Plutonium in the environment

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Since the mid-20th century, plutonium in the environment has been primarily produced by human activity. The first plants to produce

Hanford nuclear site, in Washington, and Mayak nuclear plant, in Chelyabinsk Oblast, Russia. Over a period of four decades,[1] "both released more than 200 million curies of radioactive isotopes into the surrounding environment – twice the amount expelled in the Chernobyl disaster in each instance".[2]

The majority of

marine sediments for plutonium in marine sediments, atomic bomb fallout is responsible for 66% of the 239Pu and 59% 240Pu found in the English Channel, while nuclear reprocessing is responsible for the majority of the 238Pu and 241Pu present in the Earth's oceans (nuclear weapons testing is only responsible for 6.5 and 16.5% of these isotopes respectively).[8]

Sources of plutonium

Plutonium production

Hanford site represents two-thirds of the nation's high-level radioactive waste by volume. Nuclear reactors line the riverbank at the Hanford Site along the Columbia River
in January 1960.

atomic bombs.[2]

In the 2013 book[1] on a history of these two blighted cities, Plutopia: Nuclear Families, Atomic Cities, and the Great Soviet and American Plutonium Disasters (Oxford), Kate Brown explores the health of affected citizens in both the United States and Russia, and the "slow-motion disasters" that still threaten the environments where the plants are located. According to Brown, the plants at Hanford and Mayak, over a period of four decades, "both released more than 200 million curies of radioactive isotopes into the surrounding environment -- twice the amount expelled in the Chernobyl disaster in each instance".[2]

Most of this radioactive contamination over the years at Hanford and Mayak were part of normal operations, but unforeseen accidents did occur and plant management kept this secret, as the pollution continued unabated. Even today, as pollution threats to health and the environment persist, the government keeps knowledge about the associated risks from the public.[2]

Bomb detonations

Levels of radioactivity in the trinitite glass from two different samples as measured by gamma spectroscopy on lumps of the glass. The americium content is the current content while all the other isotopes have been back calculated to shortly after the moment of detonation.
Isotopic signatures of the plutonium before and after the detonation.

About 3.5 tons of plutonium have been released into the environment by atomic bomb tests. While this might sound like a large amount it has only resulted in a very small dose to the majority of the humans on the earth. Overall the health effects of

fission products are far greater than the effects of the actinides released by a nuclear bomb detonation. The plutonium from the fuel of the bomb is converted into a high-fired oxide that is carried high into the air. It slowly falls to earth as global fallout and is not soluble, and as a result it is difficult for this plutonium to be incorporated into an organism if ingested. Much of this plutonium is absorbed into sediments of lakes, rivers and oceans. However, about 66% of the plutonium from a bomb explosion is formed by the neutron capture of uranium-238; this plutonium is not converted by the bomb into a high fired oxide as it is formed more slowly. This formed plutonium is more soluble and more harmful as fallout.[9]

Some plutonium can be deposited close to the point of detonation. The glassy

fissile
fuel used.

As the 239Pu/240Pu ratio only changed slightly during the Trinity detonation, it has been commented

Nagasaki
.

Bomb safety trials

The two basic fission weapon designs.

Plutonium has also been released into the environment in safety trials. In these experiments,

radioisotopes left on an island by the French nuclear bombs tests of the 20th century has been printed by the International Atomic Energy Agency and a section of this report deals with plutonium contamination resulting from such tests.[13]

Other related trials were conducted at

Maralinga, South Australia where both normal bomb detonations and "safety trials" have been conducted. While the activity from the fission products has decayed away almost totally (as of 2006) the plutonium remains active.[14][15]

Space

Cassini probe

Plutonium can also be introduced into the environment via the reentry of artificial satellites containing

better source needed
]

Image of (mostly) thermally isolated, RTG pellet glowing red hot because of incandescence.

Chain reactions do not occur inside RTGs, so a nuclear meltdown is impossible. In fact, some RTGs are designed so that fission does not occur at all; rather, forms of radioactive decay which cannot trigger other radioactive decays are used instead. As a result, the fuel in an RTG is consumed much more slowly and much less power is produced. RTGs are still a potential source of radioactive contamination: if the container holding the fuel leaks, the radioactive material will contaminate the environment. The main concern is that if an accident were to occur during launch or a subsequent passage of a spacecraft close to Earth, harmful material could be released into the atmosphere. However, this event is extremely unlikely with current RTG cask designs.[full citation needed]

In order to minimise the risk of the radioactive material being released, the fuel is typically stored in individual modular units with their own heat shielding. They are surrounded by a layer of iridium metal and encased in high-strength graphite blocks. These two materials are corrosion and heat-resistant. Surrounding the graphite blocks is an aeroshell, designed to protect the entire assembly against the heat of reentering the Earth's atmosphere. The plutonium fuel is also stored in a ceramic form that is heat-resistant, minimising the risk of vaporization and aerosolization. The ceramic is also highly insoluble.[full citation needed]

The US Department of Energy has conducted seawater tests and determined that the graphite casing, which was designed to withstand reentry, is stable and no release of plutonium should occur. Subsequent investigations have found no increase in the natural background radiation in the area. The Apollo 13 accident represents an extreme scenario due to the high re-entry velocities of the craft returning from cislunar space. This accident has served to validate the design of later-generation RTGs as highly safe.

