氚

**氚，³H**
基本
符号	3H
名称	氚, H-3, 超重氢
原子序	1
中子数	2
CAS号	15086-10-9
核素数据
丰度	10-18
半衰期	12.43年
衰变产物	3He
原子量	3.0160492 u
自旋	½
过剩能量	14,949.794± 0.001 keV
结合能	8,481.821± 0.004 keV
衰变模式
衰变类型	衰变能量 (MeV)
β衰变	0.018590
	氢的同位素 ; 完整核素表

氚（Tritium；符号：T或³H，注音：ㄔㄨㄢ；拼音：chuān）。亦称超重氢，是氢的同位素之一，元素符号为T或³H。它的原子核由一颗质子和两颗中子所组成，并带有放射性，会发生β衰变，放出电子变成氦-3，其半衰期为12.43年。

其名称Tritium源至现代希腊语：τρίτος，罗马化：trítos，意为“第三”。

由于氚的β衰变只会放出高速移动的电子，不会穿透人体，因此只有大量吸入氚才会对人体有害。

在地球的自然界中，相比一般的氢气，氚的含量极少。氚的产生是当宇宙射线所带的高能量中子撞击氘核，其氘核与中子结合为氚核。

氚与氘之用途类同，都是制造氢弹的原料。另外氚还可作为不需电源、有自发光能力，供暗处识别用的氚管。

氚的半衰期只有12.43年，每过12.43年就要减少一半，所以地球诞生之初存在的氚早已衰变得无影无踪了。自然界中的氚，是宇宙射线的产物，只有几千克，所以大部分是人工合成。

历史

1934年，欧内斯特·卢瑟福、马克·奥利芬特和保罗·哈特克在用氘核（由一个质子和中子组成）轰击氘后，首次发现了氚。^[2]^[3]路易斯·阿尔瓦雷茨和罗伯特·科诺格在实验中成功分离了氚，并发现了氚的放射性。^[4]^[5]威拉得·利比发现到氚可用于水和葡萄酒的放射性定年法。^[6]

衰变

氚的半衰期有多个不同的测定值。美国国家标准与技术研究院的数据为4500±8天，即12.32±0.02年。^[7]氚通过β衰变变成氦-3：

$\ce{^3_1H \to ^3_2{He^+} + {e^-} + \bar{\nu}_e}$

同时释放18.6 keV的能量。电子的动能变化平均为5.7 keV，剩余能量由几乎无法探测的电中微子带走。另外，产生的β粒子只能穿透约6.0毫米的空气，无法穿过人体皮肤的最外层。^[8]

生产

锂

氚最常见的生产方式就是透过核子反应，对锂-6进行中子活化。由锂裂变可以在陶瓷中产生氚和氦，并发生释放和扩散，称为陶瓷滋生器。在这种陶瓷滋生器中从锂-6生产氚可以使用任何能量 (高速或低速) 的中子，并且是产生 4.8 MeV 的放热反应。相比之下，氘氚聚变只释放大约 17.6 MeV 的能量。对于聚变能反应堆的应用，例如国际热核聚变实验反应堆，由含锂陶瓷组成的鹅卵石，包括 Li₂TiO₃ 和 Li₄SiO₄，正在开发用于在氦冷卵石床（也称为滋生器围包）内进行氚繁殖。 ^[9]

⁶₃Li

+

n → ⁴₂He (2.05 MeV) + ³₁T (2.75 MeV)

高能中子可以从锂-7，经由吸热反应(净热量消耗)产生氚，消耗约2.466 MeV。这项过程在1954年的布拉弗城堡核试验中，因产生超出预期的高能量而被发现。 ^[10]

⁷₃Li

+

n → ⁴₂He + ³₁T + n

硼

具有高能中子放射性的硼-10偶尔会制造出氚:^[11]

¹⁰₅B

+

n → 2 ⁴₂He + ³₁T

在硼中子捕获中更加常见的结果是⁷Li以及一颗Α粒子.^[12]

氘

在重水压水堆里，每当氘核俘获中子时，会产生氚。该反应具有相当小的吸收截面，使重水成为良好的中子减速剂，并且产生的氚相对较少。即便如此，几年后从慢化剂中清除氚可能是可取的，以减少其逃逸到环境中的风险。安省电力公司的“氚去除设施”每年处理多达2,500公吨（2,500长吨；2,800短吨）的重水，并分离出约2.5千克（5.5磅）的氚，使其可用于其他用途。^[13]

