Airborne radioactivity was detected in Europe during autumn 2017, starting from the last days of September. The source is widely suspected to be in Russia; the Russian government, however, denies that any nuclear mishaps occurred that could have caused the radiation spike. The radioactive isotope detected was
ruthenium-106
Naturally occurring ruthenium (44Ru) is composed of seven stable isotopes. Additionally, 27 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are 106Ru, with a half-life of 373.59 days; 103Ru, with a half-life of 3 ...
; across Europe, it was found to be in small quantities (from micro
becquerel
The becquerel (; symbol: Bq) is the unit of radioactivity in the International System of Units (SI). One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. For applications relatin ...
s to a few millibecquerels per cubic metre of air), not significant for the health of the population far away from the source.
[Detection of Ruthenium 106 in France and in Europe: Results of IRSN's investigations](_blank)
/ref>[Mishandling of spent nuclear fuel in Russia may have caused radioactivity to spread across Europe By Edwin CartlidgeFeb. 14, 2018](_blank)
/ref> It is estimated, however, that the radiation released posed a danger to any employees or residents within several kilometers of the currently unknown source.
Radioactivity detected
European monitoring networks declared increased radioactivity levels in Europe, coming from Eastern Europe, in the first days of October:
* the Swiss Federal Office of Public Health
The Federal Office of Public Health (FOPH) is the Swiss federal government’s centre for public health and a part of the Swiss Federal Department of Home Affairs.
In addition to developing national health policy, it also represents the inte ...
(FOPH) reported increase of radioactive particles of ruthenium-106 from 25 September
* The Institute of Radioprotection and Nuclear Safety of France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
, indicated that the relatively high levels in the beginning of October steadily decreased from 6 October, while no radioactive element was detected after 13 October.
An assessment of the French nuclear safety institute IRSN indicated that while there was no health risk for the vast majority of people in Europe, the radioactive quantity released was significant, estimated from 100 to 300 terabecquerels, which would require an evacuation of people from a radius of several kilometers from the source, as yet then unidentified. The source of the aforementioned 100–300 TBq activity corresponds approximately to 1–3 grams of the ruthenium-106 isotope.
Possible source
While the release of the gaseous noble gas element krypton-85
Krypton-85 (85Kr) is a radioisotope of krypton.
Krypton-85 has a half-life of 10.756 years and a maximum decay energy of 687 keV. It decays into stable rubidium-85. Its most common decay (99.57%) is by beta particle emission with maximum energ ...
is routine during nuclear reprocessing, the noble metal ruthenium
Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemical ...
, which is generated in a fission product yield
Nuclear fission splits a heavy nucleus such as uranium or plutonium into two lighter nuclei, which are called fission products. Yield refers to the fraction of a fission product produced per fission.
Yield can be broken down by:
# Individual ...
rate of from 0.39% to 3.103% of every fission of a nucleus of uranium or plutonium respectively, is by contrast ''generally'' in metallic form, with a high boiling point of in spent fuel. Owing to the ionizing radiation environment of spent fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor a ...
and the entry of oxygen, however, radiolysis reactions can make the more volatile compound ruthenium(VIII) oxide, which has a boiling point of approximately and is a strong oxidizer, reacting with virtually any fuel/hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...
. The use of a solution of tributyl phosphate
Tributyl phosphate, known commonly as TBP, is an organophosphorus compound with the chemical formula (CH3CH2CH2CH2O)3PO. This colourless, odorless liquid finds some applications as an extractant and a plasticizer. It is an ester of phosphoric ac ...
in the hydrocarbons kerosene
Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...
or dodecane
Dodecane (also known as dihexyl, bihexyl, adakane 12, or duodecane) is an oily liquid ''n''-alkane hydrocarbon with the chemical formula C12H26 (which has 355 isomers).
It is used as a solvent, distillation chaser, and scintillator component. It ...
, is frequent – as part of the nuclear reprocessing method known as PUREX
PUREX (plutonium uranium reduction extraction) is a chemical method used to purify fuel for nuclear reactors or nuclear weapons. PUREX is the ''de facto'' standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium ...
. Accidental airborne releases of Ru-106 have been through this pathway in the past, such as the UK's B204 reprocessing incident in 1973, where 34 employees were exposed.
With corrosion of the fuel rod
Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission.
Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing ...
