United States Nuclear Regulatory Commission - Protecting People and the Environment

Reporting of Damaged Portable Moisture-Density Gauges

HPPOS-322 PDR-9308020160

See the memorandum from R. E. Cunningham to R. W. Cooper (and others) dated July 1, 1993.

This memo clarifies the reporting requirements for damaged moisture-density gauges that often contain up to 10 millicuries of cesium-137 (Cs-137).

Whether licensees must report damaged moisture-density gauges depends on the extent of damage to the gauge. The requirement to report also depends on the level of radiation in an unrestricted area or doses to individuals resulting from the damaged gauge. The applicable reporting requirements are given in 10 CFR 20.405 (a) (1), 20.2203 (a), and 30.50 (b). The enclosure to this memo provides a detailed analysis of the reporting requirements.

In summary, reporting is required in most incidents when damage to the gauge results in one of several conditions (see enclosure):

  1. The protective housing (shielding) is damaged such that the source is not fully shielded, or cannot be moved into the shielded position [10 CFR 30.50];

  2. The source is left exposed in an unrestricted area such that the radiation levels exceed 20 mrem in any one hour (10 times the limit of 2 mrem in any one hour) [10 CFR 20.405 and 20.2203]; or

  3. The incident results in doses in excess of limits in Part 20 or in the license [10 CFR 20.405 and 20.2203].

Please note that the method of reporting and the associated time for the licensee to make the report are different for conditions 1, 2, and 3 above.

In a more serious case involving a broken sealed source that leads to contamination, reporting within 24 hours is required [10 CFR 30.50 (b) (1)]. Likewise, in a case involving a sealed source that causes, or threatens to cause, serious overexposures, immediate notification or 24-hour notification and subsequent written reporting may be required [10 CFR 20.403, 10 CFR 20.2202, and 10 CFR 20.2203]. However, these situations are beyond the scope of most damaged gauge incidents and will not be discussed here.

Finally, immediate telephonic reporting of loss or theft of a portable moisture-density gauge is required in most cases, and a written report within 30 days is required in nearly all cases.

Regulatory references: 10 CFR 20.405, 10 CFR 20.2203, 10 CFR 30.50

Subject codes: 2.2, 3.7, 11.2, 11.3

Applicability: Byproduct Material

Page Last Reviewed/Updated Friday, August 05, 2016