Tritiated water

Last updated
Tritium-oxide-2D.png
Tritiated-water-3D-vdW.png
Names
IUPAC name
[3H]2-water
Systematic IUPAC name
(3H2)Water
Other names
  • Super-heavy water
  • Tritium oxide
  • Ditritium oxide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
MeSH tritium+oxide
PubChem CID
  • InChI=1S/H2O/h1H2/i/hT2 X mark.svgN
    Key: XLYOFNOQVPJJNP-PWCQTSIFSA-N X mark.svgN
  • [3H]O[3H]
Properties
T2O or 3H2O
Molar mass 22.0315 g·mol−1
Density 1.21 g/mL
Melting point 4.48 °C (40.06 °F; 277.63 K) [1]

[2] [3]

Boiling point 101.51 °C (214.72 °F; 374.66 K)
Hazards
Main hazards
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Tritiated water is a radioactive form of water in which the usual protium atoms are replaced with tritium. In its pure form it may be called tritium oxide (T2O or 3H2O) or super-heavy water. Pure T2O is corrosive due to self-radiolysis. Diluted, tritiated water is mainly H2O plus some HTO (3HOH). It is also used as a tracer for water transport studies in life-science research. Furthermore, since it naturally occurs in minute quantities, it can be used to determine the age of various water-based liquids, such as vintage wines.

Contents

The name super-heavy water helps distinguish the tritiated material from heavy water, which contains deuterium instead.

Applications

Tritiated water can be used to measure the total volume of water in one's body. Tritiated water distributes itself into all body compartments relatively quickly. The concentration of tritiated water in urine is assumed to be similar to the concentration of tritiated water in the body. Knowing the original amount of tritiated water that was ingested and the concentration, one can calculate the volume of water in the body.

Adverse health effects

Tritiated water contains the radioactive hydrogen isotope tritium. As a low energy beta emitter with a half-life of about 12 years, it is not dangerous externally because its beta particles are unable to penetrate the skin. However, it is a radiation hazard when inhaled, ingested via food or water, or absorbed through the skin. [4] [5] HTO has a short biological half-life in the human body of 7 to 14 days, which both reduces the total effects of single-incident ingestion and precludes long-term bioaccumulation of HTO from the environment. [5] [6] Biological half-life of tritiated water in the human body, which is a measure of body water turnover, varies with season. Studies on the biological half-life of occupational radiation workers for free water tritium in the coastal region of Karnataka, India show that the biological half-life in the winter season is twice that of the summer season. [6]

Related Research Articles

Heavy water Form of water

Heavy water is a form of water that contains only deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water. The presence of the heavier hydrogen isotope gives the water different nuclear properties, and the increase of mass gives it slightly different physical and chemical properties when compared to normal water.

Polonium Chemical element, symbol Po and atomic number 84

Polonium is a chemical element with the symbol Po and atomic number 84. Polonium is a chalcogen. A rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 in uranium ores, as it is the penultimate daughter of natural uranium-238. Though slightly longer-lived isotopes exist, they are much more difficult to produce. Today, polonium is usually produced in milligram quantities by the neutron irradiation of bismuth. Due to its intense radioactivity, which results in the radiolysis of chemical bonds and radioactive self-heating, its chemistry has mostly been investigated on the trace scale only.

Radium Chemical element, symbol Ra and atomic number 88

Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) on exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are highly radioactive, with the most stable isotope being radium-226, which has a half-life of 1600 years and decays into radon gas (specifically the isotope radon-222). When radium decays, ionizing radiation is a by-product, which can excite fluorescent chemicals and cause radioluminescence.

Tritium Isotope of hydrogen with 2 neutrons

Tritium or hydrogen-3 is a rare and radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of the common isotope hydrogen-1 (protium) contains just one proton, and that of hydrogen-2 (deuterium) contains one proton and one neutron.

Nuclear chemistry branch of chemistry concerned with radioactivity, transmutation and other nuclear processes

Nuclear chemistry is the sub-field of chemistry dealing with radioactivity, nuclear processes, and transformations in the nuclei of atoms, such as nuclear transmutation and nuclear properties.

Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination.

A radioactive tracer, radiotracer, or radioactive label, is a chemical compound in which one or more atoms have been replaced by a radionuclide so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling.

Radioactive contamination US safety regulations for nuclear power and weapons

Radioactive contamination, also called radiological contamination, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids or gases, where their presence is unintended or undesirable.

