The following information was provided by the State of
Kansas via fax:
This letter is to inform [the Kansas Department of Health & Environment] that yesterday afternoon [on 4/3/13, the RSO] had attempted to move a source from its drywell into its source holder to prepare for maintenance activities in the vessel. The source seemed to be stuck in the drywell. Because the cable restraining the source does not allow the shutter to close until it completely retracted, the shutter would not close. Later last night, after consulting with VEGA Americas and [the company] on-site engineers, [the RSO] attempted again to remove the source and it was free. The source has been safely stored in its holder. There were no reportable personnel exposures. Because of the position of this source 8 feet inside a large vessel with 5 [inch] steel walls, it is shielded at least as well as inside its holder.
The shutter in question is on an Ohmart/VEGA model SHLM-CR3 source holder S/N 19077664, containing 2 Ci of Cs-137 in a model A2102 sealed source S/N 0587CO.
The source is located at [the company facility] in EI Dorado, KS . . .. It is approximately 140 feet above the ground. Operations and maintenance personnel were notified of the issue. A wipe sample was collected to check for gross leakage. None was indicated.
What [the RSO] believe[s] caused this situation was the combination of two (2) things. The reactor was being cooled with nitrogen over the past few days. It has also been raining and snowing. [The RSO] believe[s] water was drawn into the well during cooling and the nitrogen cooled that area of the reactor enough to freeze the water in the well. Ice was present on the cable as it was pulled out. Because the reactor was sufficiently cooled, the nitrogen purge was reduced, thus allowing the reactor to warm slightly by 8 PM when [the RSO] tried again.
[The RSO] feel[s] that this was not, in fact, a shutter issue, but an operational issue which [the RSO] will be cognizant of in the future. [The RSO] will simply make sure the internal temperature of this vessel is above 40 degrees F before attempting to remove the top source. Normally it is over 500 Degrees, so water intrusion is not an issue. Again, the source was always in a safe position. At no time were personnel exposed to any reportable levels of radiation.
Kansas Item Number: KS130003