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'''Nuclear safety''' covers the actions taken to prevent [[nuclear and radiation accidents]] or to limit their consequences. This covers [[nuclear power plants]] as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, power, industry, and military uses.
'''Nuclear safety''' covers the actions taken to prevent [[nuclear and radiation accidents]] or to limit their consequences. This covers [[nuclear power plants]] as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, power, industry, and military uses.


The nuclear power industry has improved the safety and performance of reactors, and has proposed new safer (but generally untested) reactor designs but there is no guarantee that the reactors will be designed, built and operated correctly.<ref name=globen/> Mistakes do occur and the designers of reactors at [[Timeline of the Fukushima nuclear accidents|Fukushima]] in Japan did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake.<ref>{{cite web |url=http://www.thebulletin.org/web-edition/columnists/hugh-gusterson/the-lessons-of-fukushima |title=The lessons of Fukushima |author=Hugh Gusterson |date=16 March 2011 |work=Bulletin of the Atomic Scientists }}</ref> According to [[UBS]] AG, the [[Fukushima I nuclear accidents]] have cast doubt on whether even an advanced economy like Japan can master nuclear safety.<ref>{{cite web |url=http://www.businessweek.com/news/2011-04-04/fukushima-crisis-worse-for-atomic-power-than-chernobyl-ubs-says.html |title=Fukushima Crisis Worse for Atomic Power Than Chernobyl, UBS Says |author=James Paton |date=April 4, 2011 |work=Bloomberg Businessweek }}</ref> Catastrophic scenarios involving terrorist attacks are also conceivable.<ref name=globen>{{cite web |url=http://www.stanford.edu/group/efmh/jacobson/Articles/I/WWSEnergyPolicyPtI.pdf |title=Providing all Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials |author=Jacobson, Mark Z. and Delucchi, Mark A. |date=2010 |work=Energy Policy |page=6 }}</ref>
The nuclear power industry has improved the safety and performance of reactors, and has proposed new safer (but generally untested) reactor designs but there is no guarantee that the reactors will be designed, built and operated correctly.<ref name=globen/> Mistakes do occur and the designers of reactors at [[Timeline of the Fukushima nuclear accidents|Fukushima]] in Japan did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake.<ref>{{cite web |url=http://www.thebulletin.org/web-edition/columnists/hugh-gusterson/the-lessons-of-fukushima |title=The lessons of Fukushima |author=Hugh Gusterson |date=16 March 2011 |work=Bulletin of the Atomic Scientists }}</ref> According to [[UBS]] AG, the [[Fukushima I nuclear accidents]] have cast doubt on whether even an advanced economy like Japan can master nuclear safety.<ref>{{cite web |url=http://www.businessweek.com/news/2011-04-04/fukushima-crisis-worse-for-atomic-power-than-chernobyl-ubs-says.html |title=Fukushima Crisis Worse for Atomic Power Than Chernobyl, UBS Says |author=James Paton |date=April 4, 2011 |work=Bloomberg Businessweek }}</ref> Catastrophic scenarios involving terrorist attacks are also conceivable.<ref name=globen>{{cite web |url=http://www.stanford.edu/group/efmh/jacobson/Articles/I/WWSEnergyPolicyPtI.pdf |title=Providing all Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials |author=Jacobson, Mark Z. and Delucchi, Mark A. |date=2010 |work=Energy Policy |page=6 }}</ref> An interdisciplinary team from MIT have estimated that given the expected growth of nuclear power from 2005 – 2055, at least four serious nuclear accidents would be expected in that period.<ref>{{cite web |url=http://www.spp.nus.edu.sg/docs/policy-briefs/201101_RSU_PolicyBrief_1-2nd_Thought_Nuclear-Sovacool.pdf |title=Second Thoughts About Nuclear Power |author=Benjamin K. Sovacool |date=January 2011 |publisher=National University of Singapore |page=8}}</ref><ref>{{cite web |url=http://web.mit.edu/nuclearpower/pdf/nuclearpower-full.pdf |title=The Future of Nuclear Power |author=Massachusetts Institute of Technology |date=2003 |work= |page=48 }}</ref>


[[Nuclear weapon]] safety, as well as the safety of military research involving nuclear materials, is generally handled by agencies different from those that oversee civilian safety, for various reasons, including secrecy.
[[Nuclear weapon]] safety, as well as the safety of military research involving nuclear materials, is generally handled by agencies different from those that oversee civilian safety, for various reasons, including secrecy.

Revision as of 21:14, 29 April 2011

Nuclear safety covers the actions taken to prevent nuclear and radiation accidents or to limit their consequences. This covers nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, power, industry, and military uses.

The nuclear power industry has improved the safety and performance of reactors, and has proposed new safer (but generally untested) reactor designs but there is no guarantee that the reactors will be designed, built and operated correctly.[1] Mistakes do occur and the designers of reactors at Fukushima in Japan did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake.[2] According to UBS AG, the Fukushima I nuclear accidents have cast doubt on whether even an advanced economy like Japan can master nuclear safety.[3] Catastrophic scenarios involving terrorist attacks are also conceivable.[1] An interdisciplinary team from MIT have estimated that given the expected growth of nuclear power from 2005 – 2055, at least four serious nuclear accidents would be expected in that period.[4][5]

Nuclear weapon safety, as well as the safety of military research involving nuclear materials, is generally handled by agencies different from those that oversee civilian safety, for various reasons, including secrecy.