Nuclear fuel cycle

Plutonium has been released into the environment in aqueous solution from

nuclear bomb
detonations.

One example of a site where plutonium entered the soil is

EXAFS was used to investigate the structure of the plutonium compound present in the soil and concrete.[22]

The XANES experiments done on plutonium in soil, concrete and standards of the different oxidation states.

Chernobyl

See also: Chernobyl disaster

Because plutonium oxide is very involatile, most of the plutonium in the reactor was not released during the fire. However that which was released can be measured. V.I. Yoschenko et al. reported that grass and forest fires can make the caesium, strontium and plutonium become mobile in the air again.[23]

Fukushima

See also:
Fukushima Daiichi nuclear disaster and Fukushima Daiichi Nuclear Power Plant

The ongoing crisis at this site includes Spent Fuel Pools on the upper floors, exposed to the elements with complex MOX and plutonium products. The Japanese Government Taskforce has asked for submissions to the International Research Institute for Nuclear Decommissioning[24] in regards to the ongoing Contaminated Water Issues.[25]

Nuclear crime

There have been 18 incidences[

highly enriched uranium (HEU) and plutonium confirmed by the IAEA.[26]

One case exists of a German man who attempted to poison his ex-wife with plutonium stolen from WAK (Wiederaufbereitungsanlage Karlsruhe), a small scale reprocessing plant where he worked. He did not steal a large amount of plutonium, just rags used for wiping surfaces and a small amount of liquid waste. The man was sent to prison for his crime.[27] At least two other people were contaminated by the plutonium.[citation needed] Two flats in Rhineland-Palatinate were also contaminated.[28] These were later cleaned at a cost of two million euro.

Environmental chemistry

Overview

Plutonium, like other actinides, readily forms a dioxide plutonyl core (PuO2). In the environment, this plutonyl core readily complexes with carbonate as well as other oxygen moieties (OH−, NO2−, NO3−, and SO42−) to form charged complexes which can be readily mobile with low affinities to soil.[citation needed]

  • PuO2(CO3)12−
  • PuO2(CO3)24−
  • PuO2(CO3)36−

PuO2 formed from neutralizing highly acidic nitric acid solutions tends to form polymeric PuO2 which is resistant to complexation. Plutonium also readily shifts valences between the +3, +4, +5 and +6 states. It is common for some fraction of plutonium in solution to exist in all of these states in equilibrium.[citation needed]

Binding to soil

Plutonium is known to bind to soil particles very strongly (see above for an X-ray spectroscopic study of plutonium in soil and concrete). While caesium has very different chemistry to the actinides, it is well known that both caesium and many of the actinides bind strongly to the minerals in soil. Hence it has been possible to use 134Cs labeled soil to study the migration of Pu and Cs in soils. It has been shown that colloidal transport processes control the migration of Cs (and will control the migration of Pu) in the soil at the Waste Isolation Pilot Plant according to R.D. Whicker and S.A. Ibrahim.[29] J.D. Chaplin et al. recently reported advances in the Diffusive gradients in thin films technique, which have provided a method to measure labile bioavailable Plutonium in soils, as well as in freshwater and seawater.[30]

Microbiological chemistry

Mary Neu (at Los Alamos in the USA) has done some work which suggests that bacteria can accumulate plutonium because the iron transport systems used by the bacteria also function as plutonium transport systems.[31][32][33]

Biology

Plutonium ingested by or injected into humans is transported in the

glove box worker were to cut his or her hand with a plutonium-contaminated object. The calcium complex has faster metal binding kinetics than the zinc
complex but if the calcium complex is used for a long time it tends to remove important minerals from the person. The zinc complex is less able to cause these effects.

Plutonium that is inhaled by humans lodges in the lungs and is slowly translocated to the

lymph nodes. Inhaled plutonium has been shown to lead to lung cancer in experimental animals.[37]

