Nuclear emergency level classification responses

Last updated

Nuclear power plants pose high risk to public health and safety if radiation is released into surrounding communities and areas. This nuclear emergency level classificationresponse system was firstly developed by the US Nuclear Regulatory Commission to allow effective and urgent responses to ultimately control and minimise any detrimental effects that nuclear chemicals can have. [1] These classifications come in four different categories – Unusual Event, Alert, Site Area Emergency (SAE), as well as General Emergency. [2] Thus, each classification has differing characteristics and purposes, depending on the situation at hand. Every nuclear power plant has a different emergency response action plan, also depending on its structure, location and nature. They were developed by thorough discussion and planning with numerous authoritative parties such as local, state, federal agencies as well as other private and non-profit groups that are in association with emergency services. Today, nuclear emergency plans are continuously being developed over time to be improved for future serious events to keep communities and nuclear power plant working members safe. There is a high emphasis for the need of these emergency responses in case of future events. Thus, nuclear plants can, and have paid up to approximately $78 million to ensure that are required measurements are readily available, and that equipment is sufficient and safe. [3] This is applicable for all nuclear power plants in the United States of America.

Contents

Nuclear Power Plant Cattenom Nuclear Power Plant Cattenom.jpg
Nuclear Power Plant Cattenom

Unusual event

The notification of an unusual event is classified as the least alerting or serious nuclear emergency classification. [4] This event does not particularly pose a risk on the power plant workers and surrounding public as it does not involve any radiological release. The exposure of radioactive material if present would be classified as minimal and therefore does not pose any health hazards. Usually there are no off-site chemical monitoring required in this type of event. Furthermore, common examples of unusual events might include a severe injury suffered by a worker or cases of chaotic weather. [5] Being the least severe event, this ensures that the necessary first steps of any nuclear emergency response are formally carried out and documented. [6] If an event goes beyond the severity of an unusual event, the next classification would be an Alert event. The recorded frequency of this type of event occurs one to two times per year. [7]

Alert

An Alert emergency response is followed by an unusual event. This is characterized by the potential threat towards a power plant’s overall safety due to damaged equipment. [8] Similarly, it does not require an emergency response by the public, however emergency agencies and power plant employees are still informed to address the event at hand. Therefore, there is no triggering of a siren to the public. Radiological materials may be released but only at a very minimal level, which is easily controlled and rectified. [9] Therefore, offsite monitoring is required. Furthermore, other secondary or back-up power plants are still functional instead of the primary power plant that is potentially damaged. Still classified as a minor emergency event response, an alert response ensures that all members and other offsite agencies are promptly and provided necessary information to be ready to take further action if the incident escalates more severely than present if needed. However generally, a public response is not required. But measurements are taken place to keep the public safe. The recorded frequency of this type of event occurs once every ten to one hundred years. [10]

Site Area Emergency

Site Area Emergency event responses are classified as more severe than alert events. This involves minor to major issues with the power plant function of equipment, which can potentially later affect the public if not sustained immediately. This imposes very high hazardous threats to workers and the as radiological materials may be released into either the air or surrounding water ways. [11] Any released material does not reach the public, so therefore no public response is required for this classification of event also. However, a siren is triggered to alert surrounding communities within a ten mile radius. Relevant information about the event is transferred to offsite authoritative parties in case of the increase severity of the situation. This includes readiness for potential evacuations and increased monitoring of nuclear material. [12] Hence, sirens are triggered to set off to vigorously notify the public of a potential nuclear threat (via local radio stations and television) and to prepare for any response if required. In addition, exposure seems to not exceed any regulations or boundaries established by the Environmental Protection Agency Protective Action Guidelines (PAGs). Examples of a site area emergency might include a reactor coolant leak or a fire within a safety system. In addition, the expected frequency of this type of event of response is of once every hundred to five thousand years. [13]

