International rating scale for nuclear events

The International rating scale for nuclear and radiological events (abbreviation INES of English International Nuclear and Radiological Event Scale ) is a specification for security events, specifically incidents and nuclear accidents in nuclear facilities , in particular the safety of nuclear power plants in question.

history

The scale was developed by an international group of experts, which was convened jointly by the International Atomic Energy Agency (IAEA) and the Organization for Economic Cooperation and Development (OECD) nuclear energy agency , and was officially introduced in 1990. The aim of the scale is to provide the public with quick information on the safety-related significance of an event based on a comprehensible classification of the events and thus to facilitate communication between experts, the media and the public.

The rating scale originally had seven levels. Level 0 was added later for events with no safety relevance.

Degrees of severity

Level 0 is classified as a deviation , levels 1 to 3 are classified as incidents and incidents , and levels 4 to 7 as accidents . The scale is based on a logarithmic scale : A transition to the next level means a degree of severity that is ten times greater. The reportable levels of events are assessed according to three aspects:

• Effects on people and the environment
• Radiological barrier impairments and surveillance measures
• Impairment of security measures

Simplified description of the individual INES levels

step	Classification	Designation original	Effects on people and the environment	Radiological barrier impairments and surveillance measures	Impairment of security measures	Examples
7th	accident	Catastrophic accident Major accident	Significant release of radioactive substances (radiological equivalence to> 50,000 TBq iodine -131) with far-reaching effects on humans and the environment, which necessitates the implementation of planned and extended countermeasures.			1986: Chernobyl disaster , Ukraine - then USSR (between 4,000,000 and 6,400,000 TBq) 2011: Fukushima Daiichi nuclear disaster , Units 1, 2 and 3, Japan (approx. 500,000 to 1,000,000 TBq → data overview )
6th		Serious accident Serious accident	Significant release of radioactive substances (radiological equivalence to> 5,000 TBq iodine -131), which makes the need to implement planned countermeasures probable. Many deaths (> 30) from radiation exposure.			1957: Kyschtym accident ( Mayak nuclear facility ), Russia - then the USSR (according to recent estimates, which are between 400,000 and 8,900,000 TBq, the accident should be assigned to INES level 7 due to the level of radioactive contamination)
5		Serious accident Accident with wider consequences	Limited release of radioactive substances (radiological equivalence to> 500 TBq iodine -131 or 2500 times the D 2 value), which makes the necessity of implementing some planned countermeasures probable. Several deaths (> 3) from radiation exposure	Severe damage (some%) to the reactor core (core meltdown) Release of large quantities of radioactive substances within a facility with a high probability of significant radiation exposure of the population		1957: Fire in the nuclear reactor at the plutonium production facility Windscale / Sellafield , Great Britain (47,000 TBq) 1969: Core meltdown in the cavern reactor in Lucens , Switzerland 1979: Reactor accident at the Three Mile Island nuclear power plant , USA (750 TBq) 1982: Chernobyl nuclear power plant, Unit 1 , Ukraine - then the USSR 1987: Goiânia accident (theft of a radiation therapy device), Brazil (44 TBq)
4th		Accident Accident with local consequences	Minor release of radioactive substances (radiological equivalence to> 50 TBq iodine -131 or 250 times the D 2 value), as a result of which the implementation of planned countermeasures with the exception of local food controls is unlikely At least one death from radiation exposure	Melting or damage to the nuclear fuel resulting in a release of more than 0.1% of the core inventory. Release of significant amounts of radioactive substances (> 5,000 TBq) within a facility with a high probability of significant radiation exposure of the population		1966: Enrico Fermi nuclear power plant , USA 1977: Bohunice nuclear power plant , Slovakia 1969 and 1980: Saint-Laurent Nuclear Power Plant , France 1993: Explosion at the Tomsk-7 military reprocessing plant , Russia 1999: Tōkai reprocessing plant , Japan
3	Accident	Serious incident incident Serious	Radiation exposure over ten times the statutory annual limit value for occupationally exposed personnel (> 60 mSv) Non-fatal deterministic damage (e.g. burns) from radiation exposure	Dose rate of more than 1 Sv / h in an operational area. Serious contamination in an area not intended by the design with a low probability of significant radiation exposure of the population	Near-accident in a nuclear power plant where safety precautions are no longer in place Loss or theft of an enclosed high-level radioactive source Wrongly enclosed highly radioactive radiation source without established adequate radiation protection instructions for its handling	1975: Incident in Greifswald / Lubmin , Germany - then GDR 1997: Fire and explosion in the Tōkai solidification plant , Japan 2002: Corrosion through reactor vessel Davis Besse , USA 2003: Release during fuel element cleaning in Paks nuclear power plant , Hungary 2005: Uranium and Plutonium released in Sellafield , UK
2		Major incident	Radiation exposure of an individual of the population in excess of 10 mSv Radiation exposure of an occupationally exposed person beyond the statutory annual limit values	Dose rate of more than 50 mSv / h in an operational area Significant contamination within the system in an area not intended for this by the design.	Incidents, events or findings with particular safety significance, but without actual effects An enclosed, highly radioactive, abandoned source, device, or package with intact safety precautions found Inadequate packaging of an enclosed, highly radioactive radiation source	1982 and 2011: Doel Nuclear Power Plant , Belgium 2001: Philippsburg , Germany, two incidents 2002: Tihange nuclear power plant , Belgium 2006: Forsmark , Sweden 2009: Dungeness , Kent , United Kingdom 2010: Leibstadt , Switzerland 2017: Cattenom Nuclear Power Plant , France
1		Disorder anomaly	Slightly exceeding the legally stipulated sales limits Radiation exposure of an individual in the population beyond the statutory limits		Events or findings with safety relevance, but with remaining essential staggered safety precautions Loss or theft of a radioactive source, device, or package with low activity	1987: Biblis nuclear power plant , Germany 2009: Cattenom Nuclear Power Plant , France 2011: Fessenheim nuclear power plant , France 2014: (discovered, existed since 2008) Leibstadt nuclear power plant , Switzerland
0	deviation	Event with little or no safety significance Below scale - No safety significance			No or only very little relevance to safety	2007: Transformer fire in the Krümmel nuclear power plant , Germany 2011: Cooling water leak in the Brunsbüttel nuclear power plant , Germany 2015: Rapid shutdown after a maintenance fault in the Gundremmingen nuclear power plant , Germany 2020: Radiation leakage at the research reactor in Garching, Germany

