Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 45195 | 11 July 2009 01:00:00 | 10 CFR 40.60(b)(1) | Unplanned Contamination Event Requiring Additional Radiological Controls (Respirators) for More than 24 Hours | An unplanned contamination event occurred on 10 July 2009. This is a reportable event in accordance with 10CFR40.60 sub paragraph (1) based on an unplanned event that resulted in additional radiological controls being required for more than 24 hours. The 24 hour period ended at 2000 CDT on 11 July 2009 (the reported event). The additional control imposed was the wearing of air purifying respirators on the fourth floor of the Feed Materials Building. The location of the event was the Feed Materials Building fourth floor. The Feed Materials Building converts milled uranium oxide material to uranium hexafluoride by using a dry process. Air samples from the fourth floor were analyzed and the airborne radioactivity averaged approximately 6.11E-11 microcuries/ml. The airborne contaminant was natural uranium ore concentrate and the physical form is a light microscopic dust. The processes in the area of elevated levels of airborne radioactivity have been secured and potential leakage paths are being investigated. The licensee will notify NRC Region II. HOO Note: See similar Event Numbers 44857, 44871, 45058, and 45163.
The isotope responsible for the increased controls was natural uranium in the chemical form of uranium tetraflouride (UF4); green salt. The amount of unplanned contamination that was released in the form of green salt was estimated to exceed 5 times the ALI (Annual Limit on Intake) (3 grams). The airborne activity averaged approximately 6.11E-11 microCuries/ml. (5.0E-11 microCuries/ml is 30% of 1 DAC (Derived Air Concentration)). The licensee states that bioassay sampling of any potentially exposed individuals will be performed within the routine sampling frequency, but prior to 7/30/09. The licensee has notified NRC Region II. Notified R2DO (O'Donohue) and NMSS EO (Kotzalas). | ||
| ENS 45163 | 24 June 2009 15:45:00 | 10 CFR 40.60(b)(1) | Access Restriction Due to Unplanned Contamination | An unplanned airborne contamination event occurred beginning June 24, 2009 at 1045 at the Honeywell Metropolis, IL facilities' pond mud calciner area. Access was restricted to the area by requiring respiratory protection to be worn. Average airborne concentrations during the following 24 hour period were 7.19 E -11 microcuries per cubic centimeter which exceeds the administrative limit of 5 E -12 microcuries per cubic centimeter. Natural uranium dust was the isotope involved. There was no known effect to employees. This event is being entered into the facilities corrective action program.
The licensee is retracting this report based on the following: (The licensee is) withdraw(ing) the event reported June 25th, 2009 Event Number 45163. Following a review of the circumstances associated with the report (the licensee) determined that the event did not meet the criteria as described in 10CFR40.60(b). The event review determined that the contamination event was expected. And the area DID have a respiratory protection requirement in place at the time of the elevated air activity. The licensee informed NRC Region 2 (John Pelchat). Notified R2DO (Musser) and NMSS (Easton). | ||
| ENS 45058 | 11 May 2009 16:30:00 | 10 CFR 40.60(b)(1) | Multiple Failures to Meet 24 Hour Reporting Criteria | On May 11, 2009, at approximately 1130 CST, licensee initial evaluation concluded that events meeting the 24 hour reporting criteria of 10CFR40.60 (b)(1) had not been reported during the period 10/17/08 through 03/29/09 (37 events total). Each event involved leakage from processing equipment located in the Feeds Material Building, (FMB). The material involved in each case was either natural uranium, or UF4 (green salt), in the form of a dry powder or dust. It is believed in each case the quantity of material exceeded 5 times the lowest ALI as specified in 10CFR40.60(b)(1)(ii), which for this material is less than 3 grams. In each case appropriate protective measures were applied when contamination was discovered. Protective measures included turning on precautionary lights, and requiring the wearing of respirators for personnel entering affected areas. Cleanup of affected areas was also conducted. A more conservative interpretation of which events are considered unplanned versus planned has been incorporated. The previous interpretation historically applied, considered the event planned, if at the first indication of leakage, mitigating actions were initiated. The more conservative interpretation will incorporate considering the event unplanned, if mitigating measures were not already in place for a planned activity at the time of discovery. This more conservative interpretation has been discussed with NRC Region II, has been adopted as the facility's practice, and communicated to licensee management. Review of personnel bioassay data indicates no resulting increase in personnel dose measurements. Review of liquid and gaseous effluent data, and sampling data from the restricted area boundary all indicate no significant increases in effluent measurements, and all analytical results are well within regulatory limits. There is no impact to plant workers or members of the public as a result of this event. Routine contamination surveys are being conducted in accordance with Health Physics program procedures, and results are reviewed with the plant ALARA committee. This event will be addressed by corrective actions in accordance with the plant Corrective Action Program. | ||
| ENS 44939 | 24 March 2009 18:30:00 | 10 CFR 40.60(b)(1) | Building Contaminated During Maintenance | The licensee was troubleshooting a green salt filter leg when approximately 100 pounds of green salt was released from a secondary dust collector drop leg pipe. Four personnel were in the area wearing respiratory protection and anti-contamination clothing. The personnel left the area and access was restricted until 1030 on 3/26/2009. The green salt contaminated four floors of the building and the four personnel. Personnel contamination was removed with removal of the anti contamination clothing and subsequent showers. Most of the floor contamination was cleaned within four hours and the remainder was completed on 3/26/2009. No contamination was released outside the building. The licensee notified the NRC Resident Inspector. | ||
