On Friday, the Nuclear Regulatory Commission announced that Idaho State University may face an $8,500 fine after losing one gram of weapons-grade plutonium. Although this quarter-sized amount of plutonium is nowhere near enough to make a nuclear weapon, it is enough to make a dirty bomb that spreads radiation, according to the Associated Press.

The missing plutonium came to the attention of the NRC while it was compiling an inspection report about how Idaho State University controlled its radioactive material. As detailed in the inspection report, last October someone notified the NRC about an event “involving a lost sealed source containing special nuclear material.” During an inventory checkup, a staff member at the university reported that there were 13 one-gram pieces of plutonium in stock, even though the university had previously reported having 14 pieces of the material to the NRC.

According to the report, the missing plutonium isotope (Pu-239) was used as a source material to demonstrate or test nuclear accident dosimeters, a device for measuring exposure to radiation, and was loaned to the university in 1991. The plutonium sample is considered a ‘sealed source,’ which means it is stored in such a way to prevent the leakage of radioactive material.

In 2003, Idaho State University found its plutonium to be leaking a small amount of radiation, but below the threshold that would have required it to report the leak to the NRC. Nevertheless it removed the plutonium from regular use and the university said it intended to return the source to the Idaho National Laboratory. Yet when no records of this transfer were found at the lab, the university began reaching out to its staff members and waste brokers that may have known the whereabouts of the material. They even went so far as to open some nuclear waste drums to look for the missing plutonium. When no records of the missing plutonium were found, the university contacted the NRC in October.

According to a 2006 report by the Department of Energy, hundreds of Pu-239 sealed sources have been distributed for public use. The DOE recommended a program to recover these plutonium sources to prevent their use in dirty bombs.

While such a small amount of plutonium probably wouldn’t do a lot of damage even if it was used to make a bomb, weapons-grade nuclear material is stolen relatively frequently outside of the US and is considered a major security issue. As far as missing nuclear material in the US goes, this isn’t the first time that a university has lost some radioactive material. In 1987, some freshmen at Harvard who belonged to a group dedicated to “anarchy and destruction” stole depleted uranium-238 from a storage facility on campus. Unfortunately for these would be anarchists, this uranium isotope cannot be used to make weapons, unlike its cousin uranium-235.