ENS 45225
ENS Event | |
|---|---|
18:30 Sep 20, 2008 | |
| Title | Lost (Then Recovered) Licensed Nuclear Material |
| Event Description | {{#Wiki_filter:This is an historical report for an incident submitted in response to an on-site inspection by an NRC Inspector (Lodhi).
On September 20, 2008 at approximately 2:30pm, while returning from an openhole job north of Buckhannon, the neutron shield and the density shield separated from the radiation compartment of an openhole logging truck near Lost Creek on Interstate 79 [exit 110] southbound. The driver continued driving to the shop. Upon return, he noticed a chain hanging freely from the radiation compartment of his truck. He looked in the compartment and noticed that both transport shields and the pig holder had been separated from the unit. He immediately called his supervisor at approximately 3:00pm, who had stopped at the BP in Lost Creek for a drink on the way to the shop, and told him that the transport shield had been separated from the wireline unit. The driver mentioned hearing something after crossing the bridge on interstate 79 South at Lost Creek. The supervisor, who was ? of a mile away from the bridge, proceeded to the spot and immediately picked up the transport shields and pig holder. The supervisor loaded the transport shields and pig holder into the box of his pick-up truck and secured them with separate chains and padlocks and returned to the facility. Upon returning to the facility with the sources, the supervisor contacted his mechanic to reweld the pig holder to the floor of the openhole wireline unit. The supervisor also contacted the camp EIC to report the incident and notify him that all equipment was resecured. The supervisor then placed both sources into the downhole storage pig until the welding was completed. According to witness statements both sources were secured with a padlock in their respective transport shields. The shields were mounted on a pig holder that was tack welded to the floor of the radiation compartment on the right rear of the truck. The radiation compartment door was secured with the T-handle closed and locked and a hasp lock on the rear of the compartment. The transport shields were chained together. Root Cause: Failure of the tack welds on the pig holder. The failure of the tack welds that held the pig holder to the truck caused the transport shields and the pig holder to be free in the radiation compartment. Secondary Cause # 1: Failure of the T-handle and the hasp lock on the compartment door. The failure of the T-handle and the hasp lock on the radiation compartment door allowed the compartment door to open freely and failed to contain the 150+ lbs of material that was inside of the compartment. Secondary Cause # 2: Hitting a pothole on interstate 79 South. When the driver of the openhole wireline unit struck the pothole on interstate 79 south it caused the transport shields and the pig holder to move inside of the radiation compartment. The movement of the equipment and the failure of the door mechanisms allowed the equipment to separate from the openhole wireline unit. Corrective Actions: Corrective actions were taken immediately to eliminate the possibility of a reoccurrence. -Complete weld along the base of the pig holder.
-Chain through both transport shields that is bolted to a structural member of the truck (floor, frame, etc).
-Heavy hasp lock (bolt style) on the exterior of the radiation compartment door.
Research: Research was conducted to verify that there were no overexposures included calculating the expected dose in the worst case scenario with the transportation shields removed from the wireline unit. Surface reading: 2.0 mR/hr
TI: 0.4 mR/hr
Time along 79: 30 minutes
Expected dose if a person were sitting on the shield for � hour: 1 mR
A survey meter reading was taken at nine feet from the transport shields in order to estimate the potential for exposure to members of the public who would be traveling southbound on interstate 79. 9 ft Reading: 0.02 mR/hr
Average Speed: 70 miles per hour = 369,600 feet per hour
Possible exposure: 0.02/369,600 = 0.00000005411255411 mR.
