57-471: (Redirected from Tu ) [REDACTED] Look up TU , tu , tú , or ես in Wiktionary, the free dictionary. Tu or TU may refer to: Language [ edit ] Tu language Tu (cuneiform) , a cuneiform sign tu or tú the 2nd-person singular subject pronoun in many languages; see personal pronoun T–V distinction (from
114-426: A chemical shim produces small but non-negligible quantities of tritium. Tritium is also produced in heavy water-moderated reactors whenever a deuterium nucleus captures a neutron. This reaction has a small absorption cross section , making heavy water a good neutron moderator , and relatively little tritium is produced. Even so, cleaning tritium from the moderator may be desirable after several years to reduce
171-419: A triton ) contains one proton and two neutrons , whereas the nucleus of the common isotope hydrogen-1 ( protium ) contains one proton and no neutrons, and that of non-radioactive hydrogen-2 ( deuterium ) contains one proton and one neutron. Tritium is the heaviest particle-bound isotope of hydrogen. It is one of the few nuclides with a distinct name. The use of the name hydrogen-3, though more systematic,
228-530: A warhead is continually undergoing radioactive decay, becoming unavailable for fusion. Also, its decay product , helium-3, absorbs neutrons. This can offset or reverse the intended effect of the tritium, which was to generate many free neutrons, if too much helium-3 has accumulated. Therefore, boosted bombs need fresh tritium periodically. The estimated quantity needed is 4 grams (0.14 oz) per warhead. To maintain constant levels of tritium, about 0.20 grams (0.0071 oz) per warhead per year must be supplied to
285-446: A Finnish trade union Tunisair (IATA airline code TU) Transunion , a consumer credit reporting agency Tupolev , a Russian aerospace and defence company Teknisk Ukeblad , a Norwegian engineering magazine The Times Union , an Albany newspaper New York City Teachers Union (1916–1964), commonly known as the "TU" Trout Unlimited , conservation group Units of measurement [ edit ] TU (time unit) ,
342-1063: A derisive reference to the University of Texas at Austin by students and supporters of in-state rival Texas A&M University In other countries [ edit ] University of Tartu ( Tartu Ülikool ), Estonia Any Technische Universität , i.e. university of technology in German-speaking countries Technische Universiteit Delft , Netherlands Technische Universiteit Eindhoven , Netherlands Tezpur University , Assam, India Thapar University , Patiala, India Thammasat University , Thailand Tianjin University , Tianjin, China Tibet University , Lhasa, Tibet Autonomous Region, China Tooling University , an American non-profit educational technology company Tribhuvan University , Kathmandu, Nepal Technological Universities of Myanmar Triam Udom Suksa School Other uses [ edit ] Tren Urbano ,
399-648: A fixed production rate, and losses proportional to the inventory. Tritium for American nuclear weapons was produced in special heavy water reactors at the Savannah River Site until their closures in 1988. With the Strategic Arms Reduction Treaty (START) after the end of the Cold War , the existing supplies were sufficient for the new, smaller number of nuclear weapons for some time. 225 kg (496 lb) of tritium
456-525: A helium-cooled pebble bed, also known as a breeder blanket. High-energy neutrons can also produce tritium from lithium-7 in an endothermic reaction, consuming 2.466 MeV. This was discovered when the 1954 Castle Bravo nuclear test produced an unexpectedly high yield. Prior to this test, it was incorrectly assumed that 3 Li would absorb a neutron to become 3 Li , which would beta-decay to 4 Be , which in turn would decay to two 2 He nuclei on
513-478: A moderator of a natural uranium reactor which needs to keep neutron absorption outside the fuel as low as feasible. Some facilities that remove tritium also remove (or at least reduce the content of) O and O, which can – at least in principle – be used for isotope labeling . India, which also has a large fleet of pressurized heavy water reactors (initially CANDU technology but since indigenized and further developed IPHWR technology), also removes at least some of
