Nuclear safety, as explained by the International Atomic Energy Agency (IAEA), means "achieving proper working conditions, preventing accidents, or reducing the effects of accidents to protect workers, the public, and the environment from harmful radiation." The IAEA also says nuclear security involves "preventing, detecting, and responding to theft, sabotage, unauthorized access, illegal movement, or other harmful actions involving nuclear materials, radioactive substances, or related facilities."
This includes nuclear power plants, other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, energy, industrial, and military purposes.
The nuclear power industry has made reactors safer and more efficient, and has created new reactor designs that are even safer. However, perfect safety cannot be guaranteed. Problems can arise from human mistakes or unexpected events that have bigger effects than planned. For example, the designers of reactors at Fukushima in Japan did not expect that a tsunami caused by an earthquake would stop the backup systems meant to keep the reactor stable after the earthquake. Serious issues could also happen from terrorist attacks, wars, insider sabotage, or cyberattacks.
Nuclear weapon safety and safety related to military research with nuclear materials are usually managed by different groups than those responsible for civilian safety, often because of secrecy. People are worried about terrorist groups getting materials needed to make nuclear bombs.
Overview of nuclear processes and safety issues
As of 2011, nuclear safety is important in many situations, including:
Except for certain types of weapons and research projects, all safety concerns related to nuclear power come from the need to reduce exposure from eating or breathing radioactive materials and radiation from radioactive materials in the environment.
Nuclear safety includes at a minimum:
• Getting, moving, storing, processing, and safely getting rid of materials used in nuclear reactions
• Keeping nuclear power plants safe
• Managing nuclear weapons, materials that could be used as weapons, and other radioactive materials safely
• Handling, keeping track of, and using radioactive materials properly in industrial, medical, and research settings
• Safely getting rid of nuclear waste
• Setting limits on how much radiation people can be exposed to
Responsible agencies
The International Atomic Energy Agency (IAEA) works with countries around the world to promote safe, secure, and peaceful use of nuclear technology. Some scientists believe that the 2011 nuclear accidents in Japan showed that the nuclear industry needs more oversight, leading to calls for the IAEA to have a stronger role in monitoring nuclear power plants worldwide.
The IAEA Convention on Nuclear Safety was created in Vienna on June 17, 1994, and became effective on October 24, 1996. Its goals are to keep nuclear safety at a high level around the world, to protect nuclear facilities from possible radiation dangers, and to prevent accidents that could cause radiation harm.
The convention was developed after the Three Mile Island and Chernobyl accidents. Experts from many countries, including the IAEA, worked together to create it. The rules for countries that signed the convention are based on safety principles from the IAEA document The Safety of Nuclear Installations (IAEA Safety Series No. 110, published in 1993). These rules cover laws and regulations, the organizations that oversee safety, and requirements for nuclear plants, such as location, design, construction, and emergency planning.
In 2014, the convention was updated with the Vienna Declaration on Nuclear Safety, which added new safety rules:
1. New nuclear power plants must be designed and built to prevent accidents and reduce radiation risks if accidents occur.
2. Existing nuclear plants must be regularly checked for safety improvements throughout their lifetime.
3. Countries must use IAEA safety standards and other good practices when regulating nuclear plants.
Najmedin Meshkati of the University of Southern California, writing in 2011, noted problems with nuclear regulation in some countries. For example, in the United States, the Nuclear Regulatory Commission (NRC) oversees civilian nuclear safety. However, critics say that some regulators are too close to the nuclear industry to be effective. The book The Doomsday Machine gives examples, such as:
– In China, a former leader of a nuclear company was jailed for taking bribes, raising questions about the safety of China’s nuclear reactors.
– In India, the nuclear regulator reports to a government group that supports building nuclear plants, and the regulator’s leader previously worked for the company he now oversees.
– In Japan, the nuclear regulator reports to a government ministry that promotes the nuclear industry, and top jobs in the nuclear sector are often held by a small group of experts.
The book suggests that nuclear safety is at risk when regulators and the industry work closely together, as some people believe in Japan.
