Vol.:(0123456789) 1 3
Journal of Radioanalytical and Nuclear Chemistry
https://doi.org/10.1007/s10967-018-6278-2
The production of no carrier added arsenic radioisotopes in nuclear
reactors
Sandra Siri
1,2
· María Sol Segovia
1
· Isaac Marcos Cohen
1
Received: 13 August 2018
© Akadémiai Kiadó, Budapest, Hungary 2018
Abstract
The comparative advantages and drawbacks of some reactor-produced arsenic radioisotopes having favourable characteristics
for their use as tracers are discussed. The study comprises their preparation based on: (a) capture reactions on germanium; (b)
threshold reactions on germanium, selenium and bromine; (c) secondary reactions on germanium, induced by recoil protons
and tritons produced by the action of neutrons on lithium. The recommended options for the production of relatively short
half-life radionuclides are
77
As by capture on germanium or
76
As via (n,α) reaction on bromine, while two diferent ways
are applicable for the production of
74
As, longer-lived radioisotope.
Keywords Nuclear reactions · Nuclear reactors · Arsenic radioisotopes production · Arsenic tracers
Introduction
The biological role of arsenic was object of numerous stud-
ies. The toxicity of the element and its compounds is rec-
ognized since antiquity; in acute poisoning cases, the lethal
dose in humans ranges from 100 to 300 mg [1]. On the other
hand, arsenic is also considered as essential element for life
[2]; however, no specifcally identifed biochemical func-
tions have been characterised [3].
Radioactive tracers constitute a relevant tool for the
accomplishment of the investigations designed to estab-
lish the behaviour of arsenic compounds. As early as 1942,
Hunter et al. [4] carried out a work aimed to determine the
fate of trivalent arsenic in the body, using potassium arse-
nide labelled with
74
As. In more recent times, many articles
have been published in connection with the defnition of
the role of arsenic in living organisms, using radioactive
tracers (For example, [5–11]). Radioactive tracers were also
employed for analytical purposes, related with the determi-
nation of arsenic in diferent matrixes. Some examples can
be found in Ref. [12–16].
In the light of these antecedents, it is reasonable to predict
renewed future requirements for radioactive arsenic tracers.
Taking into account the toxicity of arsenic compounds, most
of the studies will require no carrier added isotopes as pri-
mary requisite. Such requirement precludes the use of arse-
nic targets and restricts the possibilities of nuclear reactors,
the most extensively employed facilities for radioisotope
production, in order to solve this particular challenge. Nev-
ertheless, some other alternatives are open, in connection
of reactor neutron induced reactions, for the synthesis of
no carrier added arsenic radioisotopes that can be used as
tracers. The objective of the present work is to discuss the
comparative advantages and drawbacks of some proposed
arsenic tracers and to analyse the feasibility of their produc-
tion in a nuclear reactor.
General considerations
Among the 29 known arsenic radioisotopes, from
64
As to
92
As [17], only six are sufciently long-lived for being used
as tracers:
71
As,
72
As,
73
As,
74
As,
76
As and
77
As (Table 1).
The analysis of the characteristics of these possible tracers
will exclude the consideration of PET applications, which
are exclusive for three positron emitters:
71
As,
72
As and
74
As.
* Sandra Siri
ssiri@cae.cnea.gov.ar
1
Centro de Tecnologías Químicas, Universidad Tecnológica
Nacional, Facultad Regional Buenos Aires, Medrano
951, C1179AAQ Ciudad Autónoma de Buenos Aires,
República Argentina
2
Centro Atómico Ezeiza, Comisión Nacional de
Energía Atómica, Presbítero González y Aragón 15,
B1802AYA Buenos Aires, Argentina