On November 8, 2013, at approximately 1045 PST, an Air Balance Technician at AREVA NP's Richland fuel fabrication plant discovered that the primary and secondary
HEPA filters servicing the ammonium diuranate (ADU) area showed visible signs of deterioration. The apparent deterioration is being reported in accordance with
10 CFR 70.50(b)(2).
The K-32A HEPA filters were examined by air balance personnel at approximately 1045 PST on November 8, 2013 based on a request to follow-up on some stack monitoring results which indicated some elevated levels (still below required administrative action levels). Air flow was diverted to HEPA filters in a parallel upper housing in order to check the filters in the lower housing. Investigation showed apparent deterioration of both the primary and final HEPA filters.
The processes running at the time served by these HEPAs were the ammonium diuranate process, miscellaneous uranium recovery process, and cylinder wash. Air monitor samples were pulled on the K-32A system. Air monitoring samples showed negligible release levels. A Health and Safety Technician survey of the downstream side of the final HEPA housing of K-32A revealed no surface contamination above 'clean' criteria.
Potential dose to a member of the public and the effect on the environment are essentially negligible. External conditions are not known to have affected the event.
A Corrective Action Report, 2013-8809, was written on November 8, 2013. The cause of the apparent deterioration is under active investigation. Steps to prevent recurrence will be developed as appropriate.
The licensee will notify the NRC Regional office and the
Washington State government.