Nuclear safety in the United States for government-controlled plants is not managed by the NRC. In the United Kingdom, nuclear safety is regulated by the Office for Nuclear Regulation (ONR) and the Defence Nuclear Safety Regulator (DNSR). In Australia, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) monitors radiation risks. Other nuclear regulatory agencies include:
– Autorité de sûreté nucléaire (France)
– Canadian Nuclear Safety Commission (Canada)
– Radiological Protection Institute of Ireland (Ireland)
– Federal Atomic Energy Agency (Russia)
– Kernfysische dienst (Netherlands)
– Pakistan Nuclear Regulatory Authority (Pakistan)
– Bundesamt für Strahlenschutz (Germany)
– Atomic Energy Regulatory Board (India)
Nuclear power plant safety and security
Nuclear power plants are some of the most complex and advanced energy systems ever created. Even the best-designed systems cannot be completely free of risks. Journalist Stephanie Cooke has explained that the 1979 Three Mile Island accident inspired a book called Normal Accidents by Charles Perrow. The book describes how nuclear accidents can happen due to unexpected problems in complex systems. The Three Mile Island event was called a "normal accident" because it was unexpected, hard to understand, impossible to stop, and unavoidable.
A major reason nuclear power systems are complex is their long lifespan. From when a nuclear plant starts being built to when its radioactive waste is safely disposed of, the process can take 100 to 150 years.
There are concerns that mistakes made by people or equipment at a nuclear facility could harm people and the environment. However, commercial nuclear reactors cannot explode like nuclear bombs because the fuel used is never enriched enough to cause such an explosion.
Nuclear reactors can fail in different ways. If the nuclear material becomes unstable and behaves unpredictably, it might cause an uncontrolled increase in power, called a power excursion. Reactors are usually designed to handle this extra heat with cooling systems. However, if the cooling system fails, the fuel could melt, and the container holding it might overheat and melt. This is called a nuclear meltdown.
After a reactor is shut down, it still needs outside power to keep its cooling systems running. This power usually comes from the electricity grid or emergency generators. If cooling systems lose power, as happened in the 2011 Fukushima I accident, serious problems can occur.
In the United States, nuclear plants are protected by high fences and armed guards. In Canada, reactors have on-site security teams with armored vehicles. The U.S. Nuclear Regulatory Commission (NRC) has rules about protecting plants from attacks, but details about these rules are not publicly shared. A nuclear reactor can be shut down in less than 5 seconds, but restarting it takes much longer, which makes it harder for attackers to release radiation.
Air attacks have been a concern since the 1972 hijacking of a plane that threatened to crash into a nuclear facility in Tennessee. The most important protection against radiation leaks from an aircraft strike is the containment building and its missile shield. Studies by the U.S. Electric Power Research Institute have shown that nuclear plants can withstand attacks similar to the September 11, 2001, terrorist attacks. Spent nuclear fuel is stored in secure areas, and stealing it for a "dirty bomb" would be extremely difficult due to the intense radiation.
Nuclear power plants are considered targets for terrorist attacks. Even when the first plants were built, security experts warned about this risk. Some older plants in Germany were not built to protect against air crashes, but newer plants have thick concrete buildings designed to withstand impacts from military aircraft traveling at about 800 km/h.
The risk of a large aircraft crashing into a nuclear plant is being studied. For example, Germany has said that its Biblis A plant might not be fully protected from a military aircraft attack. After the 2016 Brussels terrorist attacks, some nuclear plants in Europe were partially evacuated, and some employees lost access to plants because of suspected spying.
Nuclear terrorism, such as using a "dirty bomb," is a serious threat. Many nuclear plants are built near coasts to use seawater for cooling. This means designs must account for risks like flooding and tsunamis. The World Energy Council says natural disasters like earthquakes, cyclones, and floods are becoming more common. In 1999, a flood at the Blayais Nuclear Power Plant caused a Level 2 event on the International Nuclear Event Scale. The 2011 Tōhoku earthquake and tsunami led to the Fukushima I nuclear disaster.
Plants in earthquake-prone areas, such as Japan, India, China, and the United States, are designed to handle seismic risks. Damage to Japan's Kashiwazaki-Kariwa Nuclear Power Plant during an earthquake in 2007 showed the need for strong safety measures.
Title 10 CFR Part 73 (U.S. NRC)
Title 10 of the Code of Federal Regulations (CFR) Part 73, titled "Physical Protection of Plants and Materials," is managed by the Nuclear Regulatory Commission (NRC). This section includes Subparts A (General Provisions) through I (Enforcement) and Subpart T (Security Notifications, Reports, and Recordkeeping). These regulations are available online through the U.S. NRC website, as of December 20, 2023, and include the following details:
For information about vehicle barriers, refer to 10 CFR 73.55(e)(10)(i)(A) and details about vehicle barrier systems and protection from land vehicles.