570-556: A song by Ewa Farna , 2015 Other [ edit ] Tu (film) Here (2003 film) or Tu , a Croatian film Tu , a brand of clothing from Sainsbury's Tu (cake) , a type of Tibetan cake Acronyms [ edit ] Companies and organizations [ edit ] TU (union) , the international union for T-Mobile workers TU Media , a Digital Multimedia Broadcasting mobile companies in Korea Toimihenkilöunioni (Union of Salaried Employees),
627-406: A total timeframe much longer than the duration of the explosion. High-energy neutrons irradiating boron-10 , also occasionally produce tritium: A more common result of boron-10 neutron capture is Li and a single alpha particle . Especially in pressurized water reactors which only partially thermalize neutrons, the interaction between relatively fast neutrons and the boric acid added as
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#1732765476249684-926: A unit of time equal to 1024 microseconds Transmission unit , a historical unit of loss in long distance telephony Tritium unit , a measure of tritium concentration in water (1 tritium atom per 1 × 10 hydrogen atoms, or ~ 0.118 Bq/L) Tuberculin unit , a measure of strength of tuberculin Universities [ edit ] In the United States [ edit ] Taylor University , Indiana Temple University , Pennsylvania Thomas University , Georgia Touro University California , California Touro University Nevada , Nevada Towson University , Maryland Trinity University , Texas Troy University , Alabama Tufts University , Massachusetts Tulane University , Louisiana Tuskegee University , Alabama University of Tulsa , Oklahoma t.u. ,
741-415: Is 9,650 curies per gram (3.57 × 10 Bq /g). Tritium figures prominently in studies of nuclear fusion due to its favorable reaction cross section and the large amount of energy (17.6 MeV) produced through its reaction with deuterium: All atomic nuclei contain protons as their only charged particles. They therefore repel one another because like charges repel ( Coulomb's law ). However, if
798-468: Is a gas at standard temperature and pressure . Combined with oxygen , it forms tritiated water ( H 2 O ). Compared to hydrogen in its natural composition on Earth, tritium has a higher melting point (20.62 K vs. 13.99 K), a higher boiling point (25.04 K vs. 20.27 K), a higher critical temperature (40.59 K vs. 32.94 K) and a higher critical pressure (1.8317 MPa vs. 1.2858 MPa). Tritium's specific activity
855-469: Is about 0.19 millibarn and that of oxygen-17 ( O) is about 240 millibarns. While O is by far the most common isotope of oxygen in both natural oxygen and heavy water; depending on the method of isotope separation , heavy water may be slightly richer in O and O . Due to both neutron capture and (n, α ) reactions (the latter of which produce C , an undesirable long-lived beta emitter, from O) they are net "neutron consumers" and are thus undesirable in
912-404: Is an important component in nuclear weapons; it is used to enhance the efficiency and yield of fission bombs and the fission stages of hydrogen bombs in a process known as " boosting " as well as in external neutron initiators for such weapons. These are devices incorporated in nuclear weapons which produce a pulse of neutrons when the bomb is detonated to initiate the fission reaction in
969-399: Is another isotope of hydrogen, which occurs naturally with an abundance of 0.015%. Their experiment could not isolate tritium, which was first accomplished in 1939 by Luis Alvarez and Robert Cornog , who also realized tritium's radioactivity. Willard Libby recognized in 1954 that tritium could be used for radiometric dating of water and wine . The half life of tritium is listed by
1026-484: Is based on outdated dose calculation standards of National Bureau of Standards Handbook 69 circa 1963. Four millirem per year is about 1.3% of the natural background radiation (~3 mSv). For comparison, the banana equivalent dose (BED) is set at 0.1 μSv, so the statutory limit in the US is set at 400 BED. Updated dose calculation standards based on International Commission on Radiological Protection Report 30 and used in
1083-519: Is different from Wikidata All article disambiguation pages All disambiguation pages TU">TU The requested page title contains unsupported characters : ">". Return to Main Page . Tritium unit Tritium (from Ancient Greek τρίτος (trítos) 'third') or hydrogen-3 (symbol T or H ) is a rare and radioactive isotope of hydrogen with half-life ~12.3 years. The tritium nucleus (t, sometimes called