裂变

氚是铀-235、钚-239、铀-233进行核裂变时罕见的产物，约 10,000 次分裂才会产生一个氚原子 ^[14]^[15]

在核反应堆的运行中，尤其是在核燃料后处理和乏核燃料的储存中，需要考虑氚的释放或回收。氚的生产不是目标，而是副作用。它被一些核电站少量排放到大气中。^[16]

每年核设施的氚排放量^[17]
地点	核设施	最近的水域	液体排放量 (TBq)	蒸汽排放量 (TBq)	总和 (TBq)	年
英国	希舍姆核电站B	爱尔兰海	396	2.1	398	2019
英国	塞拉菲尔德后处理设施	爱尔兰海	423	56	479	2019
罗马尼亚	切尔纳沃德核电站一号机	黑海	140	152	292	2018
法国	拉海格区	英吉利海峡	11,400	60	11,460	2018
韩国	月城核电站和其它	日本海	211	154	365	2020^[18]
中国台湾	第三核能发电厂	吕宋海峡	35	9.4	44	2015
中国	福清核电站	台湾海峡	52	0.8	52	2020
中国	三门核电站	东海	20	0.4	20	2020
加拿大	布鲁斯核电站A和B	五大湖	756	994	1,750	2018
加拿大	达灵顿核电站	五大湖	220	210	430	2018
加拿大	皮克灵核电站一到四号机	五大湖	140	300	440	2015
美国	魔鬼谷核电站一和二号机	太平洋	82	2.7	84	2019

福岛第一核电站

2016年6月，氚水任务小组提交了一份针对福岛第一核电站有关氚在辐射污染水中状态的报告 ^[19] ^[20]

氦-3

氚的核裂变产物氦-3 有非常大的热中子反应截面积 (5330 barns)反应会释放出一颗质子，因此很快又会转变回核反应堆里的氚^[21]

³₂He + n → ¹₁H + ³₁T

宇宙射线

宇宙射线和大气发生作用，产生天然的氚。在自然产生的氚中，最重要的反应是快中子（能量大于 4.0 MeV^[22]）和大气中的氮的反应：

¹⁴₇N

+

n → ¹²₆C + ³₁T

在世界范围内，来自天然来源的氚的产量为每年148拍它贝克勒尔。由天然来源产生的氚的全球平衡库存大致保持在2,590拍它贝克勒尔的浓度。这是由于固定的氚生产率和与库存成正比的衰变损失。^[23]

生产历史

^[24] ^[25]^[26]^[27]

浓缩

蒸馏法、化学交换法、触媒交换/低温蒸馏法、电解法、热扩散法。^[28]

