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DEPARTMENT OF THE ARMY UNITED STATE33 ARMY TACOM LIFE CYCLE MANAGEMMT COMMAND

6601 EAST I 1 MILE ROAD WARREN, MICHIGAN 40397-wOO

Sdety Office FEB 4 2Ml

h4r. JohnMadera Regional Administrator U.S, Nuclear Regulatory Commission Division of Nuclear Safeguards 2443 WarrenviUe Road Suite 21 0 Lisle, IlIinois 605324352

Dear Mr. Madera:

SUBJECT: US Arrny 30 Day Report Pertaining to a M64A1 Mortar Sight Unit Breakage Containing a Tritium Sealed Source

Reference: NRC License no. 12-00722-06 NRC hcident Report No, 46530

This thirty-day report is in accordance with 10 CFR Part 30.50(b)(i). The incident was reported to the US Army TACOM LCMC license RSO on 6 Jan 201 1 by a US Army health physicist. The incident involved the wcantrolkd release of tritium ~ a s that resulted fiam the breakage of a mortar site Unit M64A1 (NRC SSDR No. NR-0155-D-113-5) containing 8 I curie tritium sealed source. The breakage occbrred on 4 Jan 201 1 at the New York Army National Guard Combined Support Maintenance Shop (CSMS) in a small arms roam, Rochester, NY,

The incident occurred when a New York National Guard authorized maintenance worker attempted to m o v e a come azimuth scale component from a M64A1 mortar sight unit. The courge azimuth scale is a module component of the M64A1 that contains a 1 curie tritium lamp (P/N 11733744-2). Module assemblies are authorized by the licensee to be removed and replaced with new modules in accordance with the M64A1 repair techkal manual. The maintenance worker had dfliculty removing the azimuth scale from the M44A1 sight unit and decided to force it off with a screw driver. While perfiiming this procedure the tritium lamp broke, The maintainer immediately realized he broke the tritium lamp due to the absence of illuTnination of the azimuth scale. The maintainer immediately placed the M64A1 sight in a clear plastic bag and called his local radiation sdety officer @SO) for assistance. The local RSO immediately secured the area and proceeded to perfionn leak test of the device and CSMS smdl m s room s u r f m s and involved equipment to determine the presence of contamination. The CSMS arms room was secured from entry from Jan 4-7 pending wipe test survey results from the Amy testing laboratory. Initial wipe test results showed removable tritium contamination of the M64A1 device at 52,000 dpms (0.023 uci) and the vice holding the M64Al at 69,000 dpms (0.031 uci), Initial decontamination of the small arms mom was performed by

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the local RSO on 5 Jan 201 1. A second set of survey wipe tests were performed of the surrounding equipment after the dwon that showed removable contamination less &an than 630 dpms (2.8E-4 uci). A secorid decontamination was performed on the vice ad surrounding work surfaces that reduced the removal tritium contamination to bebw the lower limit of detection of 13.8 dpms. The CSMS small arms room was reopened for use on 7 Jan 201 1 by approval of the license RSO.

The license RSO directed the maintenance worker and four National Guard persons present in the small mu room to h v e a tritium bioassay sample taken Bioassay test resub from the US Army Institute of Public Health showed the maintenance worker who had direct contact with the device had a committed effective dose equivalent (CEDE) of 1 .O mrem. nose persons who w m present in the small arms room during the time of the release had minimal tritium intake with a CEDE for each person less than 0.05 mem.

Corrective Action:

The license RSO contacted the repair worker involved in the incident directly and directed him to follow the repair procedures prescribed in the M64A1 mpair technical m a n u a l 0 and not use force ta remove the modules containing tritium lamps, In addition, &E licensee wrote and distributed an Army wide maintenance action message (MAM) on 4 Feb 201 1 directing maintainers of mortar tritium fire control devices to follow the prescribed repair procedure iu the mortar TM. The message directed maintaiuers not to remove the modules that contain the tritium lamp($) by Prying, cutting, heating or applying excessive force. The MAM will be distributed to every CSMS center in each of the states through an Army Automated Messago: Nandling System (AA4HS). The license RSO also directed the US. h y Communic&ons Electronic Command (CECOM) to distribute a maintenance message to aU CSMS National Guard maintenance shops through a newsIetter infanning fire control maintainm to follow the applicable TM and not to me force in regwing the modules during repair proceduxpis. The newsletter will be distributed by the end of F&b 20 1 1. These official notifications should prevent the Army National Guard CSMS repair shops, from repeating the incident.

The point of contact for this incident is Mr. Thomas G. Oizicki, Smjor Health Physicist, NRC License RSO, TACOM LCMC Safe ty Office,(309)782-2965,

Sincere1 y,

A/* George G. Janris

TACOM LCMC Safety Director

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