Isotopes of uranium

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Isotopes of uranium  (92U)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
232U synth 68.9 y α 228Th
SF –
233U trace 1.592×105 y [2] α 229Th
SF–
234U 0.005%2.455×105 yα 230Th
SF–
235U 0.720%7.04×108 yα 231Th
SF–
236U trace2.342×107 yα 232Th
SF–
238U 99.3%4.468×109 yα 234Th
SF–
β−β− 238Pu
Standard atomic weight Ar°(U)

Uranium (92U) is a naturally occurring radioactive element (radioelement) with no stable isotopes. It has two primordial isotopes, uranium-238 and uranium-235, that have long half-lives and are found in appreciable quantity in Earth's crust. The decay product uranium-234 is also found. Other isotopes such as uranium-233 have been produced in breeder reactors. In addition to isotopes found in nature or nuclear reactors, many isotopes with far shorter half-lives have been produced, ranging from 214U to 242U (except for 220U). The standard atomic weight of natural uranium is 238.02891(3).

Contents

Natural uranium consists of three main isotopes, 238U (99.2739–99.2752% natural abundance), 235U (0.7198–0.7202%), and 234U (0.0050–0.0059%). [5] All three isotopes are radioactive (i.e., they are radioisotopes), and the most abundant and stable is uranium-238, with a half-life of 4.4683×109 years (about the age of the Earth).

Uranium-238 is an alpha emitter, decaying through the 18-member uranium series into lead-206. The decay series of uranium-235 (historically called actino-uranium) has 15 members and ends in lead-207. The constant rates of decay in these series makes comparison of the ratios of parent-to-daughter elements useful in radiometric dating. Uranium-233 is made from thorium-232 by neutron bombardment.

Uranium-235 is important for both nuclear reactors (energy production) and nuclear weapons because it is the only isotope existing in nature to any appreciable extent that is fissile in response to thermal neutrons, i.e., thermal neutron capture has a high probability of inducing fission. A chain reaction can be sustained with a large enough (critical) mass of uranium-235. Uranium-238 is also important because it is fertile: it absorbs neutrons to produce a radioactive isotope that decays into plutonium-239, which also is fissile.

