ENS 47555
ENS Event | |
|---|---|
19:15 Dec 5, 2011 | |
| Title | Agreement State Report - Damaged Tritium Exit Sign |
| Event Description | Per the general license requirements stipulated in 10 CFR 31.5 (5), this letter is being sent to report a damaged Forever Lite model SLXTU1GB20 self-illuminating exit sign and the loss of one of its elements. The exit sign is owned by the Johns Hopkins University Applied Physics Laboratory (JHU/APL) and is possessed under a general license issued by the Nuclear Regulatory Commission (NRC). The general license requires the NRC to be notified of any damaged devices. A verbal notification was made to MDE [Maryland Department of the Environment] in a phone call on December 6, 2001 at 1:45 PM.
It has been determined that the damaged sign was removed from its mounted location during the demolition phase of a renovation project in Building 13 that started in May 2011. However, it along with three other signs from that project were not brought to JHU/APL's Hazardous Waste Accumulation Site (Building 10A) until Friday, December 2, 2011. The damaged sign was identified Monday, December 5, 2011 at 2:15 PM. It appears that the sign was damaged during removal from its mounted location and the missing element, along with the outer frame, was disposed of in the construction debris earlier this summer. The total estimated tritium activity contained within the missing element is approximately 640 mCi of which about 90% (576 mCi) may be in the form of tritium gas and about 10% (64 mCi) may be in the form of tritiated water vapor. Contamination monitoring did not reveal any tritium contamination. This could be an indication that the tube did not break during the removal of the sign nor when it was caught up in the construction debris. Bioassay sampling of the potentially exposed personnel is unfortunately not possible due to the amount of time that has transpired since the removal of the sign (the most likely time when an exposure could have occurred). However, the possibility of an exposure is extremely unlikely since there is no indication of a broken element. In addition, the nature of a construction work environment and the use of personal protective equipment (work gloves, eyewear, ...) also minimizes the possibility of inhalation, ingestion and puncture wounds which are potential tritium exposure pathways from a broken element. The damaged sign has been doubly sealed in plastic bags and is stored in JHU/APL's Hazardous Waste Accumulation Site awaiting proper disposal. JHU/APL improved its control and oversight of the self-illuminating exit sign after the last damaged sign that was found in June 2007. Based on the current investigation, the following improvements will be made to improve JHU/APL control and accountability of the generally licensed exit signs: --Annual refresher training with revised self-illuminating exit sign handling and control procedures will be provided to all JHU/APL Technical Service Department (TSD) personnel. This will help ensure a greater awareness, particularly among managers and supervisors, of the handling and control requirements. Training up to this point has been provided to maintenance personnel, electricians and others on an as needed basis. --The training will place particular emphasis on the care required to remove these signs and the need to bring them to JHU/APL's Hazardous Waste Accumulation Site in a timely manner. --For better documentation of which signs are being turned in for disposal, a log will be maintained that documents such things as make, model serial number, former mount location (Bldg, Floor ...), person disposing the sign, date disposed, and the general condition of the sign. THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf This source is not amongst those sources or devices identified by the IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source |
| Where | |
|---|---|
| Johns Hopkins Applied Physics Laboratory Laurel, Maryland (NRC Region 1) | |
| License number: | GL |
| Organization: | Maryland Dept Of The Environment |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+544.83 h22.701 days <br />3.243 weeks <br />0.746 months <br />) | |
| Opened: | Alan Jacobson 12:05 Dec 28, 2011 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Dec 28, 2011 |
| 47555 - NRC Website | |
Johns Hopkins Applied Physics Laboratory with Agreement State | |
WEEKMONTHYEARENS 475552011-12-05T19:15:0005 December 2011 19:15:00
[Table view]Agreement State Agreement State Report - Damaged Tritium Exit Sign 2011-12-05T19:15:00 | |