Monday 30 April 2012

Myths & Facts About Nuclear

                                               


Myth: Nuclear energy isn’t safe.
Fact: After more than a half-century of commercial nuclear energy production in the United States, including more than 3,500 reactor years of operation, there have been no radiation-related health effects linked to their operation. Studies by the National Cancer Institute, The United Nations Scientific Committee of the Effects of Atomic Radiation, the National Research Council’s BEIR VII study group and the National Council on Radiation Protection and Measurements all show that U.S. nuclear power plants effectively protect the public’s health and safety. Nuclear plants also are safe for workers. According to the U.S. Bureau of Labor Statistics, it is safer to work at a nuclear plant than at a fast food restaurant or a grocery store or in real estate. For more information, see the NEI fact sheet Radiation Safety: Synopses of Major Studies on Exposures to the Public and Workers.

Myth: Chernobyl could happen in the United States.
Fact: By design, it is physically impossible for any U.S. commercial nuclear energy plant to run out of control and explode like the Chernobyl RBMK reactor design did. Unlike the Chernobyl reactor, all U.S. reactors are designed to be self-limiting. During power operations, when the temperature within the reactor reaches a predetermined level, the fission process is naturally suppressed so the power level cannot spike under any circumstances. The Chernobyl RBMK reactor is banned in the United States.

Myth: A nuclear power plant can explode.
Fact: It is physically impossible for a U.S. commercial reactor to explode like a nuclear weapon. The concentration of uranium-235 within the reactor fuel is far too low to be explosive and all U.S. commercial reactors are self-limiting. During power operations, when the temperature within the reactor reaches a predetermined level, the fission process is naturally suppressed so the power level cannot spike under any circumstances. No one could intentionally or unintentionally alter a commercial nuclear reactor, its controls or its fuel to make it explode like a nuclear bomb.

Myth: The threat of a nuclear meltdown is high.
Fact: The probability of fuel melting, or core damage, in a U.S. commercial nuclear reactor is very low. Because of the lessons learned and additional precautions taken after the accident at the Three Mile Island Nuclear Station 33 years ago, risk assessments performed for the U.S. Nuclear Regulatory Commission determined that an accident that could cause core damage in the current U.S. fleet of 104 reactors could occur approximately once in 1,000 years. The risk of core damage for an individual plant is approximately once in 100,000 years. For a new nuclear reactor, the risk of core damage is less likely—once in a million years—because of enhanced safety features. Core damage does not mean radioactivity would be released from a plant, nor does it mean that anyone would be harmed. Every nuclear plant has an extremely strong containment building that encloses the reactor and multiple safety features designed to mitigate the consequences of a core damage event. Half of the fuel in the Three Mile Island reactor melted and the rest was severely damaged, but no one in or outside the plant was harmed. The potential for a nuclear plant to have a core damage accident resulting in significant release of radiation is low—once in 10,000 years for the operating plant fleet.
Note: To protect the health and safety of the public, every U.S. nuclear plant is required to have emergency plans, procedures and notification systems at the ready should a core damage event occur. Every plant is required to regularly perform emergency drills graded by the U.S. Nuclear Regulatory Commission and each must maintain high levels of performance and emergency preparedness to continue operations.

Myth: Nuclear power plants are likely targets for terrorism.
Fact: With protective measures similar to high-security military installations, U.S. nuclear plants are among the most highly protected facilities in the nation’s industrial infrastructure. It is because of their fortifications and multiple layers of security that nuclear plants present a strong deterrent to potential threats.

Myth: A nuclear power plant cannot withstand a terrorist attack.
Fact: With protective measures similar to high-security military installations, U.S. nuclear plants are among the most highly protected facilities in the nation’s industrial infrastructure. Nuclear power plants are protected 24/7 by professional security personnel armed with automatic weapons prepared to repel ground and airborne terrorist attacks. It is because of their fortifications and multiple layers of security that nuclear plants are far less likely to be targets of terrorism than the thousands of far more vulnerable potential targets across the nation. Anti-terrorism measures are regularly tested and closely coordinated with local, state and federal authorities.