For information about security lighting, refer to 10 CFR 73.55(i)(6)(ii), which outlines minimum illumination requirements.
For information about cybersecurity, refer to 10 CFR 73.54, which outlines cybersecurity requirements for nuclear facilities. Guidelines for meeting 10 CFR 73.54 requirements can be found in NEI 08-09.
Hazards of nuclear material
There are currently 47,000 tonnes of high-level nuclear waste stored in the United States. This waste is made up of approximately 94% uranium, 1.3% plutonium, 0.14% other actinides, and 5.2% fission products. About 1.0% of this waste includes long-lived isotopes such as selenium, zirconium, tellurium, palladium, tin, iodine, and cesium. Shorter-lived isotopes, including strontium, ruthenium, cesium, and promethium, make up 0.9% of the waste at one year, decreasing to 0.1% at 100 years. The remaining 3.3–4.1% consists of non-radioactive isotopes. Technical challenges exist because it is important to safely store long-lived fission products, but these challenges should not be overestimated. One tonne of waste has a measurable radioactivity of about 600 terabecquerels, which is similar to the natural radioactivity in one kilometer of Earth's crust. If buried, this waste would add only 25 parts per trillion to the total radioactivity in the environment.
Short-lived high-level nuclear waste and long-lived low-level waste differ in their radioactivity and decay times. For example, one mole of iodine-131 (131 grams) releases 3×10^20 decays in 8 days, producing 970 keV of energy per decay. In contrast, one mole of iodine-129 (129 grams) releases the same number of decays over 15.7 million years, producing 194 keV of energy per decay. Over 8 days, 131 grams of iodine-131 would release 45 gigajoules of energy, starting at an initial rate of 600 exabecquerels, producing 90 kilowatts of power, with the last decay occurring within two years. In comparison, 129 grams of iodine-129 would release 9 gigajoules of energy over 15.7 million years, starting at an initial rate of 850 megabecquerels, producing 25 microwatts of power, with the radioactivity decreasing by less than 1% over 100,000 years.
One tonne of nuclear waste reduces carbon dioxide emissions by 25 million tonnes. Radionuclides like iodine-131 and iodine-129 are either highly radioactive but short-lived or long-lived but less radioactive. For example, one mole of iodine-129 (129 grams) undergoes the same number of decays as one mole of iodine-131 (131 grams) over their respective half-lives. Iodine-131 decays quickly, releasing high energy, while iodine-129 decays very slowly, releasing low energy over millions of years. Long-lived fission products, such as technetium-99 (half-life 220,000 years) and iodine-129 (half-life 15.7 million years), are of greater concern because they may enter the biosphere more easily. Transuranic elements in spent fuel, such as neptunium-237 (half-life 2 million years) and plutonium-239 (half-life 24,000 years), remain in the environment for long periods. A solution to managing actinides and meeting energy needs may involve using an integral fast reactor (IFR). One tonne of nuclear waste completely burned in an IFR could prevent 500 million tonnes of carbon dioxide from entering the atmosphere. Otherwise, waste storage typically requires treatment, followed by long-term strategies such as permanent storage, disposal, or transforming the waste into a non-toxic form.
Governments worldwide are exploring waste management and disposal options, often involving deep geological storage. However, progress has been limited because radioactive waste must be managed over timeframes ranging from 10,000 to millions of years, based on studies of radiation dose effects. The decay rate of a radioisotope is inversely proportional to its half-life, meaning the relative radioactivity of buried human-made waste decreases over time compared to natural radioisotopes. For example, over thousands of years, after short-lived isotopes decay, burying U.S. nuclear waste would increase the radioactivity in the top 2000 feet of rock and soil in the United States (10 million square kilometers) by about 1 part in 10 million compared to natural radioisotopes in the same volume. However, the area near the burial site would have much higher concentrations of artificial radioisotopes underground than the average.
