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The article notes the error in the neutron fluence for neutrons with energies between 9 and 10 Million electron Volts (MeV) for the tabulated deuterium oxide (D2O)-moderated continuous flow (252Cf) source in the International Organization for Standardization (ISO) 8529-1. It compared the moderated 252Cf neutron spectrum from ISO 8529-1 with the bare 252Cf spectrum in ISO 8529-1. It also computed the normalized dose conversion coefficient for each of the spectra.

A study of the uncertainty of dosimeter results is required by the national accreditation programs for each dosimeter model for which accreditation is sought. Typically, the methods used to determine uncertainty have included the partial differentiation method described in the U.S. Guide to Uncertainty in Measurements or the use of Monte Carlo techniques and probability distribution functions to generate simulated dose results. Each of these techniques has particular strengths and should be employed when the areas of uncertainty are required to be understood in detail. However, the uncertainty of dosimeter results can also be determined using a Model II One-Way Analysis of Variance technique and accreditation testing data. The strengths of the technique include (1) the method is straightforward and the data are provided under accreditation testing and (2) the method provides additional data for the analysis of long-term uncertainty using Statistical Process Control (SPC) techniques. The use of SPC to compare variances and standard deviations over time is described well in other areas and is not discussed in detail in this paper. The application of Analysis of Variance to historic testing data indicated that the accuracy in a representative dosimetry system (Panasonic® Model UD-802) was 8.2%, 5.1%, and 4.8% and the expanded uncertainties at the 95% confidence level were 10.7%, 14.9%, and 15.2% for the Accident, Protection Level-Shallow, and Protection Level-Deep test categories in the Department of Energy Laboratory Accreditation Program, respectively. The 95% level of confidence ranges were (0.98 to 1.19), (0.90 to 1.20), and (0.90 to 1.20) for the three groupings of test categories, respectively.

In 2010, the U.S. Department of Energy will adopt a new set of radiation weighting factors and quality factors to be consistent with values recommended by the International Commission on Radiological Protection. The change will affect the magnitude of occupational exposure assigned to radiation workers exposed to neutron radiation. Understanding the energy response of the dosimeter and the effect of the new quantities is critical to accurately ensuring that occupational exposure remains below the established regulatory limits. Therefore, the factors used to interpret dosimeter readings must be re-evaluated for each irradiation field over the range of neutron energies in which the dosimeter is used. This paper describes one method of determining the neutron response of the dosimeter. A Monte Carlo approach was used to model the energy response of the Panasonic Model 809 dosimeter over the range of energies from 1.0 x 10(-8) to 20 MeV. The response, normalized to the response at 2.1 MeV, ranged from approximately 0.5 at 20 MeV to approximately 26 at 1 eV. The response was then divided at each energy by the appropriate dose conversion coefficient to determine the dose response of the dosimeter. The dose responses, normalized to the response at 2.1 MeV, ranged from approximately 0.4 at 20 MeV to 765 at 1 eV. Dose conversion factors were determined for various reference neutron spectra and plotted on the dose response curve. Good agreement was observed except for the case of D2O-moderated (252)Cf.