[en] The effect of six methodic factors (the method of solution mixing in a cell; background solution composition; the value of the analyzed solution aliquot; the content of the determined component in the aliquot; the method of the final point indication; the generator current value) on the accuracy parameters of the results of potassium bichromate determination on a perfected installation was studied at determination of uranium and plutonium content in nonirradiated nuclear fuel by the automatic coulometric titration (ACT) method for increase of results accuracy, obtained by this method. It is shown, that for 2 g of solution, 10 mg potassium bichromate with the current of 11 μa the value of Mean-square deviation is 0.0001-0.001. The systematic value has in many cases a negative value and it fluctuates depending on the effect of different factors from 0.7% up to the level, which slightly differs from the real value. The data obtained testify to the possibility of achieving the results of high accuracy at uranium and plutonium determination by the ACT method on a perfected installation