Speaker 1: Welcome to Brainstuff from house stuff works dot com, where
Speaker 1: smart happens Him Marshall Brain with today's question, what is
Speaker 1: high level nuclear waste and how are we dealing with
Speaker 1: it today. Let's imagine that you own a nuclear power plant.
Speaker 1: You're in a pretty good position these days because compared
Speaker 1: to a coal fired power plant, your operation is very green.
Speaker 1: You're producing lots of reliable electricity without releasing any carbon
Speaker 1: dioxide into the atmosphere. You don't release any other pollutants
Speaker 1: like sulfur or mercury into the atmosphere either, and you
Speaker 1: also are not creating huge quantities of coal ash, which
Speaker 1: at many power plants ends up being stored in immense lagoons.
Speaker 1: These lagoons raise a lot of questions in terms of
Speaker 1: long term stability, especially during floods. So as a nuclear
Speaker 1: power plant operator, you are feeling pretty good. There is
Speaker 1: in fact, only one fly in your ointment at the moment.
Speaker 1: That fly is called high level nuclear waste, and it
Speaker 1: appears every time you need to refuel your reactor. In fact,
Speaker 1: the fly grows a little bigger with each refueling. Let's
Speaker 1: take a look at how this high level nuclear waste works. First,
Speaker 1: little background The goal of a nuclear reactor is to
Speaker 1: create heat so that it can produce steam that drives
Speaker 1: a generator. The nuclear fuel in the reactor creates the
Speaker 1: heat through nuclear fission. The fuel consists of a mixture
Speaker 1: of uranium two thirty five about four percent mixed with
Speaker 1: uranium two thirty eight and other elements. The uranium two
Speaker 1: thirty five is the actual fuel for the reactor. Each
Speaker 1: fuel pellet containing the U two thirty five is very small,
Speaker 1: about the size of your little toe, but it contains
Speaker 1: the equivalent heat of perhaps a ton of coal. A
Speaker 1: typical reactor contains several tons of these all it's arranged
Speaker 1: in rods that fill the reactor core. The YouTube thirty
Speaker 1: five sitting in the core undergoes a fission process. In
Speaker 1: this process, it creates a tremendous amount of heat. In
Speaker 1: a nuclear bomb, this heat is all released in less
Speaker 1: than a second to create a gigantic explosion. In a
Speaker 1: nuclear reactor, the heat is released gradually over the course
Speaker 1: of a year or two to boil water that drives
Speaker 1: the electric generators. At the end of that year or two,
Speaker 1: the reactor shuts down for a month for refueling, and
Speaker 1: the fly in the ointment appears, between one quarter and
Speaker 1: one third of the fuel in the core is removed
Speaker 1: and replaced with fresh fuel rods. Several tons of highly
Speaker 1: radioactive material, also known as spent fuel or high level
Speaker 1: nuclear waste, now has to be managed. The spent fuel
Speaker 1: is still quite hot. It's so hot that it must
Speaker 1: be stored in a spent fuel pool. It's like a
Speaker 1: gigantic swimming pool fifty ft deep. The water is there
Speaker 1: to absorb the heat. The depth of the water protects
Speaker 1: people against the radioactivity of the fuel and also provides
Speaker 1: a margin of safety. After several years in the pool,
Speaker 1: the spent fuel has cooled enough to be manageable outside
Speaker 1: of the spent fuel pool. However, it's still highly radioactive
Speaker 1: and dangerous. In fact, it'll be highly radioactive and dangerous
Speaker 1: for thousands and thousands of years. In the ideal case,
Speaker 1: one of two things would happen at this point. One
Speaker 1: possibility is recycling. A recycling facility could reprocess the spent
Speaker 1: fuel to extract the usable uranium two thirty five and
Speaker 1: the plutonium. It could then create a new fuel and
Speaker 1: do so economically. However, in the United States, we do
Speaker 1: not recycle nuclear fuel right now. The other option would
Speaker 1: be to move the now cooled spent fuel into permanent storage.
Speaker 1: The goal would be to keep it away from people
Speaker 1: for thousands and thousands of years. The Yuck Amount Facility
Speaker 1: in Nevada was the proposed site for such long term storage,
Speaker 1: but that idea has been abandoned for now. So at
Speaker 1: the moment, nuclear power plants store their cooled spent fuel
Speaker 1: their high level nuclear waste in containers called dry casks.
Speaker 1: These are typically strong steel cylinders that are then surrounded
Speaker 1: in concrete. The combination of steel and concrete provides a
Speaker 1: secure container and protection from the radioactivity of the spent
Speaker 1: fuel inside the cask. These casks are stored on concrete
Speaker 1: pads outside the reactor facility and will remain there until
Speaker 1: the United States comes up with a better long term
Speaker 1: solution for high level nuclear waste. Be sure to check
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