Agencies

File:Iaea-vienna.JPG
IAEA headquarters in Vienna, Austria

Internationally the International Atomic Energy Agency "works with its Member States and multiple partners worldwide to promote safe, secure and peaceful nuclear technologies."[6] Some scientists say that the 2011 Japanese nuclear accidents have revealed that the nuclear industry lacks sufficient oversight, leading to renewed calls to redefine the mandate of the IAEA so that it can better police nuclear power plants worldwide.[7] There are several problems with the IAEA says Najmedin Meshkati of University of Southern California:

It recommends safety standards, but member states are not required to comply; it promotes nuclear energy, but it also monitors nuclear use; it is the sole global organization overseeing the nuclear energy industry, yet it is also weighed down by checking compliance with the Nuclear Non-Proliferation Treaty (NPT).[7]

Many nations utilizing nuclear power have special institutions overseeing and regulating nuclear safety. Civilian nuclear safety in the U.S. is regulated by the Nuclear Regulatory Commission (NRC). The safety of nuclear plants and materials controlled by the U.S. government for research, weapons production, and those powering naval vessels is not governed by the NRC.[8][9] In the UK nuclear safety is regulated by the Office for Nuclear Regulation (ONR) and the Defence Nuclear Safety Regulator (DNSR). The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is the Federal Government body that monitors and identifies solar radiation and nuclear radiation risks in Australia. It is the main body dealing with ionizing and non-ionizing radiation[10] and publishes material regarding radiation protection.[11]

Other agencies include:

Nuclear power plant

Main article: Nuclear power plant

Nuclear safety covers the actions taken to prevent nuclear and radiation accidents or to limit their consequences. This covers nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, power, industry, and military uses.

The nuclear power industry has improved the safety and performance of reactors, and has proposed new safer (but generally untested) reactor designs but there is no guarantee that the reactors will be designed, built and operated correctly.[1] Mistakes do occur and the designers of reactors at Fukushima in Japan did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake.[12] According to UBS AG, the Fukushima I nuclear accidents have cast doubt on whether even an advanced economy like Japan can master nuclear safety.[13] Catastrophic scenarios involving terrorist attacks are also conceivable.[1] An interdisciplinary team from MIT have estimated that given the expected growth of nuclear power from 2005 – 2055, at least four serious nuclear accidents would be expected in that period.[14][15]

Nuclear weapon safety, as well as the safety of military research involving nuclear materials, is generally handled by agencies different from those that oversee civilian safety, for various reasons, including secrecy.

Agencies

File:Iaea-vienna.JPG
IAEA headquarters in Vienna, Austria

Internationally the International Atomic Energy Agency "works with its Member States and multiple partners worldwide to promote safe, secure and peaceful nuclear technologies."[16] Some scientists say that the 2011 Japanese nuclear accidents have revealed that the nuclear industry lacks sufficient oversight, leading to renewed calls to redefine the mandate of the IAEA so that it can better police nuclear power plants worldwide.[7] There are several problems with the IAEA says Najmedin Meshkati of University of Southern California:

It recommends safety standards, but member states are not required to comply; it promotes nuclear energy, but it also monitors nuclear use; it is the sole global organization overseeing the nuclear energy industry, yet it is also weighed down by checking compliance with the Nuclear Non-Proliferation Treaty (NPT).[7]

Many nations utilizing nuclear power have special institutions overseeing and regulating nuclear safety. Civilian nuclear safety in the U.S. is regulated by the Nuclear Regulatory Commission (NRC). The safety of nuclear plants and materials controlled by the U.S. government for research, weapons production, and those powering naval vessels is not governed by the NRC.[17][18] In the UK nuclear safety is regulated by the Office for Nuclear Regulation (ONR) and the Defence Nuclear Safety Regulator (DNSR). The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is the Federal Government body that monitors and identifies solar radiation and nuclear radiation risks in Australia. It is the main body dealing with ionizing and non-ionizing radiation[19] and publishes material regarding radiation protection.[20]

Other agencies include:

Nuclear power plant

Main article: Nuclear power plant

Template loop detected: Template:Nuclear power plant safety

Hazards of nuclear material

Nuclear material may be hazardous if not properly handled or disposed of. Experiments of near critical mass-sized pieces of nuclear material can pose a risk of a criticality accident. David Hahn, "The Radioactive Boy Scout" who tried to build a nuclear reactor at home, serves as an excellent example of a nuclear experimenter who failed to develop or follow proper safety protocols. Such failures raise the specter of radioactive contamination.

Even when properly contained, fission byproducts which are no longer useful generate radioactive waste, which must be properly disposed of. Spent nuclear fuel that is recently removed from a nuclear reactor will generate large amounts of decay heat which will require pumped water cooling for a year or more to prevent overheating. In addition, material exposed to neutron radiation—present in nuclear reactors—may become radioactive in its own right, or become contaminated with nuclear waste. Additionally, toxic or dangerous chemicals may be used as part of the plant's operation, which must be properly handled and disposed of.

New nuclear technologies

The next nuclear plants to be built will likely be Generation III or III+ designs, and a few such are already in operation in Japan. Generation IV reactors would have even greater improvements in safety. These new designs are expected to be passively safe or nearly so, and perhaps even inherently safe (as in the PBMR designs).

Some improvements made (not all in all designs) are having three sets of emergency diesel generators and associated emergency core cooling systems rather than just one pair, having quench tanks (large coolant-filled tanks) above the core that open into it automatically, having a double containment (one containment building inside another), etc.

