swimming pool fifty ft deep. The water is there to absorb the heat. The depth of the water protects people against the radioactivity of the fuel and also provides a margin of safety. After several years in the pool, the spent fuel has cooled enough to be manageable outside of the spent fuel pool. However, it's still highly radioactive and dangerous. In fact, it'll be highly radioactive and dangerous for thousands and thousands of years. In the ideal case,

one of two things would happen at this point. One possibility is recycling. A recycling facility could reprocess the spent fuel to extract the usable uranium two thirty five and the plutonium. It could then create a new fuel and do so economically. However, in the United States, we do not recycle nuclear fuel right now. The other option would be to move the now cooled spent fuel into permanent storage. The goal would be to keep it away from people

for thousands and thousands of years. The Yuck Amount Facility in Nevada was the proposed site for such long term storage, but that idea has been abandoned for now. So at the moment, nuclear power plants store their cooled spent fuel their high level nuclear waste in containers called dry casks. These are typically strong steel cylinders that are then surrounded in concrete. The combination of steel and concrete provides a secure container and protection from the radioactivity of the spent

fuel inside the cask. These casks are stored on concrete pads outside the reactor facility and will remain there until the United States comes up with a better long term solution for high level nuclear waste. Be sure to check out our new video podcast, Stuff from the Future. Join House to Work staff as we explore the most promising and perplexing possibilities of tomorrow. The House to Worts I find app has arrived. Download it today on iTunes.