Bonderite L-GP 154N (DAG) contamination – response and proposed specification revisions

In 2013, Cameco Fuel Manufacturing (CFM) identified an atypical rubbery material in a failed graphite slurry pump that is used to circulate Bonderite L-GP 154N (DAG) and isopropyl alcohol as part of the CANLUB coating process. CFM has a robust CSA N299.1 compliant quality program; procedures were followed to identify, control and disposition all affected material. The initial investigation determined that the source of the foreign material may have been a contaminant within the graphite slurry. A Material Review Board (MRB) was initiated to help assign an incident owner, and to track details of product control and investigative activities, as well as communication of the event to the customer, supplier and other nuclear industry users of this product. The investigative activities were extensive and included an audit of the DAG manufacturing facility, numerous analyses conducted by 3rd party laboratories to identify the type and elemental composition of contaminant, and research into the potential impact of the contaminant on finished fuel. The findings were detailed in an Incident Report that was presented to the customer for review and concurrence regarding the disposition of the material. Permanent corrective actions were identified and were also detailed within the Incident Report relating to supplier and CFM process changes to decrease the likelihood of recurrence and increase the likelihood of detection. Further discussions with customers has led to proposed revisions to the Technical Specifications (TS) for Alcadag (DAG) to address a perceived supply chain risk. From this event, CFM and BWXT collaborated to discuss DAG concerns and openly share information to address risks. These activities have resulted in reduced risk not only for Cameco Fuel Manufacturing, but for the broader CANDU industry. (author)