The U.S. Regulatory Commission has fined Idaho State University after the school lost plutonium 239, which is used to develop nuclear weapons. From CNN:

University Officials say the sample, missing since 2003, does not pose a direct health issue or risk to public safety. The substance had been used by the school to conduct several research experiments.

The school realized it had lost track of the plutonium earlier this year and immediately notified the US Nuclear Regulatory Commission. ISU officials said the sample, weighing a gram, was lost as it was being taken out of service after employees only partially filled out the necessary paperwork.

Although the ISU believes the tiny speck of plutonium was transferred to a licensed disposal facility, there are no records to prove that it was.
The commission fined the university $8,500 for the lost plutonium.

The University has since updated its protocols saying, “Enhancements to ISU’s inventory system and other administrative initiatives were immediately put into place to prevent this type of discrepancy in the future.”

NRC spokesperson Victor Dricks was quoted by Newsweek magazine as saying the lost material was enough to make a so-called “dirty bomb.” Dricks would not confirm or dispute that comment when contacted by CNN.