Up to 1940, the total amount of uranium metal produced in the USA was not more than a few grams, and even this was of doubtful purity; of metallic beryllium not more than a few kilograms; and concentrated deuterium oxide (heavy water) not more than a few kilograms.
До 1949 година во САД биле произведени само неколку грама ураниум и тоа не сосем чист, неколку килограми берилиум и девтериум оксид (тешка вода).