Today we're going to look into waste — generally speaking and specifically — nuclear.
This subject, like everything else in life, generates a lot of questions. I'm sure you have a few
about the topic. Hopefully, we'll find answers to most if not all of your questions.
What is waste?
In the process of day-to-day living, people produce garbage and trash. Think of how much garbage and
trash your family collects in a day or in a week. Think of how much trash results from just one visit to
a fast-food restaurant — from bags, to straws, to soft drink containers.
Industries also have trash and garbage as a result of doing or making something. The leftovers of an
industrial process are called wastes.
Like all industries, nuclear power plants produce waste. One of the main concerns about nuclear power
plants is what to do with the waste. This brings us to our second question.
Why is this an issue?
The amount of waste nuclear power plants make is quite small compared to other industries. But some
nuclear power plant wastes are radioactive. Nuclear power plants are not the only producers of
radioactive waste. Radioactive waste is also produced by hospitals and other industrial processes. All
producers of radioactive waste must ensure that special care is taken to dispose of these materials and
also to protect workers, the public and the environment.
The way it is disposed of depends on how radioactive the waste is, the half-life of the waste, and the
physical and chemical form of the waste. These considerations help identify appropriate ways for
disposing of nuclear waste.
Radioactive waste is material (solid, liquid, and/or gaseous) that is no longer needed at the plant, has
no further value and can be disposed of. Let me give you some examples of radioactive waste:
- Fuel left over from producing nuclear energy
- Radioactive material in filters used for water that circulates through a reactor
- Paper towels or rags used to wipe up radioactive water
- Contaminated pieces of equipment
- Certain parts, such as pipes and reactor structures
Radioactive waste from nuclear power plants is classified as being either low- or high-level waste.
What is low-level waste?
Most waste that is radioactive is called low-level waste. Low-level waste is produced in virtually every
state by hospitals, universities, companies and nuclear power plants. This waste includes such things as
filters, cleanup rags, lab supplies, and discarded protective clothing. The radiation it gives off can
range from just above natural background levels to much higher levels, such as would be seen in parts
from inside the reactor vessel.
The principle sources of low-level radioactive waste at a reactor are the water and the components and
equipment that come in contact with the water. The major constituents of low-level waste from a nuclear
power plant are activation products and a very small percentage of fission products (if any leaks out of
the fuel rods). It does not include used fuel.
Low-level waste is usually sealed in special packages and buried at special sites. Today, most of the
low-level waste from nuclear power plants in the U.S. is disposed of at four sites: Barnwell, South
Carolina; Hanford, Washington; Clive, Utah; and Andrews, Texas. Packages containing low-level waste are
placed in specially-designed trenches and are covered with at least six feet of soil and packed clay. To
ensure that the materials remain undisturbed, the trenches are constantly monitored to detect radiation.
In this transparency, we see a typical radioactive
waste handling system. (Note: Trace the waste paths.)
The radioactive particles in low-level waste emit the same types of radiation that everyone receives from
nature. Most low-level waste fades away to natural levels of radioactivity in months or years. Virtually
all of it diminishes to natural levels in less than 300 years. In the U.S. there is strict regulation of
The U.S. Nuclear Regulatory Commission, for example, licenses many of the facilities that produce
low-level waste, including nuclear power plants. It also regulates low-level waste disposal. The U.S.
Environmental Protection Agency, on the other hand, develops general standards to protect the public
The U.S. Department of Energy coordinates national planning with the states for managing low-level waste.
The U.S. Geological Survey may offer technical assistance with studies of hydrology and geology of
proposed disposal sites.
Legislation passed by Congress requires state governments to be responsible for disposing of the
low-level waste generated in their states or for joining a regional compact. State governments are also
responsible for selecting and licensing a site according to Federal standards and monitoring its
What about spent nuclear fuel?
Most of the fragments of fission — the pieces left over after the atom has split — are
radioactive. Over time, these trapped fission fragments reduce the efficiency of the chain reaction. So,
about every 18 months or so, the oldest fuel assemblies, which have already released much of their
energy, are removed and replaced with fresh fuel.
Fuel that has been removed from the reactor is called spent fuel. Spent fuel is highly radioactive, and
this radioactivity produces a lot of heat. Spent fuel, after being removed from the reactor, is stored
at nuclear plant sites in steel-lined, concrete vaults filled with water (or in dry storage casks that
are air cooled). The water cools the used fuel and acts as a shield to protect workers from radiation.
During storage, the spent fuel cools down and also begins to lose its radioactivity through radioactive
decay, which we've already discussed. Because some radioactivity remains for thousands of years, the
spent fuel must be carefully and permanently isolated from the environment.
While storage on site has been environmentally safe, the policy of the U.S. government is to have a
permanent disposal site, or repository, for existing and future spent nuclear fuel. To date, scientists
around the world agree that deep underground disposal is the way to permanently manage spent nuclear
fuel. This spent fuel would be sealed in heavy metal canisters which will be buried deep underground in
solid rock formations.
In fact, deep underground geologic repositories have been endorsed by independent scientific
organizations such as the National Academy of Sciences. [Instructor might wish to identify these
In 1982, the U.S. Congress passed the Nuclear Waste Policy Act. This law set up a schedule for selecting
a site, constructing, and operating America's first high-level nuclear waste disposal facility. In
1987, Congress directed DOE to explore Yucca Mountain for a repository. In February 2002, DOE
recommended that Yucca Mountain be developed as such a use.
However, before the site can be approved, or a repository built and operated, there must be scientific
proof that public health and safety will be protected for thousands of years. The facility must meet
strict safety requirements of the U.S. Nuclear Regulatory Commission. Additional oversight would be
provided by the U.S. Environmental Protection Agency, the State of Nevada, and a Technical Review Board
appointed by the President of the United States.
Nuclear energy, a powerful force that should never be treated lightly, requires a high degree of
professional and technical care. But its risks should not be exaggerated. The technology exists to
isolate low-level waste and spent fuel safely and responsibly, without harm to humans or the
environment. And, with the help of nuclear energy, America will have clean, abundant electricity in the
Answers to Questions from Radioactive Waste Unit Outline:
||Would a small leak of radioactive waste from a nuclear repository be
detected? Why or why not?
||Yes, radiation can be detected with devices similar to and including Geiger
||How would immediate detection of even a very small leak of radioactive
waste differ from leak detection of other types of industrial toxic wastes?
||Because radioactivity can be easily detected with Geiger counters, it would be
easier to detect than most other hazardous or toxic wastes. Leaks of hazardous or toxic
wastes other than radioactive wastes are often detected by smell, color, or sensitive
chemical analytical methods which take time to perform.
||Why are there special sites for disposal of low-level waste?
||Because it must be isolated from the environment.
||Why is there a controversy over the selection of a spent nuclear fuel
||Because the waste that will be stored in these sites is highly radioactive and
will remain so for thousands of years, many people don't want it located near them. They
are worried that some of the radioactive material may somehow get (leak) into the
||Are special packaging containers built to protect the contents or keep
the contents from getting in contact with the environment?
||They are designed to keep the contents from getting in contact with the
||How are liquids processed to remove radioactive impurities?
||routing through demineralizers
||boiling off the water and leaving the solid impurities to be processed as solid waste
||storing the liquid to allow the radioactive material to decay