Event Notification Report for June 24, 2011

UNUSUAL EVENT DECLARED DUE TO INDICATIONS OF FUEL DAMAGE

The reactor operated at 10 W to 25 kW steady-state power for a total of 25 minutes. At 1257 CDT the Reactor Manager noticed that the radiation monitor (AMS-4) was reading approximately 80 times the Derived Air Concentration (DAC) for Iodine. A second continuous air monitor and a portable thin-window ionization chamber both read background levels of radiation. A high-volume air sampler was used to sample the air near the sampling location of the AMS, which draws air from the reactor deck. The filter from the air sampler read 3700 DPM after drawing 50 cubic feet of air, indicating elevated levels of activity. An HPGe (High Purity Germanium Detector) spectrograph indicated some Cs-137 in the air filter sample, but no I-131. Primary water activity and conductivity were both at normal levels. The indicated DAC of Iodine increased to a value of 149 times DAC before decreasing to 145 times DAC.

The Reactor Manager and Radiation Safety Officer agreed that fuel damage was unlikely, but the results of testing were inconclusive, and that it would be prudent to declare an Unusual Event.

* * * UPDATE FROM JEFFREY GUTHER TO CHARLES TEAL AT 1528 EDT ON 6/24/11 * * *

HPGe spectroscopy indicated only background levels of Cs-137 for a air sample, a primary water sample, and a swipe taken from the reactor deck. None of these samples showed I-131. A second portable air sample taken at the reactor deck, but on the opposite side of the deck from the radioactive sampling handling table, did not have elevated counts.

The Reactor Manager and Radiation Safety Officer agreed that the AMS-4 was most likely mis-calibrated, and the elevated levels in the first high-volume air sample were probably due to the proximity of the radioactive sample handling table to the sampling location.

Notified NRR (Grobe), NRR EO (Evans), R4DO (Deese), IRD (Grant), DHS (Hill), FEMA (Blankenship)

AGREEMENT STATE REPORT - SHUTTER FAILURE DUE TO BROKEN CABLE

The following information was obtained from the State of Pennsylvania via facsimile:

The remote shutter actuator on a Texas Nuclear gauge, Model 5197 (serial #81623) with approximately 100 mCi of Cs-137 was found inoperable. The remote shutter actuator controller cable failed. The shutter is locked in the closed position and shall remain so until repairs are made.

PA Report #: PA110013

AGREEMENT STATE REPORT - UNABLE TO RETRACT RADIOGRAPHY SOURCE

The following information was received from the State of Iowa via email:

The Iowa Department of Public Health (IDPH) was conducting a field inspection of Midwest Industrial X-Ray on Friday, June 24, 2011. The licensee was conducting 1 minute, 15 second shots on 12" diameter gas pipeline in a 10 foot deep trench. They were using a SPEC model 150 camera with a 49 Curie Iridium-192 source and SPEC control cables. After completion of the third shot, the licensee was unable to retract the source. The lead radiographer disassembled the control cable crank mechanism and manually pulled the source back into the shielded position. The licensee then reassembled the crank mechanism and attempted a third shot. Once again, they could not retract the source. The radiographer disassembled the crank mechanism, pulled the source into the shielded position and secured from any additional radiography that day. The licensee indicated that they had similar problems with SPEC control cables in the past. The radiographer and assistant radiographer's pocket dosimeters both indicated less than 5 milliRem. The licensee will submit a written report within 30 days."

The radiography was being performed in the Redfield Gas Storage facility in Redfield, IA. The event was reported by Midwest Industrial X-ray of Fargo, ND.

Iowa Report No.: IA110004