Effect of errors in the delayed-neutron data on fast reactor static and dynamic calculations

The effect of the errors in presently available delayed-neutron data on various calculations and measurements in reactor physics is analyzed. It is shown that these errors have very little influence on static calculations but may cause an error of 5 to 9% in reactivity calculations and measurements; this is a third of the discrepancy between presently observed measurements and calculations. Very large errors in predicting the dynamic behavior of large fast reactors resulted when uncertainties in the delayed-neutron spectra were considered.