However, safety risks may be the greatest when nuclear systems are the newest, and operators have less experience with them. Nuclear engineer David Lochbaum explained that almost all serious nuclear accidents occurred with what was at the time the most recent technology. He argues that "the problem with new reactors and accidents is twofold: scenarios arise that are impossible to plan for in simulations; and humans make mistakes".[21] As one director of a U.S. research laboratory put it, "fabrication, construction, operation, and maintenance of new reactors will face a steep learning curve: advanced technologies will have a heightened risk of accidents and mistakes. The technology may be proven, but people are not".[21]

Safety culture and human errors

One relatively prevalent notion in discussions of nuclear safety is that of safety culture. The International Nuclear Safety Advisory Group, defines the term as “the personal dedication and accountability of all individuals engaged in any activity which has a bearing on the safety of nuclear power plants”.[22] The goal is “to design systems that use human capabilities in appropriate ways, that protect systems from human frailties, and that protect humans from hazards associated with the system”.[22]

At the same time, there is some evidence that operational practices are not easy to change. Operators almost never follow instructions and written procedures exactly, and “the violation of rules appears to be quite rational, given the actual workload and timing constraints under which the operators must do their job”. Many attempts to improve nuclear safety culture “were compensated by people adapting to the change in an unpredicted way”.[22]

An assessment conducted by the Commissariat à l’Énergie Atomique (CEA) in France concluded that no amount of technical innovation can eliminate the risk of human-induced errors associated with the operation of nuclear power plants. Two types of mistakes were deemed most serious: errors committed during field operations, such as maintenance and testing, that can cause an accident; and human errors made during small accidents that cascade to complete failure.[21]

According to Mycle Schneider, reactor safety depends above all on a 'culture of security', including the quality of maintenance and training, the competence of the operator and the workforce, and the rigour of regulatory oversight. So a better-designed, newer reactor is not always a safer one, and older reactors are not necessarily more dangerous than newer ones. The 1978 Three Mile Island accident in the United States occurred in a reactor that had started operation only three months earlier, and the Chernobyl disaster occurred after only two years of operation. A serious loss of coolant occurred at the French Civaux-1 reactor in 1998, less than five months after start-up.[23]

However safe a plant is designed to be, it is operated by humans who are prone to errors. Laurent Stricker, a nuclear engineer and chairman of the World Association of Nuclear Operators says that operators must guard against complacency and avoid overconfidence. Experts say that the "largest single internal factor determining the safety of a plant is the culture of security among regulators, operators and the workforce — and creating such a culture is not easy".[23]

Risk assessment

Population density is one critical lens through which other risks have to be assessed, says Laurent Stricker, a nuclear engineer and chairman of the World Association of Nuclear Operators:[23]

The KANUPP plant in Karachi, Pakistan, has the most people — 8.2 million — living within 30 kilometres of a nuclear plant, although it has just one relatively small reactor with an output of 125 megawatts. Next in the league, however, are much larger plants — Taiwan's 1,933-megawatt Kuosheng plant with 5.5 million people within a 30-kilometre radius and the 1,208-megawatt Chin Shan plant with 4.7 million; both zones include the capital city of Taipei.[23]

The AP1000 has a maximum core damage frequency of 5.09 x 10−7 per plant per year. The Evolutionary Power Reactor (EPR) has a maximum core damage frequency of 4 x 10−7 per plant per year. General Electric has recalculated maximum core damage frequencies per year per plant for its nuclear power plant designs:[25]

BWR/4 -- 1 x 10-5
BWR/6 -- 1 x 10-6
ABWR -- 2 x 10-7
ESBWR -- 3 x 10-8

Beyond design basis events

As Fukushima showed, external threats — such as earthquakes, tsunamis, fires, flooding, tornadoes and terrorist attacks — are some of the greatest risk factors for a serious nuclear accident. Yet, nuclear plant operators have normally considered these accident sequences (called 'beyond design basis' events) so unlikely that they have not built in complete safeguards.[23]

Forecasting the location of the next earthquake or the size of the next tsunami is an imperfect art. Nuclear plants situated outside known geological danger zones "could pose greater accident threats in the event of an earthquake than those inside, as the former could have weaker protection built in".[23] The Fukushima I plant, for example, was "located in an area designated, on Japan's seismic risk map, as having a relatively low chance of a large earthquake and tsunami; when the 2011 tsunami arrived, it was in excess of anything its engineers had planned for".[23]

Morality

Historically many scientists and engineers have made decisions on behalf of potentially affected populations about whether a particular level of risk and uncertainty is acceptable for them. Many nuclear engineers and scientists that have made such decisions, even for good reasons relating to long term energy availability, now consider that doing so without informed consent is wrong, and that nuclear power safety and nuclear technologies should be based fundamentally on morality, rather than purely on technical, economic and business considerations.[26]

According to Stephanie Cooke, it is difficult to know what really goes on inside nuclear power plants because the industry is shrouded in secrecy. Corporations and governments control what information is made available to the public. Cooke says "when information is made available, it is often couched in jargon and incomprehensible prose".[27]

Kennette Benedict has said that nuclear technology and plant operations continue to lack transparency and to be relatively closed to public view:[28]

Despite victories like the creation of the Atomic Energy Commission, and later the Nuclear Regular Commission, the secrecy that began with the Manhattan Project has tended to permeate the civilian nuclear program, as well as the military and defense programs.[28]

Nuclear and radiation accidents

2011 Fukushima I accidents

See also: Fukushima I nuclear accidents and Timeline of the Fukushima nuclear accidents

The 40-year-old Fukushima I Nuclear Power Plant, built in the 1970s, endured Japan's worst earthquake on record in March 2011 but had its power and back-up generators knocked out by a 7-meter tsunami that followed.[29] The designers of the reactors at Fukushima did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake. Nuclear reactors are such "inherently complex, tightly coupled systems that, in rare, emergency situations, cascading interactions will unfold very rapidly in such a way that human operators will be unable to predict and master them".[30]