Danger radiation Danger radiation.svg
Danger radiation

General emergency

A general emergency event response is classified as the most severe situation. This event is characterized by the major impairment of power plant equipment. As a result, leakage and release of radiological materials significantly cannot be controlled or managed due to damaged implemented safety systems. [14] The release of nuclear chemicals will exceed the Environmental Protection Agency Protective Action Guidelines (PAGs) boundaries. Therefore, a public response is immediately required through the guidance of state and other local authorities (through local radio stations and television) to minimize the detrimental effects on surrounding communities. A public response normally involves staying indoors, or in some cases results in an evacuation. This is initially communicated through the triggering of a siren extending within a ten mile radius. Ultimately, the purpose of a general emergency response is to prioritize the health of the public through all necessary actions and to maximize all monitoring methods to sustain the situation as fast as possible through assessment of information. [15] In addition, Furthermore, the expected frequency of a general emergency event is predicted at approximately once every five thousand years. The last recorded general emergency occurred in 1979 in Three Mile Island, as well other accidents in Chernobyl and Fukushima.

Three Mile Island Accident

The Three Mile nuclear power plant incident occurred on 28 March 1979. This event was regarded as one of the most serious nuclear power plant incidents in history. In this event, one of the two reactors on the site experienced technical dysfunction. This was due to mechanical or electrical difficulties, where water could not be sent to the steam generators and therefore lead to the shutting down of the reactor itself. As a result, pressure began to increase significantly and water would pour out without any awareness from the nuclear plant staff. [16] Hence, there was an immense decrease in the coolant from the reactors, causing the power plant to be in a dangerous and hazardous state as the reactor began to melt. Immediately alarms were triggered to signify an issue within the nuclear power plant to rectify the issue as soon as possible. This incident had only released very minimal amounts of radiation. Hence, the Three Mile event did not pose any radiological health effects on both the nuclear plant staff, or public members of the community within a five-mile radius. [17] In addition, there were no evidence of any irregular patterns of health, or significant cases of cancer which the radiation could have caused. [18]

The series of events that occurred on Three Mile Island provoked the need to implement improved training and nuclear response for future events by the Nuclear Regulatory Commission (NRC) as well as the National Academy for Nuclear Training. In this incidence, a priority was made to continuously monitor the function of the cooling generator of power plants. This led to valuable information such as understanding fuel melting and more. [19] In addition, these organisations emphasised the need for excellent standards in all nuclear power plant operations and training programs. This includes skills or communication and team work amongst team members. Furthermore, the consequence of this establishment of improved training has led to increased safety and reliability. [20] Thus, it is now mandatory for a power plant to meet the standards and regulations of the NRC and INPO to allow to function. Today, the reactor design present incident is no longer used in all power plants. There have been further improvements in design to ensure safety and prevent further serious events. Ever since the incident has occurred, there has been no record of any further General Emergency response event. [21]

Three Mile Island (color)-2 Three Mile Island (color)-2.jpg
Three Mile Island (color)-2

Chernobyl Nuclear Power Plant accident

The Chernobyl (Ukraine) Nuclear Power Plant incident occurred on 26 April 1986. In this event, a steam explosion occurred due to a poorly designed reactor that was used during the time.  A fire was provoked, causing immediate emergency teams to be signified to rectify the issue. As a result, large quantities of radioactive material were released into the surrounding environment. Therefore, an eighteen-mile radius from the plant, which had approximately 115,000 residents, was required to be closed off and evacuated by government officials. [22]

The consequences of this event had led to the death of 28 nuclear power plant staff members, whereas another 106 had experienced severe illness as a result to radiation exposure. Although radiation did contaminate surrounding areas in very small amounts, it did not spread fast enough to affect members of the public. However, over time there has been a significant increase in cases of thyroid cancer in children due to the drinking of contaminated milk by the radioactive material. [23]

Due to the severity of the event and its consequence, the Nuclear Regulatory Commission (NRC) required immense planning in regulations to ensure the safety of both nuclear plant team members and the public. This includes improved nuclear reactor system designs (which is approved and reliably tested to enhance safety), emergency procedures and controls, as well as adequate back-up systems in case of a future event. [24] Since the event, nuclear engineers have regularly visited other Western nuclear power plants to obtain a better understanding on how to improve the integrity and design of power plants.[ citation needed ]