Safety culture and human errors
A common idea in nuclear safety discussions is the concept of safety culture. The International Nuclear Safety Advisory Group describes this as “the personal responsibility of all individuals involved in activities that affect the safety of nuclear power plants.” The aim is to create systems that use human skills effectively, protect systems from human mistakes, and keep people safe from dangers linked to the system.
At the same time, evidence shows that changing how workers operate is difficult. Operators rarely follow instructions or written procedures exactly. “Breaking rules often seems reasonable due to the heavy workload and time limits faced by workers.” Many efforts to improve nuclear safety culture have been undone by workers adjusting to changes in unexpected ways.
According to Selena Ng, director of Areva’s Southeast Asia and Oceania region, Japan’s Fukushima nuclear disaster was “a major warning for an industry that has not always been open about safety problems.” She stated, “There was a sense of overconfidence before Fukushima, and we cannot allow that overconfidence now.”
A study by the Commissariat à l’Énergie Atomique (CEA) in France found that no amount of technical progress can fully remove the risk of human errors in nuclear power plant operations. The most serious mistakes include errors during field tasks, like maintenance and testing, which can cause accidents, and mistakes made during small accidents that lead to total failure.
Mycle Schneider explains that reactor safety depends most on a “culture of security,” which includes the quality of maintenance and training, the skill of operators and workers, and the strictness of regulatory oversight. A newer, better-designed reactor is not always safer, and older reactors are not necessarily more dangerous than newer ones. For example, the 1979 Three Mile Island accident in the United States happened in a reactor that had been operating for only three months, and the Chernobyl disaster occurred after just two years of operation. A major coolant loss at the French Civaux-1 reactor in 1998 happened less than five months after it began operating.
No matter how safe a plant is designed, it is operated by humans who can make mistakes. Laurent Stricker, a nuclear engineer and chairman of the World Association of Nuclear Operators, says workers must avoid overconfidence. Experts note that “the biggest factor affecting a plant’s safety is the safety culture among regulators, operators, and workers — and creating such a culture is not easy.”
Investigative journalist Eric Schlosser, author of Command and Control, found that at least 700 “important” accidents and incidents involving 1,250 nuclear weapons were recorded in the United States between 1950 and 1968. Experts estimate that up to 50 nuclear weapons were lost during the Cold War.
Risks
Nuclear fission power has lower routine health risks and greenhouse gas emissions compared to coal, but it carries some very serious risks. Laurent Stricker, a nuclear engineer and leader of the World Association of Nuclear Operators, explains that population density is an important factor when considering these risks.
At the Fukushima Daiichi nuclear power plant, 172,000 people lived within a 30-kilometer radius before the 2011 disaster. Many were forced to leave or advised to do so. A study published in 2011 by Nature and Columbia University found that 21 nuclear plants have more than 1 million people living within 30 kilometers, and six plants have more than 3 million people in that area.
Black Swan events are rare but can cause major problems. Even with planning, nuclear power remains vulnerable to these events. Examples of such events include:
The AP1000 reactor has an estimated chance of serious damage to its core of 5.09 × 10 per plant per year. The Evolutionary Power Reactor (EPR) has an estimated chance of 4 × 10 per plant per year. In 2006, General Electric updated its calculations for the chance of core damage for its nuclear plant designs.
Beyond design basis events
The Fukushima I nuclear accident happened because of an event that was not planned for, called a "beyond design basis event." The tsunami and earthquake that occurred were stronger than the nuclear plant was built to handle. The accident happened because the tsunami was too strong for the seawall to stop, as the seawall was not high enough. After this event, plant operators have been very worried about unexpected events that could go beyond what their plants were designed to manage.
Transparency and ethics
According to journalist Stephanie Cooke, it is hard to know what happens inside nuclear power plants because the industry keeps many details secret. Companies and governments decide what information the public can see. Cooke explains that when information is shared, it is often written in difficult-to-understand language.
Kennette Benedict has stated that nuclear technology and plant operations still lack openness and are not easily accessible to the public. In 1986, Soviet leaders delayed reporting the Chernobyl disaster for several days. The company that operated the Fukushima plant, Tokyo Electric Power Co, was criticized for not quickly sharing information about radiation releases from the plant. Russian President Dmitry Medvedev said there should be more openness during nuclear emergencies.
In the past, many scientists and engineers have made decisions about risks and uncertainties for people who might be affected. Some nuclear engineers and scientists now believe that making such decisions without asking people for their agreement was wrong. They think nuclear safety and technology should be based on moral principles, not only on technical, economic, or business reasons.