Lacking electricity to pump water needed to cool the atomic core, engineers vented radioactive steam into the atmosphere to release pressure, leading to a series of explosions that blew out concrete walls around the reactors. Radiation readings spiked around Fukushima as the disaster widened, forcing the evacuation of 200,000 people and causing radiation levels to rise on the outskirts of Tokyo, 135 miles (210 kilometers) to the south, with a population of 30 million.[29]

Back-up diesel generators that might have averted the disaster were positioned in a basement, where they were overwhelmed by waves. The cascade of events at Fukushima had been foretold in a report published in the U.S. several decades ago:[29]

The 1990 report by the U.S. Nuclear Regulatory Commission, an independent agency responsible for safety at the country’s power plants, identified earthquake-induced diesel generator failure and power outage leading to failure of cooling systems as one of the “most likely causes” of nuclear accidents from an external event.[29]

While the report was cited in a 2004 statement by Japan’s Nuclear and Industrial Safety Agency, it seems adequate measures to address the risk were not taken by Tokyo Electric. Katsuhiko Ishibashi, a seismology professor at Kobe University, has said that Japan’s history of nuclear accidents stems from an overconfidence in plant engineering. In 2006, he resigned from a government panel on nuclear reactor safety, because the review process was rigged and “unscientific”.[29]

Louise Fréchette and Trevor Findlay have said that more effort is needed to ensure nuclear safety and improve responses to accidents:

The multiple reactor crises at Japan's Fukushima nuclear power plant reinforce the need for strengthening global instruments to ensure nuclear safety worldwide. The fact that a country that has been operating nuclear power reactors for decades should prove so alarmingly improvisational in its response and so unwilling to reveal the facts even to its own people, much less the International Atomic Energy Agency, is a reminder that nuclear safety is a constant work-in-progress. [31]

David Lochbaum, chief nuclear safety officer with the Union of Concerned Scientists, has repeatedly questioned the safety of the Fukushima I Plant's General Electric Mark 1 reactor design, which is used in almost a quarter of the United States' nuclear fleet.[32]

Following the Fukushima emergency, the European Union decided that reactors across all 27 member nations should undergo safety tests.[33]

According to UBS AG, the Fukushima I nuclear accidents are likely to hurt the nuclear power industry’s credibility more than the Chernobyl disaster in 1986:

The accident in the former Soviet Union 25 years ago 'affected one reactor in a totalitarian state with no safety culture,' UBS analysts including Per Lekander and Stephen Oldfield wrote in a report today. 'At Fukushima, four reactors have been out of control for weeks -- casting doubt on whether even an advanced economy can master nuclear safety.'[34]

According to Areva's Southeast Asia and Oceania director, Selena Ng, Japan's Fukushima I nuclear accidents are "a huge wake-up call for a nuclear industry that hasn't always been sufficiently transparent about safety issues". She said "There was a sort of complacency before Fukushima and I don't think we can afford to have that complacency now".[35]

1986 Chernobyl disaster

Main articles: Chernobyl disaster and Chernobyl disaster effects

As radioactive materials decay, they release particles that can damage the body and lead to cancer, particularly cesium-137 and iodine-131. In the 1986 nuclear accident at Chernobyl, releases of cesium-137 contaminated land. Some communities were abandoned permanently. Thousands of people who drank milk contaminated with radioactive iodine developed thyroid cancer.[36]

Other accidents

See also: List of civilian nuclear accidents, List of civilian radiation accidents, and List of military nuclear accidents

Serious nuclear and radiation accidents include the Chalk River accidents (1952, 1958 & 2008), Mayak disaster (1957), Windscale fire (1957), SL-1 accident (1961), Soviet submarine K-19 accident (1961), Three Mile Island accident (1979), Church Rock uranium mill spill (1979), Soviet submarine K-431 accident (1985), Goiânia accident (1987), Zaragoza radiotherapy accident (1990), Costa Rica radiotherapy accident (1996), Tokaimura nuclear accident (1999), Sellafield THORP leak (2005), and the Flerus IRE Cobalt-60 spill (2006).[37][38]

Health impacts

See also: Chernobyl disaster effects and Nuclear power debate

In spite of accidents like Chernobyl, studies have shown that nuclear deaths are mostly in uranium mining and that nuclear energy has generated far fewer deaths than the high pollution levels that result from the use of conventional fossil fuels.[39]

Stephanie Cooke says that it is not useful to make comparisons just in terms of number of deaths, as the way people live afterwards is also relevant, as in the case of the 2011 Japanese nuclear accidents:[40]

You have people in Japan right now that are facing either not returning to their homes forever, or if they do return to their homes, living in a contaminated area for basically ever. And knowing that whatever food they eat, it might be contaminated and always living with this sort of shadow of fear over them that they will die early because of cancer and induced by Caesium or Strontium or some other radionuclide that's laced their vegetables. It affects millions of people, it affects our land, it affects our atmosphere, we know now the radio nuclides from Fukushima are going into the sea. It doesn't just kill now, it kills later, and it could kill centuries later. Because the stuff that that's depositing, doesn't just end, it has a long, long life. It's affecting future generations, it's not just affecting this generation. So I'm not a great fan of coal-burning. I don't think any of these great big massive plants that spew pollution into the air are good. But I don't think it's really helpful to make these comparisons just in terms of number of deaths.[40]

