Page 57 - PR 2014 2016 07 Nuclear Science and Technology

Nuclear Science and Technology | Progress Report 199

effects. The ionization chambers are widely the variable dose. In spite of growth rate in
used as detectors to perform the quality con- the production of radiopharmaceutical, this
trol program of equipment with radiation, as study has shown that the improvements in the
mammographers. Four different special ion- plant have contributed to the dose reduction
ization chambers, developed at the Calibration of the workers.
Laboratory of Instruments of IPEN, were sub-
mitted to the characterization tests in standard Dosimetric Materials
X radiation beams at the LCI. The results were
satisfactory, within the limits established by The main objective of this research area is the
national and international standards. As an development of new dosimetric materials with
application, the ionization chambers were used high sensitivity, low cost and easy obtaining
for quality control tests in four mammogra- to be applied in external dosimetry.
phy clinics from different institutions, as the
repeatability and linearity of the air kerma Fricke/Alanine Gel Dosimeter
rate. The results obtained in these tests were
within the limits recommended by national DL-Alanine (C H NO ) is an amino acid tissue
3 7 2
and international standards. equivalent traditionally used as standard do-
simetric material in EPR dosimetry. Recently, it
Internal dosimetry has been studied to be applied in gel dosimetry,
considering that the addition of alanine in the
The internal dosimetry program at the Insti- Fricke gel solution improves the radiation in-
tuto de Pesquisas Energéticas e Nucleares, duced ferric ions production. The performance
IPEN, was accomplished in two steps: the of the Alanine gel solution developed at IPEN
activity measurements performed at the In is being studied using spectrophotometry and
Vivo Monitoring Laboratory and subsequent magnetic resonance imaging evaluation tech-
data analysis and dose evaluation by the Dose niques.
Calculation Group, according to the ICRP mod-
els. The purpose of this study was to take the Ceramic materials based on rare earth doped
whole body and thyroid monitoring results yttria
recorded from 2005 to 2015 to see whether the
internal contamination control procedure for The following research area aims to develop
workers were suitable even with the increase new dosimetric materials with high sensibility
in the radiopharmaceutical production. The using facile low-cost processing. Rare earths
study were based in a research called “Search (RE) which exhibit excellent chemical and
of Variables”, taking into account the dose physical proprieties are promising materials
distribution data for all the tasks recorded for dosimetry. Among RE group, yttrium oxide
by the radioprotection service in the restrict- also known as yttria (Y O ) exhibits structure
2 3
ed areas of radiopharmaceutical production characteristics that offer great possibilities
plant. This methodology aims to identify and for doping with RE. Ceramic micro rods based
determine the relevant variables that impact on undoped yttria (Y O ) and RE doped yttria
2 3
on the worker’s dose. The results presented the (Y O :RE) have been produced from assembling
2 3
following variables: occupationally exposed of nanoparticles via bio-prototyping, followed
individual, operation variable, area/cell and by sintering. Sintering of rods, which aims to
type of operational task, which depends on improve nanoparticles bond, was performed