See also

References

  1. ^ a b "Plutopia".
  2. ^ a b c d Robert Lindley (2013). "Kate Brown: Nuclear "Plutopias" the Largest Welfare Program in American History". History News Network.
  3. ^ "Plutonium" (PDF). Human Health Fact Sheet. Argonne National Laboratory, EVS. August 2005. Archived from the original (PDF) on 2009-02-25. Retrieved 2009-07-06.
  4. ^ P.K. Kuroda, Accounts of Chemical Research, 1979, 12(2), 73-78 [1]
  5. ^ Kuroda, P. K., and Myers, W. A. "Plutonium-244 Dating III Initial Ratios of Plutonium to Uranium in Lunar Samples". Journal of Radioanalytical and Nuclear Chemistry 150, 71.
  6. ^ Myers, W. A., and Kuroda, P. K. "Plutonium-244 Dating IV. Initial Ratios of Plutonium to Uranium in the Renazzo, Mokoia and Groznaya Meteorite". Journal of Radioanalytical and Nuclear Chemistry 152, 99.
  7. ^ Kuroda, P. K. "Plutonium-244 in the Early Solar System and the Pre-Fermi Natural Reactor" (The Shibata Prize Awardee's Lecture). Geochemical Journal 26, 1. (1992)
  8. ^ O. F. X. Donard, F. Bruneau, M. Moldovan, H. Garraud, V. N. Epov, and D. Boust. Analytica Chimica Acta 2007, 587, 170–179
  9. ^ Radiochemistry and Nuclear Chemistry, G. Choppin, J-O. Liljenzin and J. Rydberg, 3rd Ed, Butterworth-Heinemann, 2002
  10. ^ P.P. Parekh, T.M. Semkow, M.A. Torres, D.K. Haines, J.M. Cooper, P.M. Rosenberg and M.E. Kitto, Journal of Environmental Radioactivity, 2006, 85, 103-120
  11. ^ Y. Saito-Kokubu, F. Esaka, K. Yasuda, M. Magara, Y. Miyamoto, S. Sakurai, S. Usuda, H. Yamazaki, S. Yoshikawa and S. Nagaoka, Applied Radiation and Isotopes, 2007, 65(4), 465-468
  12. doi:10.1016/j.jenvrad.2007.01.019
  13. ISBN 92-0-101198-9
    . Retrieved 2009-07-06.
  14. ^ "Resources (martac report)" (PDF). Archived from the original (PDF) on 2011-03-28.
  15. ^ "Alan Parkinson - 2000 National Conference - MAPW Australia". Archived from the original on 2008-02-01.
  16. ^ Attila Vértes [eo; hu], Sándor Nagy, Zoltan Klencsár, Rezső G. Lovas "Handbook of nuclear chemistry", published 2003
  17. ^ "Energy, Waste and the Environment: A Geochemical Perspective" author R. Gieré, Peter Stille. Page 145.
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  20. ^ Grossman, Karl. "Nukes In Space in Wake of Columbia Tragedy". Hieronymous & Company. Retrieved 27 August 2012.
  21. ^ Clark, David L. (2002-05-29). "Cleanup at Rocky Flats". Los Alamos National Laboratory. Stanford Synchrotron Radiation Lightsource. Retrieved 2009-07-06.
  22. ^ "Plutonium Contamination Valence State Determination Using X-ray Absorption Fine Structure Permits Concrete Recycle" (PDF). Archived from the original (PDF) on 20 October 2011.
  23. ^ (Journal of Environmental Radioactivity, 2006, 86, 143-163.)
  24. ^ "International Research Institute for Nuclear Decommissioning┃TOP Page". Archived from the original on 2013-10-16. Retrieved 2013-10-13.
  25. ^ "Request for Information (RFI) for Contaminated Water Issues".
  26. ^ Bunn, Matthew & Col-Gen. E.P. Maslin (2010). "All Stocks of Weapons-Usable Nuclear Materials Worldwide Must be Protected Against Global Terrorist Threats" (PDF). Belfer Center for Science and International Affairs, Harvard University. Retrieved July 26, 2012.
  27. ^ "Wise Nc; Germany: Plutonium Soup As A Murder Weapon?". WISE News Communique. 2001-10-05. Retrieved 2009-07-06.
  28. ^ Hoefer, Hagen. "Clean-up of a GBq-Pu contamination of two apartments, contaminated by the Pu theft at the WAK (Pilot Reprocessing Plant - Karlsruhe)" (PDF).
  29. ^ Journal of Environmental Radioactivity, 2006, 88, 171-188.
  30. S2CID 237307309
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  31. ^ Neu, Mary P. (November 26, 2000). "Siderophore-Mediated Chemistry and Microbial Uptake of Plutonium" (PDF). Chemical Interactions of Actinides in the Environment. Los Alamos Science: 416–417. Retrieved 2009-07-06.
  32. PMID 11478246
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  33. ^ "Bacterial Biotransformations for the In situ Stabilization of Plutonium" (PDF). April 2005. Retrieved 2009-07-06.
  34. ^ "Pentetate calcium trisodium injection (Ca-DTPA)". Cerner Multum. Archived from the original on September 28, 2007. Retrieved 2009-07-06.
  35. ^ ORISE: Radiation Emergency Assistance Center/Training Site
  36. ^ "Pentetate zinc trisodium injection (Zn-DTPA)". Cerner Multum. Archived from the original on September 28, 2007. Retrieved 2009-07-06.
  37. ^ "CDC Radiation Emergencies | Radioisotope Brief: Plutonium-239 (Pu-239)". www.cdc.gov. 2022-04-21. Retrieved 2022-06-17.
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