1140-572: Is much less common. Naturally occurring tritium is extremely rare on Earth. The atmosphere has only trace amounts, formed by the interaction of its gases with cosmic rays . It can be produced artificially by irradiation of lithium or lithium-bearing ceramic pebbles in a nuclear reactor and is a low-abundance byproduct in normal operations of nuclear reactors. Tritium is used as the energy source in radioluminescent lights for watches, night sights for firearms, numerous instruments and tools, and novelty items such as self-illuminating key chains. It
1197-550: Is no practical separation technology on an industrial scale. Accordingly, a controlled environmental release is said to be the best way to treat low-tritium-concentration water." After a public information campaign sponsored by the Japanese government, the gradual release into the sea of the tritiated water began on 24 August 2023 and is the first of four releases through March 2024. The entire process will take "decades" to complete. China reacted with protest. The IAEA has endorsed
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#17327654762491254-531: Is used in a medical and scientific setting as a radioactive tracer . Tritium is also used as a nuclear fusion fuel, along with more abundant deuterium , in tokamak reactors and in hydrogen bombs . Tritium has also been used commercially in Betavoltaic devices such as NanoTritium batteries . Tritium was first detected in 1934 by Ernest Rutherford , Mark Oliphant and Paul Harteck after bombarding deuterium with deuterons (deuterium nuclei). Deuterium
1311-421: Is used in self-powered lighting devices called betalights , which are used for night illumination of firearm sights, watches, exit signs , map lights, navigational compasses (such as current-use M-1950 U.S. military compasses ), knives and a variety of other devices. As of 2000 , commercial demand for tritium is 400 grams (0.88 lb) per year and the cost is $ 30,000 per gram ($ 850,000/oz) or more. Tritium
1368-477: The National Institute of Standards and Technology as 4,500 ± 8 days ( 12.32 ± 0.02 years ) – an annualized rate of approximately 5.5% per year. Tritium decays into helium-3 by beta-minus decay as shown in this nuclear equation: releasing 18.6 keV of energy in the process. The electron 's kinetic energy varies, with an average of 5.7 keV, while the remaining energy is carried off by
1425-602: The Darlington Tritium Recovery Facility (DTRF) attached to the 3,512 MW electric Darlington Nuclear Generating Station in Ontario. The total production at DTRF between 1989 and 2011 was 42.5 kilograms (94 lb) – with an activity of 409 megacuries (15,100 PBq): an average of about 2 kilograms (4.4 lb) per year. Deuterium's absorption cross section for thermal neutrons is about 0.52 millibarn , whereas that of oxygen-16 ( O)
1482-524: The Israeli Basketball Premier League Tu (surname) 屠, a rare Chinese family name Du (surname) 杜 or Tu, a common Chinese family name Music [ edit ] Tú (Canadian band) , a Canadian pop music duo in the late-1980s Tu (American band) , an American duo, formed by member of King Crimson Songs [ edit ] "Tu" (Umberto Tozzi song) , 1978 "Tu", a song by Umberto Bindi , 1959 "Tu",
1539-645: The Latin pronouns tu and vos ), the use in some languages, of a different personal pronoun for formality or social distance Tsu (kana) , also romanized as tu People and names [ edit ] Tū (Tūmatauenga), a supernatural being in Māori mythology Tu people , the Monguor people of the People's Republic of China Tu language Tu Holloway (born 1989), basketball player for Maccabi Rishon LeZion in
1596-586: The NRC Regulation 10CFR20 results in a dose of 0.9 millirem (9 μSv) per year at 740 Bq/L (20 nCi/L). Tritiation of drug candidates allows detailed analysis of their absorption and metabolism . Tritium has also been used for biological radiometric assays, in a process akin to radiocarbon dating . For example, [ H] retinyl acetate was traced through the bodies of rats. The beta particles from small amounts of tritium cause chemicals called phosphors to glow. This radioluminescence
