Information Notice 2001-01:The Importance of Accurate Inventory Controls to Prevent the Unauthorized Possession of Radioactive Material

WASHINGTON, D.C. 20555-0001

March 26, 2001



All material licensees.


The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to alert addressees to potential hazards associated with the failure to maintain accurate inventories of licensed material. The circumstances described below involve the failures to maintain accurate inventories of licensed material, which led to unauthorized possession of several sealed and/or unsealed sources of radiation. In one case, an unsealed source created a significant contamination problem at a small university. The contamination apparently had been present for several years.

It is expected that recipients will review this information for applicability to their operations and consider actions, as appropriate. However, information contained in this IN does not constitute new NRC requirements; therefore, no specific action nor written response is required.

Description of Circumstances:

NRC recently performed a routine inspection of a small university authorized to possess and use millicurie (megabecquerel) quantities of phosphorous-32, sulfur-35, carbon-14, hydrogen-3, and iodine-125, and a 20-millicurie (740 megabecquerel) strontium-90 sealed source. During the inspection, a locked safe labeled as containing radioactive materials was identified. When the safe was opened, several radionuclides were found, including a small empty vial labeled as 5 millicuries (185 megabecquerel) of americium-241, and two americium-241 sealed sources.

Surveys of the safe and the floor around the safe identified removable contamination. Additional contamination was identified in an unrestricted area outside the room where the safe was stored. The licensee reported the contamination to NRC and indicated that it suspected the radionuclide to be americium-241. Using alpha detection equipment, extensive contamination was identified in several areas outside the storage room and in a classroom on the second floor. Using gamma spectroscopy, NRC confirmed the radionuclide to be americium-241. The university has had to expend significant resources in assessing and remediating contaminated areas. Preliminary assessments of personnel exposure indicate that at least two individuals have had intakes of americium-241.

The inspection identified that 5 millicuries (175 megabecquerel) of unsealed americium-241 had been authorized on the university's license in 1970. The material had been placed in storage and not used since 1980. University staff apparently failed to maintain an accurate inventory of the licensed material, and University management was not aware it was still in possession of the material in the safe. In 1991 a license amendment removed the americium-241 and several other radionuclides from the license.

A separate inspection at a different university also identified radioactive material that was not identified on current inventories, and was not authorized on the university's NRC license. In this case, the licensee had maintained physical control of the material and no contamination was identified.

To top of page


In the cases discussed here, NRC believes that the licensees relied on specific individuals involved with using radioactive material as the basis for source accountability. The failure to maintain accurate accountability of the material led to removal of authority to possess the material from subsequent licenses. Possession of unauthorized material is a violation of NRC regulations. Loss of control can result in significant accidental radiation exposure to occupational workers and members of the public, as well as affect public confidence in licensee programs.

Licensees are required to perform an annual review of their radiation safety programs (10 CFR 20.1101). Such a review should include an inventory of radioactive material to verify that possession (both types and quantities) of material is as authorized on the NRC license. Maintaining accurate running inventories of licensed material is always a prudent practice, and is required by many types of NRC licenses.

This IN requires no specific action nor written response. If you have any questions about the information in this notice, please contact the technical contact below or the appropriate regional office.


Donald A. Cool, Director
Division of Industrial and Medical Nuclear Safety
Office of Nuclear Material Safety and Safeguards

Technical Contact: Kevin G. Null, Region III
Attachments: 1. List of recently issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices

(ADAMS Accession Number ML010710110)

To top of page

Page Last Reviewed/Updated Wednesday, March 24, 2021