Event reporting according to INES in Germany

The INES classification is carried out by the power plant operator when an event occurs. On behalf of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety , an expert from the Gesellschaft für Anlagen- und Reaktorsicherheit gGmbH then acts as an INES officer to review the classification. INES officers are appointed in each INES member country. If the classification of the INES officer deviates from the classification of the power plant operator during his review, he will first contact the operator directly. If the operator does not adjust the INES level, the INES officer informs the responsible state authority and the Federal Environment Ministry. Events from INES level 2 are reported directly to the IAEA in Vienna by the INES officer.

See also : Reportable event

criticism

Weaknesses on the INES scale became apparent through comparisons between the Chernobyl disaster and the Fukushima accident. Three points were raised:

1. It does not differentiate between magnitude (how severe is the incident in the reactor?) And intensity (what effects does the incident have on the environment?). B. is the case with an earthquake scale.
2. It is a discrete scale that does not allow gradations between the individual degrees of severity. In addition, it is not defined for events above level 7; it is therefore not a continuous scale.
3. It was designed as a public relations tool rather than an objective scientific measure.

According to nuclear safety experts, the INES scale will be revised in the future. The reason for this is the confusing way in which it was used to assess the Fukushima accident: the severity of the accident is not determined by the IAEA but by a national authority. Initially, the event was designated as "5" on the INES scale, separately for the individual reactors concerned. However, the accident was later upgraded to "7".

David Smythe mentions that the INES scale of an incident must be determined from a 200 page manual. A continuous magnitude scale (NAMS, Nuclear Accident Magnitude Scale ) designed by him attempts to remedy this deficiency.

Other authors also criticize INES as inconsistent and accuse the IAEA of the fact that many events affecting nuclear safety have not yet been rated using the INES scale. Similar to Smythe, it is stated that the damage incurred - including the economic one - would not be reflected by the INES scale. If this were the case, the Fukushima disaster would have to be rated 10 or 11 instead of just 7.