List of isotopes


Nuclide
[n 1] 		Historic
name		 Z N Isotopic mass (Da) [6]
[n 2] [n 3] 		Half-life [1]
Decay
mode [1]
[n 4] 		Daughter
isotope
[n 5] [n 6] 		Spin and
parity [1]
[n 7] [n 8] 		Natural abundance (mole fraction)
Excitation energy [n 8] Normal proportion [1] Range of variation
214U [7] 921220.52+0.95
−0.21 ms		 α 210Th0+
215U92123215.026720(11)1.4(0.9) msα211Th5/2−#
β+?215Pa
216U [8] 92124216.024760(30)2.25+0.63
−0.40 ms		α212Th0+
216mU2206 keV0.89+0.24
−0.16 ms		α212Th8+
217U [9] 92125217.024660(86)#19.3+13.3
−5.6 ms		α213Th(1/2−)
β+?217Pa
218U [8] 92126218.023505(15)650+80
−70 μs		α214Th0+
218mU2117 keV390+60
−50 μs		α214Th8+
IT?218U
219U92127219.025009(14)60(7) μsα215Th(9/2+)
β+?219Pa
221U92129221.026323(77)0.66(14) μsα217Th(9/2+)
β+?221Pa
222U92130222.026058(56)4.7(0.7) μsα218Th0+
β+?222Pa
223U92131223.027961(63)65(12) μsα219Th7/2+#
β+?223Pa
224U92132224.027636(16)396(17) μsα220Th0+
β+?224Pa
225U92133225.029385(11)62(4) msα221Th5/2+#
226U92134226.029339(12)269(6) msα222Th0+
227U92135227.0311811(91)1.1(0.1) minα223Th(3/2+)
β+?227Pa
228U92136228.031369(14)9.1(0.2) minα (97.5%)224Th0+
EC (2.5%)228Pa
229U92137229.0335060(64)57.8(0.5) minβ+ (80%)229Pa(3/2+)
α (20%)225Th
230U92138230.0339401(48)20.23(0.02) dα226Th0+
SF  ?(various)
CD (4.8×10−12%)208 Pb
22 Ne
231U92139231.0362922(29)4.2(0.1) dEC231Pa5/2+#
α (.004%)227Th
232U 92140232.0371548(19)68.9(0.4) yα228Th0+
CD (8.9×10−10%)208Pb
24Ne
SF (10−12%)(various)
CD?204Hg
28Mg
233U 92141233.0396343(24)1.592(2)×105 yα229Th5/2+Trace [n 9]
CD (≤7.2×10−11%)209Pb
24Ne
SF ?(various)
CD ?205Hg
28Mg
234U [n 10] [n 11] Uranium II92142234.0409503(12)2.455(6)×105 yα230Th0+[0.000054(5)] [n 12] 0.000050–
0.000059
SF (1.64×10−9%)(various)
CD (1.4×10−11%)206Hg
28Mg
CD (≤9×10−12%)208Pb
26Ne
CD (≤9×10−12%)210Pb
24Ne
234mU1421.257(17) keV33.5(2.0) ms IT 234U6−
235U [n 13] [n 14] [n 15] Actin Uranium
Actino-Uranium		92143235.0439281(12)7.038(1)×108 yα231Th7/2−[0.007204(6)]0.007198–
0.007207
SF (7×10−9%)(various)
CD (8×10−10%)215Pb
20Ne
CD (8×10−10%)210Pb
25Ne
CD (8×10−10%)207Hg
28Mg
235m1U0.076737(18) keV25.7(1) minIT235U1/2+
235m2U2500(300) keV3.6(18) msSF(various)
236U Thoruranium [10] 92144236.0455661(12)2.342(3)×107 yα232Th0+Trace [n 16]
SF (9.6×10−8%)(various)
CD (≤2.0×10−11%) [11] 208Hg
28Mg
CD (≤2.0×10−11%) [11] 206Hg
30Mg
236m1U1052.5(6) keV100(4) nsIT236U4−
236m2U2750(3) keV120(2) nsIT (87%)236U(0+)
SF (13%)(various)
237U92145237.0487283(13)6.752(2) d β− 237Np1/2+Trace [n 17]
237mU274.0(10) keV155(6) nsIT237U7/2−
238U [n 11] [n 13] [n 14] Uranium I92146238.050787618(15) [12] 4.468(3)×109 yα234Th0+[0.992742(10)]0.992739–
0.992752
SF (5.44×10−5%)(various)
β−β− (2.2×10−10%)238Pu
238mU2557.9(5) keV280(6) nsIT (97.4%)238U0+
SF (2.6%)(various)
239U92147239.0542920(16)23.45(0.02) minβ−239Np5/2+Trace [n 18]
239m1U133.7991(10) keV780(40) nsIT239U1/2+
239m2U2500(900)# keV>250 nsSF?(various)0+
IT?239U
240U92148240.0565924(27)14.1(0.1) hβ−240Np0+Trace [n 19]
α?236Th
241U [13] 92149241.06031(5)~40 min [14] [15] β−241Np7/2+#
242U92150242.06296(10) [14] 16.8(0.5) minβ−242Np0+
This table header & footer:
  1. ↑ mU – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ↑ Modes of decay:
    CD: Cluster decay
    EC: Electron capture
    SF: Spontaneous fission
  5. ↑ Bold italics symbol as daughter – Daughter product is nearly stable.
  6. ↑ Bold symbol as daughter – Daughter product is stable.
  7. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  8. 1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  9. ↑ Intermediate decay product of 237Np
  10. ↑ Used in uranium–thorium dating
  11. 1 2 Used in uranium–uranium dating
  12. ↑ Intermediate decay product of 238U
  13. 1 2 Primordial radionuclide
  14. 1 2 Used in Uranium–lead dating
  15. ↑ Important in nuclear reactors
  16. ↑ Intermediate decay product of 244Pu, also produced by neutron capture of 235U
  17. ↑ Neutron capture product, parent of trace quantities of 237Np
  18. ↑ Neutron capture product; parent of trace quantities of 239Pu
  19. ↑ Intermediate decay product of 244Pu

