Page 32 - PR 2014 2016 03 Applications of Ionizing Radiations

74 Application of Ionizing Radiations | Progress Report

to obtain qualitative and quantitative data sys- 41 Ar was transferred, by the portable radiation
tems, in physical and physicochemical studies meter Teletector ® Probe 6150 AD-t/H.
transfers. In the production of gaseous radio-
isotopes used as tracers in industrial process Sealed source production for
measurements, argon-41 ( Ar) and krypton-79 gammagraphy and industrial
41
79
( Kr) have low reactivity with other chemi- process control
cal elements. Ar is a transmitter range with
41
high-energy (1.29MeV) and a high percentage Radioactive sealed sources production for
of this energy transformation (99.1%), resulting radiography and industrial process control.
in relatively small quantities required in rela- The gamma writing is an important non-de-
tion to the other, for an efficient detection, even structive technique to analyze metallic compo-
in large thicknesses components. Nowadays, nents from small to large ones that need high
the production of gaseous radioisotopes in performance and security in operation. The
nuclear research reactors is performed in small non-existence of internal failures is checked
quantities (batches), through quartz ampoules by gamma rays radiography, because of its
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containing natural gas Ar or Kr. In this sense, great penetration characteristics that allow
40
the aim of this study is to develop an irradia- obtaining the photographic record of failures.
tion system for gaseous radioisotope produc- This non-destructive analysis is used for qual-
tion in continuous scale, applied in industrial ity control of welded components in chemical,
applications of emission tomography and flow nuclear, and mechanical industries, such as
measurement. The irradiation system may pro- pipelines, turbines, reservoirs, and pressure
duce Ar with activity of 7.4x10 Bq (20Ci) per vessels. According to the International Atomic
41
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irradiation cycle, through the Reactor IEA-R1 Energy Agency (IAEA) information, the petro-
with 4.5MW and average thermal neutron chemical and chemical process industries are
flux of 4.71x10 ncm -2s-1 to meet an existing the mains users and beneficiaries of the radio-
13
demand in NDT and inspections companies, isotope technology. Radioisotope techniques
and even needed by the Radiation Technolo- are very competitive and are largely applied
gy Centre, at IPEN/CNEN-SP. The irradiation for troubleshooting and process analysis of
system consists of an aluminium irradiation technically complex, continuously operating
capsule, transfer lines, needle valves, stripy industrial plants. Due to this fact, the applica-
connections, quick connectors, manometer, tion of sealed sources becomes more diversi-
vacuum system, dewar, lead shielding, storage
and transport cylinders, among other compo-
nents. The irradiation system was approved
in the leakage and stability tests (bubble test,
pressurization, evacuation and with leak de-
tector equipment SPECTRON 600 T). In the
experimental production, alanine dosimeters
were distributed into various components of
the irradiation system, obtaining 1.07x10 Bq
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(2.9Ci) of Ar. In addition, exposure rates were
41
determined in the lead shielding wall, in which
the liquefied radioactive gas was concentrated,
and in the storage and transport cylinders after Figure 50. Laboratory Sealed Source Production.

Instituto de Pesquisas Energéticas e Nucleares