HPS ANSI/HPS N13.41 PDF

The final decision on whether to use multiple dosimeters for external dosimetry purposes instead of a strategically placed single dosimeter is left to the judgment of radiation ANSI/HPS N13.41-2011 2 protection professionals. Once multiple dosimeter use has been deemed appropriate, this standard contains criteria applicable to routine occupational activities on when and how to use them to monitor the body and extremities of individuals exposed to external sources of ionizing radiation. Such conditions may be encountered at medical, research, commercial, weapons disposition, fuel processing, power reactors and other sites. In addition, recommendations for selecting dosimeter types, placement of dosimeters on the body, interpretation of multiple dosimeter results, and recording of dose information are presented. A program that is compliant with this standard shall include the requirements of the standard, but not necessarily its recommendations.

This standard does not address the cases of internal deposition of radioactive materials, external contamination of the body, or working conditions that do not permit job pre-planning. Sudden or unexpected changes in the radiation environment as might occur during accidents are also beyond the scope of this standard. Fetal monitoring is not addressed because it represents a special case not necessarily related to nonuniform irradiation. (Fetal monitoring is for the purpose of estimating the dose to a separate entity, the fetus, and demonstrating an appropriate rate of equivalent dose accumulation for the period of gestation. Since it is not an example of multiple dosimetry, it is not addressed herein.¹) Skin exposures where the area of irradiation is less than 10 cm² (e.g., from a hot particle) are not addressed.² Finally, the recommendations of this standard do not supercede specific regulations or license requirements.

This standard assumes that dosimeter assemblies worn for multiple dosimetry purposes are calibrated and processed to provide an estimate of equivalent dose. Specific guidance on dosimeter processing methodologies, calibrations, and performance criteria are included only by reference.

¹The dose to the fetus from external sources is often assessed by mounting a dosimeter on the abdomen of the pregnant worker.

²The National Council on Radiation Protection and Measurements, in NCRP Report No. 106, Limit for Exposure to "Hot Particles" on the Skin, provides guidance on assessing the radiation exposure of small skin areas (NCRP 1999).