PIECEWISE POLYNOMIAL APPROXIMATIONS TO THE ICRP 116 EFFECTIVE DOSE COEFFICIENTS: PHOTONS AND NEUTRONS

Area of Science:

• Radiological Physics
• Radiation Protection
• Computational Dosimetry

Background:

• Accurate estimation of effective dose per unit fluence is crucial for external radiation exposure assessments.
• Existing models may not fully incorporate the latest recommendations from the International Commission on Radiological Protection (ICRP).

Purpose of the Study:

• To develop and present fitting equations for estimating effective dose per unit fluence across a wide range of photon and neutron energies.
• To update radiation protection data based on ICRP Publication 116 and ICRP Publication 103.

Main Methods:

• Fitting piecewise polynomial functions to dose coefficients from ICRP Publication 116 for 8 irradiation geometries.
• Incorporating the latest definition of effective dose as per ICRP Publication 103.
• Modifying the Monte Carlo N-Particle radiation transport code version 6 (MCNP6) with the developed fitting functions.

Main Results:

• Developed fitting equations that generally reproduce ICRP 116 data within 3% or better for photon energies from 10 keV to 10 GeV and neutron energies from 0.001 eV to 10 GeV.
• Successfully integrated the fitting functions into the MCNP6 code.
• Demonstrated the application of the modified code through a sample problem.

Conclusions:

• The developed fitting equations provide a reliable method for estimating effective dose per unit fluence.
• These equations will serve as a basis for revising the American National Standards Institute/American Nuclear Society 6.1.1-1991 standard.
• The updated data enhances the accuracy of radiation protection assessments in various applications.