Fukushima

The Fukushima incident is classified as another General Emergency classification response. In March 2011, Japan experienced an earthquake with a magnitude of 9.0, as well as a 14-metre-high tsunami. [25] These natural disasters affected four nuclear plant sites in Fukushima (Japan) through major damage in many generators and backup systems. Although they were still functional after the events, systems began to fail as reactors began to overheat and therefore began to melt. As a result, radioactive material was exposed and released to much of the surrounding areas in Japan. This posed many health hazards for the public, which led to the evacuation responses of residents. [26]

The Nuclear Regulatory Commission had responsibility to take both short- and long-term actions to rectify and maintain the General Emergency event. The NRC immediately monitored the potential effects in places including Hawaii, Alaska and locations in the West of the United States because of the natural disasters in Japan. Furthermore, Japanese engineers received expertise advice from other United States agencies to help improve the overall design of the power plants that were utilised during the time. [27] In addition, other management and emergency response plans were designed and planned in case of a General Emergency event like the one that occurred in Fukushima again. Furthermore, NRC acted to examine whether their current nuclear power plants require improvement to enhance the safety of both workers as well as the public. Also, the quality of preparedness for future emergency events was examined. As of 2012, the requirements of future power plant reactors require them to cooperate additional emergency equipment (pumps and generators), installing equipment that continuously monitor water levels, and installing systems that monitors (and relieves) pressure in generators to prevent serious events in the future. [28]

Related Research Articles

<span class="mw-page-title-main">Nuclear fallout</span> Residual radioactive material following a nuclear blast

Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes. The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated. Fallout may get entrained with the products of a pyrocumulus cloud and fall as black rain. This radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron-activated by exposure, is a form of radioactive contamination.

<span class="mw-page-title-main">Three Mile Island accident</span> 1979 nuclear accident in Pennsylvania

The Three Mile Island accident was a partial nuclear meltdown of the Unit 2 reactor (TMI-2) of the Three Mile Island Nuclear Generating Station on the Susquehanna River in Londonderry Township, near Harrisburg, Pennsylvania. The reactor accident began at 4:00 a.m. on March 28, 1979, and released radioactive gases and radioactive iodine into the environment. It is the worst accident in U.S. commercial nuclear power plant history. On the seven-point logarithmic International Nuclear Event Scale, the TMI-2 reactor accident is rated Level 5, an "Accident with Wider Consequences".

<span class="mw-page-title-main">Nuclear meltdown</span> Reactor accident due to core overheating

A nuclear meltdown is a severe nuclear reactor accident that results in core damage from overheating. The term nuclear meltdown is not officially defined by the International Atomic Energy Agency or by the United States Nuclear Regulatory Commission. It has been defined to mean the accidental melting of the core of a nuclear reactor, however, and is in common usage a reference to the core's either complete or partial collapse.

<span class="mw-page-title-main">Nuclear Regulatory Commission</span> Government agency of the United States

The United States Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operations on January 19, 1975, as one of two successor agencies to the United States Atomic Energy Commission. Its functions include overseeing reactor safety and security, administering reactor licensing and renewal, licensing radioactive materials, radionuclide safety, and managing the storage, security, recycling, and disposal of spent fuel.

<span class="mw-page-title-main">Nuclear and radiation accidents and incidents</span> Severe disruptive events involving fissile or fusile materials

A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility." Examples include lethal effects to individuals, large radioactivity release to the environment, or a reactor core melt. The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant amounts of radioactive isotopes are released, such as in the Chernobyl disaster in 1986 and Fukushima nuclear disaster in 2011.

<span class="mw-page-title-main">International Nuclear Event Scale</span> Scale to enable communication of safety information in nuclear accidents

The International Nuclear and Radiological Event Scale (INES) was introduced in 1990 by the International Atomic Energy Agency (IAEA) in order to enable prompt communication of safety significant information in case of nuclear accidents.

<span class="mw-page-title-main">Three Mile Island Nuclear Generating Station</span> Closed nuclear power plant in Pennsylvania, United States

Three Mile Island Nuclear Generating Station is a closed nuclear power plant on Three Mile Island in Pennsylvania on the Susquehanna River just south of Harrisburg. It has two separate units, TMI-1 and TMI-2.