Non-Nuclear Futures: The Case for an Ethical Energy Strategy is a 1975 book written by Amory B. Lovins and John H. Price. The book argues that the most important issues in the nuclear power debate are not technical disagreements but relate to personal values. The authors believed that nuclear reactors were less reliable and took longer to build, which led to problems like higher costs, incorrect predictions about energy needs, and pressure from unions.
Nuclear and radiation accidents
The nuclear industry has a strong safety record, and the number of deaths per megawatt hour is the lowest among major energy sources. According to Zia Mian and Alexander Glaser, "the past six decades have shown that nuclear technology does not tolerate error." Nuclear power is often considered a high-risk technology with the potential for catastrophic events because "no matter how effective safety devices are, some accidents are unavoidable and are a normal part of the system." In short, system failures cannot be avoided.
When making decisions about nuclear power, it is important to consider the possibility of catastrophic accidents and their economic costs. Kristin Shrader-Frechette has stated, "if reactors were safe, nuclear industries would not require government-guaranteed, accident-liability protection to generate electricity." No private insurance company or group of companies would take on the huge risks from severe nuclear accidents.
The Hanford Site is a mostly closed nuclear production facility on the Columbia River in Washington state, operated by the U.S. federal government. Plutonium made at Hanford was used in the first nuclear bomb tested at Trinity and in the bomb dropped on Nagasaki, Japan. During the Cold War, the site expanded to include nine reactors and five plutonium processing plants, producing plutonium for most of the 60,000 weapons in the U.S. nuclear arsenal. Early safety practices and waste disposal methods were poor, and government records show that radioactive materials were released into the air and the Columbia River, harming residents and ecosystems. Although the reactors were shut down after the Cold War, the site left behind 53 million gallons of high-level radioactive waste, 25 million cubic feet of solid radioactive waste, 200 square miles of contaminated groundwater, and ongoing discoveries of hidden contamination. Hanford holds two-thirds of the nation's high-level radioactive waste by volume. Today, it is the most contaminated nuclear site in the U.S. and the focus of the country's largest environmental cleanup.
The Chernobyl disaster was a nuclear accident that occurred on April 26, 1986, at the Chernobyl Nuclear Power Plant in Ukraine. An explosion and fire released large amounts of radioactive material into the atmosphere, spreading across Western USSR and Europe. It is the worst nuclear accident in history and one of only two classified as a level 7 event on the International Nuclear Event Scale (the other being the Fukushima Daiichi disaster). Over 500,000 workers helped contain the contamination, and the effort cost about 18 billion rubles, harming the Soviet economy. The accident raised concerns about nuclear safety and slowed the industry's growth for years.
UNSCEAR has studied the effects of the Chernobyl disaster for 20 years. In addition to 57 deaths directly caused by the accident, UNSCEAR predicted in 2005 that up to 4,000 additional cancer deaths could occur among 600,000 people exposed to significant radiation (including cleanup workers, evacuees, and residents of highly contaminated areas). Russia, Ukraine, and Belarus continue to face the costs of decontamination and healthcare related to the disaster.
Eleven of Russia's reactors are of the RBMK 1000 type, the same design as the one at Chernobyl. Some of these reactors were supposed to be shut down but instead received life extensions and had their output increased by about 5%. Critics say this design is inherently unsafe and cannot be improved through upgrades. Russian environmental groups argue that extending reactor lifetimes violates Russian law because the projects did not undergo proper environmental reviews.
Despite reassurances, a major nuclear accident similar to the 1986 Chernobyl disaster occurred in 2011 in Japan, a highly developed country. In 2012, Japan's Nuclear Safety Commission Chairman Haruki Madarame told a parliamentary inquiry that "Japan's atomic safety rules are inferior to global standards and left the country unprepared for the Fukushima disaster." Safety rules were flawed, and enforcement was weak, including inadequate protection against tsunamis.
A 2012 report in The Economist stated: "The reactors at Fukushima were of an old design. The risks they faced were not well understood. The operating company was poorly regulated and did not know what was happening. Operators made mistakes. Safety inspectors fled. Some equipment failed. Officials downplayed the risks and gave incorrect information about radiation spread, leading to evacuations from less to more contaminated areas."
