ENS 48261
ENS Event | |
|---|---|
07:00 Oct 1, 2011 | |
| Title | Agreement State Report - Student Received Potential Inhalation Overexposure |
| Event Description | The following information was received from the State of Nevada via email:
A graduate student inhaled a mixture of U-233 and U-238 while working in the lab grinding a compound of Uranium Octoxide. [The graduate student] used a glove box instead of the hood with the HEPA filter, contrary to UNLV [University of Nevada Las Vegas] approved procedure. This happened twice and could have been between October 1, 2011 and April 1, 2012. The first bioassay, based on an inhalation date of October 1, 2011, showed 17.72 rem total. When the inhalation date was assumed to be April 1, 2012, the result was 5.52 rem. [U-233]*1.6 = [U-238] contribution. The student will be getting a third bioassay on September 5, 2012 at the Lawrence Livermore National Lab (LLNL). This will involve a low-energy chest count to detect Th-234 and an organ count, looking at the kidneys for Uranium. The student has been restricted from all lab work since April. The bioassay was done at Test America.
The following update was received from the State of Nevada via email: NMED Item No.: NV120022 Preliminary results: 1. September 5, 2012: Low-energy lung count, kidney count and hand count were performed at LLNL. The lung count was less than MDA for U-233, Th-234, U-234 & U-2235. The detect/non-detect kidney & hand counts were both non-detect. 2. September 12, 2012: Third Bioassay results received. U-238 - 0.66 dpm/sample U-235 - less than CRDL U-233/234 - 1.25 dpm/sample Notified R4DO (Hagar) and FSME Events Resource via email.
The following update was received from the State of Nevada via email: All personnel having access to the UNLV lab where the original uptake occurred had bioassay samples taken. UNLV determined that 46 persons should be in this group, including the RSO and ARSO. From the data submitted thus far, an additional graduate student appears to have received an uptake. This student has been restricted from further RAM work and a dose assessment undertaken. The actual dose will be dependent on the time and source of the uptake. If the timeframe and source are the same as that of the original graduate student, the magnitude will be the same. Thirteen remaining bioassays remain to be analyzed. Three of the thirteen are yet to be collected. The RSO attributed his elevated uptake to previous DOD work. The latest ten bioassays were collected within the last three weeks and with expedited processing results, should be available by mid-December. Notified the R4DO (Drake) and FSME Events Resource via e-mail.
The following update was received from the State of Nevada via email: Dependent on the particle size of the uptake the grad student's exposure could be either 6760 mrem for size M (medium) particles versus 154 mrem for size S (small) particles. UNLV has indicated a delay till March, 2013, for this analysis. It appears only the one Grad Student had an uptake. What corrective action(s) were taken to prevent a recurrence? Existing procedures were reviewed & rewritten, and additional new monitoring, controls, training and procedures are now in place to prevent a recurrence. Notified the R4DO (Hagar) and FSME Events Resource via e-mail.
The following is excerpted from an email received from the State of Nevada: All of the activity ratios (especially the one from the ICP-MS [Inductively Coupled Plasma Mass Spectrometry], which has the lowest uncertainty) are consistent with that of natural uranium. This supports the conclusion that the student's observed bioassay results are the result of an intake of natural uranium form non-occupational sources and not a result of material she was handling at UNLV. Notified R4DO (Whitten) and FSME Event Resource via email. |
| Where | |
|---|---|
| University Of Nevada Las Vegas, Nevada (NRC Region 4) | |
| License number: | 03-13-0305-01 |
| Organization: | Nv Div Of Rad Health |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+8048.8 h335.367 days <br />47.91 weeks <br />11.025 months <br />) | |
| Opened: | Sneha Ravikumar 15:48 Aug 31, 2012 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Apr 24, 2013 |
| 48261 - NRC Website | |
University Of Nevada with Agreement State | |
WEEKMONTHYEARENS 482612011-10-01T07:00:0001 October 2011 07:00:00
[Table view]Agreement State Agreement State Report - Student Received Potential Inhalation Overexposure 2011-10-01T07:00:00 | |