参见

参考资料

↑ Tritium. Encyclopedia Britannica. [2021-04-14] （英语）.
↑ Oliphant, M.L.; Harteck, P.; Rutherford, L. Transmutation effects observed with heavy hydrogen. Nature. 1934, 133 (3359): 413. Bibcode:1934Natur.133..413O. doi:10.1038/133413a0.
↑ Oliphant, M.L.E.; Harteck, P.; Rutherford, L. Transmutation Effects Observed with Heavy Hydrogen. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 1934, 144 (853): 692. Bibcode:1934RSPSA.144..692O. doi:10.1098/rspa.1934.0077.
↑ Alvarez, Luis; Cornog, Robert. Helium and Hydrogen of Mass 3. Physical Review. 1939, 56 (6): 613. Bibcode:1939PhRv...56..613A. doi:10.1103/PhysRev.56.613.
↑ Alvarez, Luis W.; Trower, W. Peter. Discovering Alvarez: Selected works of Luis W. Alvarez, with commentary by his students and colleagues. University of Chicago Press. 1987: 26–30. ISBN 978-0-226-81304-2.
↑ Kaufman, Sheldon; Libby, W. The natural distribution of tritium. Physical Review. 1954, 93 (6): 1337. Bibcode:1954PhRv...93.1337K. doi:10.1103/PhysRev.93.1337.
↑ Lucas, L.L.; Unterweger, M. P. Comprehensive review and critical evaluation of the half-life of tritium. Journal of Research of the National Institute of Standards and Technology. 2000, 105 (4): 541–549. PMC 4877155 . PMID 27551621. doi:10.6028/jres.105.043.
↑ Hydrogen-3 (PDF). ehso.emory.edu. Nuclide safety data sheet （英语）.
↑ Hanaor, Dorian A.H.; Kolb, Matthias H.H.; Gan, Yixiang; Kamlah, Marc; Knitter, Regina. Solution based synthesis of mixed-phase materials in the Li₂TiO₃–Li₄SiO₄ system. Journal of Nuclear Materials. 2015, 456: 151–161. Bibcode:2015JNuM..456..151H. arXiv:1410.7128 . doi:10.1016/j.jnucmat.2014.09.028.
↑ Zerriffi, Hisham. Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium. Institute for Energy and Environmental Research. 1996-01 [2010-09-15].
↑ Jones, Greg. Tritium Issues in Commercial Pressurized Water Reactors. Fusion Science and Technology. 2008, 54 (2): 329–332. doi:10.13182/FST08-A1824.
↑ Sublette, Carey. Nuclear Weapons FAQ Section 12.0 Useful Tables. Nuclear Weapons Archive. 2006-05-17 [2010-09-19].
↑ Whitlock, Jeremy. Section D: Safety and Liability – How does Ontario Power Generation manage tritium production in its CANDU moderators?. Canadian Nuclear FAQ. [2010-09-19].
↑ Tritium (Hydrogen-3) – Human Health Fact sheet (PDF). Argonne National Laboratory. 2005-08 [2010-09-19]. 已忽略未知参数|df= (帮助)
↑ Serot, O.; Wagemans, C.; Heyse, J. New results on helium and tritium gas production from ternary fission. International Conference on Nuclear Data for Science and Technology. AIP Conference Proceedings 769. American Institute of Physics: 857–860. 2005. Bibcode:2005AIPC..769..857S. doi:10.1063/1.1945141.
↑ Effluent Releases from Nuclear Power Plants and Fuel-Cycle Facilities. National Academies Press (US). 2012-03-29 （英语）.
↑ Basic policy on handling of the ALPS treated water (PDF). Ministry of Economy, Trade and Industry. 2021-04-13.
↑ 2020년도 원전주변 환경방사능 조사 및 평가보고서 [2020 Environmental Radiation Survey and Evaluation Report Around Nuclear Power Plant] (PDF). Korea Hydro & Nuclear Power: 25. 2021-04-26.
↑ Tritiated Water Task Force Report (PDF). www.meti.go.jp/english (Tokyo, Japan: Ministry of Economy, Trade and Industry) （英语）.
↑ JP Gov "No drastic technology to remove Tritium was found in internationally collected knowledge". Fukushima Diary. 2013-12.
↑ Helium-3 neutron proportional counters (PDF). mit.edu. Cambridge, MA: Massachusetts Institute of Technology.
↑ Young, P.G. & Foster, D.G., Jr. An evaluation of the neutron and gamma-ray production cross-sections for nitrogen (PDF). Los Alamos, NM: Los Alamos Scientific Laboratory. 1972-09 [2010-09-19]. 已忽略未知参数|name-list-style= (帮助)
↑ Tritium information section. Physics Department. Radiation Information Network. Idaho State University.
↑ Zerriffi, Hisham; Scoville, Herbert Jr. Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium (PDF). Institute for Energy and Environmental Research: 5. 1996-01 [2018-09-06] （英语）.
↑ Defense Programs. Savannah River Site. U.S. Departmentof Energy. [2013-03-20].
↑ Tritium Extraction Facility (PDF). Savannah River Site. Factsheets. U.S. Departmentof Energy. 2007-12 [2010-09-19].
↑ Horner, Daniel. GAO finds problems in tritium production. Arms Control Today (新闻稿). 2010-11.
↑ Vasaru Gheorghe. Tritium isotope separation. [2021-04-27].

[1] Tritium. Encyclopedia Britannica. [2021-04-14] （英语）.

[2] Oliphant, M.L.; Harteck, P.; Rutherford, L. Transmutation effects observed with heavy hydrogen. Nature. 1934, 133 (3359): 413. Bibcode:1934Natur.133..413O. doi:10.1038/133413a0.

[3] Oliphant, M.L.E.; Harteck, P.; Rutherford, L. Transmutation Effects Observed with Heavy Hydrogen. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 1934, 144 (853): 692. Bibcode:1934RSPSA.144..692O. doi:10.1098/rspa.1934.0077.

[4] Alvarez, Luis; Cornog, Robert. Helium and Hydrogen of Mass 3. Physical Review. 1939, 56 (6): 613. Bibcode:1939PhRv...56..613A. doi:10.1103/PhysRev.56.613.

[5] Alvarez, Luis W.; Trower, W. Peter. Discovering Alvarez: Selected works of Luis W. Alvarez, with commentary by his students and colleagues. University of Chicago Press. 1987: 26–30. ISBN 978-0-226-81304-2.