Actinides vs fission products

Actinides and fission products by half-life
Actinides [16] by decay chain Half-life
range (a)		 Fission products of 235U by yield [17]
4n 4n + 1 4n + 2 4n + 3 4.5–7%0.04–1.25%<0.001%
228 Ra№ 4–6 a 155 Euþ
248 Bk [18] > 9 a
244 Cmƒ 241 Puƒ 250 Cf 227 Ac№ 10–29 a 90 Sr 85 Kr 113m Cdþ
232 Uƒ 238 Puƒ 243 Cmƒ 29–97 a 137 Cs 151 Smþ 121m Sn
249 Cfƒ 242m Amƒ141–351 a

No fission products have a half-life
in the range of 100 a–210 ka ...

241 Amƒ 251 Cfƒ [19] 430–900 a
226 Ra№ 247 Bk1.3–1.6 ka
240 Pu 229 Th 246 Cmƒ 243 Amƒ4.7–7.4 ka
245 Cmƒ 250 Cm8.3–8.5 ka
239 Puƒ24.1 ka
230 Th№ 231 Pa№32–76 ka
236 Npƒ 233 Uƒ 234 U№ 150–250 ka 99 Tc₡ 126 Sn
248 Cm 242 Pu 327–375 ka 79 Se₡
1.33 Ma 135 Cs₡
237 Npƒ 1.61–6.5 Ma 93 Zr 107 Pd
236 U 247 Cmƒ 15–24 Ma 129 I₡
244 Pu80 Ma

... nor beyond 15.7 Ma [20]

232 Th№ 238 U№ 235 Uƒ№0.7–14.1 Ga

Uranium-214

Uranium-214 is the lightest known isotope of uranium. It was discovered at the Spectrometer for Heavy Atoms and Nuclear Structure (SHANS) at the Heavy Ion Research Facility in Lanzhou, China in 2021, produced by firing argon-36 at tungsten-182. It alpha-decays with a half-life of 0.5 ms. [21] [22] [23] [24]

Uranium-232

Uranium-232 has a half-life of 68.9 years and is a side product in the thorium cycle. It has been cited as an obstacle to nuclear proliferation using 233U, because the intense gamma radiation from 208Tl (a daughter of 232U, produced relatively quickly) makes 233U contaminated with it more difficult to handle. Uranium-232 is a rare example of an even-even isotope that is fissile with both thermal and fast neutrons. [25] [26]

Uranium-233

Uranium-233 is a fissile isotope that is bred from thorium-232 as part of the thorium fuel cycle. 233U was investigated for use in nuclear weapons and as a reactor fuel. It was occasionally tested but never deployed in nuclear weapons and has not been used commercially as a nuclear fuel. [27] It has been used successfully in experimental nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of around 160,000 years.

Uranium-233 is produced by neutron irradiation of thorium-232. When thorium-232 absorbs a neutron, it becomes thorium-233, which has a half-life of only 22 minutes. Thorium-233 beta decays into protactinium-233. Protactinium-233 has a half-life of 27 days and beta decays into uranium-233; some proposed molten salt reactor designs attempt to physically isolate the protactinium from further neutron capture before beta decay can occur.

Uranium-233 usually fissions on neutron absorption but sometimes retains the neutron, becoming uranium-234. The capture-to-fission ratio is smaller than the other two major fissile fuels, uranium-235 and plutonium-239; it is also lower than that of short-lived plutonium-241, but bested by very difficult-to-produce neptunium-236.

Uranium-234

234U occurs in natural uranium as an indirect decay product of uranium-238, but makes up only 55 parts per million of the uranium because its half-life of 245,500 years is only about 1/18,000 that of 238U. The path of production of 234U is this: 238U alpha decays to thorium-234. Next, with a short half-life, 234Th beta decays to protactinium-234. Finally, 234Pa beta decays to 234U. [28] [29]

234U alpha decays to thorium-230, except for the small percentage of nuclei that undergo spontaneous fission.