The licensee stated that visual inspection revealed no damage to the neutron or density shield and that this was confirmed by leak test analysis. THIS MATERIAL EVENT CONTAINS A "CATEGORY 3" LEVEL OF RADIOACTIVE MATERIAL Category 3 sources, if not safely managed or securely protected, could cause permanent injury to a person who handled them, or were otherwise in contact with them, for some hours. It could possibly - although it is unlikely - be fatal to be close to this amount of unshielded radioactive material for a period of days to weeks. These sources are typically used in practices such as fixed industrial gauges involving high activity sources (for example, level gauges, dredger gauges, conveyor gauges and spinning pipe gauges) and well logging. }}[[Event description::Description::{{#Regex_clear:This is an historical report for an incident submitted in response to an on-site inspection by an NRC Inspector (Lodhi). On September 20, 2008 at approximately 2:30pm, while returning from an openhole job north of Buckhannon, the neutron shield and the density shield separated from the radiation compartment of an openhole logging truck near Lost Creek on Interstate 79 [exit 110] southbound. The driver continued driving to the shop. Upon return, he noticed a chain hanging freely from the radiation compartment of his truck. He looked in the compartment and noticed that both transport shields and the pig holder had been separated from the unit. He immediately called his supervisor at approximately 3:00pm, who had stopped at the BP in Lost Creek for a drink on the way to the shop, and told him that the transport shield had been separated from the wireline unit. The driver mentioned hearing something after crossing the bridge on interstate 79 South at Lost Creek. The supervisor, who was ? of a mile away from the bridge, proceeded to the spot and immediately picked up the transport shields and pig holder. The supervisor loaded the transport shields and pig holder into the box of his pick-up truck and secured them with separate chains and padlocks and returned to the facility. Upon returning to the facility with the sources, the supervisor contacted his mechanic to reweld the pig holder to the floor of the openhole wireline unit. The supervisor also contacted the camp EIC to report the incident and notify him that all equipment was resecured. The supervisor then placed both sources into the downhole storage pig until the welding was completed. According to witness statements both sources were secured with a padlock in their respective transport shields. The shields were mounted on a pig holder that was tack welded to the floor of the radiation compartment on the right rear of the truck. The radiation compartment door was secured with the T-handle closed and locked and a hasp lock on the rear of the compartment. The transport shields were chained together. Root Cause: Failure of the tack welds on the pig holder. The failure of the tack welds that held the pig holder to the truck caused the transport shields and the pig holder to be free in the radiation compartment. Secondary Cause # 1: Failure of the T-handle and the hasp lock on the compartment door. The failure of the T-handle and the hasp lock on the radiation compartment door allowed the compartment door to open freely and failed to contain the 150+ lbs of material that was inside of the compartment. Secondary Cause # 2: Hitting a pothole on interstate 79 South. When the driver of the openhole wireline unit struck the pothole on interstate 79 south it caused the transport shields and the pig holder to move inside of the radiation compartment. The movement of the equipment and the failure of the door mechanisms allowed the equipment to separate from the openhole wireline unit. Corrective Actions: Corrective actions were taken immediately to eliminate the possibility of a reoccurrence. -Complete weld along the base of the pig holder.
-Chain through both transport shields that is bolted to a structural member of the truck (floor, frame, etc).
-Heavy hasp lock (bolt style) on the exterior of the radiation compartment door.
Research: Research was conducted to verify that there were no overexposures included calculating the expected dose in the worst case scenario with the transportation shields removed from the wireline unit. Surface reading: 2.0 mR/hr
TI: 0.4 mR/hr
Time along 79: 30 minutes
Expected dose if a person were sitting on the shield for � hour: 1 mR
A survey meter reading was taken at nine feet from the transport shields in order to estimate the potential for exposure to members of the public who would be traveling southbound on interstate 79. 9 ft Reading: 0.02 mR/hr
Average Speed: 70 miles per hour = 369,600 feet per hour
Possible exposure: 0.02/369,600 = 0.00000005411255411 mR.
The licensee stated that visual inspection revealed no damage to the neutron or density shield and that this was confirmed by leak test analysis. THIS MATERIAL EVENT CONTAINS A "CATEGORY 3" LEVEL OF RADIOACTIVE MATERIAL Category 3 sources, if not safely managed or securely protected, could cause permanent injury to a person who handled them, or were otherwise in contact with them, for some hours. It could possibly - although it is unlikely - be fatal to be close to this amount of unshielded radioactive material for a period of days to weeks. These sources are typically used in practices such as fixed industrial gauges involving high activity sources (for example, level gauges, dredger gauges, conveyor gauges and spinning pipe gauges) and well logging. }}| ]] |
| Where | |
|---|---|
| Superior Well Services Buckhannon, West Virginia (NRC Region 1) | |
| License number: | 37-30412-01 |
| Organization: | Superior Well Services |
| Reporting | |
| 10 CFR 20.2201(a)(1)(i) | |
| Time - Person (Reporting Time:+7342.05 h305.919 days <br />43.703 weeks <br />10.057 months <br />) | |
| Opened: | Lew Cessna 16:33 Jul 23, 2009 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Jul 23, 2009 |
| 45225 - NRC Website | |
Superior Well Services with 10 CFR 20.2201(a)(1)(i) | |
WEEKMONTHYEARENS 452252008-09-20T18:30:00020 September 2008 18:30:00
[Table view]10 CFR 20.2201(a)(1)(i) Lost (Then Recovered) Licensed Nuclear Material 2008-09-20T18:30:00 | |