Developing countries

There are concerns about developing countries "rushing to join the so-called nuclear renaissance without the necessary infrastructure, personnel, regulatory frameworks and safety culture".[41] Some countries with nuclear aspirations, like Nigeria, Kenya, Bangladesh and Venezuela, have no significant industrial experience and will require at least a decade of preparation even before breaking ground at a reactor site.[41]

The speed of the nuclear construction program in China has raised safety concerns. The challenge for the government and nuclear companies is to "keep an eye on a growing army of contractors and subcontractors who may be tempted to cut corners".[42] China is advised to maintain nuclear safeguards in a business culture where quality and safety are sometimes sacrificed in favor of cost-cutting, profits, and corruption. China has asked for international assistance in training more nuclear power plant inspectors.[42]

See also

References

  1. ^ a b c d Jacobson, Mark Z. and Delucchi, Mark A. (2010). "Providing all Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials" (PDF). Energy Policy. p. 6.{{cite web}}: CS1 maint: multiple names: authors list (link)
  2. ^ Hugh Gusterson (16 March 2011). "The lessons of Fukushima". Bulletin of the Atomic Scientists.
  3. ^ James Paton (April 4, 2011). "Fukushima Crisis Worse for Atomic Power Than Chernobyl, UBS Says". Bloomberg Businessweek.
  4. ^ Benjamin K. Sovacool (January 2011). "Second Thoughts About Nuclear Power" (PDF). National University of Singapore. p. 8.
  5. ^ Massachusetts Institute of Technology (2003). "The Future of Nuclear Power" (PDF). p. 48.
  6. ^ Vienna International Centre (March 30, 2011). "About IAEA: The "Atoms for Peace" Agency". iaea.org.
  7. ^ a b c d By Stephen Kurczy (March 17, 2011). "Japan nuclear crisis sparks calls for IAEA reform". CSMonitor.com.
  8. ^ About NRC, U.S. Nuclear Regulatory Commission, Retrieved 2007-6-1
  9. ^ Our Governing Legislation, U.S. Nuclear Regulatory Commission, Retrieved 2007-6-1
  10. ^ Health and Safety www.australia.gov.au
  11. ^ Radiation Protection www.arpansa.gov.au
  12. ^ Hugh Gusterson (16 March 2011). "The lessons of Fukushima". Bulletin of the Atomic Scientists.
  13. ^ James Paton (April 4, 2011). "Fukushima Crisis Worse for Atomic Power Than Chernobyl, UBS Says". Bloomberg Businessweek.
  14. ^ Benjamin K. Sovacool (January 2011). "Second Thoughts About Nuclear Power" (PDF). National University of Singapore. p. 8.
  15. ^ Massachusetts Institute of Technology (2003). "The Future of Nuclear Power" (PDF). p. 48.
  16. ^ Vienna International Centre (March 30, 2011). "About IAEA: The "Atoms for Peace" Agency". iaea.org.
  17. ^ About NRC, U.S. Nuclear Regulatory Commission, Retrieved 2007-6-1
  18. ^ Our Governing Legislation, U.S. Nuclear Regulatory Commission, Retrieved 2007-6-1
  19. ^ Health and Safety www.australia.gov.au
  20. ^ Radiation Protection www.arpansa.gov.au
  21. ^ a b c Benjamin K. Sovacool. A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia, Journal of Contemporary Asia, Vol. 40, No. 3, August 2010, p. 381.
  22. ^ a b c M.V. Ramana. Nuclear Power: Economic, Safety, Health, and Environmental Issues of Near-Term Technologies, Annual Review of Environment and Resources, 2009. 34, pp.139-140.
  23. ^ a b c d e f g Declan Butler (21 April 2011). "Reactors, residents and risk". Nature.
  24. ^ Severe Accidents in the Energy Sector (see pages 287,310,317)
  25. ^ Next-generation nuclear energy: The ESBWR
  26. ^ Pandora's box, A is for Atom- Adam Curtis
  27. ^ Stephanie Cooke (March 19, 2011). "Nuclear power is on trial". CNN.com.
  28. ^ a b Kennette Benedict (26 March 2011). "The road not taken: Can Fukushima put us on a path toward nuclear transparency?". Bulletin of the Atomic Scientists. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  29. ^ a b c d e Jason Clenfield (March 17, 2011). "Japan Nuclear Disaster Caps Decades of Faked Reports, Accidents". Bloomberg Businessweek.
  30. ^ Hugh Gusterson (16 March 2011). "The lessons of Fukushima". Bulletin of the Atomic Scientists.
  31. ^ Louise Fréchette and Trevor Findlay (March 28, 2011). "Nuclear safety is the world's problem". Ottawa Citizen.
  32. ^ Hannah Northey (March 28, 2011). "Japanese Nuclear Reactors, U.S. Safety to Take Center Stage on Capitol Hill This Week". New York Times.
  33. ^ James Kanter (March 25, 2011). "Europe to Test Safety of Nuclear Reactors". New York Times.
  34. ^ James Paton (April 04, 2011). "Fukushima Crisis Worse for Atomic Power Than Chernobyl, UBS Says". Bloomberg Businessweek. {{cite web}}: Check date values in: |date= (help)
  35. ^ David Fickling (April 20, 2011). "Areva Says Fukushima A Huge Wake-Up Call For Nuclear Industry". Fox Business.
  36. ^ Renee Schoof (April 12, 2011). "Japan's nuclear crisis comes home as fuel risks get fresh look". McClatchy.
  37. ^ Newtan, Samuel Upton (2007). Nuclear War 1 and Other Major Nuclear Disasters of the 20th Century, AuthorHouse.
  38. ^ The Worst Nuclear Disasters
  39. ^ [1]
  40. ^ a b Annabelle Quince (30 March 2011). "The history of nuclear power". ABC Radio National.
  41. ^ a b Louise Fréchette and Trevor Findlay (March 28, 2011). "Nuclear safety is the world's problem". Ottawa Citizen.
  42. ^ a b Keith Bradsher (December 15, 2009). "Nuclear Power Expansion in China Stirs Concerns". New York Times. Retrieved 2010-01-21.