Myth: A nuclear power plant cannot withstand the impact of a jetliner.
Fact: Following the terrorist attacks of Sept. 11, 2001, sophisticated computer modeling by some of the world’s leading structural engineers showed that nuclear power facilities that contain radioactive material can withstand a jetliner impact without releasing radiation. Likewise, all new nuclear power plants are required to withstand the direct impact of a fully fueled commercial jetliner.

Myth: Nuclear plants are vulnerable to cyber attacks.
Fact: There has never been a successful cyber attack at any U.S. nuclear plant. Unlike industries for which two-way data flow is critical (e.g. banking), nuclear power plants do not require incoming data flow. None of a plant’s safety and control systems are connected to the Internet. Any additional computers utilized in a nuclear plants are strictly controlled with their content, use and possession monitored by security personnel. Nuclear plants are protected from grid instability and are able to safely shut down in a variety of ways without computer controls under any condition including a total loss of off-site power.

Myth: Nuclear energy leads to the proliferation of nuclear weapons.
Fact: The technology to make highly concentrated uranium and plutonium for nuclear weapons is completely independent of nuclear power plant technology. It is impossible to make a nuclear weapon with the low-enriched uranium contained in commercial nuclear reactor fuel. If every commercial nuclear energy plant and all the supporting technology around the world were dismantled and none were ever built again, the proliferation of nuclear weapons would still be a threat.
Note: Nuclear energy plants reduce the threat of nuclear weapons by using warhead material as fuel and rendering it useless for weaponry. To date, the U.S.-Russia Megatons to Megawatts program has consumed more than 400 metric tons, more than the equivalent of 17,000 nuclear warheads. Strict protocols administered by the International Atomic Energy Agency (IAEA) are used to control fuel enrichment, fabrication and reprocessing facilities. The international community, through the United Nations Security Council, can take action against nations that are not complying with safeguards commitments to the IAEA.

Myth: Terrorists can use commercial reactor fuel to make nuclear weapons.
Fact: It is impossible to make a nuclear weapon with the low-enriched uranium contained in commercial nuclear reactor fuel. Only through extremely complex and expensive reprocessing could the plutonium in used nuclear fuel be isolated for use in a nuclear weapon. This requires a very large industrial complex that would take years and hundreds of millions of dollars to construct—far beyond the capability of any terrorist organization.

Myth: Reprocessing used nuclear fuel will lead to proliferation of nuclear weapons.
Fact: Reprocessing of used nuclear fuel can be designed to prevent the isolation of plutonium therefore posing no threat of proliferation. It is impossible to make a nuclear weapon with the low-enriched uranium contained in commercial nuclear reactor fuel.

Myth: Transporting radioactive materials exposes the public to unacceptable risk.
Fact: Since the 1960s, there have been more than 3,000 shipments of used nuclear fuel and high-level radioactive waste on U.S. roads, highways and railways totaling more than 1.7 million miles. There have been nine accidents, four on highways and five on railways. Because the shipping containers are so strong, there were no injuries, leaks, exposures or environmental damage. The typical high-integrity fuel shipping container can withstand a direct hit by a high-speed locomotive, an 80-mile-an-hour crash into an immovable concrete barrier, immersion in a 1,475-degree Fahrenheit fire, a direct hit by a projectile 30 times more powerful than an anti-tank weapon, immersion in 600 feet of water, and more.

Myth: The Nuclear Regulatory Commission is too “cozy” with the nuclear industry.
Fact: The commercial nuclear industry is arguably the most strictly regulated industry in the nation. The Nuclear Regulatory Commission is an independent, safety-focused, transparent regulatory agency that inspects and monitors all U.S. nuclear power plants. The NRC’s five commissioners are appointed by the president of the United States and confirmed by the U.S. Senate. The majority of the agency’s funding is drawn from nuclear energy industry user fees as mandated and administered by Congress. The NRC can impose warnings, fines and special inspections; order plants to shutdown; and modify, suspend or revoke a  plant’s operating license. Each year, the NRC utilizes an average of 3,800 person-hours of inspection effort for each reactor, including at least two full-time resident inspectors with unlimited access to their assigned facility. Specialist teams also conduct inspections throughout the year. If a plant’s performance declines, additional inspections are utilized. All NRC inspection reports, hearing information, performance ratings, enforcement orders and license information for every nuclear facility are posted on its website and open to the public. The NRC has strict ethics rules to prevent conflicts of interest between its personnel and members of the nuclear industry and can impose corrective and/or punitive actions if they occur.