Extraction of rather small amounts of 234U from natural uranium would be feasible using isotope separation, similar to normal uranium-enrichment. However, there is no real demand in chemistry, physics, or engineering for isolating 234U. Very small pure samples of 234U can be extracted via the chemical ion-exchange process, from samples of plutonium-238 that have aged somewhat to allow some decay to 234U via alpha emission.

Enriched uranium contains more 234U than natural uranium as a byproduct of the uranium enrichment process aimed at obtaining uranium-235, which concentrates lighter isotopes even more strongly than it does 235U. The increased percentage of 234U in enriched natural uranium is acceptable in current nuclear reactors, but (re-enriched) reprocessed uranium might contain even higher fractions of 234U, which is undesirable. [30] This is because 234U is not fissile, and tends to absorb slow neutrons in a nuclear reactor—becoming 235U. [29] [30]

234U has a neutron capture cross section of about 100 barns for thermal neutrons, and about 700 barns for its resonance integral—the average over neutrons having various intermediate energies. In a nuclear reactor, non-fissile isotopes capture a neutron breeding fissile isotopes. 234U is converted to 235U more easily and therefore at a greater rate than uranium-238 is to plutonium-239 (via neptunium-239), because 238U has a much smaller neutron-capture cross section of just 2.7 barns.

Uranium-235

Uranium-235 makes up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a fission chain reaction. It is the only fissile isotope that is a primordial nuclide or found in significant quantity in nature.

Uranium-235 has a half-life of 703.8 million years. It was discovered in 1935 by Arthur Jeffrey Dempster. Its (fission) nuclear cross section for slow thermal neutron is about 504.81 barns. For fast neutrons it is on the order of 1 barn. At thermal energy levels, about 5 of 6 neutron absorptions result in fission and 1 of 6 result in neutron capture forming uranium-236. [31] The fission-to-capture ratio improves for faster neutrons.

Uranium-236

Uranium-236 has a half-life of about 23 million years; and is neither fissile with thermal neutrons, nor very good fertile material, but is generally considered a nuisance and long-lived radioactive waste. It is found in spent nuclear fuel and in the reprocessed uranium made from spent nuclear fuel.

Uranium-237

Uranium-237 has a half-life of about 6.75 days. It decays into neptunium-237 by beta decay. It was discovered by Japanese physicist Yoshio Nishina in 1940, who in a near-miss discovery, inferred the creation of element 93, but was unable to isolate the then-unknown element or measure its decay properties. [32]

Uranium-238

Uranium-238 (238U or U-238) is the most common isotope of uranium found in nature. It is not fissile, but is fertile: it can capture a slow neutron and after two beta decays become fissile plutonium-239. Uranium-238 is fissionable by fast neutrons, but cannot support a chain reaction because inelastic scattering reduces neutron energy below the range where fast fission of one or more next-generation nuclei is probable. Doppler broadening of 238U's neutron absorption resonances, increasing absorption as fuel temperature increases, is also an essential negative feedback mechanism for reactor control.

About 99.284% of natural uranium is uranium-238, which has a half-life of 1.41×1017 seconds (4.468×109 years). Depleted uranium has an even higher concentration of 238U, and even low-enriched uranium (LEU) is still mostly 238U. Reprocessed uranium is also mainly 238U, with about as much uranium-235 as natural uranium, a comparable proportion of uranium-236, and much smaller amounts of other isotopes of uranium such as uranium-234, uranium-233, and uranium-232.

Uranium-239

Uranium-239 is usually produced by exposing 238U to neutron radiation in a nuclear reactor. 239U has a half-life of about 23.45 minutes and beta decays into neptunium-239, with a total decay energy of about 1.29 MeV. [33] The most common gamma decay at 74.660 keV accounts for the difference in the two major channels of beta emission energy, at 1.28 and 1.21 MeV. [34]

239Np then, with a half-life of about 2.356 days, beta-decays to plutonium-239.

Uranium-241

In 2023, in a paper published in Physical Review Letters , a group of researchers based in Korea reported that they had found uranium-241 in an experiment involving 238U+198Pt multinucleon transfer reactions. [35] [36] Its half-life is about 40 minutes. [35]

Related Research Articles

The actinide or actinoid series encompasses at least the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through nobelium. The actinide series derives its name from the first element in the series, actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide.

