Uranium Radiation Organ Dose Calculator - HELP

(last updated 6 Feb 2003)

Contents:

Introduction

This calculator performs organ-specific radiation dose calculations for individuals exposed to uranium and/or its decay products. The calculator handles exposure from inhalation and ingestion.
The calculator considers the uranium-isotopes U-238, U-235, and U-234 and their major decay products.
The set of dose coefficients used is from ICRP 72 (Public).

If organ-specific results are not required, see the more sophisticated Uranium Radiation Individual Dose Calculator
The calculator only determines exposure to radiation; the chemical toxicity of uranium is not covered (see Uranium Toxicity).
The calculator only determines doses for adults. For age-specific dose calculations, see the Uranium Radiation Age-specific Dose Calculator.
The calculator only determines doses to exposed individuals. For collective dose calculations, see the Nuclear Fuel Population Health Risk Calculator.
The calculator only determines doses for situations, where the pathway and the rate of exposure to a contaminant is known. Otherwise, some more sophisticated software has to be used (see Uranium Mine and Mill Resident Individual Dose Calculator and Dose calculation software).

The parameters used for the calculation can be set in the Input table. These parameters show reasonable initial values which can be modified as needed. There are no other hidden parameters used in the calculation. Any assumptions made for the calculations are described on this page.

Input

Material Input
Enter number and select appropriate mass unit and material type.
It is assumed that short lived decay products are in equilibrium with their parent nuclides.

Activities [Bq]
No input is required, if data was entered in the Material Input section: the appropriate activities are entered automatically.
But, for nuclide mixes other than those given in the Material Type pick list, activities can be entered directly. It is also possible to modify activity data after selection from the pick list.

Parameters
The Calculator assumes a single uptake resulting in calculation of a dose (in Sv) and the associated risk of contracting fatal cancer.

The Calculator uses the dose coefficients from ICRP 72. At present, the dose coefficients of ICRP 60/61 new window (1990) are widely used, while revised dose coefficients have been presented for workers in ICRP 68 new window (1995) and for the public in ICRP 72 new window (1997). The new dose factors show significant differences from the old ones for the nuclides of interest.
All coefficients used are for adults.
For inhalation, an activity median aerodynamic diameter (AMAD) of 1 µm is assumed, and the solubility Class can be selected according to the chemical of the uranium:
 F: UF6, UO2F2, UO2(NO3)2   (f1 = 0.02)
 M: UO3, UF4, UCl4   (f1 = 0.02)
 S: UO2, U3O8   (f1 = 0.002)
For decay products, the calculator assumes the same solubility class as for the parent nuclide.
For ingestion , there is no distinction between solubility classes in ICRP 72.

The Risk Factor describes the risk of contracting fatal cancer per effective dose equivalent received.

Output

The Results field shows the Committed Effective Dose (CED) and the corresponding risk of contracting fatal cancer.
In addition, the organ doses for some important organs are shown, and the weighted contributions of these organ doses to the Committed Effective Dose and the Risk.
Moreover, for each organ, the nuclide which is the major contributor to the organ dose, and its fraction of contribution to the organ dose is mentioned.
The limited accuracy of the organ dose factors used may result in minor inconsistencies.

The contents of the Results field can be highlighted for copying and pasting to other applications.