Taurus Advanced is designed to meet the needs of internal dose specialists and researchers. All the capabilities of Taurus Base are present in the advanced version, which extends the functionality of Taurus to include more complex operations:

• Taurus Base functionality +
• Changeable model parameter values.
• Linked intake regimes and the ability to have different model parameter values characterising the material for different intake regimes.
• Absorbed doses in each calendar year.
• Default and user-specified isotopic mixtures of uranium, such as natural, depleted and enriched uranium.
• Default and user-specified isotopic mixtures of plutonium, such as fuel-grade, weapon-grade, LWG, etc.
• Ability to specify other nuclide mixtures.
• Wound model implementation.
• Bayesian tool for advanced statistical analysis.

Further Information

• HRTM particle transport rates.
• Deposition model.
• Geometric standard deviation of aerosol size distribution.
• Density and shape factor of aerosol.
• Ability to display regional fractions.
• Ability to change breathing rate (i.e. vary fraction of time spent in each activity).

Linked intake regimes and parameter values

An intake regime defines both the mode of intake (inhalation of aerosols or vapours, ingestion, injection, wound) and the time of intake (e.g. an acute intake on a certain date, or a chronic intake between two dates). This option enables the user to deal with up to 20 separate intake regimes simultaneously. When calculating doses or predicting bioassay quantities, the software automatically includes the contribution from each intake. It is also possible to assign different model parameter values separately to each intake regime characterising the material. The regime would have the same indicator radionuclide. The parameters it is possible to change are:

• Absorption parameters (f_r, s_r, s_s, f_b, s_b and f_a).
• Aerosol parameters (AMAD, AMTD, GSD, density and shape factor).
• Physiological parameters (breathing rate and physical activity fractions).

Dose

The advanced version gives users a high degree of control over absorbed doses in calendar years. The output can be ordered by year or by tissue, consistent with the UK's compensation scheme.

Nuclide Mixtures

This option enables the user to specify a mixture of the 880 nuclides which are included in ICRP OIR Parts 2, 3, 4, and 5. Predefined uranium and plutonium mixtures are available for mixtures common in the nuclear industry (enriched, depleted, or natural uranium, etc.) or these mixtures can be specified directly. The isotopic abundances of the uranium and plutonium mixtures can be expressed either as mass percentage or activity percentage.

Uptake from wounds

The US National Council on Radiation Protection and Measurements (NCRP) wound model is implemented to allow for intakes from a wound site. This functionality is integrated automatically with all of the calculations (dosimetry, bioassay and intake fitting).

Bayesian Tool

The Bayesian Analysis tool enables the user to calculate the posterior probability distribution and summary statistics (e.g., mean, standard deviation) of the intake(s) and the total effective dose. The chosen method is importance sampling, which requires the user to select an appropriate sampling distribution and to provide a prior probability distribution for each of the intakes. The four available types of distributions are Uniform, LogUniform, Normal and LogNormal. Plots of probability distributions are shown for intakes and the total effective dose.