05000352/LER-2005-001

LER-2005-001, Loss Of Licensed Material In The Form Of A Radiation Detector Calibration Source

Docket Number
Event date:	01-21-2005
Report date:	03-08-2005
Initial Reporting
ENS 41415	Other Unspec Reqmnt
3522005001R00 - NRC Website

Unit Conditions Prior to the Event Unit 1 was in Operational Condition (OPCON) 1 (Power Operation) at approximately 100% power. Unit 2 was in Operational Condition (OPCON) 1 (Power Operation) at approximately 100% power. There were no structures, systems or components out of service that contributed to this event.

Description of the Event

On January 22, 2005, at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br />, a radiation protection technician identified that a calibration source, LGS 1093, was missing from its storage location inside a locked cabinet. The technician reported the missing source to radiation protection supervision. An investigation was initiated but the source has not been located at this time.

The following information is required by 10CFR20.2201(b)(1):

(i)A description of the licensed material involved, including kind, quantity, and chemical and physical form Manufacturer: The Source Inc.

Model Number: Thorium 230 alpha source Part Number: LGS Source 1093 Kind: Thorium-230 Quantity: 0.0154 microcuries Chemical form: metal Physical form: 2-inch diameter disc Labeling: Standard radiation symbol and site identification number (ii)A description of the circumstances under which the loss or theft occurred Limerick radioactive source number LGS 1093 is used to perform source checks on SAC-4 alpha counters. Prior to initiating a SAC-4 source check on January 22, 2005, a Radiation Protection Technician (RPT) attempted to obtain the source from its normal storage location, which is a source cabinet located in the Shepard Calibrator Room. The Shepard Calibrator Room is a locked room located in the In-Plant Tool Room. The RPT identified that the source was not in its storage location.

The apparent cause of the event is ineffective self-check on the part of a radiation protection technician when returning the source to its storage location after performing instrument source checks.

(iii)A statement of disposition, or probable disposition, of the licensed material involved The most probable disposition of the source is that it is still located within the Radiologically Controlled Area (RCA) at Limerick Generating Station. Laundry, trash, and radwaste were searched prior to being shipped offsite. Additionally, all offsite facilities were alerted to the loss of the source and asked to contact Limerick if they locate the source. The source is labeled as radioactive and is only used in the RCA.

The travel path in which the source was used has been thoroughly searched.

(iv)Exposures of individuals to radiation, circumstances under which the exposures occurred, and the possible total effective dose equivalent to persons in unrestricted areas The source is electroplated and was intact at the time when it was lost. The activity is low and the source is a pure alpha emitting isotope. Since the source is electroplated and emits alpha type radiation, it poses no external radiation hazard.

As a result, there is no radiation dose associated with this event. The probability of external contamination is minimal because the source is electroplated.

(v)Actions that have been taken, or will be taken, to recover the material A thorough search of the plant was conducted.

All source boxes in every drawer of the cabinet were searched.

The canvas tool bag used to carry the sources in was searched.

The Shepard Room where the source cabinet is stored was thoroughly searched. The source cabinet was disassembled and searched. A thorough search was conducted of the station.

Most areas of the station were searched at least twice.

The travel path of the technician known to have last used the source was walked down and searched.

All the bags of scrubs in the Graham M. Lietch Building (Administrative Building) basement were pulled and put through the security x-ray machines in the Technical Support Center (TSC) (the technician changed in the basement at the end of shift). A quarter in a scrub bag was used as a visual reference in the x-ray machine.

The SAC-4's in the plant were disassembled to verify the source was not left inside them.

The Chemistry Source Cabinet in the chemistry count room was checked to verify the Radiation Protection source did not get stored with Chemistry sources.

Searched radioactive trash in the In-Plant Tool Room, outside the In-Plant tool room, and Chemistry Count Room, The Chemistry Labs, Radwaste HP Control Point, and HP Field Office and the 5 and 41 Line plant exits were searched.

(vi) Procedures or measures that have been, or will be, adopted to ensure against a recurrence of the loss or theft of licensed material A thorough search of the plant was conducted as described above.

The sign in sheet for handling sources was revised to require a peer check when returning sources to their storage locations.

A stand-down with RP Department personnel was conducted to review source-handling requirements.

Management observations were performed to ensure source administrative controls are adequate.

An evaluation will be performed to determine if higher activity sources can be replaced with the lowest activity necessary. This evaluation will be complete by 5/31/05.

A comprehensive self-assessment of the source control program will be conducted to ensure standards are in place to ensure no similar lost source incidents occur. This self-assessment will be complete by 4/30/05.

This event involved loss of licensed material in a quantity that exceeded 10 times the limit specified in Appendix C to Part 20.

10CFR20.2201(a)(ii) requires reporting of this event by ENS within 30 days after the occurrence. A written report is required by 10CFR20.2201(b)(1) within 30 days after making the telephone report. The report must be in accordance with the procedures described in 10CFR50.73(b), (c), (d), (e), and (g).

The ENS notification (EN 41415) was completed on February 17, 2005 at 10:28 hours. This report is being submitted pursuant to the requirements of 10CFR20.2201(b)(1).

Previous Similar Occurrences There were no previous occurrences where a calibration source was lost.