-cladding in the MAGNOX
Magnox is a type of nuclear power/production reactor that was designed to run on natural uranium with graphite as the moderator and carbon dioxide gas as the heat exchange coolant. It belongs to the wider class of gas-cooled reactors. The n ...
-reactor, spent fuel pools (an issue in the British case, due to the selection of magnesium for the coating on the fuel rods), reprocessing needed to occur within a ''few months'' at the B205 facility; most other facilities (like the French La Hague
La Hague () is a commune in the department of Manche, northwestern France. The municipality was established on 1 January 2017 by merger of the former communes of Beaumont-Hague (the seat), Acqueville, Auderville, Biville, Branville-Hague, ...
) place the spent-fuel in spent fuel pool
Spent fuel pools (SFP) are storage pools (or "ponds" in the United Kingdom) for spent fuel from nuclear reactors. They are typically 40 or more feet (12 m) deep, with the bottom 14 feet (4.3 m) equipped with storage racks designed to hold ...
s for ''about a decade'', until the Ru-106, which has a half-life of ~ 1 year, has safely decayed into Rh-106 and finally the stable Pd-106. All attempts at PUREX to less aged spent-fuel need to take into account the presence of the oxidative and volatile ruthenium(VIII) oxide.
Initially, there was no indication given for the source of these radioactive particles, apart from an October 2017 statement coming from German authorities estimating the source in the east, at more than from Germany. A later report from the German Federal Radiation Protection Service ruled in the South of the Urals and other potential locations.
The (Roshydromet) said that Ru-106 activity in St. Petersburg was at 115.4 μBq/m3 from October 2 to 6.
The French Institute of Radioprotection and Nuclear Security (IRSN) ruled out the emissions as coming from a nuclear reactor, estimating that it should have come either from a treatment site or from a center producing radioactive medicine. They estimated the source to be south of the Ural mountains, between the Urals and the Volga river, in Russia or Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
.
Roshydromet then issued a report describing a rise in beta activity of aerosols and surfaces at all monitoring posts in South Ural from September 25 to October 1, 2017. In two aerosol samples, an increase in Ru-106 activity was detected. On September 26 and 27, Ru-106 decay products were detected in the Republic of Tatarstan
The Republic of Tatarstan (russian: Республика Татарстан, Respublika Tatarstan, p=rʲɪsˈpublʲɪkə tətɐrˈstan; tt-Cyrl, Татарстан Республикасы), or simply Tatarstan (russian: Татарстан, tt ...
. On September 27 and 28, high pollution levels of aerosols and surfaces was detected in Volgograd and Rostov-on-Don. In two aerosol samples from Chelyabinsk Oblast, 986- and 440-fold activity increases were measured, as compared to the preceding month.
The Mayak reprocessing and isotope production plant is widely suspected as the source. Authorities there and at Rosatom
Rosatom, ( rus, Росатом, p=rɐsˈatəm}) also known as Rosatom State Nuclear Energy Corporation, the State Atomic Energy Corporation Rosatom or Rosatom State Corporation, is a Russian state corporation headquartered in Moscow that speciali ...
, the Russian state company running the nuclear industry, have denied a link.
On 21 November 2017 Russia reversed itself by confirming that a radiation spike was recorded at two monitoring facilities within of the plant. Russia states the published data is not sufficient to establish the air pollution source and government denies it has had any measurements or admissions of any incident.
Rosatom initially stated that it had not carried out any operations that could have led to the isotope's release into the atmosphere "for many years". In December 2017, however, senior Mayak executive Yuri Morkov admitted that ruthenium-106 is routinely released as part of the plant's processing of spent nuclear fuel. Morkov characterized the amount released as "insignificant" and denied Mayak was the source of the radiation spike.
Domestic investigation within Russia is hampered by the problem that Mayak is in the walled-off closed city
A closed city or closed town is a settlement where travel or residency restrictions are applied so that specific authorization is required to visit or remain overnight. Such places may be sensitive military establishments or secret research ins ...
of Ozyorsk, which non-resident Russians are barred from visiting without special permission, and by government harassment of nuclear critics. In Russia prominent nuclear critics experience government raids, are accused on state TV of "exploiting the nuclear issue to foment revolution", and risk criminal prosecution on charges of incitement of hatred against nuclear energy employees.[
The ]Russian Academy of Sciences
The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across ...