<span class="mw-page-title-main">Thorium</span> Chemical element with atomic number 90 (Th)

Thorium is a chemical element. It has the symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive gray when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided.

<span class="mw-page-title-main">Uranium</span> Chemical element with atomic number 92 (U)

Uranium is a chemical element; it has symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes, making them useful for dating the age of the Earth. The most common isotopes in natural uranium are uranium-238 and uranium-235. Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite.

In nuclear engineering, fissile material is material that can undergo nuclear fission when struck by a neutron of low energy. A self-sustaining thermal chain reaction can only be achieved with fissile material. The predominant neutron energy in a system may be typified by either slow neutrons or fast neutrons. Fissile material can be used to fuel thermal-neutron reactors, fast-neutron reactors and nuclear explosives.

<span class="mw-page-title-main">Nuclear fuel cycle</span> Process of manufacturing and consuming nuclear fuel

The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in the back end, which are necessary to safely manage, contain, and either reprocess or dispose of spent nuclear fuel. If spent fuel is not reprocessed, the fuel cycle is referred to as an open fuel cycle ; if the spent fuel is reprocessed, it is referred to as a closed fuel cycle.

Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material, usually consisting of plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium fuel used in the light-water reactors that predominate nuclear power generation.

<span class="mw-page-title-main">Uranium-238</span> Isotope of uranium

Uranium-238 is the most common isotope of uranium found in nature, with a relative abundance of 99%. Unlike uranium-235, it is non-fissile, which means it cannot sustain a chain reaction in a thermal-neutron reactor. However, it is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239. 238U cannot support a chain reaction because inelastic scattering reduces neutron energy below the range where fast fission of one or more next-generation nuclei is probable. Doppler broadening of 238U's neutron absorption resonances, increasing absorption as fuel temperature increases, is also an essential negative feedback mechanism for reactor control.

<span class="mw-page-title-main">Uranium-234</span> Isotope of uranium

Uranium-234 is an isotope of uranium. In natural uranium and in uranium ore, 234U occurs as an indirect decay product of uranium-238, but it makes up only 0.0055% of the raw uranium because its half-life of just 245,500 years is only about 1/18,000 as long as that of 238U. Thus the ratio of 234
U to 238
U in a natural sample is equivalent to the ratio of their half-lives. The primary path of production of 234U via nuclear decay is as follows: uranium-238 nuclei emit an alpha particle to become thorium-234. Next, with a short half-life, 234Th nuclei emit a beta particle to become protactinium-234 (234Pa), or more likely a nuclear isomer denoted 234mPa. Finally, 234Pa or 234mPa nuclei emit another beta particle to become 234U nuclei.

<span class="mw-page-title-main">Fertile material</span> Substance that can be converted into material for use in nuclear fission

Fertile material is a material that, although not fissile itself, can be converted into a fissile material by neutron absorption.

Thorium-232 is the main naturally occurring isotope of thorium, with a relative abundance of 99.98%. It has a half life of 14 billion years, which makes it the longest-lived isotope of thorium. It decays by alpha decay to radium-228; its decay chain terminates at stable lead-208.

Uranium-233 is a fissile isotope of uranium that is bred from thorium-232 as part of the thorium fuel cycle. Uranium-233 was investigated for use in nuclear weapons and as a reactor fuel. It has been used successfully in experimental nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years.

<span class="mw-page-title-main">Plutonium-239</span> Isotope of plutonium

Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in thermal spectrum nuclear reactors, along with uranium-235 and uranium-233. Plutonium-239 has a half-life of 24,110 years.

Protactinium (91Pa) has no stable isotopes. The four naturally occurring isotopes allow a standard atomic weight to be given.

Neptunium (93Np) is usually considered an artificial element, although trace quantities are found in nature, so a standard atomic weight cannot be given. Like all trace or artificial elements, it has no stable isotopes. The first isotope to be synthesized and identified was 239Np in 1940, produced by bombarding 238
U
 with neutrons to produce 239
U
, which then underwent beta decay to 239
Np
.