1653-588: The Tritiated Water Task Force released a report on the status of tritium in tritiated water at Fukushima Daiichi nuclear plant , as part of considering options for final disposal of the stored contaminated cooling water. This identified that the March 2016 holding of tritium on-site was 760 TBq (equivalent to 2.1 g of tritium or 14 mL of pure tritiated water) in a total of 860,000 m of stored water. This report also identified
1710-471: The U.S. Environmental Protection Agency , self-illuminating exit signs improperly disposed in municipal landfills have been found to contaminate waterways. The legal limits for tritium in drinking water vary widely from country to country. Some figures are given below: The American limit results in a dose of 4.0 millirems (or 40 micro sieverts in SI units ) per year per EPA regulation 40CFR141, and
1767-1007: The US. In one case, leaking water contained 7.5 microcuries (280 kBq) of tritium per liter, which is 375 times the current EPA limit for drinking water, and 28 times the World Health Organization 's recommended limit. This is equivalent to 0.777 nanograms per litre (5.45 × 10 gr/imp gal) or roughly 0.8 parts per trillion . The US Nuclear Regulatory Commission states that in normal operation in 2003, 56 pressurized water reactors released 40,600 curies (1,500,000 GBq) of tritium (maximum: 2,080 Ci (77,000 GBq); minimum: 0.1 Ci (3.7 GBq); average: 725 Ci (26,800 GBq)) and 24 boiling water reactors released 665 Ci (24.6 TBq) (maximum: 174 Ci (6,400 GBq); minimum: 0 Ci; average: 27.7 Ci (1,020 GBq)), in liquid effluents. 40,600 Ci (1,500,000 GBq) of tritium weigh about 4.207 grams (0.1484 oz). According to
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1824-513: The atoms have a high enough temperature and pressure (for example, in the core of the Sun), then their random motions can overcome such repulsion, and they can come close enough for the strong nuclear force to take effect, fusing them into heavier atoms. A tritium nucleus (triton), containing one proton and two neutrons, has the same charge as any hydrogen nucleus, and it experiences the same electrostatic repulsion when close to another nucleus. However,
1881-409: The decay (along with that of rhenium-187 ) useful for absolute neutrino mass measurements in the laboratory. The low energy of tritium's radiation makes it difficult to detect tritium-labeled compounds except by using liquid scintillation counting . Tritium is most often produced in nuclear reactors by neutron activation of lithium-6 . The release and diffusion of tritium and helium produced by
1938-513: The enactment of the Partial Nuclear Test Ban Treaty proved to be unexpectedly useful to oceanographers. The high levels of tritium oxide introduced into upper layers of the oceans have been used in the years since then to measure the rate of mixing of the upper layers of the oceans with their lower levels. Since tritium is a low energy beta (β) emitter , it is not dangerous externally (its β particles cannot penetrate
1995-451: The environment. The biological half-life of tritiated water in the human body, which is a measure of body water turn-over, varies with the season. Studies on the biological half-life of occupational radiation workers for free water tritium in a coastal region of Karnataka , India, show that the biological half-life in winter is twice that of the summer. If tritium exposure is suspected or known, drinking uncontaminated water will help replace
2052-443: The fission fuel depletes and also explodes outward, it falls below the density needed to stay critical by itself, but the fusion neutrons make the fission process progress faster and continue longer than it would without boosting. Increased yield comes overwhelmingly from the increased fission. The energy from the fusion itself is much smaller because the amount of fusion fuel is much smaller. Effects of boosting include: The tritium in
2109-672: The fission of lithium can take place within ceramics known as breeder ceramics . Production of tritium from lithium-6 in such breeder ceramics is possible with neutrons of any energy, though the cross section is higher when the incident neutrons have lower energy, reaching more than 900 barns for thermal neutrons . This is an exothermic reaction, yielding 4.8 MeV . In comparison, fusion of deuterium with tritium releases about 17.6 MeV. For applications in proposed fusion energy reactors, such as ITER , pebbles consisting of lithium bearing ceramics including Li 2 TiO 3 and Li 4 SiO 4 , are being developed for tritium breeding within
