Office of Public Affairs Region III

2443 Warrenville Road

Lisle IL 60532



No. III-07-025

Contact:  Viktoria Mitlyng

Phone: 630-829-9663


                                            November 29, 2007


Web site:




            The Nuclear Regulatory Commission has proposed a $65,000 fine against Exelon Generation Company for failure to properly implement its program for control and accounting of special nuclear materials at the Dresden Nuclear Station between 1959 and 2007. The plant is located in Morris, Ill.


            The NRC qualifies the following isotopes as special nuclear material: plutonium, uranium-233, uranium enriched in the isotope U-233 or U-235.


            In May 2007, the Dresden Nuclear Station reported to the NRC that the plant could not account for two fuel pellets and a number of in-core detectors which totaled less than one gram of fuel material. The discovery was made during a review of the station’s special nuclear material accounting records. According to a 1977 Dresden report, the fuel pellets were supposed to be placed in the spent fuel pool but could not be located during the 2007 inspection. During the same review, station personnel determined that some records for storing and shipping in-core detectors were missing. In-core detectors are used to measure the activity of neutrons in the reactor core.


            These accounting failures, although unacceptable, did not result in a safety or security hazard. The pellets could not have been removed from the plant by individuals without alarming the radiation monitoring equipment. The missing pellets and in-core detectors are likely still on-site or could have been transferred to an NRC-regulated disposal site.


In June 2007, the NRC conducted an inspection of the plant’s Material Control & Accounting program. NRC inspectors found that, contrary to NRC regulations, the utility failed to keep complete records; establish, maintain, and follow written Material Control & Accounting procedures sufficient to account for special nuclear material at the plant; and conduct a physical inventory of all special nuclear material on a yearly basis. The inspection report is not available to the public because it contains plant security information.



“The NRC takes the issue of accounting for nuclear materials very seriously,” said Regional Administrator James Caldwell. “Even though the missing material at Dresden does not represent a danger to the public, the NRC is taking strong measures to make sure that all special nuclear material is accounted for at Dresden and at every nuclear plant in the country.”


Dresden has conducted an extensive search for the pellets and the in-core detectors. The utility has also implemented corrective actions to make sure the accounting problems do not recur. Dresden’s Material Control & Accounting procedures have been revised. Exelon is revising corporate procedures to ensure that visual verification of special nuclear material is performed on an annual basis for all required locations and that all special nuclear material records are retained for the lifetime of every Exelon plant.


            Further information about this enforcement action can be accessed at the NRC web site at:




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