Page 25 - PR 2014 2016 09 Nuclear Reactors and Fuel Cycle

Nuclear Reactors and Fuel Cycle | Progress Report 269

Training program generators have been imported. Currently, the
Besides of the internal operator retraining world’s Mo supplying depends on the op-
99
program, it was started the training of eight eration of research reactors which are aged
new operators. around 40 years and, therefore, are not capable
of reliable operation. This situation makes the
Maintenance program 99 Mo production chain particularly vulnerable.

An extensive program of testing, preventive Recent crises in the supply of Mo has pro-
99

99
maintenance and calibration was carried out foundly affected the distribution of Mo/ gen-
to assure performance and reliable measures erators in Brazil and encouraged the starting
by equipments and systems related to reactor of the RMB - Brazilian Multipurpose Reactor,
operation and control. which has as one of the objectives to make
the country independent in the production of
Monthly activity report radioactive isotopes for medicine. The success
A report containing the activities and moni- of RMB Project will require the manufacturing
tored and controlled operational parameters technology of irradiation targets for the Mo
99
of the reactor are issued monthly. This report production from nuclear fission. As IPEN in its
encloses the number of reactor operation, dis- history has been developing fuel for research
sipated energy, reactor core data, chemical reactors, and the manufacture of irradiation
and physical characteristics of the pool water, targets is based on this type of technology,
radioisotopes concentration in the pool water, IPEN began developing the technology to fabri-
number of reactor shutdown, number of irradi- cate these targets. The manufacturing process-
ated samples in the reactor core and pneumatic es of two types of targets using low enriched
system and, finally, the radioprotection data. uranium (LEU) are being studied. The first one
is based on UAl -Al dispersion targets, which
x
Management system is being used commercially in Argentina and
Since 2002, the Quality Management System Australia. The second one is based on thin foils
that supports the scope “Operation and Main- of metallic uranium, which was developed by
tenance of the IEA-R1 Reactor and Irradiation Indonesia with US support.
Services” was certified by Fundação Carlos Al-
berto Vanzolini in compliance with NBR ISO The UAl -Al dispersion targets are fabricated
x
9001, being submitted to annual internal and according to the picture-frame technique, as
external reevaluation. shown in Figure 32. The roll billet consists of a
picture frame, two cover and briquettes. This
Development of irradiation targets for components were assembled and joined by
99 Mo production by nuclear fission Tungsten Inert Gas (TIG) welding and then

rolled to form the targets. Prior to the roll-
The use of radioisotopes in medicine is cer- ing operation, the briquettes were degassed
tainly one of the most important social uses of at 250°C for 3 hours under vacuum of 0.8 x
nuclear energy. The 99m Tc, generated from the 10-3 mbar. The assemblies were hot-rolled at
99 Mo nuclear decay, is the most suitable radio- 450°C in four rolling passes. The final speci-
nuclide for single photon emission computed fied thickness for the target was reached with
tomography imaging technique. The 99m Tc is two cold-rolling passes. Fifteen targets were
supplied as Mo/ 99m Tc generators, which pro- fabricated in a single rolling operation. The
99
99
vide 99m Tc as the Mo decays. In Brazil, the intermetallic is prepared from a mixture of