2166-431: The fissionable core (pit) of the bomb, after it is compressed to a critical mass by explosives. Actuated by an ultrafast switch like a krytron , a small particle accelerator drives ions of tritium and deuterium to energies above the 15 keV or so needed for deuterium-tritium fusion and directs them into a metal target where the tritium and deuterium are adsorbed as hydrides . High-energy fusion neutrons from
2223-420: The metabolism of OBT is less understood than that of H HO. Tritium can incorporate to RNA and DNA molecules within organisms which can lead to somatic and genetic impacts. These can emerge in later generations. H HO 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 H HO from
2280-574: The metro system in San Juan, Puerto Rico Tu Hundred , a district of Vccästmanland in Sweden Universal Time , "Tempus Universalis" Thulium , a chemical element with obsolete symbol Tu Translation unit , a single cognitive unit of text Translation unit (programming) , the ultimate input to the compiler See also [ edit ] Tú (disambiguation) UT (disambiguation) Tuesday Topics referred to by
2337-407: The most important reaction for natural production, a fast neutron (which must have energy greater than 4.0 MeV ) interacts with atmospheric nitrogen : Worldwide, the production of tritium from natural sources is 148 peta becquerels per year. The global equilibrium inventory of tritium created by natural sources remains approximately constant at 2,590 petabecquerels. This is due to
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2394-409: The nearly undetectable electron antineutrino . Beta particles from tritium can penetrate only about 6.0 millimetres (0.24 in) of air, and they are incapable of passing through the dead outermost layer of human skin. Because of their low energy compared to other beta particles, the amount of bremsstrahlung generated is also lower. The unusually low energy released in the tritium beta decay makes
2451-401: The neutrons in the triton increase the attractive strong nuclear force when close enough to another nucleus. As a result, tritium can fuse more easily with other light atoms, than ordinary hydrogen can. The same is true, albeit to a lesser extent, of deuterium. This is why brown dwarfs ("failed" stars ) cannot fuse normal hydrogen, but they do fuse a small minority of deuterium nuclei. Like
2508-498: The operation of nuclear reactors , especially in the reprocessing of nuclear fuel and storage of spent nuclear fuel . The production of tritium is not a goal, but a side-effect. It is discharged to the atmosphere in small quantities by some nuclear power plants. Voloxidation is an optional additional step in nuclear reprocessing that removes volatile fission products (such as all isotopes of hydrogen) before an aqueous process begins. This would in principle enable economic recovery of
2565-476: The other isotopes of hydrogen , tritium is difficult to confine. Rubber, plastic, and some kinds of steel are all somewhat permeable. This has raised concerns that if tritium were used in large quantities, in particular for fusion reactors , it might contribute to radioactive contamination , though its short half-life should prevent significant long-term accumulation in the atmosphere. The high levels of atmospheric nuclear weapons testing that took place prior to
2622-448: The pit. Before detonation, a few grams of tritium–deuterium gas are injected into the hollow " pit " of fissile material. The early stages of the fission chain reaction supply enough heat and compression to start deuterium–tritium fusion; then both fission and fusion proceed in parallel, the fission assisting the fusion by continuing heating and compression, and the fusion assisting the fission with highly energetic (14.1- MeV ) neutrons. As
2679-510: The plan. The water released is diluted to reduce the tritium concentration to less than 1500 Bq/L, far below the limit recommended in drinking water by the WHO. Tritium's decay product helium-3 has a very large cross section (5330 barns) for reacting with thermal neutrons , expelling a proton; hence, it is rapidly converted back to tritium in nuclear reactors . Tritium occurs naturally due to cosmic rays interacting with atmospheric gases. In
