Top: delayed gamma fraction determined for a set of fits with the signal normalization set between the stabilization of the reactor power t_Stab and the insertion of the cadmium blade t_SCRAM, using either BF₃ detector as neutron signal reference. A build-up of the delayed gamma signal can be seen – presenting here as an exponential reduction in delayed gamma fraction. After about 8 min a saturation of build-up is seen. Bottom: by using the fitted exponential decay, we used the arbitrary threshold of having observed 95% of the fitted decay we determine the respective delayed neutron fraction estimate by estimating the mean and standard deviation of all accepted samples.