3
Another uranium series, the
235
U series, usually referred to as the actinium series,
can be presented in a form like that in Fig. 1 or using a relevant table with some
basic data (Table 1). In both series there are some prominent radionuclides, such as
radium, polonium, radon and many others, which can be found in uranium ore and
then extracted in a sufficiently pure form for suitable applications. One such example is radium which was widely used for the early treatment of cancer patients.
Up until now, science has recognized something like 21 different uranium isotopes, most of them artificially engineered using nuclear reactions and chemical
processes. Most of them have marginal practical significance; some are characterized by extremely short half-lives or are found on the earth only in trace
concentrations.
The history of uranium began more than 200 years ago, from its discovery in
1789 by Martin H. Klaproth to recent years when uranium became one of the most
vital elements, alone or in the form of its decay products. One may formally distinguish between the uranium eras up to 1896, when its radioactivity was revealed,
through the second period up to the 1940s, when it was used in research, medicine,
glass and ceramic industries as well as in radon spas. During the third period, uranium fission began to be utilized in nuclear reactors and, regretfully, also in nuclear
bombs.
It took some time before reliable information was acquired relevant to the deleterious biological effects associated with the internal and external exposure to uranium and its decay products. After intensive medical and epidemiological studies as
Table 1 Radionuclides in the
235 U series which finally decay to the stable
207 Pb (After, Martin
2013; Morss et al. 2006; L’Annunziata 2003)
Nuclide
Decay (particles emitted)
Half-life
Symbol
Name
235 U
Uranium
α
7.04 × 10
8 y
231 Th
Thorium
β
−
25.64 h
231 Pa
Protactinium
α
3.25 × 10
4 y
227 Ac
Actinium
β
−
, α
21.6 y
223 Fr
Francium
β
−
, α
22 min
227 Th
Thallium
α
18.7 day
219 At
Astat
α, β
−
0.9 min
223 Ra
Radium
α
11.68 day
215 Bi
Bismuth
β
−
8 min
219 Rn
Radon
α
3.92 s
215 Po
Polonium
α, β
−
1.83 × 10
−3 s
211 Pb
Lead
β
−
36.1 min
215 At
Astat
α
≈10
−4
s
211 Bi
Bismuth
α, β
−
2.16 min
207 Tl
Thallium
β
−
4.79 min
211 Po
Polonium
α
0.52 s
207 Pb
Lead
Stable
–
Uranium in the Beginning of the Nuclear Age: Reflections on the Historical Role…
Another uranium series, the
235
U series, usually referred to as the actinium series,
can be presented in a form like that in Fig. 1 or using a relevant table with some
basic data (Table 1). In both series there are some prominent radionuclides, such as
radium, polonium, radon and many others, which can be found in uranium ore and
then extracted in a sufficiently pure form for suitable applications. One such example is radium which was widely used for the early treatment of cancer patients.
Up until now, science has recognized something like 21 different uranium isotopes, most of them artificially engineered using nuclear reactions and chemical
processes. Most of them have marginal practical significance; some are characterized by extremely short half-lives or are found on the earth only in trace
concentrations.
The history of uranium began more than 200 years ago, from its discovery in
1789 by Martin H. Klaproth to recent years when uranium became one of the most
vital elements, alone or in the form of its decay products. One may formally distinguish between the uranium eras up to 1896, when its radioactivity was revealed,
through the second period up to the 1940s, when it was used in research, medicine,
glass and ceramic industries as well as in radon spas. During the third period, uranium fission began to be utilized in nuclear reactors and, regretfully, also in nuclear
bombs.
It took some time before reliable information was acquired relevant to the deleterious biological effects associated with the internal and external exposure to uranium and its decay products. After intensive medical and epidemiological studies as
Table 1 Radionuclides in the
235 U series which finally decay to the stable
207 Pb (After, Martin
2013; Morss et al. 2006; L’Annunziata 2003)
Nuclide
Decay (particles emitted)
Half-life
Symbol
Name
235 U
Uranium
α
7.04 × 10
8 y
231 Th
Thorium
β
−
25.64 h
231 Pa
Protactinium
α
3.25 × 10
4 y
227 Ac
Actinium
β
−
, α
21.6 y
223 Fr
Francium
β
−
, α
22 min
227 Th
Thallium
α
18.7 day
219 At
Astat
α, β
−
0.9 min
223 Ra
Radium
α
11.68 day
215 Bi
Bismuth
β
−
8 min
219 Rn
Radon
α
3.92 s
215 Po
Polonium
α, β
−
1.83 × 10
−3 s
211 Pb
Lead
β
−
36.1 min
215 At
Astat
α
≈10
−4
s
211 Bi
Bismuth
α, β
−
2.16 min
207 Tl
Thallium
β
−
4.79 min
211 Po
Polonium
α
0.52 s
207 Pb
Lead
Stable
–
Uranium in the Beginning of the Nuclear Age: Reflections on the Historical Role…