A single kilogram of uranium produces about 2 million times more energy than 1 kilogram of coal. Some may consider that a spectacular feat since you don't have to heat uranium to make that happen; it heats itself through a process called fission. Nuclear reactors cause atoms in some materials to split, unleashing the energy stored in those atoms. Though the pros of nuclear energy are numerous, there are cons that must be considered. You may know about the nuclear waste that fission creates, but that's only one of the disadvantages of nuclear power generation.

A nuclear reactor's core houses thousands of metal rods that hold uranium fuel. As fission proceeds, the fuel releases heat that causes water surrounding the rods to boil, produce steam and rotate a turbine that makes electricity. A nuclear power plant accident is capable of releasing dangerous radiation that harms people and the environment. Even though the Nuclear Regulatory Commission monitors plant operation and construction closely, nuclear mishaps are still possible and have occurred.

The Three Mile Island nuclear reactor in Pennsylvania experienced a partial meltdown in 1979. A meltdown occurs when a reactor core overheats and radioactive fuel escapes. If that hot fuel melts through barriers designed to keep it in, radioactive material could escape into the area outside the reactor. Safety measures have tightened since the Three Mile Island incident. In 1986, a reactor in Chernobyl sent radioactive material as far as Sweden and large swathes of the surrounding region are still considered uninhabitable today. More recently, three reactor building explosions and three core meltdowns occurred at Japan's Fukushima nuclear plant after an earthquake and tsunami rocked the country in 2011. The accident contaminated air, water, homes and farms and displaced 160,000 people. In 2015, extremely low levels of radiation from the Fukushima mishap were recorded on North American shores. As of April 2015, radiation wasn't considered high enough to significantly threaten marine or human life.

Electricity sent to customers from the nuclear power plant is the good news; the bad news -- nuclear waste -- sits in secure storage sites around the country. All American nuclear power plants collectively produce around 2,000 metric tons of radioactive waste yearly. You can't simply toss this waste into a landfill because radiation can harm living creatures and the environment. Thousands of years can pass before plutonium and some other elements in this waste lose their radioactivity. It's also expensive and risky to transport nuclear waste to its final destination over public roads. Despite ongoing efforts and the expenditure of $10 billion, the nation's proposed central storage site at Yucca Mountain in Arizona is still not approved for construction. As of April 2015, the United States is still depending on scattered interim storage sites.

It's expensive to build new nuclear power plants because of several factors. To construct a large nuclear reactor, you need thousands of components, thousands of workers, costly materials, such as high-quality steel, and systems that provide the reactor with ventilation, cooling, communication and electricity. According to the Union of Concerned Scientists, the cost for a nuclear power plant hovered around $9 billion as of 2008. The UCS estimated that, if plans proposed in 2009 had been built, the taxpayers would have been on the hook for as much as $1.6 trillion. Post Cold War-era design methods are one of the biggest cons of nuclear power generation, and it's why plants cost so much. Because older designs were not standardized, builders would customize new plants their own way. As plants got bigger, their costs scaled up as well because they needed more expensive materials. Newer modular designs that use mass-produced materials could reduce plant construction costs. Nuclear power plants are relatively inexpensive to operate after they're built.