Myth: Nuclear plant license renewal is a “rubber stamp” by the NRC.
Fact: The Nuclear Regulatory Commission’s license renewal process takes an average of two years to complete and costs the owners of the facility between $10 million and $20 million. The application for license renewal (ranging from several thousand to tens of thousands of pages of required information for one reactor) involves at least 60,000 person-hours of preparation by the company that owns the facility. The public is encouraged to participate in the process through public meetings and public comment periods on rules, renewal guidance and other documents. In addition, parties and members of the public have an opportunity to request a formal adjudicatory hearing if they believe they would be adversely affected by the renewal. The NRC must determine that a plant can continue to operate safely throughout the extended period of operation to issue the license renewal. A license renewal does not guarantee that a nuclear plant can operate for the extended 20-year period. The plant must continue to meet regulatory safety standards, or the NRC can order it to shut down and can modify or revoke the unit’s license.
Note: The original 40-year term for nuclear power plant licenses was not based on an expected operating life span, but was selected by Congress for the Atomic Energy Act of 1954 because this was the typical amortization period for an electric power plant at that time.

Myth: An inadvertent criticality (sustained chain reaction) occurred in a damaged Fukushima Daiichi reactor.
Fact: There is no evidence a criticality occurred in any of the damaged Fukushima Daiichi reactors since the accident in March 2011. A criticality is a sustained chain reaction of fission within the nuclear fuel that generates large amounts of heat and radiation. Spontaneous fission of uranium atoms occurs naturally within the fuel of all reactors and produces small amounts of heat and radiation. Conditions within the damaged reactors at Fukushima do not support criticality. The control rods that absorb neutrons necessary to support a chain reaction are commingled with the fuel thereby minimizing the possibility of a criticality. Operators also can mix boron, a highly effective neutron absorber, in cooling water circulated through the damaged reactors.
Myth: Nations operate and maintain their nuclear energy facilities the same.
Fact: There are distinct differences between nations’ nuclear energy industries. For example. the United States has a single, independent federal regulator, the U.S. Nuclear Regulatory Commission, while Japan has four regulating bodies with overlapping responsibilities. The U.S. nuclear energy sector implemented an  industrywide safety culture program to assess and improve organizational prioritization of safety issues, and all U.S. nuclear energy companies fund an industry watchdog organization, the Institute of Nuclear Power Operations, to maximized safety performance and achieve operational excellence above and beyond NRC requirements. The Japanese nuclear industry has no similar entities. There also are significant differences in plant maintenance, emergency preparedness, reactor operator training and licensing, and plant command and control protocols.

Myth: Some U.S. nuclear plants do not meet NRC fire protection safety standards.
Fact: All 104 U.S. nuclear energy facilities comply with U.S. Nuclear Regulatory Commission fire protection standards under Appendix R or a specific license condition of the NRC’s codified fire protection  regulation, or the National Fire Protection Association fire protection standard (NFPA 805) that was approved by the NRC in 2004. NRC resident inspectors perform quarterly and annual inspections at every facility. Every three years, NRC engineers perform a comprehensive review of the physical aspects of fire protection program implementation, and all of the underlying analysis of fire protection requirements. If any deficiencies are identified at any time, licensees must respond as directed by the NRC. NEI’s Myths & Facts: Fire Protection details the fire protection program
Note: In a half-century of commercial nuclear energy plant operations, only one fire in 1975, at Unit 1 of the Browns Ferry nuclear plant in Alabama, affected plant safety systems. The worst fire ever at a U.S. nuclear power plant injured no one, released no radiation to the environment, and resulted in fundamental improvements in fire protection measures and regulatory requirements being instituted at all U.S. nuclear power plants.

No comments:

Post a Comment