See also

• List of accidents in nuclear facilities (INES levels 4 to 7)
• List of accidents in European nuclear facilities (INES levels 2 to 3)
• List of reportable events in German nuclear facilities (INES level 1 to 3)
• Central reporting and evaluation point for incidents and malfunctions
• INES ratings of the Fukushima nuclear disaster

Web links

• Current INES reports from the IAEA
• The International Nuclear and Radiological Event Scale , User Manual, Edition 2008 (English, PDF; 2.5 MB)
• International Atomic Energy Agency (IAEA )
• Federal Office for Radiation Protection : Reports on the reportable events in nuclear facilities in the Federal Republic of Germany
• International evaluation scale for significant events in nuclear facilities in brief (PDF; 28 kB), 12/2001

Individual evidence

1. ↑ http://www.world-nuclear-news.org/RS_Event_scale_revised_for_further_clarity_0510081.html
2. ↑ ^{a b} Announcement on the use of the German version of the handbook of the International Nuclear and Radiological Event Scale (INES) in nuclear facilities and in radiation protection outside of nuclear technology dated February 20, 2015 (BAnz AT March 30, 2015 B1). (PDF; 4.36 MB) Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety , accessed on January 6, 2019 . 
3. ^ ^{A b} International Nuclear Events Scale (INES). IAEA , accessed April 13, 2011 .  
4. ↑ ^{a b c} INES - International Nuclear Event Scale. Society for Plant and Reactor Safety , accessed on February 3, 2012 .  
5. ^ Chernobyl: Assessment of Radiological and Health Impact, Chapter 2 . ( Memento of April 20, 2011 on WebCite ) 2002, archived from the original , accessed April 6, 2011.
6. ↑ ^{a b} INES (the International Nuclear and Radiological Event Scale) Rating on the Events in Fukushima Dai-ichi Nuclear Power Station by the Tohoku District - off the Pacific Ocean Earthquake ( Memento from April 12, 2011 on WebCite ) (English, pdf) . NISA / METI, April 12, 2011, archived from the original , accessed April 12, 2011.
7. ^ ^{A b} Rob Edwards: Russia's Toxic Shocker . In: New Scientist . December 6, 1997, p. 15 ( online ).
8. ↑ Helmholtz-Zentrum-München : Podcasts 2007 - audio contribution: 50 years of radiation accident at Kysthym (article with mp3 podcast and PDF)  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Interview with Dr. Peter Jacob, September 25, 2007  
9. ^ Three Mile Island experience and its influence on radiation protection procedures. Journal of the Society for Radiological Protection, March 26, 1985, accessed March 23, 2011 . 
10. ↑ Report of the IAEA on the Goiânia accident (English) . September 1988 ( Online (PDF; 6.7 MB)).
11. ↑ Erwin Yurtschitsch: The real catastrophe in Tomsk-7. Focus No. 16 (1993), April 19, 1993, accessed March 13, 2016 . 
12. ^ Ulrich Weissenburger: Nuclear environmental hazard in Russia. (No longer available online.) In: Wochenbericht 21/96. DIW Berlin, February 26, 2007, archived from the original on August 8, 2007 ; accessed on March 13, 2016 . 
13. ↑ Ministry for Environment and Transport Baden-Württemberg (Ed.): Final report of the Ministry for Environment and Transport Baden-Württemberg on the reportable events 06/2001, 07/2001 and 08/2001 in the Philippsburg nuclear power plant, block 2 . Stuttgart June 2003 ( PDF [accessed April 13, 2011]).
14. ^ Incident at the Leibstadt nuclear power plant. In: NZZ Online. Neue Zürcher Zeitung , September 1, 2010, accessed on September 4, 2010 . 
15. ↑ Süddeutsche Zeitung: Research reactor Garching: radioactivity leaked. Retrieved May 16, 2020 . 
16. ↑ Paul Laufs, Reactor Safety for Power Plants, Volume 1, Springer-Vieweg 2018, p. 264
17. ^ Geoff Brumfiel: Nuclear agency faces reform calls. International Atomic Energy Agency's remit under scrutiny. In: Nature. Springer, April 26, 2011, accessed on August 26, 2016 . 
18. ^ David Smythe: An objective nuclear accident magnitude scale for quantification of severe and catastrophic events. In: Physics Today. doi: 10.1063 / PT.4.0509 .
19. ^ Spencer Wheatley, Benjamin Sovacool and Didier Sornette: Of Disasters and Dragon Kings: A Statistical Analysis of Nuclear Power Incidents & Accidents . April 10, 2015, arxiv : 1504.02380v1 .