ENS 42908
ENS Event | |
|---|---|
12:16 Oct 16, 2006 | |
| Title | Unusual Event - High Airborne Particulate in the Reactor Building |
| Event Description | Even though there have been no operations on going over the weekend, airborne activities have increased to above ten times the normal levels. Activity levels were increasing during work processes last week but did not reach abnormally high levels. The licensee is taking air samples and swipe surveys to determine the source. The element of interest is Americium. Workers entering the building are required to wear filter masks.
Conditions at time of incident: SAFSTOR, decommissioning work in progress involving saw-cutting of Upper Control Rod Drive Mechanism (UCRDM) seal inject supply and effluent lines, plasma arc cutting of metal in Reactor Vessel upper cavity, and welding of lifting lugs on Reactor Vessel upper cavity expansion joint structure. Description: Thursday afternoon October 12, 2006, air samples of Reactor Building indicated higher levels of Americium-241 (Am-241) than normal. As of Monday morning October 16, 2006, Reactor Building ventilation through HEPA filters had not reduced the level of Am-241 as expected. Unusual Event was declared and investigations commenced to identify source of contamination. Immediate evaluation/corrective actions: Upper cavity work was halted Thursday afternoon following the air sample results. It was believed that welding or plasma arc cutting in the upper cavity had created the airborne problem. Air sampling on Friday October 13, 2006, indicated Am-241 levels still remained higher than normal. At that time, all personnel entering the Reactor Building were required to wear respirators. Air sampling continued through the weekend. When Am-241 levels had not decreased to acceptable levels by Monday morning, October 16, 2006, an Unusual Event was declared due to the unexpected nature of the airborne activity, lack of identification of the source of the activity, and activity level being greater than 10 times normal for the nuclide Am-241. Following declaration, the Operations Review Committee (ORC) was convened. Various strategies for identifying the source of the contamination were discussed and established. Surveys were conducted in the Reactor Building basement and the source of the contamination was tentatively identified as effluent from the UCRDM draining that occurred on Thursday morning October 12, 2006. Further analysis and clean-up is in progress. Notified the R3DO (Skokowski).
The licensee secured from their Unusual Event at 0727 CDT. The licensee determined the source of the airborne activity, completed decontamination procedures and ventilated though a HEPA filter. Airborne samples are satisfactory. Notified R3DO (R. Skokowski), NMSS (M. Burgess), IRD (M. Leach), DHS (G. Gray), FEMA (K. Biscoe), and NORAD-NC (Hardaway). |
| Where | |
|---|---|
| La Crosse File:Dairyland Power Cooperative icon.png Wisconsin (NRC Region 3) | |
| Reporting | |
| Emergency class: | Unusual Event |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration | |
| Time - Person (Reporting Time:+-3.05 h-0.127 days <br />-0.0182 weeks <br />-0.00418 months <br />) | |
| Opened: | Dan Tesar 09:13 Oct 16, 2006 |
| NRC Officer: | Bill Gott |
| Last Updated: | Oct 17, 2006 |
| 42908 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 42908\u003C/a\u003E - \u003Ca href=\"/La_Crosse\" title=\"La Crosse\"\u003ELa Crosse\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EUnusual Event - High Airborne Particulate in the Reactor Building\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 42908 - La Crosse\n","link":"","lat":43.56,"lon":-91.23166666666667,"icon":"Dairyland Power Cooperative icon.png"}],"imageoverlays":null} | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Decommissioned (0 %) |
| After | Decommissioned (0 %) |
La CrosseFile:Dairyland Power Cooperative icon.png with 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | |
WEEKMONTHYEARENS 429082006-10-16T12:16:00016 October 2006 12:16:00
[Table view]10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event - High Airborne Particulate in the Reactor Building 2006-10-16T12:16:00 | |