Hazards of nuclear material

Nuclear material may be hazardous if not properly handled or disposed of. Experiments of near critical mass-sized pieces of nuclear material can pose a risk of a criticality accident. David Hahn, "The Radioactive Boy Scout" who tried to build a nuclear reactor at home, serves as an excellent example of a nuclear experimenter who failed to develop or follow proper safety protocols. Such failures raise the specter of radioactive contamination.

Even when properly contained, fission byproducts which are no longer useful generate radioactive waste, which must be properly disposed of. Spent nuclear fuel that is recently removed from a nuclear reactor will generate large amounts of decay heat which will require pumped water cooling for a year or more to prevent overheating. In addition, material exposed to neutron radiation—present in nuclear reactors—may become radioactive in its own right, or become contaminated with nuclear waste. Additionally, toxic or dangerous chemicals may be used as part of the plant's operation, which must be properly handled and disposed of.

New nuclear technologies

The next nuclear plants to be built will likely be Generation III or III+ designs, and a few such are already in operation in Japan. Generation IV reactors would have even greater improvements in safety. These new designs are expected to be passively safe or nearly so, and perhaps even inherently safe (as in the PBMR designs).

Some improvements made (not all in all designs) are having three sets of emergency diesel generators and associated emergency core cooling systems rather than just one pair, having quench tanks (large coolant-filled tanks) above the core that open into it automatically, having a double containment (one containment building inside another), etc.

However, safety risks may be the greatest when nuclear systems are the newest, and operators have less experience with them. Nuclear engineer David Lochbaum explained that almost all serious nuclear accidents occurred with what was at the time the most recent technology. He argues that "the problem with new reactors and accidents is twofold: scenarios arise that are impossible to plan for in simulations; and humans make mistakes".[1] As one director of a U.S. research laboratory put it, "fabrication, construction, operation, and maintenance of new reactors will face a steep learning curve: advanced technologies will have a heightened risk of accidents and mistakes. The technology may be proven, but people are not".[1]

Safety culture and human errors

One relatively prevalent notion in discussions of nuclear safety is that of safety culture. The International Nuclear Safety Advisory Group, defines the term as “the personal dedication and accountability of all individuals engaged in any activity which has a bearing on the safety of nuclear power plants”.[2] The goal is “to design systems that use human capabilities in appropriate ways, that protect systems from human frailties, and that protect humans from hazards associated with the system”.[2]

At the same time, there is some evidence that operational practices are not easy to change. Operators almost never follow instructions and written procedures exactly, and “the violation of rules appears to be quite rational, given the actual workload and timing constraints under which the operators must do their job”. Many attempts to improve nuclear safety culture “were compensated by people adapting to the change in an unpredicted way”.[2]

An assessment conducted by the Commissariat à l’Énergie Atomique (CEA) in France concluded that no amount of technical innovation can eliminate the risk of human-induced errors associated with the operation of nuclear power plants. Two types of mistakes were deemed most serious: errors committed during field operations, such as maintenance and testing, that can cause an accident; and human errors made during small accidents that cascade to complete failure.[1]

According to Mycle Schneider, reactor safety depends above all on a 'culture of security', including the quality of maintenance and training, the competence of the operator and the workforce, and the rigour of regulatory oversight. So a better-designed, newer reactor is not always a safer one, and older reactors are not necessarily more dangerous than newer ones. The 1978 Three Mile Island accident in the United States occurred in a reactor that had started operation only three months earlier, and the Chernobyl disaster occurred after only two years of operation. A serious loss of coolant occurred at the French Civaux-1 reactor in 1998, less than five months after start-up.[3]

However safe a plant is designed to be, it is operated by humans who are prone to errors. Laurent Stricker, a nuclear engineer and chairman of the World Association of Nuclear Operators says that operators must guard against complacency and avoid overconfidence. Experts say that the "largest single internal factor determining the safety of a plant is the culture of security among regulators, operators and the workforce — and creating such a culture is not easy".[3]

Risk assessment

Population density is one critical lens through which other risks have to be assessed, says Laurent Stricker, a nuclear engineer and chairman of the World Association of Nuclear Operators:[3]

The KANUPP plant in Karachi, Pakistan, has the most people — 8.2 million — living within 30 kilometres of a nuclear plant, although it has just one relatively small reactor with an output of 125 megawatts. Next in the league, however, are much larger plants — Taiwan's 1,933-megawatt Kuosheng plant with 5.5 million people within a 30-kilometre radius and the 1,208-megawatt Chin Shan plant with 4.7 million; both zones include the capital city of Taipei.[3]

The AP1000 has a maximum core damage frequency of 5.09 x 10−7 per plant per year. The Evolutionary Power Reactor (EPR) has a maximum core damage frequency of 4 x 10−7 per plant per year. General Electric has recalculated maximum core damage frequencies per year per plant for its nuclear power plant designs:[5]

BWR/4 -- 1 x 10-5
BWR/6 -- 1 x 10-6
ABWR -- 2 x 10-7
ESBWR -- 3 x 10-8

Beyond design basis events

As Fukushima showed, external threats — such as earthquakes, tsunamis, fires, flooding, tornadoes and terrorist attacks — are some of the greatest risk factors for a serious nuclear accident. Yet, nuclear plant operators have normally considered these accident sequences (called 'beyond design basis' events) so unlikely that they have not built in complete safeguards.[3]