<span class="mw-page-title-main">Containment building</span> Structure surrounding a nuclear reactor to prevent radioactive releases

A containment building is a reinforced steel, concrete or lead structure enclosing a nuclear reactor. It is designed, in any emergency, to contain the escape of radioactive steam or gas to a maximum pressure in the range of 275 to 550 kPa. The containment is the fourth and final barrier to radioactive release, the first being the fuel ceramic itself, the second being the metal fuel cladding tubes, the third being the reactor vessel and coolant system.

<span class="mw-page-title-main">Nuclear safety and security</span> Regulations for uses of radioactive materials

Nuclear safety is defined by the International Atomic Energy Agency (IAEA) as "The achievement of proper operating conditions, prevention of accidents or mitigation of accident consequences, resulting in protection of workers, the public and the environment from undue radiation hazards". The IAEA defines nuclear security as "The prevention and detection of and response to, theft, sabotage, unauthorized access, illegal transfer or other malicious acts involving nuclear materials, other radioactive substances or their associated facilities".

<span class="mw-page-title-main">Comparison of Chernobyl and other radioactivity releases</span>

This article compares the radioactivity release and decay from the Chernobyl disaster with various other events which involved a release of uncontrolled radioactivity.

<span class="mw-page-title-main">Nuclear safety in the United States</span> US safety regulations for nuclear power and weapons

Nuclear safety in the United States is governed by federal regulations issued by the Nuclear Regulatory Commission (NRC). The NRC regulates all nuclear plants and materials in the United States except for nuclear plants and materials controlled by the U.S. government, as well those powering naval vessels.

<span class="mw-page-title-main">Fukushima Daiichi Nuclear Power Plant</span> Disabled nuclear power plant in Japan

The Fukushima Daiichi Nuclear Power Plant is a disabled nuclear power plant located on a 3.5-square-kilometre (860-acre) site in the towns of Ōkuma and Futaba in Fukushima Prefecture, Japan. The plant suffered major damage from the magnitude 9.1 earthquake and tsunami that hit Japan on March 11, 2011. The chain of events caused radiation leaks and permanently damaged several of its reactors, making them impossible to restart. The working reactors were not restarted after the events.

A design-basis event (DBE) is a postulated event used to establish the acceptable performance requirements of the structures, systems, and components, such that a nuclear power plant can withstand the event and not endanger the health or safety of the plant operators or the wider public. Similar terms are design-basis accident (DBA) and maximum credible accident.

<span class="mw-page-title-main">Lists of nuclear disasters and radioactive incidents</span>

These are lists of nuclear disasters and radioactive incidents.

<span class="mw-page-title-main">Nuclear reactor accidents in the United States</span> Nuclear Reactor and Power Plant Accidents that have occurred in the past years

The United States Government Accountability Office reported more than 150 incidents from 2001 to 2006 of nuclear plants not performing within acceptable safety guidelines. According to a 2010 survey of energy accidents, there have been at least 56 accidents at nuclear reactors in the United States. The most serious of these was the Three Mile Island accident in 1979. Davis-Besse Nuclear Power Plant has been the source of two of the top five most dangerous nuclear incidents in the United States since 1979. Relatively few accidents have involved fatalities.

<span class="mw-page-title-main">Fukushima nuclear accident casualties</span> Possible casualties and related deaths caused by the Fukushima nuclear disaster

The Fukushima Daiichi nuclear accident genshiryoku hatsudensho jiko) was a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima I Nuclear Power Plant, following the Tōhoku earthquake and tsunami on 11 March 2011. It was the largest nuclear disaster since the Chernobyl disaster of 1986, and the radiation released exceeded official safety guidelines. Despite this, there were no deaths caused by acute radiation syndrome. Given the uncertain health effects of low-dose radiation, cancer deaths cannot be ruled out. However, studies by the World Health Organization and Tokyo University have shown that no discernible increase in the rate of cancer deaths is expected. Predicted future cancer deaths due to accumulated radiation exposures in the population living near Fukushima have ranged in the academic literature from none to hundreds.

<span class="mw-page-title-main">Investigations into the Fukushima nuclear accident</span>

Investigations into the Fukushima Daiichi Nuclear Disaster (or Accident) began on 11 March 2011 when a series of equipment failures, core melt and down, and releases of radioactive materials occurred at the Fukushima Daiichi Nuclear Power Station from the 2011 off the Pacific coast of Tohoku Earthquake and tsunami on the same day.

