Event Notification Report for June 09, 2013

AGREEMENT STATE REPORT - POTENTIAL OVEREXPOSURE

The State of Kansas was notified by the licensee that on 6/9/2013, personnel dosimetry indicated that one assistant radiographer had received a potential overexposure, and two other assistant radiographers had received potential elevated exposure. The licensee reported that the dosimetry had been stored improperly and in close proximity to a location where a source change out had occurred. Corrective actions taken by the licensee include establishment of a controlled dosimetry storage location and additional training of personnel on the use of dosimetry. The individual with the potential overexposure was removed from radiography duties and given alternate work assignments. All three individuals were notified of the dosimetry readings.

The dosimeter readings were 5.046 rem, 1.133 rem and 0.633 rem.

* * * UPDATE FROM JAMES HARRIS VIA FAX AT 1050 EDT ON 6/17/13 * * *

The following information was obtained from the State of Kansas via fax:

"Based on the last dosimetry report [received by the licensee], several employees have received a high dose. The reported doses are Employee 1 - 5046 mR, Employee 2 - 1133 mR, and Employee 3 - 633 mR.

"The three employees are radiographers assistants acting under one of the 4 licensed radiographers. The three radiographers assistants never worked together on any single job. The only common denominator between the three assistants is that their film badges were stored in the same general area. The licensed radiographers that were assigned to them received no such high dose rates. The three assistants also did not have any off-scale readings from dosimetry nor did they report any unusual incidences. All three also stated they did not believe that they could possibly have received an unusually high dose during that time period based on dosimetry, rate alarm, and survey meter readings.

"Upon further investigation, it was discovered that the three were leaving their film badges in their [work] uniforms in a controlled area within the shop between shifts. During this time period, radiographic operations were conducted at the shop facility. Additionally, there was a source change conducted by two radiographers in the controlled area of the shop during this time. During times these employees were not working, their [work] uniforms would have been located in the controlled area allowing their badges to be exposed during radiographic operations.

"In conclusion, there are two possible explanations for the substantial increases in exposure to the three assistants badges. Conclusion one would be that excessive heat and humidity played a role in the increased readings found with the badges. Conclusion two would involve film badges in close proximity to the area where radiographic operations were being conducted with the individuals assigned to those badges being absent at the time, therefore creating an erroneous reading leading to the obvious assumption that the badges alone were exposed, not the individuals associated with these badges being exposed.

"Corrective action taken at this time: Badges will be stored in the office, [with the proper controls in place] when not being worn. Retraining [was] conducted on the physical properties of the film badge and how badges become exposed through various means.

"Based on the reading of employee 1's badge, he will not be involved in radiographic operations nor be allowed in the controlled areas near radiation in the shop until a full investigation is completed."

The State of Kansas is still investigating this event.

Kansas Case No.: KS130005

Notified R4DO (Walker) and FSME Events Resource via email.

PART 21 - AUXILIARY FEEDWATER LEVEL CONTROL VALVE STEM/PLUG ASSEMBLY OUT OF TOLERANCE

"On June 9, 2013, Auxiliary Feedwater Level Control Valve [AFW LCV] 1-LCV-3-156-A, failed its closed-to-open stroke time during quarterly surveillance testing. This level control valve is a basic component which regulates auxiliary feedwater (AFW) flow to Steam Generator 2. The valve failed to open during two attempts. Local observation during testing indicated that the valve 'popped' off the seat, and then traveled smoothly to its full open position on the third and fourth attempt. The failure was determined to be a Maintenance Rule Functional Failure and a CC1 Functional Failure. There were no previous indication(s) of this failure mode during the previous quarterly stroke time testing. The valve internals were replaced on October 7, 2009, during a refueling outage.

"TVA installed a new trim kit which included the cage, lower seat ring, and stem/plug assembly. The valve was returned to service on June 12, 2013, following successful post modification testing. A Kepner-Tregoe (K-T) problem analysis revealed the direct cause was binding due to the stem/plug assembly being out of tolerance. Upon inspection, the Total Indicated Run-out (TIR) of the stem/plug assembly removed from the affected valve was determined to be 0.022 inches. The valve was manufactured by Dresser Masoneilan with a TIR specification of less than or equal to 0.005 inches. The valve model and stem/plug assembly part numbers are:

"Valve: Masoneilan Model 37-20721, 4 inch Control Valve
"Stem: 012160204-215-J000
"Plug: 011501710-1H6U

"Inspection of the five unused spare stem/plug assemblies in storage had a TIR that ranged from 0.006 to 0.022 inches, which is outside vendor specifications. Because the stem/plug assembly removed from the affected AFW LCV and five of the unused stem/plug assemblies were found to be out-of-tolerance, a condition exists and is being reported in accordance with 10CFR50 Part 21.21(d).

"Similar LCVs in the AFW systems were tested and are OPERABLE with no known defects.

"A detailed report using NRC Form 366, Licensee Event Report, will be submitted to the NRC by 09/15/13 in accordance with 10CFR50 Part 21.21(d)(3)(ii)."

The licensee has notified the NRC Resident Inspector.