This toolkit contains programs to model radiation safety aspects of uranium mining and processing. Originally, it was called the "Radon Toolkit" and only contained programs to calculate radon source terms for various situations and model the behavior of radon and its progeny in various scenarios. Since then, tools for gamma radiation and Long-Lived Radioactive Dust have been included. Other tools will be added as they become available. Changes and corrections are documented here. We hope you find these tools useful. You may use these tools at no charge, as long a you give credit where credit is due. If you find a bug or have a suggestion, please let us know at admin@eic.nu. Standard disclaimer applies.

We are introducing a subscription based professional version which offers additional functionality. 

Please click on the hyperlinks to open each calculator. (You may have to tell your browser to allow JavaScript to run.) Fill out the column called "Input Fields" and click the "Calculate Now" button. 

Radon Source Term Calculations:

Radon Released from a Massive Source
This calculates the amount of radon released from a pile of uranium ore. As radon is continually generated by the decay of radium, some fraction of radon (the emanation fraction) escapes. Grade, mass and emanation fraction are input into the program and the amount of radon generated per second is returned.

Radon Released from an Area Source
This calculates the amount of radon released from a surface. As radon is continually generated by the decay of radium, some fraction of radon escapes from the ore matrix. Radon which is generated too deep below the surface will not reach the surface before it decays. Grade, area, emanation fraction and the depth which contributes to exhalation are input into the program and the amount of radon generated per second is returned.

Radon Generated By a Process
This calculates the amount of radon as the ore matrix is stressed or destroyed. Normally, only a very small fraction of radon escapes the ore matrix. The rest of the radon stays in the ore matrix until it decays. When the ore matrix is stressed of destroyed some of this stored radon is released. Examples of this are grinding and leaching processes. Grade, feed rate and the fraction of radon released are input into the program and the amount of radon generated per second is returned.

Radon Released by a Water Inflow
This calculates the amount of radon entering a mine working through a water inflow based on the amount of radon in the pore space of the ore and the water inflow rate.

Radon Models:

Closed Chamber Model as a Function of Time
A fixed volume of air is considered. Radon is continually injected but no radon or progeny escape the volume. The chamber volume, the radon source term, the initial radon and progeny concentrations are input. The program models the growth and decay of radon and its progeny until time t. Various radon related parameters are output.

Mine Tunnel Model (Concentrations)
The Mine Tunnel Model is the classic "Radon Model". It is very similar to the Closed Chamber Model, except that the volume is considered to be moving through a tunnel. Radon is continually injected into the volume by the walls of the tunnel. The program models the growth and decay of radon and its progeny as the volume moves through the mine. Various radon concentration related parameters are output.

Mine Tunnel Model (Flux)
This is identical to "Mine Tunnel Model (Concentrations)", except that the total flux of radon and its progeny is used instead of the concentrations. The flux model is more useful when combining several tunnels into a complex mine ventilation network. The flux entering a node equals the flux exiting a node.

Single Chamber Model
Radon is continually released into a single room and mixes with the air. Ventilation removes radon and radon progeny. The eventual (steady state) radon and progeny concentrations are calculated. 

Double Chamber Model
In this model, radon is released into the first room and mixes with the air. Ventilation removes radon and radon progeny. A fraction of the air, containing both radon and progeny, leaks into a second room. The eventual (steady state) radon and progeny concentrations in both rooms are calculated. 

Double Chamber Model (Short Version)
This is identical to the "Double Chamber Model", except that the not all of the output quantities are displayed. This version will print on a single page, if you use a small text size in your browser.

Complex Mine Model
This models the radon and progeny concentrations in the whole mine at the same time. Please print and read the user manual (30/05/2006) before attempting to use this program. The free version is limited to 20 branches.

There is no limit on the number of branches that the professional version can handle. (You must have an account on our system to access the professional version.)

Radon Gas, Progeny and Long Lived Radioactive Dust (LLRD) Analysis:

Radon Gas Measurement by Delayed Count

The purpose of this calculator is to convert the counts recorded from a radon filled scintillation cell into a radon concentration value.

Usually, one would use the VS472 Radon Sniffer in "Sniff" mode to get a quick (15 second or 5 minute) reading of radon gas concentrations. In "Sniff" mode, the radon sniffers display the radon gas concentration directly and no calculations are required. However, if an area of low radon concentration must be sampled directly after sampling in an area of high radon concentration and a very accurate result is required, a second scintillation cell must be used, as described in the Grab Sampling Setup section of the VS472 User Manual.

This grab sampling method must be used with other instruments, which do not have the VS472's advanced sniff algorithm.

LLRD

This is the standard reference method used by regulatory agencies for assessing airborne uranium ore or uranium concentrate concentrations. One draws air through a filter and then counts the gross alpha activity on the filter. 

Rolle Method

This is the most common method of determining radon progeny concentrations in Canadian uranium mines. One draws air through a filter and then counts the gross alpha activity on the filter. 

Kusnetz Method

This is an older method of determining radon progeny concentrations that is still used in some applications. One draws air through a filter and then counts the gross alpha activity on the filter. 

Radon Progeny Analysis

Three different methods are used to analyze the air sample for radon progeny concentration. The Rolle method returns only the total potential alpha energy, while the Tsivoglou and Busigin methods calculate the concentration of  Po-218, Pb-214 and Bi-214 as well. The Tsivoglou method is the most accurate when the radon progeny concentration during the 5 minute sampling time is expected to be constant (i.e. in a radon chamber).  The Busigin method is the most accurate when the radon progeny concentration during the 5 minute sampling time could fluctuate (i.e. in a uranium mine). 

Gamma Dose Rate Calculation:

JavaShield
Calculates the gamma dose rate from uranium ore as a function of ore grade for various geometries and shielding materials. Some other common sources are also supported. Please print and read the documentation before attempting to use this program. 

The program predicts the effective dose rate (in Sv/h), using UNSCEAR's suggested conversion factor of 1 Gy = 0.7 Sv. However, most gamma meters try to display the dose equivalent rate (also in Sv/h), using 1 Gy = 1 Sv. They also often use the conversion of 1 R = 1 rad, instead of 1 R = 0.876 rad). That means the values calculated by this program typically are ~ 0.6 of the values displayed on survey meters. Please understand your results!

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