Influence of the control bars pattern on the response of the operation channels of the TRIGA Mark III reactor

The local flow perturbations not generated by movements of bars not planned adequately to operate the reactor to 1 MW of thermal power, are reflected in the independent responses of the operation channels of the same one, find variations average from 17% to 30% for the channel of the power percent and of until 10% for the logarithmic channel. For the case of the lineal and percent power channels, these are between 14% and 46% as maximum when moving some of the bars. These variations can diminish until 5% in the channel of the power percent and until 3% on the average for the logarithmic one, all times when the calculated bars pattern for that irradiation considers that all the bars operate inside the lineal region of its calibration curve with approximately the same reactivity value each one and that during the operation the required reactivity compensations are carried out with the diametrically opposed bar to the irradiation installation used in that experiment. (Author)