Lesson Learned Statement:Radiological controls inspector coverage is required for specific work activities where there is a high potential for unanticipated exposure. In order to minimize exposure, the use of proper protective equipment for both the inspector and those performing assigned tasks must be thoroughly evaluated during job planning. Remember, inspectors can potentially become exposed to the same radiation sources as those performing the assigned work. Also, when low-energy photon activity from plutonium is present, electronic dosimeters must be used, as this low-energy activity is not within the sensitivity range of self-reading dosimeters (SRDs).
Discussion:Facility operators were assigned a task to bag out 7 High Efficiency Particulate Air (HEPA) filters. A radiological controls inspector was assigned to provide coverage for the bagout procedure. All personnel were dressed in two pair of coveralls, wore air-supplied hoods and wore self-reading dosimeters. In addition, the operators wore lead aprons and supplemental electronic SRDs. During the course of the bagout, the inspector came within 1-2 feet of the source. This was not anticipated and the inspector was exposed to low-energy photon radiation. If the inspector had been equipped with a lead apron, he would have been protected from the low-energy photons just as the operators were protected. Another concern is that, because the low-energy photon activity associated with plutonium is not within the instrument range sensitivity of the SRD, none of the SRD readings would indicate the elevated dose. Wearing electronic dosimeters would have provided measurement of actual exposure levels.
Recommended Actions:When working with plutonium where there is a potential for exposure to low- energy photon activity, ensure that the dosimetry used has sufficient sensitivity to detect low-energy photon activity. Also, when planning job activities, thoroughly assess the duties of the inspectors and/or observers as they could become exposed to the same radiation as those performing the job activity.
Originator:HB-Line Facility, Savannah River Site
Validator:Lester Lee (301) 903-4006
Name Of Authorized Derivative Classifier:Dennis R. Stanford, (803) 557-8234
Name Of Reviewing Official:N/A
Priority Descriptor:Yellow / Caution
Keywords:RADIATION, EXPOSURE, HEPA, LOW-ENERGY PHOTON ACTIVITY, INSPECTOR
References:SR--WSRC-HBLINE-1996-0007, Personal Radiation Exposure in Excess of Annual Administrative Exposure Limits
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DOE Function / Work Categories:Radiation Protection
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