Plutonium (94Pu) is an artificial element, except for trace quantities resulting from neutron capture by uranium, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. It was synthesized long before being found in nature, the first isotope synthesized being plutonium-238 in 1940. Twenty-one plutonium radioisotopes have been characterized. The most stable are plutonium-244 with a half-life of 80.8 million years; plutonium-242 with a half-life of 373,300 years; and plutonium-239 with a half-life of 24,110 years; and plutonium-240 with a half-life of 6,560 years. This element also has eight meta states; all have half-lives of less than one second.

<span class="mw-page-title-main">Thorium fuel cycle</span> Nuclear fuel cycle

The thorium fuel cycle is a nuclear fuel cycle that uses an isotope of thorium, 232
Th
, as the fertile material. In the reactor, 232
Th
 is transmuted into the fissile artificial uranium isotope 233
U
 which is the nuclear fuel. Unlike natural uranium, natural thorium contains only trace amounts of fissile material, which are insufficient to initiate a nuclear chain reaction. Additional fissile material or another neutron source is necessary to initiate the fuel cycle. In a thorium-fuelled reactor, 232
Th
 absorbs neutrons to produce 233
U
. This parallels the process in uranium breeder reactors whereby fertile 238
U
 absorbs neutrons to form fissile 239
Pu
. Depending on the design of the reactor and fuel cycle, the generated 233
U
 either fissions in situ or is chemically separated from the used nuclear fuel and formed into new nuclear fuel.

<span class="mw-page-title-main">Spent nuclear fuel</span> Nuclear fuel thats been irradiated in a nuclear reactor

Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor. It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and, depending on its point along the nuclear fuel cycle, it will have different isotopic constituents than when it started.

<span class="mw-page-title-main">Weapons-grade nuclear material</span> Nuclear material pure enough to be used for nuclear weapons

Weapons-grade nuclear material is any fissionable nuclear material that is pure enough to make a nuclear weapon and has properties that make it particularly suitable for nuclear weapons use. Plutonium and uranium in grades normally used in nuclear weapons are the most common examples.

Uranium-236 (236U) is an isotope of uranium that is neither fissile with thermal neutrons, nor very good fertile material, but is generally considered a nuisance and long-lived radioactive waste. It is found in spent nuclear fuel and in the reprocessed uranium made from spent nuclear fuel.

<span class="mw-page-title-main">Nuclear transmutation</span> 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.