's Nuclear Safety Institute set up an international committee to investigate the incident. The French Institute of Radioprotection and Nuclear Security (IRSN) provided a report to the committee in January 2018. The report concluded that the most likely source of the pollution is a spent fuel treatment facility located in a region between Volga and Ural. A possible reason for the release of radioactivity at Mayak PA might be an unsuccessful attempt to produce cerium
Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the +3 ...
-144 for the European scientific project Borexino
Borexino is a particle physics experiment to study low energy (sub-MeV) solar neutrinos. The detector is the world's most radio-pure liquid scintillator calorimeter. It is placed within a stainless steel sphere which holds the photomultiplier t ...
. Mayak PA had agreed to deliver cerium-144 in early 2018, but canceled the contract in December 2017. Mayak PA was the only facility capable of producing cerium-144 from "fresh" spent nuclear fuel 2–3 years old. Usually spent fuel is not processed earlier than five years after extraction. The Ru106/Ru103 ratio in analyzed environmental samples during the pollution spread was characteristic of "fresh" spent fuel. While the non-Russian members of the committee accepted the conclusions of IRSN's report, the Russian members maintain that an inspection by Rostechnadzor of the Mayak PA facility in November 2017 showed no anomalies and a rare meteorological event may have transported the ruthenium-106 from somewhere else to the apparent region of origin.
In 2019 a number of European nuclear scientific research groups published "clear evidence" that the leak originated from Southern Urals
Southern Ural - the south, the widest part of the Ural Mountains, stretches from the river Ufa (near the village of Lower Ufaley) to the Ural River. From the west and east the Southern Ural is limited to the East European, West Siberian Plain and ...
, where Mayak
The Mayak Production Association (russian: Производственное объединение «Маяк», , from 'lighthouse') is one of the biggest nuclear facilities in the Russian Federation, housing a reprocessing plant. The closest ...
plant is located.
Timeline of European detection and public notice
* the Swiss Federal Office of Public Health
The Federal Office of Public Health (FOPH) is the Swiss federal government’s centre for public health and a part of the Swiss Federal Department of Home Affairs.
In addition to developing national health policy, it also represents the inte ...
(FOPH) reported increase of radioactive particles of ruthenium-106 since 25 September
* The Austria
Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
n Ministry of the Environment informed the public on 3 October 2017
* The Norwegian
Norwegian, Norwayan, or Norsk may refer to:
*Something of, from, or related to Norway, a country in northwestern Europe
* Norwegians, both a nation and an ethnic group native to Norway
* Demographics of Norway
*The Norwegian language, including ...
Nuclear Safety Authority (NRPA) also released information on low levels of ruthenium isotope in the atmosphere
* The Greek Atomic Energy Commission (EEAE) informed of increased radiation in the atmosphere in Athens since 27 September
Similar announcements came from other authorities:
* The German
German(s) may refer to:
* Germany (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
Office for Radiation Protection reported increased radioactivity since 29 September
* The Finnish
Finnish may refer to:
* Something or someone from, or related to Finland
* Culture of Finland
* Finnish people or Finns, the primary ethnic group in Finland
* Finnish language, the national language of the Finnish people
* Finnish cuisine
See also ...
Radiation and Nuclear Safety Authority
The Radiation and Nuclear Safety Authority ( fi, Säteilyturvakeskus, sv, Strålsäkerhetscentralen), often abbreviated as STUK, is a government agency tasked with nuclear safety and radiation monitoring in Finland. The agency is a division of ...
STUK issued an announcement on 3 October reporting increased radioactivity in samples since 28 September
* The Nuclear Safety Administration of the Republic of Slovenia
Slovenia ( ; sl, Slovenija ), officially the Republic of Slovenia (Slovene: , abbr.: ''RS''), is a country in Central Europe. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, and ...
announced detection of low levels of ruthenium-106 in the atmosphere on 9 October
* The Institute of Radioprotection and Nuclear Safety of France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
, indicated that the relatively high levels in the beginning of October have steadily decreased from 6 October, while no radioactive element was detected after 13 October.
References
{{Reflist
External links
* Report on th
IRSN investigation of the incident, January 2018
September 2017 events in Russia
2017 in the environment
Radiation accidents and incidents
Nuclear energy in Russia
Environment of Europe
Environment of Russia
Ruthenium
September 2017 events in Europe