AbstractA diffusion coefficient for hydrogen in ingot uranium was determined at 800°C on 1-in. long slug blanks. A value of 14.2×10−5cm2/sec was obtained from 15 determinations. The precision of the average value at the 95% confidence level was±3.6%. Three methods of cleaning (preparatory to analysis) were employed, no bias being detected among them. An equation was used to calculate the total gas dissolved in a sample by measuring the gas evolved after a short time and using the diffusion coefficient. In a comparison of the total evolved gas (3-hr extraction) with the calculated total gas (½-hr extraction), an error of<±2% was obtained from 15 samples.