ENS 51275
ENS Event | |
|---|---|
05:00 Jul 21, 2015 | |
| Title | Fixed Gauge Shutter Stuck in the Open Position |
| Event Description | A fixed gauge shutter was determined to be stuck in the open position on 7/21/15. The device manufacturer was called and arrived on location on 7/24/15, and determined that the device "dip tube" is bent and the device will have to be removed for repair. The device is a Tracerco Profiler Series Fixed Density Profiler (Serial # 101020) with either 49 or 62 30mCi Am-241 sources (1470 mCi or 1860 mCi Am-241 aggregate). The device is located inside a process vessel on an offshore platform. Radiation measurements taken outside the process vessel indicate no detectable radiation. The have been no radiation exposures. The manufacturer will remove the device and repair it.
The following was received from the licensee via email: In accordance with 10 CFR 30.50(b)(2), Chevron submitted a verbal notification to the NRC Operations Center at 2014 hrs. EDT on July 29, 2015. We [Chevron USA, Inc.] are submitting this written report to verify the information conveyed in the verbal report. Test separator MBD1010 on Chevron's Jack/St. Malo oil and gas production platform is equipped with a Tracerco Profiler Series Model T-240 fixed density profiler, serial number T240-FM-1-324. On July 21, 2015, it was discovered that this profiler's shutter was in the open position and would not close. Tracerco, the manufacturer of the device, was immediately notified. Tracerco inspected the profiler on July 24, 2015 and confirmed that the shutter would not close. Tracerco's initial investigation indicated that the density profiler source and detector tubes were bent, prohibiting the movement of the shutter. The Jack/St. Malo platform is located in Walker Ridge Block 718, OCS-G 32703, approximately 190 miles offshore Louisiana in the Outer Continental Shelf. The test separator is located on the Production Module lower deck. The shielded source housing and shutter mechanism are located on the Production Module mezzanine deck, which sits immediately above the separator. The profiler source tube contains 62 Americium 241 sources, 30 milliCuries per source, for a total of 1,860 milliCuries. Tracerco, the manufacturer of the profiler, is onsite and is developing a plan for disassembly and removal of the device from the separator using appropriate shielding and other protective measures to minimize potential exposures. If entry into the separator with the sources still in place is deemed necessary, Tracerco will implement appropriate radiation safety measures to minimize exposures. The device and sources will be stored in appropriate containers during shipment to Tracerco; turnover of the sources to Tracerco will be documented. As any repairs to the device or vessel entry would not constitute routine maintenance, Chevron personnel will not be involved in repairing or removing the profiler. There has been no exposure of platform personnel. Although the shutter remains in the open position, no one has entered the separator, and no radiation is detectable at the exterior of the separator. The separator is coated in insulation, covering the manways that provide access to the interior of the separator. Tracerco has been working on the Production Module mezzanine deck and has partially removed the profiler from the separator to assess its condition. Tracerco has established a barricade around the work area to prevent unauthorized access. Their monitoring indicates no exposures beyond five feet from the sources. Tracerco reports that the radiation detected appears to be lower than expected for fully unshielded sources. Tracerco has conducted wipe tests and has found no leakage from the sources." Notified R4DO (Warnick) and NMSS Events Notification via email.
The following report was received via e-mail: The incident investigation indicated a deflector plate inside the test separator became disconnected and struck the profiler. Under the supervision of Tracerco, entry was made into the vessel and the damaged profiler removed and returned to Tracerco's Pasadena, Texas facility for repairs. The deflector plate was reinstalled in the separator per manufacturer's specifications. The profiler was not re-installed. Tracerco reported the results of the wipe test taken at the time of the removal of the profiler showed no contamination. Notified the R4DO (Warnick) and NMSS Events Resource (via e-mail). |
| Where | |
|---|---|
| Chevron Usa, Inc Covington, Louisiana (NRC Region 4) | |
| License number: | 17-29267-01 |
| Organization: | Chevron Usa, Inc |
| Reporting | |
| 10 CFR 30.50(b)(2), Licensed Material Protection Equipment Failure | |
| Time - Person (Reporting Time:+207.23 h8.635 days <br />1.234 weeks <br />0.284 months <br />) | |
| Opened: | James Grimsley 20:14 Jul 29, 2015 |
| NRC Officer: | Daniel Mills |
| Last Updated: | Sep 2, 2015 |
| 51275 - NRC Website | |
Chevron Usa, Inc with 10 CFR 30.50(b)(2) | |
WEEKMONTHYEARENS 512752015-07-21T05:00:00021 July 2015 05:00:00
[Table view]10 CFR 30.50(b)(2) Fixed Gauge Shutter Stuck in the Open Position 2015-07-21T05:00:00 | |