Causal Analysis of the Unanticipated Extremity Exposure at HFEF.

摘要

The Hot Fuel Examination Facility (HFEF) is a Hazard Category 2 nuclear facility, located at the Materials and Fuels Complex (MFC) at the Idaho National Laboratory (INL), in which Post-Irradiation Examination (PIE) processes are conducted within a large, inert hot cell. One of the PIE processes involves dismantling irradiated fuel and placing portions of the structural material and/or fuel in metallurgical (Met) mounts in the Station 2M Containment Box. HFEF Operators cut and prepare the Met mounts according to procedure and a Process Work Sheets (PWS) submitted by a Principal Investigator (PI), which is reviewed by HFEF support personnel and approved by HFEF facility management. Approximately four hundred Met mount samples had been processed in HFEF so far this year. The Fuel Conditioning Facility (FCF) Radiological Control (RadCon) Supervisor was contacted by the External Dosimetry Lead on October 5, 2011 to report that a Hot Fuel Examination Facility (HFEF) Operators right hand (finger) extremity dosimetry had abnormally high results (i.e., 3.58 rem). The FCF RadCon Supervisor informed the HFEF RadCon Engineer and the Materials and Fuels Complex (MFC) RadCon Manager of the concerns with the extremity dose results. The HFEF RadCon Engineer notified the HFEF Management of the results and restricted the affected Operator from performing any radiological work. A critique was held on October 6, 2011 and was continued and completed on October 10, 2011. The HFEF RadCon Engineer reviewed the affected Operators external dosimetry results and other HFEF Operators external dosimetry results and based his review on Radiological Work Permit (RWP) access and RWP entries for all HFEF activities requiring extremity dosimetry.