Bulletin 79-22: Possible Leakage of Tubes of Tritium Gas Used in Timepieces for Luminosity
SSINS: 6820 Accession No: 7908130463 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 September 5, 1979 IE Bulletin No. 79-22 POSSIBLE LEAKAGE OF TUBES OF TRITIUM GAS USED IN TIMEPIECES FOR LUMINOSITY Description of Circumstances: In June and July 1979, inspections were performed by the Arizona Atomic Energy Commission with the assistance of the Nuclear Regulatory Commission at American Atomics Corporation, Tuscon, Arizona. American Atomics manufactures small tubes containing tritium gas for distribution to other licensees some of which place the tubes in timepieces for distribution to other companies for sale. The inspection disclosed an allegation regarding irregularities in quality control during manufacture or testing of the tubes. A few tubes were reported by consignees as having lost luminosity indicating the tritium had leaked out of the tubes. Action to be Taken by NRC Licensees who Received Tubes Containing Gaseous Tritium from American Atomics Corporation: 1. Examine a minimum of 100 tubes in stock to determine if complete luminosity is lost, indicating either loss of tritium or that tritium may not have been put in the tubes. Report in writing: (a) the total number of tubes in stock at the time of sampling, (b) the number of tubes examined, and (c) the number of tubes with apparent loss of luminosity (i.e., failure). 2. Select a random sample of at least 100 tubes from stock supplies and soak test the tubes in lots of five for 24 hours in a volume of water equal to 10 times the volume of the tubes to determine leakage of tritium. Report in writing: (a) the number of tubes in stock when the sample was selected, (b) the total number of tubes that were tested, and (c) the number of five tube lots found to be leaking in excess of 50 nanocuries per 24 hours. 3. For those licensees who also posses an NRC exempt distribution license for distribution to the public of timepieces containing tritium gas tubes, report in writing: (a) the number of failure during quality assurance testing of completed lots of timepieces (e.g., vibration tests, drop tests, etc.) (b) the lot sizes used for the testing and, (c) whether the testing was performed by the recipient of this Bulletin or by American Atomics Corporation. The reports submitted should cover the first calendar quarter of 1979. 4. Review receiving inspection records for tubes received during the first calendar quarter of 1979. Report in writing: (a) the total number of tubes received during the period, and (b) the number of tubes rejected due to apparent loss of luminosity. . Draft IE Bulletin No. 79-22 Page 2 of 2 September 5, 1979 Reports concerning Items 1, 2, 3, and 4 should be submitted to the Director of the appropriate NRC REgional Office with a copy sent to the NRC Office of Inspection and Enforcement, Division of Fuel Facilities and Materials Safety Inspection, Washington, D.C. 20555 within 45 days/ Approved by GAO, B180225 (R0072); clearance expires 7-31-80. Approval was given under a blanket clearance specifically for generic problems.
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