Everyone has opinions, but it’s important that they be based on facts. Learn about three of the most misunderstood topics related to nuclear energy: radiation, waste, and nuclear accidents. See if what you thought you knew matches actual scientific research and data.
- Radiation is really bad, right?
- Nuclear power creates a lot of dangerous waste, right?
- The accident at Three Mile Island proves nuclear plants are unsafe, right?
Radiation is really bad, right?
Releases of radioactive materials from nuclear power plants could have harmful effects on people and the environment. That’s why utilities are required to monitor releases to the environment to ensure that they do not exceed limits established by the Nuclear Regulatory Commission (NRC), based on recommendations by the U.S. Environmental Protection Agency (EPA).
All of us are exposed to and use non-harmful radiation each and every day, however, and the vast majority of it comes from natural sources such as the sun. In fact, the average American receives about 360 millirem (the most commonly used measure of radiation) of radiation each year, 300 millirem of which come from natural sources such as rocks and soil, the sun, and radon, a radioactive gas caused by the decay of naturally occurring uranium and thorium in the earth. We also use radiation every time we use a microwave or a toaster, watch television, use a cell phone, have the dentist x-ray our teeth, and ride on an airplane. Exposure to low-level radiation is a fact of life.
While some radiation, such as ultraviolet rays from the sun, can become harmful with prolonged exposure, it’s primarily only when radiation has enough energy in it to change atoms in living tissues that it becomes harmful. This type of radiation, known as “ionizing radiation,” is the kind used in chest x-rays, many manufacturing processes, and in nuclear power plants to generate electricity. Less than one-tenth of one percent of the average American’s exposure to radiation comes from the nuclear power industry.
Among the highest priorities for safe nuclear plant operation is minimizing radiation exposure to workers and the public. U.S. nuclear power plants are designed to protect against harmful radiation releases through multiple safety systems, many of which have continually improved through technological development. (See the section on Reactors and Power Plants to learn more about protective measures.)
State and federal regulations limit the amount of radiation that can be emitted by nuclear power plants. NRC regulations state that people who live near a nuclear power plant cannot be exposed to more than 100 millirem of radiation from that facility annually. Operating data show that power plants actually expose their neighbors to far less than 1 millirem per year. For comparison, airline pilots who regularly fly the New York to Toyko route are exposed to 900 millirem of radiation each year.
Despite the theoretical risk factors, radiation studies for almost a century and follow-up studies of hundreds of thousands of occupationally exposed workers have not revealed any adverse health effects caused by normal exposure to artificial radiation, according to the NRC. Dose limits are even smaller for the general public—only a small fraction of those for radiation workers.
Links to learn more…..
Facts about radiation
Fact Sheet on Biological Effects of Radiation
Answers to Questions Radiation and You
Nuclear power creates a lot of dangerous waste, right?
Like most industries, nuclear power plants produce waste. One of the main concerns about nuclear power plants is not the amount of waste created, which is quite small compared with other industries, but rather with the radioactivity of some of the waste.
The fission process creates radioactive waste products. After about three cycles, these waste products build up in the fuel rods, making the chain reaction more difficult. Utility companies generally replace one-third of the fuel rods every 12 to 18 months to keep power plants in continuous operation. Please see the section “What is Nuclear Waste?” to learn more about different types of waste and how it is handled.
The accident at Three Mile Island proves nuclear plants are unsafe, right?
No discussion of U.S. nuclear plant safety would be complete without taking into account the March 1979 accident at Unit 2 of the Three Mile Island (TMI) plant near Harrisburg, Pennsylvania. In that accident, instrumentation malfunctioned and incorrectly showed the reactor was filling up with water, when it was actually losing coolant.
Most experts have concluded that the equipment malfunction was exacerbated by human error. Operators made a relatively minor incident more serious by cutting off backup systems. This error caused the water level to drop low enough to uncover all but about two feet of the reactor’s 12-foot-long fuel assemblies. Without cooling water surrounding the fuel, its extremely high temperature caused melting and damage to a large part of the reactor core. As a result of this damage, radioactive material normally confined to the fuel escaped into the reactor’s cooling water system.
The accident at TMI was a serious commercial reactor accident from an economic standpoint. It also point out the need to keep seeking ways to improve power plant safety and training. Ultimately, however, the plant’s safety systems protected public health and safety. The protective barriers designed into the facility protected TMI personnel and the public. There were no injuries during the accident, and no offsite property contamination. Over the longer term, recent studies of the population near the TMI plant show no change in the normal incidence of cancer.
Today, Unit 2 at TMI is permanently shut down and defueled, with the reactor coolant system drained, the radioactive water decontaminated and evaporated, radioactive waste shipped off-site to an appropriate disposal site, reactor fuel and core debris shipped to a Department of Energy facility, and the remainder of the site being monitored. Unit 1 at TMI still safely operates and has done so without incident for nearly 40 years.
TMI remains the most serious and costly accident in U.S. commercial nuclear power plant history. The incident became a catalyst, however, for action by the nuclear power industry that led to a full review, and subsequent improvements in plant design, safety, emergency planning, and operations maintenance.
Continuous improvements have resulted in nuclear power being one of our safest and most reliable energy technologies. In addition, new nuclear fuel has been processed, fabricated, and safely shipped across the United States for more than half a century. In total, nuclear power’s overall safety record is one of the best of any industry in the nation.
To learn more, read the NRC: Fact Sheet on Three Mile Island
*“Nuclear Energy: Poised for Expansion,” Harold McFarlane, Idaho National Laboratory, May 2006.