The designers of the Fukushima I Nuclear Power Plant reactors did not expect that a tsunami caused by an earthquake would disable backup systems meant to stabilize the reactors after the earthquake. Nuclear reactors are "inherently complex systems where, in rare emergencies, events can happen so quickly that human operators cannot predict or control them."
Backup diesel generators, which could have prevented the disaster, were placed in a basement and quickly destroyed by tsunami waves. A report published in the U.S. decades earlier had predicted such events, and Japan's Nuclear and Industrial Safety Agency referenced it in 2004. However, TEPCO, the plant operator, did not take adequate steps to address the risk. Katsuhiko Ishibashi, a seismology professor at Kobe University, said Japan's history of nuclear accidents stems from overconfidence in plant engineering. In 2006, he resigned from a government safety panel because the process was biased and "unscientific."
According to the International Atomic Energy Agency, Japan "underestimated the danger of tsunamis and failed to prepare adequate backup systems at the Fukushima Daiichi plant." This criticism highlights the weak oversight caused by close ties between regulators and industry. The IAEA also noted that the disaster revealed a lack of backup systems. Once power was lost, critical functions like cooling systems failed. Three reactors overheated, causing meltdowns that led to explosions and the release of large amounts of radioactive material into the air.
Louise Fréchette and Trevor Findlay have said more effort is needed to improve nuclear safety and responses to accidents. David Lochbaum, chief nuclear safety officer with the Union of Concerned Scientists, has repeatedly questioned the safety of the Fukushima I Plant.
Health impacts
There are currently 437 nuclear power plants operating worldwide. However, five major nuclear accidents have happened in the past. These accidents occurred at Kyshtym (1957), Windscale (1957), Three Mile Island (1979), Chernobyl (1986), and Fukushima (2011). A report in The Lancet states that the effects of these accidents on people and communities are different and long-lasting.
Despite these accidents, studies show that most nuclear-related deaths occur during uranium mining. Nuclear energy has caused far fewer deaths than the high pollution levels from using traditional fossil fuels. However, the nuclear power industry depends on uranium mining, which is a dangerous industry with many accidents and fatalities.
Journalist Stephanie Cooke explains that comparing only the number of deaths is not helpful, because how people live after an accident also matters. For example, the 2011 Japanese nuclear accident forced more than 80,000 residents to leave their homes near the power plant.
A survey by the Iitate, Fukushima local government collected responses from about 1,743 people who evacuated from a village near the damaged Fukushima Daiichi Plant. The survey found that many residents feel increasing frustration and uncertainty because of the nuclear crisis and the difficulty of returning to their previous lives. Sixty percent of respondents said their health and their families’ health had worsened after evacuating. Thirty-nine point nine percent reported feeling more easily upset than before the disaster.
Chemicals in radioactive waste can cause cancer. For example, Iodine 131 was released during the Chernobyl and Fukushima disasters. It absorbed into soil and then moved into leafy plants. If animals eat the plants, Iodine 131 remains in their milk. When Iodine 131 enters the human body, it moves to the thyroid gland in the neck and can cause thyroid cancer.
Other elements in nuclear waste can also cause cancer. For example, Strontium 90 can cause breast cancer and leukemia. Plutonium 239 can cause liver cancer.
Improvements to nuclear fission technologies
Changes to fuel pellets and cladding are being made to improve the safety of current power plants.
New reactor designs have been created over time to increase safety. These designs include systems that work without needing people to operate them and Small Modular Reactors. While these designs aim to build trust, they might cause people to lose trust in older reactors that do not include these safety features.
The next nuclear plants to be built will likely use Generation III or III+ designs. Some of these are already in use in Japan. Generation IV reactors would have even more safety improvements. These designs are expected to work without needing people to operate them or to be nearly impossible to cause accidents, like in the PBMR designs.
Some safety improvements include having three sets of emergency diesel generators and cooling systems instead of just one, having large coolant-filled tanks above the reactor core that open automatically, and having two layers of protection around the reactor.
About 120 reactors, including all reactors in Switzerland before and all reactors in Japan after the Fukushima accident, have systems that release gas during accidents while keeping harmful materials inside. These systems are attached to the reactor’s protective structure.
