University officials say the sample, which has been missing since 2003, does not represent a direct health problem or a risk to public safety. The substance had been used by the school to conduct several research experiments.
The school realized that it had lost track of plutonium earlier this year and immediately notified the US Nuclear Regulatory Commission. UU ISU officials said the sample, which weighed one gram, was lost when it withdrew from service after employees only partially filled out the necessary documentation.
Although the ISU believes that the small plutonium speck was transferred to an authorized disposal facility, there are no records to prove it was.
The commission fined the university with $ 8,500 for the lost plutonium.
Since then, the University has updated its protocols saying: "Improvements in the inventory system of the ISU and other administrative initiatives were implemented immediately to avoid this type of discrepancies in the future."
NRC spokesman Victor Dricks was quoted by Newsweek magazine as saying that the lost material was enough to make a so-called "dirty bomb". Dricks did not confirm or question that comment when contacted by CNN.