Nuclear fission product Atoms or particles produced by nuclear fission

Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release of heat energy, and gamma rays. The two smaller nuclei are the fission products..

Tritium radioluminescence Use of gaseous tritium to create visible light

Tritium radioluminescence is the use of gaseous tritium, a radioactive isotope of hydrogen, to create visible light. Tritium emits electrons through beta decay and, when they interact with a phosphor material, light is emitted through the process of phosphorescence. The overall process of using a radioactive material to excite a phosphor and ultimately generate light is called radioluminescence. As tritium illumination requires no electrical energy, it has found wide use in applications such as emergency exit signs, illumination of wristwatches, and portable yet very reliable sources of low intensity light which won't degrade human night vision. Gun sights for night use and small lights used mostly by military personnel fall under the latter application.

Neutron activation Induction of radioactivity by neutron radiation

Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitting gamma rays, or particles such as beta particles, alpha particles, fission products, and neutrons. Thus, the process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product. Such radioactive nuclei can exhibit half-lives ranging from small fractions of a second to many years.

Iodine-131 is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nuclear energy, medical diagnostic and treatment procedures, and natural gas production. It also plays a major role as a radioactive isotope present in nuclear fission products, and was a significant contributor to the health hazards from open-air atomic bomb testing in the 1950s, and from the Chernobyl disaster, as well as being a large fraction of the contamination hazard in the first weeks in the Fukushima nuclear crisis. This is because 131I is a major fission product of uranium and plutonium, comprising nearly 3% of the total products of fission. See fission product yield for a comparison with other radioactive fission products. 131I is also a major fission product of uranium-233, produced from thorium.

Isotopes of hydrogen hydrogen with different numbers of neutrons

Hydrogen (1H) has three naturally occurring isotopes, sometimes denoted 1
H
, 2
H
, and 3
H
. 1
H
and 2
H
are stable, while 3
H
has a half-life of 12.32±0.02 years. Heavier isotopes also exist, all of which are synthetic and have a half-life of less than one zeptosecond (10−21 s). Of these, 5H is the least stable, while 7H is the most.

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Environmental radioactivity Radioactivity naturally present within the Earth

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Radioactivity in the life sciences

Radioactivity is generally used in life sciences for highly sensitive and direct measurements of biological phenomena, and for visualizing the location of biomolecules radiolabelled with a radioisotope.

Nuclear transmutation Conversion of an atom from one element to another

Nuclear transmutation is the conversion of one chemical element or an isotope into another chemical element. Nuclear transmutation occurs in any process where the number of protons or neutrons in the nucleus of an atom is changed.

The committed dose in radiological protection is a measure of the stochastic health risk due to an intake of radioactive material into the human body. Stochastic in this context is defined as the probability of cancer induction and genetic damage, due to low levels of radiation. The SI unit of measure is the sievert.

In chemistry, the decay technique is a method to generate chemical species such as radicals, carbocations, and other potentially unstable covalent structures by radioactive decay of other compounds. For example, decay of a tritium-labeled molecule yields an ionized helium atom, which might then break off to leave a cationic molecular fragment.

References

  1. W. M. Jones (1952). "The Triple Point Temperature of Tritium Oxide". Journal of the American Chemical Society. 74 (23): 6065–6066. doi:10.1021/ja01143a070.
  2. "hydrogen (H) - chemical element".
  3. Paesani, Francesco; Yoo, Soohaeng; Bakker, Huib J.; Xantheas, Sotiris S. (5 August 2010). "Nuclear Quantum Effects in the Reorientation of Water". J. Phys. Chem. Lett. 1 (15): 2316–2321. doi:10.1021/jz100734w.
  4. Osborne, R.V. (August 2007) Review of the Greenpeace report: "Tritium Hazard Report: Pollution and Radiation Risk from Canadian Nuclear Facilities", nuclearfaq.ca
  5. 1 2 Fact Sheet on Tritium, Radiation Protection Limits, and Drinking Water Standards, U.S. Nuclear Regulatory Commission
  6. 1 2 Singh, V. P.; Pai, R. K.; Veerender, D. D.; Vishnu, M. S.; Vijayan, P.; Managanvi, S. S.; Badiger, N. M.; Bhat, H. R. (2010). "Estimation of biological half-life of tritium in coastal region of India". Radiation Protection Dosimetry. 142 (2–4): 153–159. doi:10.1093/rpd/ncq219. PMID   20870665.