However, safety risks may be higher with new nuclear systems because operators have less experience with them. A nuclear engineer named David Lochbaum explained that most serious nuclear accidents happened with the newest technology at the time. He said the problem with new reactors is that unexpected situations can occur, and people may make mistakes. A director of a U.S. research laboratory added that building and operating new reactors will be challenging because people may not know how to use advanced technologies correctly, even if the technology itself is proven.
Developing countries
Some people are worried that developing countries may try to quickly join the nuclear energy expansion without having the needed tools, workers, rules, or safety habits. Countries like Nigeria, Kenya, Bangladesh, and Venezuela want to use nuclear power but lack experience in large industries. These nations may need at least ten years of planning before starting to build nuclear reactors.
In 2010, a Nuclear Security Summit led by the Obama administration encouraged China and the United States to help secure nuclear materials in countries such as Ghana and Nigeria. These efforts included changing Chinese-made Miniature Neutron Source Reactors (MNSRs) to use low-enriched uranium instead of highly enriched uranium. This change makes the reactors safer because low-enriched uranium cannot be easily used to make weapons.
China and the United States worked together to create the China Center of Excellence on Nuclear Security, which opened in 2015. The Center provides training, discussion, and demonstrations about nuclear security in the Asia Pacific region.
Nuclear security and terrorist attacks
Nuclear power plants, civilian research reactors, naval fuel facilities, uranium enrichment plants, and fuel fabrication plants are at risk of attacks that could cause large areas to become contaminated with radiation. Attack threats include ground-based actions by groups targeting equipment that could lead to a reactor core meltdown or the spread of radioactivity. Other threats include external attacks, such as an aircraft crashing into a reactor site or cyberattacks targeting computer systems.
The United States 9/11 Commission noted that nuclear power plants were considered possible targets for the September 11, 2001 attacks. If terrorists damage safety systems enough to cause a reactor core meltdown or harm spent fuel pools, this could result in widespread radiation contamination. The Federation of American Scientists has stated that if nuclear energy use increases, nuclear facilities must be made much safer to prevent attacks that could release large amounts of radiation into communities. Some new reactor designs include passive safety features that may improve protection. In the United States, the Nuclear Regulatory Commission (NRC) conducts "Force on Force" (FOF) exercises at all nuclear power plant sites at least once every three years to test security readiness.
Nuclear reactors are often targeted during military conflicts. Over the past 30 years, they have been attacked during air strikes, occupations, invasions, and military campaigns. Since 1980, the peace group Plowshares has carried out acts of civil disobedience that have shown how nuclear weapons facilities can be accessed, revealing major security weaknesses at U.S. nuclear weapons plants. The National Nuclear Security Administration has recognized the seriousness of the 2012 Plowshares action. Experts have raised concerns about relying on private contractors to secure facilities that handle the government's most dangerous military materials. Nuclear weapons materials on the black market are a global issue, and there is worry about a militant group detonating a small, crude nuclear weapon in a major city, which could cause many deaths and property damage. Stuxnet is a computer worm discovered in June 2010 that is believed to have been created by the United States and Israel to attack Iran's nuclear facilities.
Nuclear fusion research
Nuclear fusion power is a new type of energy technology that scientists are still studying. Unlike nuclear power plants today, which split atoms apart (a process called fission), fusion power joins atoms together. This process could be safer and create less radioactive waste than fission. Fusion reactions are possible, but they are very challenging to achieve and have not yet been used in a working power plant. Scientists have studied fusion since the 1950s.
The International Thermonuclear Experimental Reactor (ITER) project started in 2007. However, the project has faced many delays and higher costs than planned. It is now expected to begin operations in 2027, which is 11 years later than originally planned. A future commercial fusion power plant called DEMO has been suggested. Another idea for a fusion power plant is based on a different method called inertial fusion.
At first, scientists thought fusion electricity could be produced quickly, like fission power. However, the need to keep reactions going continuously and control hot plasma has made progress slower than expected. In 2010, more than 60 years after the first fusion experiments, scientists still believed commercial fusion power might not be possible until after 2050.
More stringent safety standards
Matthew Bunn, a former adviser at the US Office of Science and Technology Policy, and Heinonen, a former assistant director at the IAEA, have stated that stricter nuclear safety standards are needed. They suggest six key areas for improvement, including the following: Coastal nuclear sites need better protection from rising sea levels, strong waves, flooding, and the possibility of becoming isolated due to these conditions.