<span class="mw-page-title-main">Accident rating of the Fukushima nuclear accident</span> INES rating of the Fukushima nuclear disaster

The Fukushima Daiichi nuclear disaster genshiryoku hatsudensho jiko) was a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima I Nuclear Power Plant, following the Tōhoku earthquake and tsunami on 11 March 2011. It is the largest nuclear disaster since the Chernobyl disaster of 1986.

References

  1. ↑ "Emergency Preparedness At Nuclear Plants". NEI.
  2. ↑ "Nuclear Power Plants Emergency Classification Levels". www.floridadisaster.org. Retrieved 15 May 2019.
  3. ↑ "Emergency Preparedness at Nuclear Plants".
  4. ↑ "Nuclear Emergency Classification Levels". gohsep.la.gov. Retrieved 15 May 2019.
  5. ↑ "Nuclear Power Plants Emergency Classification Levels". www.floridadisaster.org. Retrieved 15 May 2019.
  6. ↑ "Methodology for Development of Emergency Action Levels" (PDF). Nuclear Energy Institute: Page. February 2008.
  7. ↑ "Draft Emergency Action Level Guidelines for Nuclear Power Plants" (PDF). U.S Nuclear Regulatory Commission: 3. September 1979.
  8. ↑ "Nuclear Power Plants Emergency Classification Levels".
  9. ↑ "Nuclear Power Plants Emergency Classification Levels".
  10. ↑ "Draft Emergency Action Level Guidelines for Nuclear Power Plants". U.S Nuclear Regulatory Commission.
  11. ↑ "Nuclear Emergency Classification Levels".
  12. ↑ "Methodology for Development of Emergency Action Levels" (PDF). NRC.
  13. ↑ "Draft Emergency Action Level Guidelines for Nuclear Power Plants" (PDF). U.S Nuclear Regulatory Commission.
  14. ↑ "Emergency Preparedness Classification".
  15. ↑ "Draft Emergency Action Level Guidelines for Nuclear Power Plants" (PDF). U.S Nuclear Regulatory Commission.
  16. ↑ "NRC: Backgrounder on the Three Mile Island Accident". www.nrc.gov. Retrieved 7 June 2019.
  17. ↑ "Three Mile Island | TMI 2 |Three Mile Island Accident. - World Nuclear Association". www.world-nuclear.org. Retrieved 7 June 2019.
  18. ↑ "Three Mile Island | TMI 2 |Three Mile Island Accident. - World Nuclear Association". www.world-nuclear.org. Retrieved 7 June 2019.
  19. ↑ "Three Mile Island: Nuclear Accident in History". Report to the Congress of the United States.
  20. ↑ "Backgrounder on the Three Mile Island Accident".
  21. ↑ "Three Mile Island | TMI 2 |Three Mile Island Accident. - World Nuclear Association". www.world-nuclear.org. Retrieved 7 June 2019.
  22. ↑ "NRC: Backgrounder on Chernobyl Nuclear Power Plant Accident". www.nrc.gov. Retrieved 7 June 2019.
  23. ↑ "NRC: Backgrounder on Chernobyl Nuclear Power Plant Accident". www.nrc.gov. Retrieved 7 June 2019.
  24. ↑ "Chernobyl | Chernobyl Accident | Chernobyl Disaster - World Nuclear Association". www.world-nuclear.org. Retrieved 7 June 2019.
  25. ↑ "NRC: Backgrounder on NRC Response to Lessons Learned from Fukushima". www.nrc.gov. Retrieved 7 June 2019.
  26. ↑ "Assessment of the Impact on Australia from the Fukushima Dai-Ichi Nuclear Power Plant Incident" (PDF). Australian Radiation Protection and Nuclear Safety Agency.
  27. ↑ "Fukushima Daiichi Accident - World Nuclear Association". www.world-nuclear.org. Retrieved 7 June 2019.
  28. ↑ "Fukushima Daiichi Accident - World Nuclear Association". www.world-nuclear.org. Retrieved 7 June 2019.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.