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Nuclear Science and Technology | Progress Report 207
Nuclear Energy Commission, according to make the 6 mm diameter pellets (Figure 45).
the type of the radionuclide and the practice. The CaSO :Dy pellets are destined to the in-
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Continuous improvements in IPEN’s installa- dividual, area and environmental monitoring
tions which handle radioactive materials have through the thermoluminescence dosimetry.
required actualization in safety programs. Besides, they could be applied to the high
doses, retrospective and clinical dosimetry as
During the period from January 2014 to De- well as solid state dosimetry research. Pellets
cember 2016, approximately 2,400 direct mea- of several materials such as quartz, emerald,
surements of both whole-body and thyroid topaz, jade for instance can be also produced
contents have been carried out in workers by means of the same referred method. The
as well as the internal dose evaluation. The requests of CaSO :Dy crystals and pellets from
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committed effective dose higher than the many institutions have been attended by the
annual limit on intake in this period was not laboratory.
achieved. In addition, the LMIV have partic-
ipated in a research group of the National Routine External Dosimetry
Council for Scientific and Technological De-
velopment which involves eight other insti- The external dosimetry laboratory applies
tutions. the thermoluminescent (TL) technique and
CaSO :Dy based dosimeters developed at IPEN
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Dosimetric material production to carry out individual, area and environmen-
- pellets of CaSO :Dy tal monitoring.
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The Dosimetric Materials Laboratory devel- The individual monitoring service is autho-
oped and patented the CaSO :Dy crystals rized by the Brazilian Nuclear Energy Com-
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growth system and the method to produce mission - CNEN by mean of the Essays and
the Teflon ® sintered pellets. The CaSO :Dy Calibration Services Evaluation Committee
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crystals grow in the sealed system and are - CASEC. It completely satisfies CNEN’s reg-
cold pressed with the binding material to ulatory norms, besides presenting a brake in
IPEN’s quality control system, being respon-
sible for the external exposure monitoring
of all occupationally exposed individuals at
IPEN, other autarchies, governmental offices
and even some private facilities.
The area and environmental monitoring are
performed to different society sectors, such
as research institutes, universities and private
foundations and companies.
High Dose Dosimetry
Alanine/Electron Paramagnetic Resonance
(EPR) dosimetric system provides a second-
Figure 45- CaSO :Dy dosemeters. ary standard for routine radiation dosimetry
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