References

  1. 1 2 3 4 5 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ↑ Magurno, B.A.; Pearlstein, S, eds. (1981). Proceedings of the conference on nuclear data evaluation methods and procedures. BNL-NCS 51363, vol. II (PDF). Upton, NY (USA): Brookhaven National Lab. pp. 835 ff. Retrieved 2014-08-06.
  3. ↑ "Standard Atomic Weights: Uranium". CIAAW. 1999.
  4. ↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN   1365-3075.
  5. ↑ "Uranium Isotopes". GlobalSecurity.org. Retrieved 14 March 2012.
  6. ↑ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
  7. ↑ Zhang, Z. Y.; Yang, H. B.; Huang, M. H.; Gan, Z. G.; Yuan, C. X.; Qi, C.; Andreyev, A. N.; Liu, M. L.; Ma, L.; Zhang, M. M.; Tian, Y. L.; Wang, Y. S.; Wang, J. G.; Yang, C. L.; Li, G. S.; Qiang, Y. H.; Yang, W. Q.; Chen, R. F.; Zhang, H. B.; Lu, Z. W.; Xu, X. X.; Duan, L. M.; Yang, H. R.; Huang, W. X.; Liu, Z.; Zhou, X. H.; Zhang, Y. H.; Xu, H. S.; Wang, N.; Zhou, H. B.; Wen, X. J.; Huang, S.; Hua, W.; Zhu, L.; Wang, X.; Mao, Y. C.; He, X. T.; Wang, S. Y.; Xu, W. Z.; Li, H. W.; Ren, Z. Z.; Zhou, S. G. (2021). "New α-Emitting Isotope U214 and Abnormal Enhancement of α-Particle Clustering in Lightest Uranium Isotopes". Physical Review Letters. 126 (15): 152502. arXiv: 2101.06023 . Bibcode:2021PhRvL.126o2502Z. doi:10.1103/PhysRevLett.126.152502. PMID   33929212. S2CID   231627674.
  8. 1 2 Zhang, M. M.; Tian, Y. L.; Wang, Y. S.; Zhang, Z. Y.; Gan, Z. G.; Yang, H. B.; Huang, M. H.; Ma, L.; Yang, C. L.; Wang, J. G.; Yuan, C. X.; Qi, C.; Andreyev, A. N.; Huang, X. Y.; Xu, S. Y.; Zhao, Z.; Chen, L. X.; Wang, J. Y.; Liu, M. L.; Qiang, Y. H.; Li, G. S.; Yang, W. Q.; Chen, R. F.; Zhang, H. B.; Lu, Z. W.; Xu, X. X.; Duan, L. M.; Yang, H. R.; Huang, W. X.; Liu, Z.; Zhou, X. H.; Zhang, Y. H.; Xu, H. S.; Wang, N.; Zhou, H. B.; Wen, X. J.; Huang, S.; Hua, W.; Zhu, L.; Wang, X.; Mao, Y. C.; He, X. T.; Wang, S. Y.; Xu, W. Z.; Li, H. W.; Niu, Y. F.; Guo, L.; Ren, Z. Z.; Zhou, S. G. (4 August 2022). "Fine structure in the α decay of the 8+ isomer in 216, 218U". Physical Review C. 106 (2): 024305. doi:10.1103/PhysRevC.106.024305. ISSN   2469-9985. S2CID   251359451.
  9. ↑ Gan, ZaiGuo; Jiang, Jian; Yang, HuaBin; Zhang, ZhiYuan; Ma, Long; Yu, Lin; Wang, JianGuo; Tian, YuLin; Ding, Bing; Huang, TianHeng; Wang, YongSheng; Guo, Song; Sun, MingDao; Wang, KaiLong; Zhou, ShanGui; Ren, ZhongZhou; Zhou, XiaoHong; Xu, HuShan (1 August 2016). "α decay studies of the neutron-deficient uranium isotopes 215-217U". Chinese Science Bulletin. 61 (22): 2502–2511. doi: 10.1360/N972015-01316 . Retrieved 24 June 2023.
  10. ↑ Trenn, Thaddeus J. (1978). "Thoruranium (U-236) as the extinct natural parent of thorium: The premature falsification of an essentially correct theory". Annals of Science. 35 (6): 581–97. doi:10.1080/00033797800200441.
  11. 1 2 Bonetti, R.; Guglielmetti, A. (2007). "Cluster radioactivity: an overview after twenty years" (PDF). Romanian Reports in Physics. 59: 301–310. Archived from the original (PDF) on 19 September 2016.
  12. ↑ Kromer, Kathrin; Lyu, Chunhai; Bieroń, Jacek; Door, Menno; Enzmann, Lucia; Filianin, Pavel; Gaigalas, Gediminas; Harman, Zoltán; Herkenhoff, Jost; Huang, Wenjia; Keitel, Christoph H.; Eliseev, Sergey; Blaum, Klaus (2024-02-06). "Atomic mass determination of uranium-238". Physical Review C. 109 (2). American Physical Society (APS). arXiv: 2312.17041 . doi:10.1103/physrevc.109.l021301. ISSN   2469-9985.
  13. ↑ Niwase, T.; Watanabe, Y. X.; Hirayama, Y.; et al. (2023). "Discovery of New Isotope 241U and Systematic High-Precision Atomic Mass Measurements of Neutron-Rich Pa-Pu Nuclei Produced via Multinucleon Transfer Reactions" (PDF). Physical Review Letters. 130 (13): 132502-1–132502-6. doi:10.1103/PhysRevLett.130.132502. PMID   37067317. S2CID   257976576.
