The mistake was revealed in a federal newsletter devoted to issues of state secrecy, and set off a debate among nuclear experts about what dangers, if any, the disclosures posed, according to the report.
It also prompted a flurry of investigations in Washington into why the document had been made public.
Some experts argued that any dangers from the disclosure were minimal, given that the general outlines of the most sensitive information were already known publicly.
But David Albright, an analyst who tracks nuclear proliferation, said information that shows where nuclear fuels are stored "can provide thieves or terrorists inside information that can help them seize the material, which is why that kind of data is not given out."
So far the reasons for the mistake remain a mystery.