Forecasting the location of the next earthquake or the size of the next tsunami is an imperfect art. Nuclear plants situated outside known geological danger zones "could pose greater accident threats in the event of an earthquake than those inside, as the former could have weaker protection built in".[3] The Fukushima I plant, for example, was "located in an area designated, on Japan's seismic risk map, as having a relatively low chance of a large earthquake and tsunami; when the 2011 tsunami arrived, it was in excess of anything its engineers had planned for".[3]

Morality

Historically many scientists and engineers have made decisions on behalf of potentially affected populations about whether a particular level of risk and uncertainty is acceptable for them. Many nuclear engineers and scientists that have made such decisions, even for good reasons relating to long term energy availability, now consider that doing so without informed consent is wrong, and that nuclear power safety and nuclear technologies should be based fundamentally on morality, rather than purely on technical, economic and business considerations.[6]

According to Stephanie Cooke, it is difficult to know what really goes on inside nuclear power plants because the industry is shrouded in secrecy. Corporations and governments control what information is made available to the public. Cooke says "when information is made available, it is often couched in jargon and incomprehensible prose".[7]

Kennette Benedict has said that nuclear technology and plant operations continue to lack transparency and to be relatively closed to public view:[8]

Despite victories like the creation of the Atomic Energy Commission, and later the Nuclear Regular Commission, the secrecy that began with the Manhattan Project has tended to permeate the civilian nuclear program, as well as the military and defense programs.[8]

Nuclear and radiation accidents

2011 Fukushima I accidents

See also: Fukushima I nuclear accidents and Timeline of the Fukushima nuclear accidents

The 40-year-old Fukushima I Nuclear Power Plant, built in the 1970s, endured Japan's worst earthquake on record in March 2011 but had its power and back-up generators knocked out by a 7-meter tsunami that followed.[9] The designers of the reactors at Fukushima did not anticipate that a tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake. Nuclear reactors are such "inherently complex, tightly coupled systems that, in rare, emergency situations, cascading interactions will unfold very rapidly in such a way that human operators will be unable to predict and master them".[10]

Lacking electricity to pump water needed to cool the atomic core, engineers vented radioactive steam into the atmosphere to release pressure, leading to a series of explosions that blew out concrete walls around the reactors. Radiation readings spiked around Fukushima as the disaster widened, forcing the evacuation of 200,000 people and causing radiation levels to rise on the outskirts of Tokyo, 135 miles (210 kilometers) to the south, with a population of 30 million.[9]

Back-up diesel generators that might have averted the disaster were positioned in a basement, where they were overwhelmed by waves. The cascade of events at Fukushima had been foretold in a report published in the U.S. several decades ago:[9]

The 1990 report by the U.S. Nuclear Regulatory Commission, an independent agency responsible for safety at the country’s power plants, identified earthquake-induced diesel generator failure and power outage leading to failure of cooling systems as one of the “most likely causes” of nuclear accidents from an external event.[9]

While the report was cited in a 2004 statement by Japan’s Nuclear and Industrial Safety Agency, it seems adequate measures to address the risk were not taken by Tokyo Electric. Katsuhiko Ishibashi, a seismology professor at Kobe University, has said that Japan’s history of nuclear accidents stems from an overconfidence in plant engineering. In 2006, he resigned from a government panel on nuclear reactor safety, because the review process was rigged and “unscientific”.[9]

Louise Fréchette and Trevor Findlay have said that more effort is needed to ensure nuclear safety and improve responses to accidents:

The multiple reactor crises at Japan's Fukushima nuclear power plant reinforce the need for strengthening global instruments to ensure nuclear safety worldwide. The fact that a country that has been operating nuclear power reactors for decades should prove so alarmingly improvisational in its response and so unwilling to reveal the facts even to its own people, much less the International Atomic Energy Agency, is a reminder that nuclear safety is a constant work-in-progress. [11]

David Lochbaum, chief nuclear safety officer with the Union of Concerned Scientists, has repeatedly questioned the safety of the Fukushima I Plant's General Electric Mark 1 reactor design, which is used in almost a quarter of the United States' nuclear fleet.[12]

Following the Fukushima emergency, the European Union decided that reactors across all 27 member nations should undergo safety tests.[13]

According to UBS AG, the Fukushima I nuclear accidents are likely to hurt the nuclear power industry’s credibility more than the Chernobyl disaster in 1986:

The accident in the former Soviet Union 25 years ago 'affected one reactor in a totalitarian state with no safety culture,' UBS analysts including Per Lekander and Stephen Oldfield wrote in a report today. 'At Fukushima, four reactors have been out of control for weeks -- casting doubt on whether even an advanced economy can master nuclear safety.'[14]

According to Areva's Southeast Asia and Oceania director, Selena Ng, Japan's Fukushima I nuclear accidents are "a huge wake-up call for a nuclear industry that hasn't always been sufficiently transparent about safety issues". She said "There was a sort of complacency before Fukushima and I don't think we can afford to have that complacency now".[15]

1986 Chernobyl disaster

Main articles: Chernobyl disaster and Chernobyl disaster effects

As radioactive materials decay, they release particles that can damage the body and lead to cancer, particularly cesium-137 and iodine-131. In the 1986 nuclear accident at Chernobyl, releases of cesium-137 contaminated land. Some communities were abandoned permanently. Thousands of people who drank milk contaminated with radioactive iodine developed thyroid cancer.[16]

Other accidents

See also: List of civilian nuclear accidents, List of civilian radiation accidents, and List of military nuclear accidents