| ENS 44871 | 23 February 2009 16:30:00 | 10 CFR 40.60(b)(1) | Airborne Contamination Over the Limit in the Feed Materials Building | |||
| ENS 44857 | 16 February 2009 16:30:00 | 10 CFR 40.60(b)(1) | 24-Hour Report Involving an Unplanned Contamination Event | An unplanned contamination event occurred on February 16th, 2009. This is a reportable event in accordance with 10CFR40.60 paragraph (1) based on an unplanned event that results in additional radiological controls being required for more than 24 hours. The 24 hour period ended at 1030 on February 17th, 2009. The additional controls imposed was wearing a half-face respirator in the basement of the Feed Materials Building. The Feed Materials Building converts uranium ore concentrates into uranium hexafluoride. Air samples from the basement were analyzed and the airborne radioactivity average was approximately 8.27 e-11 �Ci/ml. The airborne radioactivity exceeded the MTW action level of 30% of a DAC (5.0 e-11 �Ci/ml). One DAC is 1.7e-10. Uranium Tetrafluoride (green salt) was the material that was airborne in the basement. An elevator that is used to transport green salt to different levels of the Feed Materials Building was leaking around an inspection cover which caused the airborne radioactive material. The licensee attributes the contamination to a failed gasket. The airborne contamination was discovered during routine air sampling which is performed daily. There is no plan to perform personnel testing for uptake or ingestion at this time. | ||
| ENS 44444 | 27 August 2008 15:00:00 | 10 CFR 40.60(b)(1) | Unplanned Contamination Event | An unplanned contamination event occurred on August 27, 2008. The event is reportable in accordance with 10CFR40.60 subparagraph (1) based on an unplanned event that resulted in additional radiological controls or by prohibiting entry into the area. The 24 hour period ended at 10:00 a.m. on August 28, 2008. The additional control imposed is to wear air purifying respirators on the second floor of the feed materials building. Air samples from the second floor analyzed and the airborne radioactivity average is approximately 6.7e-11 microCuries/ml. The airborne contamination is natural uranium ore concentrates and the physical form is a light dusty material. The area of contamination is in the Feed Material building while using the prepared feed mill. | ||
| ENS 41977 | 9 September 2005 15:00:00 | 10 CFR 40.60(b)(1) | Unplanned Contamination Event | An unplanned contamination event occurred on 8 September 2005. This is a reportable event in accordance with 10CFR40.60 sub paragraph(1) based on an unplanned event that resulted in additional radiological controls being required for more than 24 hours. The 24 hour period ended at 1000 on 9 September 2005 (the reported event date). The additional control imposed was the wearing of air purifying respirators on the second floor of the Feed Materials Building. The location of the events was the Feed Materials Building second floor. The Feed Materials Building converts milled uranium oxide material to uranium hexafluoride by using a dry process. Air samples from the second floor were analyzed and the airborne radioactivity averaged approximately 6.5E-11 microCuries/ml. The airborne contaminant was natural uranium ore concentrate and the physical form is a light microscopic dust. The processes in the area of the elevated levels of airborne radioactivity have been secured and potential leakage paths are being investigated. The licensee stated that bioassay sampling of exposed individuals will be performed within the routine sampling frequency, but prior to 09/30/05. The licensee notified NRC Region 2 (D. Collins). | ||
| ENS 41879 | 25 July 2005 14:18:00 | 10 CFR 40.60(b)(1) | Unplanned Contamination Event Due to Filter Failure | An unplanned contamination event occurred on 25 July 2005. This is a reportable event in accordance with 10 CFR 40.60 sub paragraph (1) based on additional radiological controls being required for more than 24 hours. The additional control imposed was the requirement to wear air purifying respirators in the Feed Materials Building. The location of the event was the Feed Materials Building. The Feed Materials Building is where milled uranium oxide material is converted to uranium hexafluoride. Located on the sixth floor, the Ash Vacuum Cleaner filters failed which allowed spar and dust filter fines containing uranium to exit the discharge from the Ash Vacuum Cleaner. Due to the proximity of the Ash Vacuum Cleaner discharge and the inlet to the building ventilation, some the material was picked up by the ventilation system and distributed throughout the Feed Materials Building. A dust plume was noted coming from the discharge line of the Ash Vacuum Cleaner at approximately 0918. At approximately the same time, personnel in the building noted dust being emitted from the building ventilation system registers. The Ash Vacuum Cleaner was secured at approximately 0920. Personnel recognized the potential for airborne radioactivity and immediately required respiratory protection for all personnel in the building. Special bioassay samples were required for 19 people who were present in the building during the occurrence. The results of the special bioassays indicated no uptake of radioactivity by the personnel sampled. Fixed air samplers analyzed after the event on all floor indicated air activity in the range of 5x10 E-11microcuries/ml to 60x10 E-11microcuries/ml. Air samples and contamination surveys performed downwind were background levels. Cleanup of the granular material in the Feed Material Building commenced immediately. The isotope release was U-238, the chemical form is UF4, and the physical form is granular. The Feed Materials Building has now been cleaned of contamination that was due to this event. The licensee has notified NRC Region 2 (Hartland), NRC HQ (Raddatz) and NRC Regional Inspector (Gibson). |