  14. 1 2 Mukunth, Vasudevan (2023-04-05). "In pursuit of a 'magic number', physicists discover new uranium isotope". The Hindu . ISSN   0971-751X . Retrieved 2023-04-12.
  15. ↑ Yirka, Bob (April 5, 2023). "Previously unknown isotope of uranium discovered". Phys.org . Retrieved 2023-04-12.
  16. ↑ Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
  17. ↑ Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor.
  18. ↑ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics. 71 (2): 299. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4.
    "The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk248 with a half-life greater than 9 [years]. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
  19. ↑ This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".
  20. ↑ Excluding those "classically stable" nuclides with half-lives significantly in excess of 232Th; e.g., while 113mCd has a half-life of only fourteen years, that of 113Cd is eight quadrillion years.
  21. ↑ "Physicists Discover New Uranium Isotope: Uranium-214". Sci-News.com. 14 May 2021. Retrieved 15 May 2021.
  22. ↑ Zhang, Z. Y.; et al. (2021). "New α -Emitting Isotope 214 U and Abnormal Enhancement of α -Particle Clustering in Lightest Uranium Isotopes". Physical Review Letters. 126 (15): 152502. arXiv: 2101.06023 . Bibcode:2021PhRvL.126o2502Z. doi:10.1103/PhysRevLett.126.152502. PMID   33929212. S2CID   231627674 . Retrieved 15 May 2021.
  23. ↑ "Lightest-known form of uranium created". Live Science. 3 May 2021. Retrieved 15 May 2021.
  24. ↑ "Physicists have created a new and extremely rare kind of uranium". New Scientist. Retrieved 15 May 2021.
  25. ↑ "Uranium 232". Nuclear Power. Archived from the original on 26 February 2019. Retrieved 3 June 2019.
  26. ↑ "INCIDENT NEUTRON DATA". atom.kaeri.re.kr. 2011-12-14.
  27. ↑ C. W. Forsburg; L. C. Lewis (1999-09-24). "Uses For Uranium-233: What Should Be Kept for Future Needs?" (PDF). Ornl-6952. Oak Ridge National Laboratory.
  28. ↑ Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.
  29. 1 2 Ronen, Y., ed. (1990). High converting water reactors. CRC Press. p. 212. ISBN   0-8493-6081-1. LCCN   89-25332.
  30. 1 2 Use of Reprocessed Uranium (PDF). Technical Document. Vienna: International Atomic Energy Agency. 2009. ISBN   978-92-0-157109-0. ISSN   1684-2073.
  31. ↑ B. C. Diven; J. Terrell; A. Hemmendinger (1 January 1958). "Capture-to-Fission Ratios for Fast Neutrons in U235". Physical Review Letters. 109 (1): 144–150. Bibcode:1958PhRv..109..144D. doi:10.1103/PhysRev.109.144.
  32. ↑ Ikeda, Nagao (July 25, 2011). "The discoveries of uranium 237 and symmetric fission — From the archival papers of Nishina and Kimura". Proceedings of the Japan Academy. Series B, Physical and Biological Sciences. 87 (7): 371–376. doi:10.2183/pjab.87.371. PMC   3171289 . PMID   21785255.
  33. ↑ CRC Handbook of Chemistry and Physics, 57th Ed. p. B-345
  34. ↑ CRC Handbook of Chemistry and Physics, 57th Ed. p. B-423
  35. 1 2 Yirka, Bob; Phys.org. "Previously unknown isotope of uranium discovered". phys.org. Retrieved 2023-04-10.
  36. ↑ Niwase, T.; Watanabe, Y. X.; Hirayama, Y.; Mukai, M.; Schury, P.; Andreyev, A. N.; Hashimoto, T.; Iimura, S.; Ishiyama, H.; Ito, Y.; Jeong, S. C.; Kaji, D.; Kimura, S.; Miyatake, H.; Morimoto, K. (2023-03-31). "Discovery of New Isotope $^{241}\mathrm{U}$ and Systematic High-Precision Atomic Mass Measurements of Neutron-Rich Pa-Pu Nuclei Produced via Multinucleon Transfer Reactions". Physical Review Letters. 130 (13): 132502. doi:10.1103/PhysRevLett.130.132502. PMID   37067317. S2CID   257976576.
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