Serious nuclear and radiation accidents include the Chalk River accidents (1952, 1958 & 2008), Mayak disaster (1957), Windscale fire (1957), SL-1 accident (1961), Soviet submarine K-19 accident (1961), Three Mile Island accident (1979), Church Rock uranium mill spill (1979), Soviet submarine K-431 accident (1985), Goiânia accident (1987), Zaragoza radiotherapy accident (1990), Costa Rica radiotherapy accident (1996), Tokaimura nuclear accident (1999), Sellafield THORP leak (2005), and the Flerus IRE Cobalt-60 spill (2006).[17][18]

Health impacts

See also: Chernobyl disaster effects and Nuclear power debate

In spite of accidents like Chernobyl, studies have shown that nuclear deaths are mostly in uranium mining and that nuclear energy has generated far fewer deaths than the high pollution levels that result from the use of conventional fossil fuels.[19]

Stephanie Cooke says that it is not useful to make comparisons just in terms of number of deaths, as the way people live afterwards is also relevant, as in the case of the 2011 Japanese nuclear accidents:[20]

You have people in Japan right now that are facing either not returning to their homes forever, or if they do return to their homes, living in a contaminated area for basically ever. And knowing that whatever food they eat, it might be contaminated and always living with this sort of shadow of fear over them that they will die early because of cancer and induced by Caesium or Strontium or some other radionuclide that's laced their vegetables. It affects millions of people, it affects our land, it affects our atmosphere, we know now the radio nuclides from Fukushima are going into the sea. It doesn't just kill now, it kills later, and it could kill centuries later. Because the stuff that that's depositing, doesn't just end, it has a long, long life. It's affecting future generations, it's not just affecting this generation. So I'm not a great fan of coal-burning. I don't think any of these great big massive plants that spew pollution into the air are good. But I don't think it's really helpful to make these comparisons just in terms of number of deaths.[20]

Developing countries

There are concerns about developing countries "rushing to join the so-called nuclear renaissance without the necessary infrastructure, personnel, regulatory frameworks and safety culture".[21] Some countries with nuclear aspirations, like Nigeria, Kenya, Bangladesh and Venezuela, have no significant industrial experience and will require at least a decade of preparation even before breaking ground at a reactor site.[21]

The speed of the nuclear construction program in China has raised safety concerns. The challenge for the government and nuclear companies is to "keep an eye on a growing army of contractors and subcontractors who may be tempted to cut corners".[22] China is advised to maintain nuclear safeguards in a business culture where quality and safety are sometimes sacrificed in favor of cost-cutting, profits, and corruption. China has asked for international assistance in training more nuclear power plant inspectors.[22]

See also

References

  1. ^ a b c Benjamin K. Sovacool. A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia, Journal of Contemporary Asia, Vol. 40, No. 3, August 2010, p. 381.
  2. ^ a b c M.V. Ramana. Nuclear Power: Economic, Safety, Health, and Environmental Issues of Near-Term Technologies, Annual Review of Environment and Resources, 2009. 34, pp.139-140.
  3. ^ a b c d e f g Declan Butler (21 April 2011). "Reactors, residents and risk". Nature.
  4. ^ Severe Accidents in the Energy Sector (see pages 287,310,317)
  5. ^ Next-generation nuclear energy: The ESBWR
  6. ^ Pandora's box, A is for Atom- Adam Curtis
  7. ^ Stephanie Cooke (March 19, 2011). "Nuclear power is on trial". CNN.com.
  8. ^ a b Kennette Benedict (26 March 2011). "The road not taken: Can Fukushima put us on a path toward nuclear transparency?". Bulletin of the Atomic Scientists. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  9. ^ a b c d e Jason Clenfield (March 17, 2011). "Japan Nuclear Disaster Caps Decades of Faked Reports, Accidents". Bloomberg Businessweek.
  10. ^ Hugh Gusterson (16 March 2011). "The lessons of Fukushima". Bulletin of the Atomic Scientists.
  11. ^ Louise Fréchette and Trevor Findlay (March 28, 2011). "Nuclear safety is the world's problem". Ottawa Citizen.
  12. ^ Hannah Northey (March 28, 2011). "Japanese Nuclear Reactors, U.S. Safety to Take Center Stage on Capitol Hill This Week". New York Times.
  13. ^ James Kanter (March 25, 2011). "Europe to Test Safety of Nuclear Reactors". New York Times.
  14. ^ James Paton (April 04, 2011). "Fukushima Crisis Worse for Atomic Power Than Chernobyl, UBS Says". Bloomberg Businessweek. {{cite web}}: Check date values in: |date= (help)
  15. ^ David Fickling (April 20, 2011). "Areva Says Fukushima A Huge Wake-Up Call For Nuclear Industry". Fox Business.
  16. ^ Renee Schoof (April 12, 2011). "Japan's nuclear crisis comes home as fuel risks get fresh look". McClatchy.
  17. ^ Newtan, Samuel Upton (2007). Nuclear War 1 and Other Major Nuclear Disasters of the 20th Century, AuthorHouse.
  18. ^ The Worst Nuclear Disasters
  19. ^ [2]
  20. ^ a b Annabelle Quince (30 March 2011). "The history of nuclear power". ABC Radio National.
  21. ^ a b Louise Fréchette and Trevor Findlay (March 28, 2011). "Nuclear safety is the world's problem". Ottawa Citizen.
  22. ^ a b Keith Bradsher (December 15, 2009). "Nuclear Power Expansion in China Stirs Concerns". New York Times. Retrieved 2010-01-21.
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