2736-470: The produced tritium but even if the tritium is only disposed and not used, it has the potential to reduce tritium contamination in the water used, reducing radioactivity released when the water is discharged since tritiated water cannot be removed from "ordinary" water except by isotope separation. Given the specific activity of tritium at 9,650 curies per gram (357 TBq/g), one TBq is equivalent to roughly 2.8 milligrams (0.043 gr). In June 2016
2793-634: The reactors of the commercial Watts Bar Nuclear Plant from 2003 to 2005 followed by extraction of tritium from the rods at the Tritium Extraction Facility at the Savannah River Site beginning in November 2006. Tritium leakage from the rods during reactor operations limits the number that can be used in any reactor without exceeding the maximum allowed tritium levels in the coolant. Tritium has an atomic mass of 3.016 049 28 Da . Diatomic tritium ( T 2 or H 2 )
2850-417: The reducing concentration of tritium in the water extracted from the buildings etc. for storage, seeing a factor of ten decrease over the five years considered (2011–2016), 3.3 MBq/L to 0.3 MBq/L (after correction for the 5% annual decay of tritium). According to a report by an expert panel considering the best approach to dealing with this issue, " Tritium could be separated theoretically , but there
2907-400: The resulting fusion radiate in all directions. Some of these strike plutonium or uranium nuclei in the primary's pit, initiating a nuclear chain reaction . The quantity of neutrons produced is large in absolute numbers, allowing the pit to quickly achieve neutron levels that would otherwise need many more generations of chain reaction, though still small compared to the total number of nuclei in
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#17327654762492964-407: The risk of its escaping to the environment. Ontario Power Generation 's "Tritium Removal Facility" is capable of processing up to 2,500 tonnes (2,500 long tons; 2,800 short tons) of heavy water a year, and it separates out about 2.5 kg (5.5 lb) of tritium, making it available for other uses. CANDU reactors typically produce 130 grams (4.6 oz) of tritium per year, which is recovered at
3021-401: The same term [REDACTED] This disambiguation page lists articles associated with the title TU . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=TU&oldid=1258229341 " Category : Disambiguation pages Hidden categories: Short description
3078-442: The skin), but it can be a radiation hazard if inhaled, ingested via food or water, or absorbed through the skin. Organisms can take up H HO, as they would H 2 O. Plants convert H HO into organically bound tritium (OBT), and are consumed by animals. H HO is retained in humans for around 12 days, with a small portion of it remaining in the body. Tritium can be passed along the food chain as one organism feeds on another, though
3135-433: The tritium from the body. Increasing sweating, urination or breathing can help the body expel water and thereby the tritium contained in it. However, care should be taken that neither dehydration nor a depletion of the body's electrolytes results, as the health consequences of those things (particularly in the short term) can be more severe than those of tritium exposure. Tritium has leaked from 48 of 65 nuclear sites in
3192-556: The tritium produced in the moderator/coolant of its reactors but due to the dual use nature of tritium and the Indian nuclear bomb program, less information about this is publicly available than for Canada. Tritium is an uncommon product of the nuclear fission of uranium-235 , plutonium-239 , and uranium-233 , with a production of about one atom per 10 fissions. The main pathways of tritium production include ternary fission . The release or recovery of tritium needs to be considered in
3249-400: Was produced in the United States from 1955 to 1996. Since it continually decays into helium-3, the total amount remaining was about 75 kg (165 lb) at the time of the report, and about 16 kg (35 lb) as of 2023. Tritium production was resumed with irradiation of rods containing lithium (replacing the usual control rods containing boron , cadmium , or hafnium ), at
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