[en] Full text: The work began replacing, in first place, the units with flux mapping detectors only, taking care not to replace detectors of the reactor regulation system and safety systems in order do not have an impairment on the safety systems in case of replacement program's interruption during the first steps of replacements. During the phase of connectors installing in the seventh vertical flux unit (7th VFD) the original Twinax cable was found with a lack of its original properties. The internal conductor insulation was stiffened. For that reason, the internal conductor insulation became very difficult to handle without possible cable damage. Immediately, it was decided to stop the detectors replacement because the general schedule of the outage must delayed by the additional unexpected task of cable replacement. Besides, properly replacement cable was not available at de plant. A series of insulation measurements were made on the detectors cables, including those which were not replaced. A periodical control of insulation resistance measures of detectors and cables was arranged to be carried out during normal operation, until the next outage. In the next Annual Outage the detectors replacement was completed and the PVC cables was replaced by KKK cables with EQ requirements At the present a decision making process must be realized taking into account the Long Term Operation of Plant. (author)