[6] Kaufman, Sheldon; Libby, W. The natural distribution of tritium. Physical Review. 1954, 93 (6): 1337. Bibcode:1954PhRv...93.1337K. doi:10.1103/PhysRev.93.1337.

[7] Lucas, L.L.; Unterweger, M. P. Comprehensive review and critical evaluation of the half-life of tritium. Journal of Research of the National Institute of Standards and Technology. 2000, 105 (4): 541–549. PMC 4877155 . PMID 27551621. doi:10.6028/jres.105.043.

[8] Hydrogen-3 (PDF). ehso.emory.edu. Nuclide safety data sheet （英语）.

[9] Hanaor, Dorian A.H.; Kolb, Matthias H.H.; Gan, Yixiang; Kamlah, Marc; Knitter, Regina. Solution based synthesis of mixed-phase materials in the Li₂TiO₃–Li₄SiO₄ system. Journal of Nuclear Materials. 2015, 456: 151–161. Bibcode:2015JNuM..456..151H. arXiv:1410.7128 . doi:10.1016/j.jnucmat.2014.09.028.

[ieer-10] Zerriffi, Hisham. Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium. Institute for Energy and Environmental Research. 1996-01 [2010-09-15].

[11] Jones, Greg. Tritium Issues in Commercial Pressurized Water Reactors. Fusion Science and Technology. 2008, 54 (2): 329–332. doi:10.13182/FST08-A1824.

[12] Sublette, Carey. Nuclear Weapons FAQ Section 12.0 Useful Tables. Nuclear Weapons Archive. 2006-05-17 [2010-09-19].

[13] Whitlock, Jeremy. Section D: Safety and Liability – How does Ontario Power Generation manage tritium production in its CANDU moderators?. Canadian Nuclear FAQ. [2010-09-19].

[anl-14] Tritium (Hydrogen-3) – Human Health Fact sheet (PDF). Argonne National Laboratory. 2005-08 [2010-09-19]. 已忽略未知参数|df= (帮助)

[15] Serot, O.; Wagemans, C.; Heyse, J. New results on helium and tritium gas production from ternary fission. International Conference on Nuclear Data for Science and Technology. AIP Conference Proceedings 769. American Institute of Physics: 857–860. 2005. Bibcode:2005AIPC..769..857S. doi:10.1063/1.1945141.

[:0-16] Effluent Releases from Nuclear Power Plants and Fuel-Cycle Facilities. National Academies Press (US). 2012-03-29 （英语）.

[Policy-17] Basic policy on handling of the ALPS treated water (PDF). Ministry of Economy, Trade and Industry. 2021-04-13.

[18] 2020년도 원전주변 환경방사능 조사 및 평가보고서 [2020 Environmental Radiation Survey and Evaluation Report Around Nuclear Power Plant] (PDF). Korea Hydro & Nuclear Power: 25. 2021-04-26.

[TWTFR-19] Tritiated Water Task Force Report (PDF). www.meti.go.jp/english (Tokyo, Japan: Ministry of Economy, Trade and Industry) （英语）.

[20] JP Gov "No drastic technology to remove Tritium was found in internationally collected knowledge". Fukushima Diary. 2013-12.

[21] Helium-3 neutron proportional counters (PDF). mit.edu. Cambridge, MA: Massachusetts Institute of Technology.

[22] Young, P.G. & Foster, D.G., Jr. An evaluation of the neutron and gamma-ray production cross-sections for nitrogen (PDF). Los Alamos, NM: Los Alamos Scientific Laboratory. 1972-09 [2010-09-19]. 已忽略未知参数|name-list-style= (帮助)

[physics.isu.edu-RIN-Tritium-23] Tritium information section. Physics Department. Radiation Information Network. Idaho State University.

[IEER_Production-24] Zerriffi, Hisham; Scoville, Herbert Jr. Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium (PDF). Institute for Energy and Environmental Research: 5. 1996-01 [2018-09-06] （英语）.

[25] Defense Programs. Savannah River Site. U.S. Departmentof Energy. [2013-03-20].

[26] Tritium Extraction Facility (PDF). Savannah River Site. Factsheets. U.S. Departmentof Energy. 2007-12 [2010-09-19].

[27] Horner, Daniel. GAO finds problems in tritium production. Arms Control Today (新闻稿). 2010-11.

[28] Vasaru Gheorghe. Tritium isotope separation. [2021-04-27].

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