ENS 45407
ENS Event | |
|---|---|
20:30 Oct 2, 2009 | |
| Title | 24 Hour Report on Process Exhaust Hepa Filter Damage |
| Event Description | At approximately 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br /> on 10/1/09 during a follow-up investigation of an event which occurred at mid-day on 9/27/09, conditions were discovered that may have met the criteria for reporting in accordance with 10 CFR 70.50.b.2.
The incinerator was shutdown on 9/25/09 in preparation for performing dioctyl sebacate (DOS) efficiency testing on 9/27/09 of the final HEPA filters in K50 Solid Waste Uranium Recovery (SWUR) exhaust gas treatment system. At approximately noon that Sunday, an event occurred that, in hindsight, was a probable fire in the packed column scrubber in the exhaust gas treatment system. This event was terminated in a timely fashion by reinitiating water flow to the packed column. Indications of high heat and possible fire in the packed column included high temperatures and observed 'smoke' from mechanical flanges on the downstream ducting of the packed column. Subsequent to the observed high heat event in the packed column, high temperatures of the downstream north HEPA housing (in-service) were observed. The high temperatures in the HEPA housing were believed to be from the high heat event in the packed column. The continuous airborne effluent sample for the K50 stack (downstream of HEPA filters) was counted to evaluated whether a release had occurred. The results of the sample were at the low end of the normal range for this stack, indicating no active release had occurred. Continuous monitoring of the system assured the termination of the packed column and HEPA housing high heat events. The systems were continuously monitored and cooled down to near ambient conditions on Monday, 9/28/09. On Monday morning a valve was removed between the quench column and the packed column of the scrubber system. The valve on the packed column side showed high heat damage. A visual inspection on the bottom of the packed column indicated significant degradation of the internals, including the lower fiberglass distribution plate and high surface area polypropylene balls. This evidence points to a high heat event/fire within the packed column. The ignition source is still under investigation as the furnace was completely cold. There is an electric re-heater mounted immediately above the packed column which may have been the ignition source. Disassembly of the packed column is awaiting access platform construction. Continuing the investigation on 10/1/09 at approximately 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br /> the HEPA filter housing was opened for inspection. This inspection found significant deterioration of one of the two HEPA units in each of the primary and final banks. The loss of both the primary and final HEPA units constituted a loss of equipment in accordance with 10 CFR 70.50.2. A Condition Report in the Corrective Action Program has been initiated and a causal analysis is being performed. The system continues to be in a shutdown condition. |
| Where | |
|---|---|
| Areva Np Inc Richland Richland, Washington (NRC Region 2) | |
| License number: | SNM-1227 |
| Reporting | |
| 10 CFR 70.50(b)(2) | |
| Time - Person (Reporting Time:+-3.27 h-0.136 days <br />-0.0195 weeks <br />-0.00448 months <br />) | |
| Opened: | Robert Link 17:14 Oct 2, 2009 |
| NRC Officer: | Charles Teal |
| Last Updated: | Oct 2, 2009 |
| 45407 - NRC Website | |
Areva Np Inc Richland with 10 CFR 70.50(b)(2) | |
WEEKMONTHYEARENS 495242013-11-08T18:45:0008 November 2013 18:45:00
[Table view]10 CFR 70.50(b)(2) Apparent Deterioration of Primary and Secondary Hepa Filters ENS 454072009-10-02T20:30:0002 October 2009 20:30:00 10 CFR 70.50(b)(2) 24 Hour Report on Process Exhaust Hepa Filter Damage ENS 454022009-10-01T02:10:0001 October 2009 02:10:00 10 CFR 70.50(b)(2) 24 Hour Report on Process Exhaust Hepa Filter Deterioraton ENS 453102009-08-29T13:15:00029 August 2009 13:15:00 10 CFR 70.50(b)(2) Nuclear Criticality Detection System Inoperable 2013-11-08T18:45:00 | |