What Are the Consequences of a Nuclear Reactor Accident?

What is a nuclear meltdown? This term is often used to describe a severe nuclear reactor accident. A meltdown is possible when a nuclear power plant component or system fails and then causes the core of the reactor to stop being controlled properly and cooled properly to a point where the sealed nuclear fuel assemblies, that contain the plutonium or uranium, start to overheat and then melt. This is a very serious situation due to the possibility of the reactor containment failing which can result in the core's highly toxic and radioactive components being released into the environment and atmosphere.

Causes

In certain types of reactors, a loss of pressure can cause the core's fuel assemblies to melt. Other causes include an uncontrolled power excursion, a loss of coolant accident or anything that causes a fire to erupt near a fuel assembly.

In terms of a loss of pressure control accident, the pressure of the confined coolant drops far lower than specification without the ability to restore it. In terms of a loss of coolant accident, either the loss of a way to make sure adequate flow rate of the coolant or physical loss of the coolant occurs.

In terms of an uncontrolled power excursion accident power in the reactor suddenly spikes and this exceeds reactor design specifications because of an acute increase in reactor reactivity.

Environmental Effects

Animals are at risk for damage at the genetic and cellular level. If DNA becomes damaged, cellular mutations can be triggered, which can result in life-threatening diseases like cancer. If small blood vessels or capillaries are damaged, animals are at risk for serious health issues, such as aneurysms or heart failure. The intense heat that often comes along with radiation may cause mass death of animal species because many animals may not be able to withstand such temperatures.

In plants, the seeds may suffer cellular damage due to radiation. This may prevent sprouting and germination. If this occurs, plant reproduction can be adversely affected. Radiation may also cause growing plants to suffer genetic mutations which can negatively impact their ability to survive.

Microbes can be killed or damaged by radiation. The damage can vary from genetic damage to cell wall and other cellular structure damage. If a microbe suffers from genetic damage, its ability to reproduce can be negatively impacted. There is also a change a mutation could be triggered that could result in the death of the microbe.

Human Health Effects

Radiation can have serious, and even deadly, effects on the human body, such as cancer, cardiovascular disorder and death. Short-term effects can include diarrhea, fever, nausea and vomiting and headache. After a few days of exposure, effects can include confusion and disorientation, weakness, fatigue and listlessness, dysentery or vomiting blood, wounds that will not heal, dizziness, low blood pressure, and hair loss and baldness. Chronic effects can include premature aging, genetic mutation, cancer, cardiovascular disorders, reproductive system disorders, and nervous system disorders.

Chernobyl

On April 26, 1886 the world's worst nuclear radiation disaster occurred at the Chernobyl nuclear power plant. Located in what is now the Ukraine, about 80 miles north of Kiev. The accident occurred due to normal safety guidelines being disregarded because normal reactor operations were suspended for an experiment. Chernobyl caused 2,500 deaths. Areas all over Europe were contaminated with radiation. The surface soils were greatly contaminated, though, the groundwater was not highly contaminated. Four square kilometers of pine forest in the immediate area became a reddish-brown color and then died because of the radiation. Animals were also affected and either suffered no longer being able to reproduce or death. To this day, there is still an increased incidence in thyroid cancer in the area near Chernobyl. While thyroid cancer is highly treatable when caught early, it is inevitable that not all who develop it will survive.

Resources

University of Pittsburgh: Risks of Nuclear Power

Scientific American: What Happens During a Nuclear Meltdown?