United States Nuclear Regulatory Commission - Protecting People and the Environment

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. 
Page Last Reviewed/Updated Tuesday, July 23, 2013